Merge branch 'main' of https://bdgit.educoder.net/ps63zfhkr/Notes-master

src/Notes

@@ -1 +1 @@
-Subproject commit 81a66024fe48eaa2206b854430856fe3875ff3ba
+Subproject commit 9dbbf988b9c09a1bfe0bc754bdbd76709b7ff5b1

src/data/Contact.java

@@ -0,0 +1,98 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.data;
+
+import android.content.Context;
+import android.database.Cursor;
+import android.provider.ContactsContract.CommonDataKinds.Phone;
+import android.provider.ContactsContract.Data;
+import android.telephony.PhoneNumberUtils;
+import android.util.Log;
+
+import java.util.HashMap;
+
+/**
+ * 用于处理联系人信息的工具类，提供根据电话号码查询联系人姓名的功能。
+ */
+public class Contact {
+    // 用于缓存电话号码与联系人姓名的映射，减少频繁的数据库查询
+    private static HashMap<String, String> sContactCache;
+    
+    // 用于日志打印
+    private static final String TAG = "Contact";
+
+    // 用于查询联系人信息的 SQL 选择条件 (selection)
+    private static final String CALLER_ID_SELECTION = "PHONE_NUMBERS_EQUAL(" + Phone.NUMBER
+    + ",?) AND " + Data.MIMETYPE + "='" + Phone.CONTENT_ITEM_TYPE + "'"
+    + " AND " + Data.RAW_CONTACT_ID + " IN "
+            + "(SELECT raw_contact_id "
+            + " FROM phone_lookup"
+            + " WHERE min_match = '+')";
+
+    /**
+     * 根据电话号码查询联系人姓名，如果之前已经查询过该号码，会直接从缓存中获取
+     *
+     * @param context 上下文对象，用于访问联系人数据
+     * @param phoneNumber 需要查询的电话号码
+     * @return 对应电话号码的联系人姓名，如果没有找到，则返回 null
+     */
+    public static String getContact(Context context, String phoneNumber) {
+        // 如果缓存为空，初始化缓存 HashMap
+        if(sContactCache == null) {
+            sContactCache = new HashMap<String, String>();
+        }
+
+        // 如果缓存中已经有该电话号码的联系人信息，则直接返回缓存中的结果
+        if(sContactCache.containsKey(phoneNumber)) {
+            return sContactCache.get(phoneNumber);
+        }
+
+        // 替换 selection 中的占位符 "+" 为通过 PhoneNumberUtils 转换的号码格式
+        String selection = CALLER_ID_SELECTION.replace("+",
+                PhoneNumberUtils.toCallerIDMinMatch(phoneNumber));
+        
+        // 使用内容解析器查询联系人数据
+        Cursor cursor = context.getContentResolver().query(
+                Data.CONTENT_URI,  // 查询的 URI
+                new String[] { Phone.DISPLAY_NAME },  // 查询的列，获取联系人的显示名称
+                selection,  // 查询条件
+                new String[] { phoneNumber },  // 查询参数，传入电话号码
+                null);  // 不需要排序
+
+        // 如果查询成功且结果不为空
+        if (cursor != null && cursor.moveToFirst()) {
+            try {
+                // 获取联系人名称
+                String name = cursor.getString(0);
+                // 将联系人姓名存入缓存中，避免下次查询时再次访问数据库
+                sContactCache.put(phoneNumber, name);
+                return name;
+            } catch (IndexOutOfBoundsException e) {
+                // 如果在游标操作中出现异常，记录日志并返回 null
+                Log.e(TAG, " Cursor get string error " + e.toString());
+                return null;
+            } finally {
+                // 无论查询是否成功，都需要关闭游标
+                cursor.close();
+            }
+        } else {
+            // 如果没有找到匹配的联系人，记录日志并返回 null
+            Log.d(TAG, "No contact matched with number:" + phoneNumber);
+            return null;
+        }
+    }
+}

src/data/Notes.java

@@ -0,0 +1,278 @@
+// 包声明，表明该类属于 net.micode.notes.data 包
+package net.micode.notes.data;
+
+// 导入所需的 Android 类，用于处理 URI 相关操作
+import android.net.Uri;
+
+// Notes 类的定义
+public class Notes {
+    // 定义一个字符串常量，用于表示权限
+    public static final String AUTHORITY = "micode_notes";
+    // 定义一个日志标签
+    public static final String TAG = "Notes";
+    // 定义三种类型的常量，分别表示笔记、文件夹和系统
+    public static final int TYPE_NOTE = 0;
+    public static final int TYPE_FOLDER = 1;
+    public static final int TYPE_SYSTEM = 2;
+
+    /**
+     * 以下是系统文件夹的标识符
+     * {@link Notes#ID_ROOT_FOLDER } 是默认文件夹
+     * {@link Notes#ID_TEMPARAY_FOLDER } 用于存储不属于任何文件夹的笔记
+     * {@link Notes#ID_CALL_RECORD_FOLDER} 用于存储通话记录
+     */
+    // 根文件夹的 ID
+    public static final int ID_ROOT_FOLDER = 0;
+    // 临时文件夹的 ID
+    public static final int ID_TEMPARAY_FOLDER = -1;
+    // 通话记录文件夹的 ID
+    public static final int ID_CALL_RECORD_FOLDER = -2;
+    // 垃圾桶文件夹的 ID
+    public static final int ID_TRASH_FOLER = -3;
+
+    // 定义一些 Intent 额外信息的字符串常量，可能用于在不同组件之间传递数据
+    public static final String INTENT_EXTRA_ALERT_DATE = "net.micode.notes.alert_date";
+    public static final String INTENT_EXTRA_BACKGROUND_ID = "net.micode.notes.background_color_id";
+    public static final String INTENT_EXTRA_WIDGET_ID = "net.micode.notes.widget_id";
+    public static final String INTENT_EXTRA_WIDGET_TYPE = "net.micode.notes.widget_type";
+    public static final String INTENT_EXTRA_FOLDER_ID = "net.micode.notes.folder_id";
+    public static final String INTENT_EXTRA_CALL_DATE = "net.micode.notes.call_date";
+
+    // 定义一些与小部件相关的类型常量
+    public static final int TYPE_WIDGET_INVALIDE = -1;
+    public static final int TYPE_WIDGET_2X = 0;
+    public static final int TYPE_WIDGET_4X = 1;
+
+    // DataConstants 内部类，可能用于存储一些数据相关的常量
+    public static class DataConstants {
+        // 定义文本笔记和通话笔记的内容项类型
+        public static final String NOTE = TextNote.CONTENT_ITEM_TYPE;
+        public static final String CALL_NOTE = CallNote.CONTENT_ITEM_TYPE;
+    }
+
+    /**
+     * 用于查询所有笔记和文件夹的 URI
+     */
+    // 通过拼接权限和路径生成的 URI
+    public static final Uri CONTENT_NOTE_URI = Uri.parse("content://" + AUTHORITY + "/note");
+
+    /**
+     * 用于查询数据的 URI
+     */
+    // 通过拼接权限和路径生成的 URI
+    public static final Uri CONTENT_DATA_URI = Uri.parse("content://" + AUTHORITY + "/data");
+
+    // 定义一个接口，包含了笔记列的信息
+    public interface NoteColumns {
+        /**
+         * 行的唯一 ID
+         * <P> 类型：INTEGER (long) </P>
+         */
+        public static final String ID = "_id";
+
+        /**
+         * 笔记或文件夹的父 ID
+         * <P> 类型：INTEGER (long) </P>
+         */
+        public static final String PARENT_ID = "parent_id";
+
+        /**
+         * 笔记或文件夹的创建日期
+         * <P> 类型：INTEGER (long) </P>
+         */
+        public static final String CREATED_DATE = "created_date";
+
+        /**
+         * 最新修改日期
+         * <P> 类型：INTEGER (long) </P>
+         */
+        public static final String MODIFIED_DATE = "modified_date";
+
+
+        /**
+         * 提醒日期
+         * <P> 类型：INTEGER (long) </P>
+         */
+        public static final String ALERTED_DATE = "alert_date";
+
+        /**
+         * 文件夹的名称或笔记的文本内容
+         * <P> 类型：TEXT </P>
+         */
+        public static final String SNIPPET = "snippet";
+
+        /**
+         * 笔记的小部件 ID
+         * <P> 类型：INTEGER (long) </P>
+         */
+        public static final String WIDGET_ID = "widget_id";
+
+        /**
+         * 笔记的小部件类型
+         * <P> 类型：INTEGER (long) </P>
+         */
+        public static final String WIDGET_TYPE = "widget_type";
+
+        /**
+         * 笔记的背景颜色 ID
+         * <P> 类型：INTEGER (long) </P>
+         */
+        public static final String BG_COLOR_ID = "bg_color_id";
+
+        /**
+         * 对于文本笔记，它没有附件；对于多媒体笔记，它至少有一个附件
+         * <P> 类型：INTEGER </P>
+         */
+        public static final String HAS_ATTACHMENT = "has_attachment";
+
+        /**
+         * 文件夹中的笔记数量
+         * <P> 类型：INTEGER (long) </P>
+         */
+        public static final String NOTES_COUNT = "notes_count";
+
+        /**
+         * 文件类型：文件夹或笔记
+         * <P> 类型：INTEGER </P>
+         */
+        public static final String TYPE = "type";
+
+        /**
+         * 最后同步的 ID
+         * <P> 类型：INTEGER (long) </P>
+         */
+        public static final String SYNC_ID = "sync_id";
+
+        /**
+         * 表示是否本地修改的标志
+         * <P> 类型：INTEGER </P>
+         */
+        public static final String LOCAL_MODIFIED = "local_modified";
+
+        /**
+         * 移动到临时文件夹之前的原始父 ID
+         * <P> 类型：INTEGER </P>
+         */
+        public static final String ORIGIN_PARENT_ID = "origin_parent_id";
+
+        /**
+         * gtask 的 ID
+         * <P> 类型：TEXT </P>
+         */
+        public static final String GTASK_ID = "gtask_id";
+
+        /**
+         * 版本代码
+         * <P> 类型：INTEGER (long) </P>
+         */
+        public static final String VERSION = "version";
+    }
+
+    // 定义一个接口，包含了数据列的信息
+    public interface DataColumns {
+        /**
+         * 行的唯一 ID
+         * <P> 类型：INTEGER (long) </P>
+         */
+        public static final String ID = "_id";
+
+        /**
+         * 该行表示的项的 MIME 类型
+         * <P> 类型：Text </P>
+         */
+        public static final String MIME_TYPE = "mime_type";
+
+        /**
+         * 该数据所属笔记的引用 ID
+         * <P> 类型：INTEGER (long) </P>
+         */
+        public static final String NOTE_ID = "note_id";
+
+        /**
+         * 笔记或文件夹的创建日期
+         * <P> 类型：INTEGER (long) </P>
+         */
+        public static final String CREATED_DATE = "created_date";
+
+        /**
+         * 最新修改日期
+         * <P> 类型：INTEGER (long) </P>
+         */
+        public static final String MODIFIED_DATE = "modified_date";
+
+        /**
+         * 数据的内容
+         * <P> 类型：TEXT </P>
+         */
+        public static final String CONTENT = "content";
+
+
+        /**
+         * 通用数据列，其含义取决于 {@link #MIMETYPE}，用于整数数据类型
+         * <P> 类型：INTEGER </P>
+         */
+        public static final String DATA1 = "data1";
+
+        /**
+         * 通用数据列，其含义取决于 {@link #MIMETYPE}，用于整数数据类型
+         * <P> 类型：INTEGER </P>
+         */
+        public static final String DATA2 = "data2";
+
+        /**
+         * 通用数据列，其含义取决于 {@link #MIMETYPE}，用于文本数据类型
+         * <P> 类型：TEXT </P>
+         */
+        public static final String DATA3 = "data3";
+
+        /**
+         * 通用数据列，其含义取决于 {@link #MIMETYPE}，用于文本数据类型
+         * <P> 类型：TEXT </P>
+         */
+        public static final String DATA4 = "data4";
+
+        /**
+         * 通用数据列，其含义取决于 {@link #MIMETYPE}，用于文本数据类型
+         * <P> 类型：TEXT </P>
+         */
+        public static final String DATA5 = "data5";
+    }
+
+    // 定义一个静态内部类 TextNote，实现了 DataColumns 接口，可能是为了表示文本笔记的数据信息
+    public static final class TextNote implements DataColumns {
+        /**
+         * 模式，指示文本是否处于复选列表模式
+         * <P> 类型：Integer 1: 复选列表模式 0: 正常模式 </P>
+         */
+        public static final String MODE = DATA1;
+
+        public static final int MODE_CHECK_LIST = 1;
+
+        public static final String CONTENT_TYPE = "vnd.android.cursor.dir/text_note";
+
+        public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/text_note";
+
+        public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/text_note");
+    }
+
+    // 定义一个静态内部类 CallNote，实现了 DataColumns 接口，可能是为了表示通话笔记的数据信息
+    public static final class CallNote implements DataColumns {
+        /**
+         * 此记录的通话日期
+         * <P> 类型：INTEGER (long) </P>
+         */
+        public static final String CALL_DATE = DATA1;
+
+        /**
+         * 此记录的电话号码
+         * <P> 类型：TEXT </P>
+         */
+        public static final String PHONE_NUMBER = DATA3;
+
+        public static final String CONTENT_TYPE = "vnd.android.cursor.dir/call_note";
+
+        public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/call_note";
+
+        public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/call_note");
+    }
+}

src/data/NotesDatabaseHelper.java

@@ -0,0 +1,337 @@
+// 该类继承自 SQLiteOpenHelper，用于管理笔记应用的数据库操作
+public class NotesDatabaseHelper extends SQLiteOpenHelper {
+    // 数据库名称
+    private static final String DB_NAME = "note.db";
+    // 数据库版本
+    private static final int DB_VERSION = 4;
+
+    // 定义表名的接口
+    public interface TABLE {
+        public static final String NOTE = "note";
+        public static final String DATA = "data";
+    }
+
+    // 日志标签
+    private static final String TAG = "NotesDatabaseHelper";
+    // 单例模式的实例
+    private static NotesDatabaseHelper mInstance;
+
+    // 创建笔记表的 SQL 语句
+    private static final String CREATE_NOTE_TABLE_SQL =
+        "CREATE TABLE " + TABLE.NOTE + "(" +
+            NoteColumns.ID + " INTEGER PRIMARY KEY," +
+            NoteColumns.PARENT_ID + " INTEGER NOT NULL DEFAULT 0," +
+            NoteColumns.ALERTED_DATE + " INTEGER NOT NULL DEFAULT 0," +
+            NoteColumns.BG_COLOR_ID + " INTEGER NOT NULL DEFAULT 0," +
+            NoteColumns.CREATED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," +
+            NoteColumns.HAS_ATTACHMENT + " INTEGER NOT NULL DEFAULT 0," +
+            NoteColumns.MODIFIED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," +
+            NoteColumns.NOTES_COUNT + " INTEGER NOT NULL DEFAULT 0," +
+            NoteColumns.SNIPPET + " TEXT NOT NULL DEFAULT ''," +
+            NoteColumns.TYPE + " INTEGER NOT NULL DEFAULT 0," +
+            NoteColumns.WIDGET_ID + " INTEGER NOT NULL DEFAULT 0," +
+            NoteColumns.WIDGET_TYPE + " INTEGER NOT NULL DEFAULT -1," +
+            NoteColumns.SYNC_ID + " INTEGER NOT NULL DEFAULT 0," +
+            NoteColumns.LOCAL_MODIFIED + " INTEGER NOT NULL DEFAULT 0," +
+            NoteColumns.ORIGIN_PARENT_ID + " INTEGER NOT NULL DEFAULT 0," +
+            NoteColumns.GTASK_ID + " TEXT NOT NULL DEFAULT ''," +
+            NoteColumns.VERSION + " INTEGER NOT NULL DEFAULT 0" +
+        ")";
+
+    // 创建数据（笔记内容）表的 SQL 语句
+    private static final String CREATE_DATA_TABLE_SQL =
+        "CREATE TABLE " + TABLE.DATA + "(" +
+            DataColumns.ID + " INTEGER PRIMARY KEY," +
+            DataColumns.MIME_TYPE + " TEXT NOT NULL," +
+            DataColumns.NOTE_ID + " INTEGER NOT NULL DEFAULT 0," +
+            NoteColumns.CREATED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," +
+            NoteColumns.MODIFIED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," +
+            DataColumns.CONTENT + " TEXT NOT NULL DEFAULT ''," +
+            DataColumns.DATA1 + " INTEGER," +
+            DataColumns.DATA2 + " INTEGER," +
+            DataColumns.DATA3 + " TEXT NOT NULL DEFAULT ''," +
+            DataColumns.DATA4 + " TEXT NOT NULL DEFAULT ''," +
+            DataColumns.DATA5 + " TEXT NOT NULL DEFAULT ''" +
+        ")";
+
+    // 创建数据表的笔记 ID 索引的 SQL 语句
+    private static final String CREATE_DATA_NOTE_ID_INDEX_SQL =
+        "CREATE INDEX IF NOT EXISTS note_id_index ON " +
+        TABLE.DATA + "(" + DataColumns.NOTE_ID + ");";
+
+    // 当笔记的父 ID 更新时，增加父文件夹笔记数量的触发器 SQL 语句
+    private static final String NOTE_INCREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER =
+        "CREATE TRIGGER increase_folder_count_on_update "+
+        " AFTER UPDATE OF " + NoteColumns.PARENT_ID + " ON " + TABLE.NOTE +
+        " BEGIN " +
+        "  UPDATE " + TABLE.NOTE +
+        "   SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + " + 1" +
+        "  WHERE " + NoteColumns.ID + "=new." + NoteColumns.PARENT_ID + ";" +
+        " END";
+
+    // 当笔记的父 ID 更新时，减少父文件夹笔记数量的触发器 SQL 语句
+    private static final String NOTE_DECREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER =
+        "CREATE TRIGGER decrease_folder_count_on_update " +
+        " AFTER UPDATE OF " + NoteColumns.PARENT_ID + " ON " + TABLE.NOTE +
+        " BEGIN " +
+        "  UPDATE " + TABLE.NOTE +
+        "   SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + "-1" +
+        "  WHERE " + NoteColumns.ID + "=old." + NoteColumns.PARENT_ID +
+        "  AND " + NoteColumns.NOTES_COUNT + ">0" + ";" +
+        " END";
+
+    // 当插入新笔记到文件夹时，增加父文件夹笔记数量的触发器 SQL 语句
+    private static final String NOTE_INCREASE_FOLDER_COUNT_ON_INSERT_TRIGGER =
+        "CREATE TRIGGER increase_folder_count_on_insert " +
+        " AFTER INSERT ON " + TABLE.NOTE +
+        " BEGIN " +
+        "  UPDATE " + TABLE.NOTE +
+        "   SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + " + 1" +
+        "  WHERE " + NoteColumns.ID + "=new." + NoteColumns.PARENT_ID + ";" +
+        " END";
+
+    // 当从文件夹删除笔记时，减少父文件夹笔记数量的触发器 SQL 语句
+    private static final String NOTE_DECREASE_FOLDER_COUNT_ON_DELETE_TRIGGER =
+        "CREATE TRIGGER decrease_folder_count_on_delete " +
+        " AFTER DELETE ON " + TABLE.NOTE +
+        " BEGIN " +
+        "  UPDATE " + TABLE.NOTE +
+        "   SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + "-1" +
+        "  WHERE " + NoteColumns.ID + "=old." + NoteColumns.PARENT_ID +
+        "  AND " + NoteColumns.NOTES_COUNT + ">0;" +
+        " END";
+
+    // 当插入数据类型为笔记时，更新笔记内容的触发器 SQL 语句
+    private static final String DATA_UPDATE_NOTE_CONTENT_ON_INSERT_TRIGGER =
+        "CREATE TRIGGER update_note_content_on_insert " +
+        " AFTER INSERT ON " + TABLE.DATA +
+        " WHEN new." + DataColumns.MIME_TYPE + "='" + DataConstants.NOTE + "'" +
+        " BEGIN" +
+        "  UPDATE " + TABLE.NOTE +
+        "   SET " + NoteColumns.SNIPPET + "=new." + DataColumns.CONTENT +
+        "  WHERE " + NoteColumns.ID + "=new." + DataColumns.NOTE_ID + ";" +
+        " END";
+
+    // 当数据类型为笔记的数据更新时，更新笔记内容的触发器 SQL 语句
+    private static final String DATA_UPDATE_NOTE_CONTENT_ON_UPDATE_TRIGGER =
+        "CREATE TRIGGER update_note_content_on_update " +
+        " AFTER UPDATE ON " + TABLE.DATA +
+        " WHEN old." + DataColumns.MIME_TYPE + "='" + DataConstants.NOTE + "'" +
+        " BEGIN" +
+        "  UPDATE " + TABLE.NOTE +
+        "   SET " + NoteColumns.SNIPPET + "=new." + DataColumns.CONTENT +
+        "  WHERE " + NoteColumns.ID + "=new." + DataColumns.NOTE_ID + ";" +
+        " END";
+
+    // 当数据类型为笔记的数据删除时，更新笔记内容的触发器 SQL 语句
+    private static final String DATA_UPDATE_NOTE_CONTENT_ON_DELETE_TRIGGER =
+        "CREATE TRIGGER update_note_content_on_delete " +
+        " AFTER delete ON " + TABLE.DATA +
+        " WHEN old." + DataColumns.MIME_TYPE + "='" + DataConstants.NOTE + "'" +
+        " BEGIN" +
+        "  UPDATE " + TABLE.NOTE +
+        "   SET " + NoteColumns.SNIPPET + "=''" +
+        "  WHERE " + NoteColumns.ID + "=old." + DataColumns.NOTE_ID + ";" +
+        " END";
+
+    // 当笔记删除时，删除属于该笔记的数据的触发器 SQL 语句
+    private static final String NOTE_DELETE_DATA_ON_DELETE_TRIGGER =
+        "CREATE TRIGGER delete_data_on_delete " +
+        " AFTER DELETE ON " + TABLE.NOTE +
+        " BEGIN" +
+        "  DELETE FROM " + TABLE.DATA +
+        "   WHERE " + DataColumns.NOTE_ID + "=old." + NoteColumns.ID + ";" +
+        " END";
+
+    // 当文件夹删除时，删除属于该文件夹的笔记的触发器 SQL 语句
+    private static final String FOLDER_DELETE_NOTES_ON_DELETE_TRIGGER =
+        "CREATE TRIGGER folder_delete_notes_on_delete " +
+        " AFTER DELETE ON " + TABLE.NOTE +
+        " BEGIN" +
+        "  DELETE FROM " + TABLE.NOTE +
+        "   WHERE " + NoteColumns.PARENT_ID + "=old." + NoteColumns.ID + ";" +
+        " END";
+
+    // 当文件夹移动到回收站时，移动属于该文件夹的笔记的触发器 SQL 语句
+    private static final String FOLDER_MOVE_NOTES_ON_TRASH_TRIGGER =
+        "CREATE TRIGGER folder_move_notes_on_trash " +
+        " AFTER UPDATE ON " + TABLE.NOTE +
+        " WHEN new." + NoteColumns.PARENT_ID + "=" + Notes.ID_TRASH_FOLER +
+        " BEGIN" +
+        "  UPDATE " + TABLE.NOTE +
+        "   SET " + NoteColumns.PARENT_ID + "=" + Notes.ID_TRASH_FOLER +
+        "  WHERE " + NoteColumns.PARENT_ID + "=old." + NoteColumns.ID + ";" +
+        " END";
+
+
+    // 构造函数，调用父类的构造函数
+    public NotesDatabaseHelper(Context context) {
+        super(context, DB_NAME, null, DB_VERSION);
+    }
+
+
+    // 创建笔记表的方法，执行 SQL 语句，重建触发器，创建系统文件夹
+    public void createNoteTable(SQLiteDatabase db) {
+        db.execSQL(CREATE_NOTE_TABLE_SQL);
+        reCreateNoteTableTriggers(db);
+        createSystemFolder(db);
+        Log.d(TAG, "note table has been created");
+    }
+
+
+    // 重建笔记表触发器的方法，先删除旧触发器，再创建新触发器
+    private void reCreateNoteTableTriggers(SQLiteDatabase db) {
+        db.execSQL("DROP TRIGGER IF EXISTS increase_folder_count_on_update");
+        db.execSQL("DROP TRIGGER IF EXISTS decrease_folder_count_on_update");
+        db.execSQL("DROP TRIGGER IF EXISTS decrease_folder_count_on_delete");
+        db.execSQL("DROP TRIGGER IF EXISTS delete_data_on_delete");
+        db.execSQL("DROP TRIGGER IF EXISTS increase_folder_count_on_insert");
+        db.execSQL("DROP TRIGGER IF EXISTS folder_delete_notes_on_delete");
+        db.execSQL("DROP TRIGGER IF EXISTS folder_move_notes_on_trash");
+
+        db.execSQL(NOTE_INCREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER);
+        db.execSQL(NOTE_DECREASE_FOLDER_COUNT_ON_UPDATE_TRigger);
+        db.execSQL(NOTE_DECREASE_FOLDER_COUNT_ON_DELETE_TRIGGER);
+        db.execSQL(NOTE_DELETE_DATA_ON_DELETE_TRIGGER);
+        db.execSQL(NOTE_INCREASE_FOLDER_COUNT_ON_INSERT_TRIGGER);
+        db.execSQL(FOLDER_DELETE_NOTES_ON_DELETE_TRIGGER);
+        db.execSQL(FOLDER_MOVE_NOTES_ON_TRASH_TRIGGER);
+    }
+
+
+    // 创建系统文件夹的方法，向笔记表插入不同系统文件夹的记录
+    private void createSystemFolder(SQLiteDatabase db) {
+        ContentValues values = new ContentValues();
+
+        // 通话记录文件夹
+        values.put(NoteColumns.ID, Notes.ID_CALL_RECORD_FOLDER);
+        values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
+        db.insert(TABLE.NOTE, null, values);
+
+        // 根文件夹
+        values.clear();
+        values.put(NoteColumns.ID, Notes.ID_ROOT_FOLDER);
+        values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
+        db.insert(TABLE.NOTE, null, values);
+
+        // 临时文件夹
+        values.clear();
+        values.put(NoteColumns.ID, Notes.ID_TEMPARAY_FOLDER);
+        values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
+        db.insert(TABLE.NOTE, null, values);
+
+        // 回收站文件夹
+        values.clear();
+        values.put(NoteColumns.ID, Notes.ID_TRASH_FOLER);
+        values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
+        db.insert(TABLE.NOTE, null, values);
+    }
+
+
+    // 创建数据（笔记内容）表的方法，执行 SQL 语句，重建触发器，创建索引
+    public void createDataTable(SQLiteDatabase db) {
+        db.execSQL(CREATE_DATA_TABLE_SQL);
+        reCreateDataTableTriggers(db);
+        db.execSQL(CREATE_DATA_NOTE_ID_INDEX_SQL);
+        Log.d(TAG, "data table has been created");
+    }
+
+
+    // 重建数据（笔记内容）表触发器的方法，先删除旧触发器，再创建新触发器
+    private void reCreateDataTableTriggers(SQLiteDatabase db) {
+        db.execSQL("DROP TRIGGER IF EXISTS update_note_content_on_insert");
+        db.execSQL("DROP TRIGGER IF EXISTS update_note_content_on_update");
+        db.execSQL("DROP TRIGGER IF EXISTS update_note_content_on_delete");
+
+        db.execSQL(DATA_UPDATE_NOTE_CONTENT_ON_INSERT_TRIGGER);
+        db.execSQL(DATA_UPDATE_NOTE_CONTENT_ON_UPDATE_TRIGGER);
+        db.execSQL(DATA_UPDATE_NOTE_CONTENT_ON_DELETE_TRIGGER);
+    }
+
+
+    // 获取单例的方法，确保只有一个实例存在
+    static synchronized NotesDatabaseHelper getInstance(Context context) {
+        if (mInstance == null) {
+            mInstance = new NotesDatabaseHelper(context);
+        }
+        return mInstance;
+    }
+
+
+    // 重写 onCreate 方法，创建数据库时调用创建笔记表和数据（笔记内容）表的方法
+    @Override
+    public void onCreate(SQLiteDatabase db) {
+        createNoteTable(db);
+        createDataTable(db);
+    }
+
+
+    // 重写 onUpgrade 方法，处理数据库升级
+    @Override
+    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
+        boolean reCreateTriggers = false;
+        boolean skipV2 = false;
+
+        if (oldVersion == 1) {
+            upgradeToV2(db);
+            skipV2 = true; // 这次升级包括从 v2 到 v3 的升级
+            oldVersion++;
+        }
+
+        if (oldVersion == 2 &&!skipV2) {
+            upgradeToV3(db);
+            reCreateTriggers = true;
+            oldVersion++;
+        }
+
+        if (oldVersion == 3) {
+            upgradeToV4(db);
+            oldVersion++;
+        }
+
+
+        if (reCreateTriggers) {
+            reCreateNoteTableTriggers(db);
+            reCreateDataTableTriggers(db);
+        }
+
+
+        if (oldVersion!= newVersion) {
+            throw new IllegalStateException("Upgrade notes database to version " + newVersion
+                    + "fails");
+        }
+    }
+
+
+    // 升级到 v2 的方法，删除旧表，重新创建笔记表和数据（笔记内容）表
+    private void upgradeToV2(SQLiteDatabase db) {
+        db.execSQL("DROP TABLE IF EXISTS " + TABLE.NOTE);
+        db.execSQL("DROP TABLE IF EXISTS " + TABLE.DATA);
+        createNoteTable(db);
+        createDataTable(db);
+    }
+
+
+    // 升级到 v3 的方法，删除旧触发器，添加新列，插入回收站系统文件夹
+    private void upgradeToV3(SQLiteDatabase db) {
+        // 删除未使用的触发器
+        db.execSQL("DROP TRIGGER IF EXISTS update_note_modified_date_on_insert");
+        db.execSQL("DROP TRIGGER IF EXISTS update_note_modified_date_on_delete");
+        db.execSQL("DROP TRIGGER IF EXISTS update_note_modified_date_on_update");
+        // 添加 gtask id 列
+        db.execSQL("ALTER TABLE " + TABLE.NOTE + " ADD COLUMN " + NoteColumns.GTASK_ID
+                + " TEXT NOT NULL DEFAULT ''");
+        // 插入回收站系统文件夹
+        ContentValues values = new ContentValues();
+        values.put(NoteColumns.ID, Notes.ID_TRASH_FOLER);
+        values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
+        db.insert(TABLE.NOTE, null, values);
+    }
+
+
+    // 升级到 v4 的方法，添加版本列
+    private void upgradeToV4(SQLiteDatabase db) {
+        db.execSQL("ALTER TABLE " + TABLE.NOTE + " ADD COLUMN " + NoteColumns.VERSION
+                + " INTEGER NOT NULL DEFAULT 0");
+    }
+}

src/data/NotesProvider.java

@@ -0,0 +1,306 @@
+// 该类继承自 ContentProvider，用于为笔记应用提供内容提供器服务
+public class NotesProvider extends ContentProvider {
+    // 用于匹配不同 URI 的 UriMatcher
+    private static final UriMatcher mMatcher;
+    // 数据库辅助类的实例
+    private NotesDatabaseHelper mHelper;
+    // 日志标签
+    private static final String TAG = "NotesProvider";
+    // 定义不同 URI 的匹配码
+    private static final int URI_NOTE = 1;
+    private static final int URI_NOTE_ITEM = 2;
+    private static final int URI_DATA = 3;
+    private static final int URI_DATA_ITEM = 4;
+    private static final int URI_SEARCH = 5;
+    private static final int URI_SEARCH_SUGGEST = 6;
+
+
+    static {
+        // 初始化 UriMatcher，并添加不同的 URI 匹配规则
+        mMatcher = new UriMatcher(UriMatcher.NO_MATCH);
+        mMatcher.addURI(Notes.AUTHORITY, "note", URI_NOTE);
+        mMatcher.addURI(Notes.AUTHORITY, "note/#", URI_NOTE_ITEM);
+        mMatcher.addURI(Notes.AUTHORITY, "data", URI_DATA);
+        mMatcher.addURI(Notes.AUTHORITY, "data/#", URI_DATA_ITEM);
+        mMatcher.addURI(Notes.AUTHORITY, "search", URI_SEARCH);
+        mMatcher.addURI(Notes.AUTHORITY, SearchManager.SUGGEST_URI_PATH_QUERY, URI_SEARCH_SUGGEST);
+        mMatcher.addURI(Notes.AUTHORITY, SearchManager.SUGGEST_URI_PATH_QUERY + "/*", URI_SEARCH_SUGGEST);
+    }
+
+
+    // 搜索结果的投影，用于查询时显示的列信息
+    private static final String NOTES_SEARCH_PROJECTION = NoteColumns.ID + ","
+        + NoteColumns.ID + " AS " + SearchManager.SUGGEST_COLUMN_INTENT_EXTRA_DATA + ","
+        + "TRIM(REPLACE(" + NoteColumns.SNIPPET + ", x'0A','')) AS " + SearchManager.SUGGEST_COLUMN_TEXT_1 + ","
+        + "TRIM(REPLACE(" + NoteColumns.SNIPPET + ", x'0A','')) AS " + SearchManager.SUGGEST_COLUMN_TEXT_2 + ","
+        + R.drawable.search_result + " AS " + SearchManager.SUGGEST_COLUMN_ICON_1 + ","
+        + "'" + Intent.ACTION_VIEW + "' AS " + SearchManager.SUGGEST_COLUMN_INTENT_ACTION + ","
+        + "'" + Notes.TextNote.CONTENT_TYPE + "' AS " + SearchManager.SUGGEST_COLUMN_INTENT_DATA;
+
+
+    // 搜索笔记片段的 SQL 查询语句
+    private static String NOTES_SNIPPET_SEARCH_QUERY = "SELECT " + NOTES_SEARCH_PROJECTION
+        + " FROM " + TABLE.NOTE
+        + " WHERE " + NoteColumns.SNIPPET + " LIKE?"
+        + " AND " + NoteColumns.PARENT_ID + "<>" + Notes.ID_TRASH_FOLER
+        + " AND " + NoteColumns.TYPE + "=" + Notes.TYPE_NOTE;
+
+
+    // 当 ContentProvider 被创建时调用，获取数据库辅助类的单例
+    @Override
+    public boolean onCreate() {
+        mHelper = NotesDatabaseHelper.getInstance(getContext());
+        return true;
+    }
+
+
+    // 执行查询操作，根据不同的 URI 进行不同的查询处理
+    @Override
+    public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs,
+            String sortOrder) {
+        Cursor c = null;
+        SQLiteDatabase db = mHelper.getReadableDatabase();
+        String id = null;
+        switch (mMatcher.match(uri)) {
+            // 查询笔记表
+            case URI_NOTE:
+                c = db.query(TABLE.NOTE, projection, selection, selectionArgs, null, null,
+                        sortOrder);
+                break;
+            // 查询笔记表的具体项
+            case URI_NOTE_ITEM:
+                id = uri.getPathSegments().get(1);
+                c = db.query(TABLE.NOTE, projection, NoteColumns.ID + "=" + id
+                        + parseSelection(selection), selectionArgs, null, null, sortOrder);
+                break;
+            // 查询数据表
+            case URI_DATA:
+                c = db.query(TABLE.DATA, projection, selection, selectionArgs, null, null,
+                        sortOrder);
+                break;
+            // 查询数据表的具体项
+            case URI_DATA_ITEM:
+                id = uri.getPathSegments().get(1);
+                c = db.query(TABLE.DATA, projection, DataColumns.ID + "=" + id
+                        + parseSelection(selection), selectionArgs, null, null, sortOrder);
+                break;
+            // 处理搜索和搜索建议的查询
+            case URI_SEARCH:
+            case URI_SEARCH_SUGGEST:
+                if (sortOrder!= null || projection!= null) {
+                    throw new IllegalArgumentException(
+                            "do not specify sortOrder, selection, selectionArgs, or projection" + "with this query");
+                }
+
+
+                String searchString = null;
+                if (mMatcher.match(uri) == URI_SEARCH_SUGGEST) {
+                    if (uri.getPathSegments().size() > 1) {
+                        searchString = uri.getPathSegments().get(1);
+                    }
+                } else {
+                    searchString = uri.getQueryParameter("pattern");
+                }
+
+
+                if (TextUtils.isEmpty(searchString)) {
+                    return null;
+                }
+
+
+                try {
+                    searchString = String.format("%%%s%%", searchString);
+                    c = db.rawQuery(NOTES_SNIPPET_SEARCH_QUERY,
+                            new String[] { searchString });
+                } catch (IllegalStateException ex) {
+                    Log.e(TAG, "got exception: " + ex.toString());
+                }
+                break;
+            default:
+                throw new IllegalArgumentException("Unknown URI " + uri);
+        }
+        if (c!= null) {
+            c.setNotificationUri(getContext().getContentResolver(), uri);
+        }
+        return c;
+    }
+
+
+    // 执行插入操作，根据不同的 URI 插入数据到不同的表中
+    @Override
+    public Uri insert(Uri uri, ContentValues values) {
+        SQLiteDatabase db = mHelper.getWritableDatabase();
+        long dataId = 0, noteId = 0, insertedId = 0;
+        switch (mMatcher.match(uri)) {
+            // 插入笔记表
+            case URI_NOTE:
+                insertedId = noteId = db.insert(TABLE.NOTE, null, values);
+                break;
+            // 插入数据表
+            case URI_DATA:
+                if (values.containsKey(DataColumns.NOTE_ID)) {
+                    noteId = values.getAsLong(DataColumns.NOTE_ID);
+                } else {
+                    Log.d(TAG, "Wrong data format without note id:" + values.toString());
+                }
+                insertedId = dataId = db.insert(TABLE.DATA, null, values);
+                break;
+            default:
+                throw new IllegalArgumentException("Unknown URI " + uri);
+        }
+        // 通知笔记 URI 的变化
+        if (noteId > 0) {
+            getContext().getContentResolver().notifyChange(
+                    ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId), null);
+        }
+
+
+        // 通知数据 URI 的变化
+        if (dataId > 0) {
+            getContext().getContentResolver().notifyChange(
+                    ContentUris.withAppendedId(Notes.CONTENT_DATA_URI, dataId), null);
+        }
+
+
+        return ContentUris.withAppendedId(uri, insertedId);
+    }
+
+
+    // 执行删除操作，根据不同的 URI 删除不同表中的数据
+    @Override
+    public int delete(Uri uri, String selection, String[] selectionArgs) {
+        int count = 0;
+        String id = null;
+        SQLiteDatabase db = mHelper.getWritableDatabase();
+        boolean deleteData = false;
+        switch (mMatcher.match(uri)) {
+            // 删除笔记表中的数据
+            case URI_NOTE:
+                selection = "(" + selection + ") AND " + NoteColumns.ID + ">0 ";
+                count = db.delete(TABLE.NOTE, selection, selectionArgs);
+                break;
+            // 删除笔记表中的具体项
+            case URI_NOTE_ITEM:
+                id = uri.getPathSegments().get(1);
+                // 不允许删除系统文件夹（ID 小于等于 0）
+                long noteId = Long.valueOf(id);
+                if (noteId <= 0) {
+                    break;
+                }
+                count = db.delete(TABLE.NOTE,
+                        NoteColumns.ID + "=" + id + parseSelection(selection), selectionArgs);
+                break;
+            // 删除数据表中的数据
+            case URI_DATA:
+                count = db.delete(TABLE.DATA, selection, selectionArgs);
+                deleteData = true;
+                break;
+            // 删除数据表中的具体项
+            case URI_DATA_ITEM:
+                id = uri.getPathSegments().get(1);
+                count = db.delete(TABLE.DATA,
+                        DataColumns.ID + "=" + id + parseSelection(selection), selectionArgs);
+                deleteData = true;
+                break;
+            default:
+                throw new IllegalArgumentException("Unknown URI " + uri);
+        }
+        if (count > 0) {
+            if (deleteData) {
+                getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null);
+            }
+            getContext().getContentResolver().notifyChange(uri, null);
+        }
+        return count;
+    }
+
+
+    // 执行更新操作，根据不同的 URI 更新不同表中的数据
+    @Override
+    public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
+        int count = 0;
+        String id = null;
+        SQLiteDatabase db = mHelper.getWritableDatabase();
+        boolean updateData = false;
+        switch (mMatcher.match(uri)) {
+            // 更新笔记表中的数据
+            case URI_NOTE:
+                increaseNoteVersion(-1, selection, selectionArgs);
+                count = db.update(TABLE.NOTE, values, selection, selectionArgs);
+                break;
+            // 更新笔记表中的具体项
+            case URI_NOTE_ITEM:
+                id = uri.getPathSegments().get(1);
+                increaseNoteVersion(Long.valueOf(id), selection, selectionArgs);
+                count = db.update(TABLE.NOTE, values, NoteColumns.ID + "=" + id
+                        + parseSelection(selection), selectionArgs);
+                break;
+            // 更新数据表中的数据
+            case URI_DATA:
+                count = db.update(TABLE.DATA, values, selection, selectionArgs);
+                updateData = true;
+                break;
+            // 更新数据表中的具体项
+            case URI_DATA_ITEM:
+                id = uri.getPathSegments().get(1);
+                count = db.update(TABLE.DATA, values, DataColumns.ID + "=" + id
+                        + parseSelection(selection), selectionArgs);
+                updateData = true;
+                break;
+            default:
+                throw new IllegalArgumentException("Unknown URI " + uri);
+        }
+
+
+        if (count > 0) {
+            if (updateData) {
+                getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null);
+            }
+            getContext().getContentResolver().notifyChange(uri, null);
+        }
+        return count;
+    }
+
+
+    // 解析选择条件，添加 AND 操作符
+    private String parseSelection(String selection) {
+        return (!TextUtils.isEmpty(selection)? " AND (" + selection + ')' : "");
+    }
+
+
+    // 增加笔记的版本号
+    private void increaseNoteVersion(long id, String selection, String[] selectionArgs) {
+        StringBuilder sql = new StringBuilder(120);
+        sql.append("UPDATE ");
+        sql.append(TABLE.NOTE);
+        sql.append(" SET ");
+        sql.append(NoteColumns.VERSION);
+        sql.append("=" + NoteColumns.VERSION + "+1 ");
+
+
+        if (id > 0 ||!TextUtils.isEmpty(selection)) {
+            sql.append(" WHERE ");
+        }
+        if (id > 0) {
+            sql.append(NoteColumns.ID + "=" + String.valueOf(id));
+        }
+        if (!TextUtils.isEmpty(selection)) {
+            String selectString = id > 0? parseSelection(selection) : selection;
+            for (String args : selectionArgs) {
+                selectString = selectString.replaceFirst("\\?", args);
+            }
+            sql.append(selectString);
+        }
+
+
+        mHelper.getWritableDatabase().execSQL(sql.toString());
+    }
+
+
+    // 获取 URI 的类型，当前未实现
+    @Override
+    public String getType(Uri uri) {
+        // TODO Auto-generated method stub
+        return null;
+    }
+}

src/gtask/data/MetaData.java

@@ -0,0 +1,136 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.gtask.data;
+
+import android.database.Cursor;
+import android.util.Log;
+
+import net.micode.notes.tool.GTaskStringUtils;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+
+/**
+ * MetaData 类继承自 Task 类，表示一个任务的元数据。
+ * 它包含了与任务相关的附加信息，如任务的 GID 等元数据。
+ */
+public class MetaData extends Task {
+    private final static String TAG = MetaData.class.getSimpleName();  // 用于日志记录的 TAG
+
+    private String mRelatedGid = null;  // 用于存储与该任务关联的 GID（Google Task ID）
+
+    /**
+     * 设置 Meta 数据，包含任务的 GID 和其他元数据。
+     * 
+     * @param gid 任务的 GID
+     * @param metaInfo 任务的元数据，以 JSON 对象的形式传递
+     */
+    public void setMeta(String gid, JSONObject metaInfo) {
+        try {
+            // 将 GID 添加到 metaInfo 中
+            metaInfo.put(GTaskStringUtils.META_HEAD_GTASK_ID, gid);
+        } catch (JSONException e) {
+            // 如果发生异常，记录错误日志
+            Log.e(TAG, "failed to put related gid");
+        }
+        // 设置当前任务的备注信息为 metaInfo 的字符串表示
+        setNotes(metaInfo.toString());
+        // 设置任务名称为默认的 Meta 任务名称
+        setName(GTaskStringUtils.META_NOTE_NAME);
+    }
+
+    /**
+     * 获取当前任务所关联的 GID。
+     * 
+     * @return 返回与任务关联的 GID
+     */
+    public String getRelatedGid() {
+        return mRelatedGid;
+    }
+
+    /**
+     * 判断当前任务是否值得保存。
+     * 只有当备注信息（notes）不为 null 时，任务才值得保存。
+     * 
+     * @return 如果备注信息不为空，则返回 true，否则返回 false
+     */
+    @Override
+    public boolean isWorthSaving() {
+        return getNotes() != null;
+    }
+
+    /**
+     * 通过远程 JSON 数据设置任务内容。
+     * 如果备注（notes）不为空，它将尝试从中提取与任务关联的 GID。
+     * 
+     * @param js 传入的远程 JSON 数据
+     */
+    @Override
+    public void setContentByRemoteJSON(JSONObject js) {
+        // 调用父类的相应方法，设置基本的任务内容
+        super.setContentByRemoteJSON(js);
+        
+        // 如果备注不为空，尝试解析其中的 GID 信息
+        if (getNotes() != null) {
+            try {
+                // 将备注内容转换为 JSON 对象
+                JSONObject metaInfo = new JSONObject(getNotes().trim());
+                // 从 metaInfo 中获取 GID 并存储
+                mRelatedGid = metaInfo.getString(GTaskStringUtils.META_HEAD_GTASK_ID);
+            } catch (JSONException e) {
+                // 如果解析失败，记录警告日志，并将 GID 设置为 null
+                Log.w(TAG, "failed to get related gid");
+                mRelatedGid = null;
+            }
+        }
+    }
+
+    /**
+     * 本方法不应被调用。该方法会抛出 IllegalAccessError。
+     * 
+     * @param js 传入的本地 JSON 数据
+     * @throws IllegalAccessError 如果调用此方法，将抛出异常
+     */
+    @Override
+    public void setContentByLocalJSON(JSONObject js) {
+        throw new IllegalAccessError("MetaData:setContentByLocalJSON should not be called");
+    }
+
+    /**
+     * 本方法不应被调用。该方法会抛出 IllegalAccessError。
+     * 
+     * @return 返回值永远不会被调用
+     * @throws IllegalAccessError 如果调用此方法，将抛出异常
+     */
+    @Override
+    public JSONObject getLocalJSONFromContent() {
+        throw new IllegalAccessError("MetaData:getLocalJSONFromContent should not be called");
+    }
+
+    /**
+     * 本方法不应被调用。该方法会抛出 IllegalAccessError。
+     * 
+     * @param c 数据库游标
+     * @return 返回值永远不会被调用
+     * @throws IllegalAccessError 如果调用此方法，将抛出异常
+     */
+    @Override
+    public int getSyncAction(Cursor c) {
+        throw new IllegalAccessError("MetaData:getSyncAction should not be called");
+    }
+
+}

src/gtask/data/Node.java

@@ -0,0 +1,104 @@
+// 该类是一个抽象类，作为节点的基类，可能用于同步操作相关的数据管理
+public abstract class Node {
+    // 定义同步操作的各种状态码
+    public static final int SYNC_ACTION_NONE = 0;
+    public static final int SYNC_ACTION_ADD_REMOTE = 1;
+    public static final int SYNC_ACTION_ADD_LOCAL = 2;
+    public static final int SYNC_ACTION_DEL_REMOTE = 3;
+    public static final int SYNC_ACTION_DEL_LOCAL = 4;
+    public static final int SYNC_ACTION_UPDATE_REMOTE = 5;
+    public static final int SYNC_ACTION_UPDATE_LOCAL = 6;
+    public static final int SYNC_ACTION_UPDATE_CONFLICT = 7;
+    public static final int SYNC_ACTION_ERROR = 8;
+
+
+    // 节点的全局唯一标识符
+    private String mGid;
+    // 节点的名称
+    private String mName;
+    // 最后修改时间
+    private long mLastModified;
+    // 节点是否已删除的标记
+    private boolean mDeleted;
+
+
+    // 构造函数，初始化成员变量
+    public Node() {
+        mGid = null;
+        mName = "";
+        mLastModified = 0;
+        mDeleted = false;
+    }
+
+
+    // 获取创建操作的 JSON 对象，具体实现由子类完成
+    public abstract JSONObject getCreateAction(int actionId);
+
+
+    // 获取更新操作的 JSON 对象，具体实现由子类完成
+    public abstract JSONObject getUpdateAction(int actionId);
+
+
+    // 根据远程的 JSON 对象设置节点的内容，具体实现由子类完成
+    public abstract void setContentByRemoteJSON(JSONObject js);
+
+
+    // 根据本地的 JSON 对象设置节点的内容，具体实现由子类完成
+    public abstract void setContentByLocalJSON(JSONObject js);
+
+
+    // 从节点的内容获取本地的 JSON 对象，具体实现由子类完成
+    public abstract JSONObject getLocalJSONFromContent();
+
+
+    // 获取同步操作的状态，具体实现由子类完成
+    public abstract int getSyncAction(Cursor c);
+
+
+    // 设置节点的全局唯一标识符
+    public void setGid(String gid) {
+        this.mGid = gid;
+    }
+
+
+    // 设置节点的名称
+    public void setName(String name) {
+        this.mName = name;
+    }
+
+
+    // 设置节点的最后修改时间
+    public void setLastModified(long lastModified) {
+        this.mLastModified = lastModified;
+    }
+
+
+    // 设置节点是否已删除
+    public void setDeleted(boolean deleted) {
+        this.mDeleted = deleted;
+    }
+
+
+    // 获取节点的全局唯一标识符
+    public String getGid() {
+        return this.mGid;
+    }
+
+
+    // 获取节点的名称
+    public String getName() {
+        return this.mName;
+    }
+
+
+    // 获取节点的最后修改时间
+    public long getLastModified() {
+        return this.mLastModified;
+    }
+
+
+    // 获取节点是否已删除的信息
+    public boolean getDeleted() {
+        return this.mDeleted;
+    }
+}

src/gtask/data/SqlData.java

@@ -0,0 +1,175 @@
+// 该类用于处理与 SQL 数据相关的操作，可能是在笔记应用中对数据的管理和同步操作
+public class SqlData {
+    // 日志标签，使用类的简单名称
+    private static final String TAG = SqlData.class.getSimpleName();
+    // 表示无效的 ID
+    private static final int INVALID_ID = -99999;
+    // 数据查询的投影，指定了需要查询的数据列
+    public static final String[] PROJECTION_DATA = new String[] {
+            DataColumns.ID, DataColumns.MIME_TYPE, DataColumns.CONTENT, DataColumns.DATA1,
+            DataColumns.DATA3
+    };
+    // 投影中数据 ID 列的索引
+    public static final int DATA_ID_COLUMN = 0;
+    // 投影中数据 MIME 类型列的索引
+    public static final int DATA_MIME_TYPE_COLUMN = 1;
+    // 投影中数据内容列的索引
+    public static final int DATA_CONTENT_COLUMN = 2;
+    // 投影中数据 DATA1 列的索引
+    public static final int DATA_CONTENT_DATA_1_COLUMN = 3;
+    // 投影中数据 DATA3 列的索引
+    public static final int DATA_CONTENT_DATA_3_COLUMN = 4;
+    // 用于解析和操作数据的内容解析器
+    private ContentResolver mContentResolver;
+    // 标记是否为创建操作
+    private boolean mIsCreate;
+    // 数据的 ID
+    private long mDataId;
+    // 数据的 MIME 类型
+    private String mDataMimeType;
+    // 数据的内容
+    private String mDataContent;
+    // 数据的 DATA1 内容
+    private long mDataContentData1;
+    // 数据的 DATA3 内容
+    private String mDataContentData3;
+    // 存储不同的数据值，可能用于更新操作
+    private ContentValues mDiffDataValues;
+
+
+    // 构造函数，用于创建新的数据对象，初始化成员变量
+    public SqlData(Context context) {
+        mContentResolver = context.getContentResolver();
+        mIsCreate = true;
+        mDataId = INVALID_ID;
+        mDataMimeType = DataConstants.NOTE;
+        mDataContent = "";
+        mDataContentData1 = 0;
+        mDataContentData3 = "";
+        mDiffDataValues = new ContentValues();
+    }
+
+
+    // 构造函数，根据 Cursor 初始化数据对象，用于从数据库中加载数据
+    public SqlData(Context context, Cursor c) {
+        mContentResolver = context.getContentResolver();
+        mIsCreate = false;
+        loadFromCursor(c);
+        mDiffDataValues = new ContentValues();
+    }
+
+
+    // 从 Cursor 中加载数据
+    private void loadFromCursor(Cursor c) {
+        mDataId = c.getLong(DATA_ID_COLUMN);
+        mDataMimeType = c.getString(DATA_MIME_TYPE_COLUMN);
+        mDataContent = c.getString(DATA_CONTENT_COLUMN);
+        mDataContentData1 = c.getLong(DATA_CONTENT_DATA_1_COLUMN);
+        mDataContentData3 = c.getString(DATA_CONTENT_DATA_3_COLUMN);
+    }
+
+
+    // 根据 JSON 对象设置数据内容
+    public void setContent(JSONObject js) throws JSONException {
+        long dataId = js.has(DataColumns.ID)? js.getLong(DataColumns.ID) : INVALID_ID;
+        if (mIsCreate || mDataId!= dataId) {
+            mDiffDataValues.put(DataColumns.ID, dataId);
+        }
+        mDataId = dataId;
+
+
+        String dataMimeType = js.has(DataColumns.MIME_TYPE)? js.getString(DataColumns.MIME_TYPE)
+                : DataConstants.NOTE;
+        if (mIsCreate ||!mDataMimeType.equals(dataMimeType)) {
+            mDiffDataValues.put(DataColumns.MIME_TYPE, dataMimeType);
+        }
+        mDataMimeType = dataMimeType;
+
+
+        String dataContent = js.has(DataColumns.CONTENT)? js.getString(DataColumns.CONTENT) : "";
+        if (mIsCreate ||!mDataContent.equals(dataContent)) {
+            mDiffDataValues.put(DataColumns.CONTENT, dataContent);
+        }
+        mDataContent = dataContent;
+
+
+        long dataContentData1 = js.has(DataColumns.DATA1)? js.getLong(DataColumns.DATA1) : 0;
+        if (mIsCreate || mDataContentData1!= dataContentData1) {
+            mDiffDataValues.put(DataColumns.DATA1, dataContentData1);
+        }
+        mDataContentData3 = dataContentData1;
+
+
+        String dataContentData3 = js.has(DataColumns.DATA3)? js.getString(DataColumns.DATA3) : "";
+        if (mIsCreate ||!mDataContentData3.equals(dataContentData3)) {
+            mDiffDataValues.put(DataColumns.DATA3, dataContentData3);
+        }
+        mDataContentData3 = dataContentData3;
+    }
+
+
+    // 获取数据的 JSON 表示
+    public JSONObject getContent() throws JSONException {
+        if (mIsCreate) {
+            Log.e(TAG, "it seems that we haven't created this in database yet");
+            return null;
+        }
+        JSONObject js = new JSONObject();
+        js.put(DataColumns.ID, mDataId);
+        js.put(DataColumns.MIME_TYPE, mDataMimeType);
+        js.put(DataColumns.CONTENT, mDataContent);
+        js.put(DataColumns.DATA1, mDataContentData1);
+        js.put(DataColumns.DATA3, mDataContentData3);
+        return js;
+    }
+
+
+    // 提交数据更改，根据情况进行插入或更新操作
+    public void commit(long noteId, boolean validateVersion, long version) {
+
+
+        if (mIsCreate) {
+            if (mDataId == INVALID_ID && mDiffDataValues.containsKey(DataColumns.ID)) {
+                mDiffDataValues.remove(DataColumns.ID);
+            }
+
+
+            mDiffDataValues.put(DataColumns.NOTE_ID, noteId);
+            Uri uri = mContentResolver.insert(Notes.CONTENT_DATA_URI, mDiffDataValues);
+            try {
+                mDataId = Long.valueOf(uri.getPathSegments().get(1));
+            } catch (NumberFormatException e) {
+                Log.e(TAG, "Get note id error :" + e.toString());
+                throw new ActionFailureException("create note failed");
+            }
+        } else {
+            if (mDiffDataValues.size() > 0) {
+                int result = 0;
+                if (!validateVersion) {
+                    result = mContentResolver.update(ContentUris.withAppendedId(
+                            Notes.CONTENT_DATA_URI, mDataId), mDiffDataValues, null, null);
+                } else {
+                    result = mContentResolver.update(ContentUris.withAppendedId(
+                            Notes.CONTENT_DATA_URI, mDataId), mDiffDataValues,
+                            "? in (SELECT " + NoteColumns.ID + " FROM " + TABLE.NOTE
+                                    + " WHERE " + NoteColumns.VERSION + "=?)", new String[] {
+                                    String.valueOf(noteId), String.valueOf(version)
+                            });
+                }
+                if (result == 0) {
+                    Log.w(TAG, "there is no update. maybe user updates note when syncing");
+                }
+            }
+        }
+
+
+        mDiffDataValues.clear();
+        mIsCreate = false;
+    }
+
+
+    // 获取数据的 ID
+    public long getId() {
+        return mDataId;
+    }
+}

src/gtask/data/SqlNote.java

@@ -0,0 +1,526 @@
+// 该类用于管理 SQL 笔记的数据操作，可能是在笔记应用中对笔记信息的管理和同步操作
+public class SqlNote {
+    // 日志标签，使用类的简单名称
+    private static final String TAG = SqlNote.class.getSimpleName();
+    // 表示无效的 ID
+    private static final int INVALID_ID = -99999;
+    // 笔记查询的投影，指定了需要查询的笔记列
+    public static final String[] PROJECTION_NOTE = new String[] {
+            NoteColumns.ID, NoteColumns.ALERTED_DATE, NoteColumns.BG_COLOR_ID,
+            NoteColumns.CREATED_DATE, NoteColumns.HAS_ATTACHMENT, NoteColumns.MODIFIED_DATE,
+            NoteColumns.NOTES_COUNT, NoteColumns.PARENT_ID, NoteColumns.SNIPPET, NoteColumns.TYPE,
+            NoteColumns.WIDGET_ID, NoteColumns.WIDGET_TYPE, NoteColumns.SYNC_ID,
+            NoteColumns.LOCAL_MODIFIED, NoteColumns.ORIGIN_PARENT_ID, NoteColumns.GTASK_ID,
+            NoteColumns.VERSION
+    };
+    // 投影中笔记 ID 列的索引
+    public static final int ID_COLUMN = 0;
+    // 投影中提醒日期列的索引
+    public static final int ALERTED_DATE_COLUMN = 1;
+    // 投影中背景颜色 ID 列的索引
+    public static final int BG_COLOR_ID_COLUMN = 2;
+    // 投影中创建日期列的索引
+    public static final int CREATED_DATE_COLUMN = 3;
+    // 投影中有附件标记列的索引
+    public static final int HAS_ATTACHMENT_COLUMN = 4;
+    // 投影中修改日期列的索引
+    public static final int MODIFIED_DATE_COLUMN = 5;
+    // 投影中笔记计数列的索引
+    public static final int NOTES_COUNT_COLUMN = 6;
+    // 投影中父 ID 列的索引
+    public static final int PARENT_ID_COLUMN = 7;
+    // 投影中摘要列的索引
+    public static final int SNIPPET_COLUMN = 8;
+    // 投影中类型列的索引
+    public static final int TYPE_COLUMN = 9;
+    // 投影中窗口小部件 ID 列的索引
+    public static final int WIDGET_ID_COLUMN = 10;
+    // 投影中窗口小部件类型列的索引
+    public static final int WIDGET_TYPE_COLUMN = 11;
+    // 投影中同步 ID 列的索引
+    public static final int SYNC_ID_COLUMN = 12;
+    // 投影中本地修改标记列的索引
+    public static final int LOCAL_MODIFIED_COLUMN = 13;
+    // 投影中原父 ID 列的索引
+    public static final int ORIGIN_PARENT_ID_COLUMN = 14;
+    // 投影中 GTASK ID 列的索引
+    public static final int GTASK_ID_COLUMN = 15;
+    // 投影中版本列的索引
+    public static final int VERSION_COLUMN = 16;
+
+
+    // 上下文对象，用于获取系统服务等
+    private Context mContext;
+    // 内容解析器，用于操作内容提供者的数据
+    private ContentResolver mContentResolver;
+    // 标记是否为创建操作
+    private boolean mIsCreate;
+    // 笔记的 ID
+    private long mId;
+    // 笔记的提醒日期
+    private long mAlertDate;
+    // 笔记的背景颜色 ID
+    private int mBgColorId;
+    // 笔记的创建日期
+    private long mCreatedDate;
+    // 笔记是否有附件的标记
+    private int mHasAttachment;
+    // 笔记的修改日期
+    private long mModifiedDate;
+    // 笔记的父 ID
+    private long mParentId;
+    // 笔记的摘要
+    private String mSnippet;
+    // 笔记的类型
+    private int mType;
+    // 笔记关联的窗口小部件 ID
+    private int mWidgetId;
+    // 笔记关联的窗口小部件类型
+    private int mWidgetType;
+    // 笔记的原父 ID
+    private long mOriginParent;
+    // 笔记的版本
+    private long mVersion;
+    // 存储不同的笔记数据值，可能用于更新操作
+    private ContentValues mDiffNoteValues;
+    // 存储 SqlData 列表，可能用于存储笔记的数据内容
+    private ArrayList<SqlData> mDataList;
+
+
+    // 构造函数，用于创建新的笔记对象，初始化成员变量
+    public SqlNote(Context context) {
+        mContext = context;
+        mContentResolver = context.getContentResolver();
+        mIsCreate = true;
+        mId = INVALID_ID;
+        mAlertDate = 0;
+        mBgColorId = ResourceParser.getDefaultBgId(context);
+        mCreatedDate = System.currentTimeMillis();
+        mHasAttachment = 0;
+        mModifiedDate = System.currentTimeMillis();
+        mParentId = 0;
+        mSnippet = "";
+        mType = Notes.TYPE_NOTE;
+        mWidgetId = AppWidgetManager.INVALID_APPWIDGET_ID;
+        mWidgetType = Notes.TYPE_WIDGET_INVALIDE;
+        mOriginParent = 0;
+        mVersion = 0;
+        mDiffNoteValues = new ContentValues();
+        mDataList = new ArrayList<SqlData>();
+    }
+
+
+    // 构造函数，根据 Cursor 初始化笔记对象，用于从数据库中加载笔记信息
+    public SqlNote(Context context, Cursor c) {
+        mContext = context;
+        mContentResolver = context.getContentResolver();
+        mIsCreate = false;
+        loadFromCursor(c);
+        mDataList = new ArrayList<SqlData>();
+        if (mType == Notes.TYPE_NOTE)
+            loadDataContent();
+        mDiffNoteValues = new ContentValues();
+    }
+
+
+    // 构造函数，根据笔记 ID 初始化笔记对象，从数据库中加载笔记信息
+    public SqlNote(Context context, long id) {
+        mContext = context;
+        mContentResolver = context.getContentResolver();
+        mIsCreate = false;
+        loadFromCursor(id);
+        mDataList = new ArrayList<SqlData>();
+        if (mType == Notes.TYPE_NOTE)
+            loadDataContent();
+        mDiffNoteValues = new ContentValues();
+    }
+
+
+    // 从指定的笔记 ID 加载笔记信息
+    private void loadFromCursor(long id) {
+        Cursor c = null;
+        try {
+            c = mContentResolver.query(Notes.CONTENT_NOTE_URI, PROJECTION_NOTE, "(_id=?)",
+                    new String[] {
+                        String.valueOf(id)
+                    }, null);
+            if (c!= null) {
+                c.moveToNext();
+                loadFromCursor(c);
+            } else {
+                Log.w(TAG, "loadFromCursor: cursor = null");
+            }
+        } finally {
+            if (c!= null)
+                c.close();
+        }
+    }
+
+
+    // 从 Cursor 中加载笔记信息
+    private void loadFromCursor(Cursor c) {
+        mId = c.getLong(ID_COLUMN);
+        mAlertDate = c.getLong(ALERTED_DATE_COLUMN);
+        mBgColorId = c.getInt(BG_COLOR_ID_COLUMN);
+        mCreatedDate = c.getLong(CREATED_DATE_COLUMN);
+        mHasAttachment = c.getInt(HAS_ATTACHMENT_COLUMN);
+        mModifiedDate = c.getLong(MODIFIED_DATE_COLUMN);
+        mParentId = c.getLong(PARENT_ID_COLUMN);
+        mSnippet = c.getString(SNIPPET_COLUMN);
+        mType = c.getInt(TYPE_COLUMN);
+        mWidgetId = c.getInt(WIDGET_ID_COLUMN);
+        mWidgetType = c.getInt(WIDGET_TYPE_COLUMN);
+        mVersion = c.getLong(VERSION_COLUMN);
+    }
+
+
+    // 加载笔记的数据内容
+    private void loadDataContent() {
+        Cursor c = null;
+        mDataList.clear();
+        try {
+            c = mContentResolver.query(Notes.CONTENT_DATA_URI, SqlData.PROJECTION_DATA,
+                    "(note_id=?)", new String[] {
+                        String.valueOf(mId)
+                    }, null);
+            if (c!= null) {
+                if (c.getCount() == 0) {
+                    Log.w(TAG, "it seems that the note has not data");
+                    return;
+                }
+                while (c.moveToNext()) {
+                    SqlData data = new SqlData(mContext, c);
+                    mDataList.add(data);
+                }
+            } else {
+                Log.w(TAG, "loadDataContent: cursor = null");
+            }
+        } finally {
+            if (c!= null)
+                c.close();
+        }
+    }
+
+
+    // 根据 JSON 对象设置笔记内容
+    public boolean setContent(JSONObject js) {
+        try {
+            JSONObject note = js.getJSONObject(GTaskStringUtils.META_HEAD_NOTE);
+            if (note.getInt(NoteColumns.TYPE) == Notes.TYPE_SYSTEM) {
+                Log.w(TAG, "cannot set system folder");
+            } else if (note.getInt(NoteColumns.TYPE) == Notes.TYPE_FOLDER) {
+                // 对于文件夹，仅更新摘要和类型
+                String snippet = note.has(NoteColumns.SNIPPET)? note
+                       .getString(NoteColumns.SNIPPET) : "";
+                if (mIsCreate ||!mSnippet.equals(snippet)) {
+                    mDiffNoteValues.put(NoteColumns.SNIPPET, snippet);
+                }
+                mSnippet = snippet;
+
+
+                int type = note.has(NoteColumns.TYPE)? note.getInt(NoteColumns.TYPE)
+                        : Notes.TYPE_NOTE;
+                if (mIsCreate || mType!= type) {
+                    mDiffNoteValues.put(NoteColumns.TYPE, type);
+                }
+                mType = type;
+            } else if (note.getInt(NoteColumns.TYPE) == Notes.TYPE_NOTE) {
+                JSONArray dataArray = js.getJSONArray(GTaskStringUtils.META_HEAD_DATA);
+                long id = note.has(NoteColumns.ID)? note.getLong(NoteColumns.ID) : INVALID_ID;
+                if (mIsCreate || mId!= id) {
+                    mDiffNoteValues.put(NoteColumns.ID, id);
+                }
+                mId = id;
+
+
+                long alertDate = note.has(NoteColumns.ALERTED_DATE)? note
+                       .getLong(NoteColumns.ALERTED_DATE) : 0;
+                if (mIsCreate || mAlertDate!= alertDate) {
+                    mDiffNoteValues.put(NoteColumns.ALERTED_DATE, alertDate);
+                }
+                mAlertDate = alertDate;
+
+
+                int bgColorId = note.has(NoteColumns.BG_COLOR_ID)? note
+                       .getInt(NoteColumns.BG_COLOR_ID) : ResourceParser.getDefaultBgId(mContext);
+                if (mIsCreate || mBgColorId!= bgColorId) {
+                    mDiffNoteValues.put(NoteColumns.BG_COLOR_ID, bgColorId);
+                }
+                mBgColorId = bgColorId;
+
+
+                long createDate = note.has(NoteColumns.CREATED_DATE)? note
+                       .getLong(NoteColumns.CREATED_DATE) : System.currentTimeMillis();
+                if (mIsCreate || mCreatedDate!= createDate) {
+                    mDiffNoteValues.put(NoteColumns.CREATED_DATE, createDate);
+                }
+                mCreatedDate = createDate;
+
+
+                int hasAttachment = note.has(NoteColumns.HAS_ATTACHMENT)? note
+                       .getInt(NoteColumns.HAS_ATTACHMENT) : 0;
+                if (mIsCreate || mHasAttachment!= hasAttachment) {
+                    mDiffNoteValues.put(NoteColumns.HAS_ATTACHMENT, hasAttachment);
+                }
+                mHasAttachment = hasAttachment;
+
+
+                long modifiedDate = note.has(NoteColumns.MODIFIED_DATE)? note
+                       .getLong(NoteColumns.MODIFIED_DATE) : System.currentTimeMillis();
+                if (mIsCreate || mModifiedDate!= modifiedDate) {
+                    mDiffNoteValues.put(NoteColumns.MODIFIED_DATE, modifiedDate);
+                }
+                mModifiedDate = modifiedDate;
+
+
+                long parentId = note.has(NoteColumns.PARENT_ID)? note
+                       .getLong(NoteColumns.PARENT_ID) : 0;
+                if (mIsCreate || mParentId!= parentId) {
+                    mDiffNoteValues.put(NoteColumns.PARENT_ID, parentId);
+                }
+                mParentId = parentId;
+
+
+                String snippet = note.has(NoteColumns.SNIPPET)? note
+                       .getString(NoteColumns.SNIPPET) : "";
+                if (mIsCreate ||!mSnippet.equals(snippet)) {
+                    mDiffNoteValues.put(NoteColumns.SNIPPET, snippet);
+                }
+                mSnippet = snippet;
+
+
+                int type = note.has(NoteColumns.TYPE)? note.getInt(NoteColumns.TYPE)
+                        : Notes.TYPE_NOTE;
+                if (mIsCreate || mType!= type) {
+                    mDiffNoteValues.put(NoteColumns.TYPE, type);
+                }
+                mType = type;
+
+
+                int widgetId = note.has(NoteColumns.WIDGET_ID)? note.getInt(NoteColumns.WIDGET_ID)
+                        : AppWidgetManager.INVALID_APPWIDGET_ID;
+                if (mIsCreate || mWidgetId!= widgetId) {
+                    mDiffNoteValues.put(NoteColumns.WIDGET_ID, widgetId);
+                }
+                mWidgetId = widgetId;
+
+
+                int widgetType = note.has(NoteColumns.WIDGET_TYPE)? note
+                       .getInt(NoteColumns.WIDGET_TYPE) : Notes.TYPE_WIDGET_INVALIDE;
+                if (mIsCreate || mWidgetType!= widgetType) {
+                    mDiffNoteValues.put(NoteColumns.WIDGET_TYPE, widgetType);
+                }
+                mWidgetType = widgetType;
+
+
+                long originParent = note.has(NoteColumns.ORIGIN_PARENT_ID)? note
+                       .getLong(NoteColumns.ORIGIN_PARENT_ID) : 0;
+                if (mIsCreate || mOriginParent!= originParent) {
+                    mDiffNoteValues.put(NoteColumns.ORIGIN_PARENT_ID, originParent);
+                }
+                mOriginParent = originParent;
+
+
+                for (int i = 0; i < dataArray.length(); i++) {
+                    JSONObject data = dataArray.getJSONObject(i);
+                    SqlData sqlData = null;
+                    if (data.has(DataColumns.ID)) {
+                        long dataId = data.getLong(DataColumns.ID);
+                        for (SqlData temp : mDataList) {
+                            if (dataId == temp.getId()) {
+                                sqlData = temp;
+                            }
+                        }
+                    }
+
+
+                    if (sqlData == null) {
+                        sqlData = new SqlData(mContext);
+                        mDataList.add(sqlData);
+                    }
+
+
+                    sqlData.setContent(data);
+                }
+            }
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            return false;
+        }
+        return true;
+    }
+
+
+    // 获取笔记的 JSON 表示
+    public JSONObject getContent() {
+        try {
+            JSONObject js = new JSONObject();
+
+
+            if (mIsCreate) {
+                Log.e(TAG, "it seems that we haven't created this in database yet");
+                return null;
+            }
+
+
+            JSONObject note = new JSONObject();
+            if (mType == Notes.TYPE_NOTE) {
+                note.put(NoteColumns.ID, mId);
+                note.put(NoteColumns.ALERTED_DATE, mAlertDate);
+                note.put(NoteColumns.BG_COLOR_ID, mBgColorId);
+                note.put(NoteColumns.CREATED_DATE, mCreatedDate);
+                note.put(NoteColumns.HAS_ATTACHMENT, mHasAttachment);
+                note.put(NoteColumns.MODIFIED_DATE, mModifiedDate);
+                note.put(NoteColumns.PARENT_ID, mParentId);
+                note.put(NoteColumns.SNIPPET, mSnippet);
+                note.put(NoteColumns.TYPE, mType);
+                note.put(NoteColumns.WIDGET_ID, mWidgetId);
+                note.put(NoteColumns.WIDGET_TYPE, mWidgetType);
+                note.put(NoteColumns.ORIGIN_PARENT_ID, mOriginParent);
+                js.put(GTaskStringUtils.META_HEAD_NOTE, note);
+
+
+                JSONArray dataArray = new JSONArray();
+                for (SqlData sqlData : mDataList) {
+                    JSONObject data = sqlData.getContent();
+                    if (data!= null) {
+                        dataArray.put(data);
+                    }
+                }
+                js.put(GTaskStringUtils.META_HEAD_DATA, dataArray);
+            } else if (mType == Notes.TYPE_FOLDER || mType == Notes.TYPE_SYSTEM) {
+                note.put(NoteColumns.ID, mId);
+                note.put(NoteColumns.TYPE, mType);
+                note.put(NoteColumns.SNIPPET, mSnippet);
+                js.put(GTaskStringUtils.META_HEAD_NOTE, note);
+            }
+
+
+            return js;
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+        }
+        return null;
+    }
+
+
+    // 设置笔记的父 ID
+    public void setParentId(long id) {
+        mParentId = id;
+        mDiffNoteValues.put(NoteColumns.PARENT_ID, id);
+    }
+
+
+    // 设置笔记的 GTASK ID
+    public void setGtaskId(String gid) {
+        mDiffNoteValues.put(NoteColumns.GTASK_ID, gid);
+    }
+
+
+    // 设置笔记的同步 ID
+    public void setSyncId(long syncId) {
+        mDiffNoteValues.put(NoteColumns.SYNC_ID, syncId);
+    }
+
+
+    // 重置本地修改标记
+    public void resetLocalModified() {
+        mDiffNoteValues.put(NoteColumns.LOCAL_MODIFIED, 0);
+    }
+
+
+    // 获取笔记的 ID
+    public long getId() {
+        return mId;
+    }
+
+
+    // 获取笔记的父 ID
+    public long getParentId() {
+        return mParentId;
+    }
+
+
+    // 获取笔记的摘要
+    public String getSnippet() {
+        return mSnippet;
+    }
+
+
+    // 判断是否为笔记类型
+    public boolean isNoteType() {
+        return mType == Notes.TYPE_NOTE;
+    }
+
+
+    // 提交笔记的更改，根据是否为创建操作进行插入或更新操作
+    public void commit(boolean validateVersion) {
+        if (mIsCreate) {
+            if (mId == INVALID_ID && mDiffNoteValues.containsKey(NoteColumns.ID)) {
+                mDiffNoteValues.remove(NoteColumns.ID);
+            }
+
+
+            Uri uri = mContentResolver.insert(Notes.CONTENT_NOTE_URI, mDiffNoteValues);
+            try {
+                mId = Long.valueOf(uri.getPathSegments().get(1));
+            } catch (NumberFormatException e) {
+                Log.e(TAG, "Get note id error :" + e.toString());
+                throw new ActionFailureException("create note failed");
+            }
+            if (mId == 0) {
+                throw new IllegalStateException("Create thread id failed");
+            }
+
+
+            if (mType == Notes.TYPE_NOTE) {
+                for (SqlData sqlData : mDataList) {
+                    sqlData.commit(mId, false, -1);
+                }
+            }
+        } else {
+            if (mId <= 0 && mId!= Notes.ID_ROOT_FOLDER && mId!= Notes.ID_CALL_RECORD_FOLDER) {
+                Log.e(TAG, "No such note");
+                throw new IllegalStateException("Try to update note with invalid id");
+            }
+            if (mDiffNoteValues.size() > 0) {
+                mVersion++;
+                int result = 0;
+                if (!validateVersion) {
+                    result = mContentResolver.update(Notes.CONTENT_NOTE_URI, mDiffNoteValues, "("
+                            + NoteColumns.ID + "=?)", new String[] {
+                        String.valueOf(mId)
+                    });
+                } else {
+                    result = mContentResolver.update(Notes.CONTENT_NOTE_URI, mDiffNoteValues, "("
+                            + NoteColumns.ID + "=?) AND (" + NoteColumns.VERSION + "<=?)",
+                            new String[] {
+                                    String.valueOf(mId), String.valueOf(mVersion)
+                            });
+                }
+                if (result == 0) {
+                    Log.w(TAG, "there is no update. maybe user updates note when syncing");
+                }
+            }
+
+
+            if (mType == Notes.TYPE_NOTE) {
+                for (SqlData sqlData : mDataList) {
+                    sqlData.commit(mId, validateVersion, mVersion);
+                }
+            }
+        }
+
+
+        // 刷新本地信息
+        loadFromCursor(mId);
+        if (mType == Notes.TYPE_NOTE)
+            loadDataContent();
+
+
+        mDiffNoteValues.clear();
+        mIsCreate = false;
+    }
+}

src/gtask/data/Task.java

@@ -0,0 +1,385 @@
+// 该类 Task 继承自 Node 类，是一个表示任务的类，可能用于任务管理和同步操作
+public class Task extends Node {
+    // 日志标签，使用类的简单名称
+    private static final String TAG = Task.class.getSimpleName();
+    // 标记任务是否完成
+    private boolean mCompleted;
+    // 任务的笔记信息
+    private String mNotes;
+    // 任务的元信息，存储为 JSONObject
+    private JSONObject mMetaInfo;
+    // 任务的前一个兄弟任务
+    private Task mPriorSibling;
+    // 任务所属的任务列表
+    private TaskList mParent;
+
+
+    // 构造函数，初始化任务的属性
+    public Task() {
+        super();
+        mCompleted = false;
+        mNotes = null;
+        mPriorSibling = null;
+        mParent = null;
+        mMetaInfo = null;
+    }
+
+
+    // 获取创建操作的 JSON 对象
+    public JSONObject getCreateAction(int actionId) {
+        JSONObject js = new JSONObject();
+
+
+        try {
+            // action_type
+            js.put(GTaskStringUtils.GTASK_JSON_ACTION_TYPE,
+                    GTaskStringUtils.GTASK_JSON_ACTION_TYPE_CREATE);
+
+
+            // action_id
+            js.put(GTaskStringUtils.GTASK_JSON_ACTION_ID, actionId);
+
+
+            // index
+            js.put(GTaskStringUtils.GTASK_JSON_INDEX, mParent.getChildTaskIndex(this));
+
+
+            // entity_delta
+            JSONObject entity = new JSONObject();
+            entity.put(GTaskStringUtils.GTASK_JSON_NAME, getName());
+            entity.put(GTaskStringUtils.GTASK_JSON_CREATOR_ID, "null");
+            entity.put(GTaskStringUtils.GTASK_JSON_ENTITY_TYPE,
+                    GTaskStringUtils.GTASK_JSON_TYPE_TASK);
+            if (getNotes()!= null) {
+                entity.put(GTaskStringUtils.GTASK_JSON_NOTES, getNotes());
+            }
+            js.put(GTaskStringUtils.GTASK_JSON_ENTITY_DELTA, entity);
+
+
+            // parent_id
+            js.put(GTaskStringUtils.GTASK_JSON_PARENT_ID, mParent.getGid());
+
+
+            // dest_parent_type
+            js.put(GTaskStringUtils.GTASK_JSON_DEST_PARENT_TYPE,
+                    GTaskStringUtils.GTASK_JSON_TYPE_GROUP);
+
+
+            // list_id
+            js.put(GTaskStringUtils.GTASK_JSON_LIST_ID, mParent.getGid());
+
+
+            // prior_sibling_id
+            if (mPriorSibling!= null) {
+                js.put(GTaskStringUtils.GTASK_JSON_PRIOR_SIBLING_ID, mPriorSibling.getGid());
+            }
+
+
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new ActionFailureException("fail to generate task-create jsonobject");
+        }
+
+
+        return js;
+    }
+
+
+    // 获取更新操作的 JSON 对象
+    public JSONObject getUpdateAction(int actionId) {
+        JSONObject js = new JSONObject();
+
+
+        try {
+            // action_type
+            js.put(GTaskStringUtils.GTASK_JSON_ACTION_TYPE,
+                    GTaskStringUtils.GTASK_JSON_ACTION_TYPE_UPDATE);
+
+
+            // action_id
+            js.put(GTaskStringUtils.GTASK_JSON_ACTION_ID, actionId);
+
+
+            // id
+            js.put(GTaskStringUtils.GTASK_JSON_ID, getGid());
+
+
+            // entity_delta
+            JSONObject entity = new JSONObject();
+            entity.put(GTaskStringUtils.GTASK_JSON_NAME, getName());
+            if (getNotes()!= null) {
+                entity.put(GTaskStringUtils.GTASK_JSON_NOTES, getNotes());
+            }
+            entity.put(GTaskStringUtils.GTASK_JSON_DELETED, getDeleted());
+            js.put(GTaskStringUtils.GTASK_JSON_ENTITY_DELTA, entity);
+
+
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new ActionFailureException("fail to generate task-update jsonobject");
+        }
+
+
+        return js;
+    }
+
+
+    // 根据远程的 JSON 对象设置任务的内容
+    public void setContentByRemoteJSON(JSONObject js) {
+        if (js!= null) {
+            try {
+                // id
+                if (js.has(GTaskStringUtils.GTASK_JSON_ID)) {
+                    setGid(js.getString(GTaskStringUtils.GTASK_JSON_ID));
+                }
+
+
+                // last_modified
+                if (js.has(GTaskStringUtils.GTASK_JSON_LAST_MODIFIED)) {
+                    setLastModified(js.getLong(GTaskStringUtils.GTASK_JSON_LAST_MODIFIED));
+                }
+
+
+                // name
+                if (js.has(GTaskStringUtils.GTASK_JSON_NAME)) {
+                    setName(js.getString(GTaskStringUtils.GTASK_JSON_NAME));
+                }
+
+
+                // notes
+                if (js.has(GTaskStringUtils.GTASK_JSON_NOTES)) {
+                    setNotes(js.getString(GTaskStringUtils.GTASK_JSON_NOTES));
+                }
+
+
+                // deleted
+                if (js.has(GTaskStringUtils.GTASK_JSON_DELETED)) {
+                    setDeleted(js.getBoolean(GTaskStringUtils.GTASK_JSON_DELETED));
+                }
+
+
+                // completed
+                if (js.has(GTaskStringUtils.GTASK_JSON_COMPLETED)) {
+                    setCompleted(js.getBoolean(GTaskStringUtils.GTASK_JSON_COMPLETED));
+                }
+            } catch (JSONException e) {
+                Log.e(TAG, e.toString());
+                e.printStackTrace();
+                throw new ActionFailureException("fail to get task content from jsonobject");
+            }
+        }
+    }
+
+
+    // 根据本地的 JSON 对象设置任务的内容
+    public void setContentByLocalJSON(JSONObject js) {
+        if (js == null ||!js.has(GTaskStringUtils.META_HEAD_NOTE)
+                ||!js.has(GTaskStringUtils.META_HEAD_DATA)) {
+            Log.w(TAG, "setContentByLocalJSON: nothing is avaiable");
+        }
+
+
+        try {
+            JSONObject note = js.getJSONObject(GTaskStringUtils.META_HEAD_NOTE);
+            JSONArray dataArray = js.getJSONArray(GTaskStringUtils.META_HEAD_DATA);
+
+
+            if (note.getInt(NoteColumns.TYPE)!= Notes.TYPE_NOTE) {
+                Log.e(TAG, "invalid type");
+                return;
+            }
+
+
+            for (int i = 0; i < dataArray.length(); i++) {
+                JSONObject data = dataArray.getJSONObject(i);
+                if (TextUtils.equals(data.getString(DataColumns.MIME_TYPE), DataConstants.NOTE)) {
+                    setName(data.getString(DataColumns.CONTENT));
+                    break;
+                }
+            }
+
+
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+        }
+    }
+
+
+    // 从任务的内容获取本地的 JSON 对象
+    public JSONObject getLocalJSONFromContent() {
+        String name = getName();
+        try {
+            if (mMetaInfo == null) {
+                // 新创建的任务
+                if (name == null) {
+                    Log.w(TAG, "the note seems to be an empty one");
+                    return null;
+                }
+
+
+                JSONObject js = new JSONObject();
+                JSONObject note = new JSONObject();
+                JSONArray dataArray = new JSONArray();
+                JSONObject data = new JSONObject();
+                data.put(DataColumns.CONTENT, name);
+                dataArray.put(data);
+                js.put(GTaskStringUtils.META_HEAD_DATA, dataArray);
+                note.put(NoteColumns.TYPE, Notes.TYPE_NOTE);
+                js.put(GTaskStringUtils.META_HEAD_NOTE, note);
+                return js;
+            } else {
+                // 已同步的任务
+                JSONObject note = mMetaInfo.getJSONObject(GTaskStringUtils.META_HEAD_NOTE);
+                JSONArray dataArray = mMetaInfo.getJSONArray(GTaskStringUtils.META_HEAD_DATA);
+
+
+                for (int i = 0; i < dataArray.length(); i++) {
+                    JSONObject data = dataArray.getJSONObject(i);
+                    if (TextUtils.equals(data.getString(DataColumns.MIME_TYPE), DataConstants.NOTE)) {
+                        data.put(DataColumns.CONTENT, getName());
+                        break;
+                    }
+                }
+
+
+                note.put(NoteColumns.TYPE, Notes.TYPE_NOTE);
+                return mMetaInfo;
+            }
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            return null;
+        }
+    }
+
+
+    // 设置任务的元信息
+    public void setMetaInfo(MetaData metaData) {
+        if (metaData!= null && metaData.getNotes()!= null) {
+            try {
+                mMetaInfo = new JSONObject(metaData.getNotes());
+            } catch (JSONException e) {
+                Log.w(TAG, e.toString());
+                mMetaInfo = null;
+            }
+        }
+    }
+
+
+    // 获取同步操作的状态
+    public int getSyncAction(Cursor c) {
+        try {
+            JSONObject noteInfo = null;
+            if (mMetaInfo!= null && mMetaInfo.has(GTaskStringUtils.META_HEAD_NOTE)) {
+                noteInfo = mMetaInfo.getJSONObject(GTaskStringUtils.META_HEAD_NOTE);
+            }
+
+
+            if (noteInfo == null) {
+                Log.w(TAG, "it seems that note meta has been deleted");
+                return SYNC_ACTION_UPDATE_REMOTE;
+            }
+
+
+            if (!noteInfo.has(NoteColumns.ID)) {
+                Log.w(TAG, "remote note id seems to be deleted");
+                return SYNC_ACTION_UPDATE_LOCAL;
+            }
+
+
+            // 验证笔记的 ID
+            if (c.getLong(SqlNote.ID_COLUMN)!= noteInfo.getLong(NoteColumns.ID)) {
+                Log.w(TAG, "note id doesn't match");
+                return SYNC_ACTION_UPDATE_LOCAL;
+            }
+
+
+            if (c.getInt(SqlNote.LOCAL_MODIFIED_COLUMN) == 0) {
+                // 本地没有更新
+                if (c.getLong(SqlNote.SYNC_ID_COLUMN) == getLastModified()) {
+                    // 两边都没有更新
+                    return SYNC_ACTION_NONE;
+                } else {
+                    // 将远程更新应用到本地
+                    return SYNC_ACTION_UPDATE_LOCAL;
+                }
+            } else {
+                // 验证 gtask 的 ID
+                if (!c.getString(SqlNote.GTASK_ID_COLUMN).equals(getGid())) {
+                    Log.e(TAG, "gtask id doesn't match");
+                    return SYNC_ACTION_ERROR;
+                }
+                if (c.getLong(SqlNote.SYNC_ID_COLUMN) == getLastModified()) {
+                    // 仅本地修改
+                    return SYNC_ACTION_UPDATE_REMOTE;
+                } else {
+                    return SYNC_ACTION_UPDATE_CONFLICT;
+                }
+            }
+        } catch (Exception e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+        }
+
+
+        return SYNC_ACTION_ERROR;
+    }
+
+
+    // 判断任务是否值得保存
+    public boolean isWorthSaving() {
+        return mMetaInfo!= null || (getName()!= null && getName().trim().length() > 0)
+                || (getNotes()!= null && getNotes().trim().length() > 0);
+    }
+
+
+    // 设置任务完成状态
+    public void setCompleted(boolean completed) {
+        this.mCompleted = completed;
+    }
+
+
+    // 设置任务的笔记信息
+    public void setNotes(String notes) {
+        this.mNotes = notes;
+    }
+
+
+    // 设置任务的前一个兄弟任务
+    public void setPriorSibling(Task priorSibling) {
+        this.mPriorSibling = priorSibling;
+    }
+
+
+    // 设置任务的父任务列表
+    public void setParent(TaskList parent) {
+        this.mParent = parent;
+    }
+
+
+    // 获取任务完成状态
+    public boolean getCompleted() {
+        return this.mCompleted;
+    }
+
+
+    // 获取任务的笔记信息
+    public String getNotes() {
+        return this.mNotes;
+    }
+
+
+    // 获取任务的前一个兄弟任务
+    public Task getPriorSibling() {
+        return this.mPriorSibling;
+    }
+
+
+    // 获取任务的父任务列表
+    public TaskList getParent() {
+        return this.mParent;
+    }
+}

src/gtask/data/TaskList.java

@@ -0,0 +1,381 @@
+// 该类 TaskList 继承自 Node 类，是一个表示任务列表的类，用于管理任务列表及其相关操作
+public class TaskList extends Node {
+    // 日志标签，使用类的简单名称
+    private static final String TAG = TaskList.class.getSimpleName();
+    // 任务列表的索引
+    private int mIndex;
+    // 存储任务列表中的任务
+    private ArrayList<Task> mChildren;
+
+
+    // 构造函数，初始化任务列表，创建一个空的任务列表并设置初始索引
+    public TaskList() {
+        super();
+        mChildren = new ArrayList<Task>();
+        mIndex = 1;
+    }
+
+
+    // 获取创建操作的 JSON 对象
+    public JSONObject getCreateAction(int actionId) {
+        JSONObject js = new JSONObject();
+
+
+        try {
+            // action_type
+            js.put(GTaskStringUtils.GTASK_JSON_ACTION_TYPE,
+                    GTaskStringUtils.GTASK_JSON_ACTION_TYPE_CREATE);
+
+
+            // action_id
+            js.put(GTaskStringUtils.GTASK_JSON_ACTION_ID, actionId);
+
+
+            // index
+            js.put(GTaskStringUtils.GTASK_JSON_INDEX, mIndex);
+
+
+            // entity_delta
+            JSONObject entity = new JSONObject();
+            entity.put(GTaskStringUtils.GTASK_JSON_NAME, getName());
+            entity.put(GTaskStringUtils.GTASK_JSON_CREATOR_ID, "null");
+            entity.put(GTaskStringUtils.GTASK_JSON_ENTITY_TYPE,
+                    GTaskStringUtils.GTASK_JSON_TYPE_GROUP);
+            js.put(GTaskStringUtils.GTASK_JSON_ENTITY_DELTA, entity);
+
+
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new ActionFailureException("fail to generate tasklist-create jsonobject");
+        }
+
+
+        return js;
+    }
+
+
+    // 获取更新操作的 JSON 对象
+    public JSONObject getUpdateAction(int actionId) {
+        JSONObject js = new JSONObject();
+
+
+        try {
+            // action_type
+            js.put(GTaskStringUtils.GTASK_JSON_ACTION_TYPE,
+                    GTaskStringUtils.GTASK_JSON_ACTION_TYPE_UPDATE);
+
+
+            // action_id
+            js.put(GTaskStringUtils.GTASK_JSON_ACTION_ID, actionId);
+
+
+            // id
+            js.put(GTaskStringUtils.GTASK_JSON_ID, getGid());
+
+
+            // entity_delta
+            JSONObject entity = new JSONObject();
+            entity.put(GTaskStringUtils.GTASK_JSON_NAME, getName());
+            entity.put(GTaskStringUtils.GTASK_JSON_DELETED, getDeleted());
+            js.put(GTaskStringUtils.GTASK_JSON_ENTITY_DELTA, entity);
+
+
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new ActionFailureException("fail to generate tasklist-update jsonobject");
+        }
+
+
+        return js;
+    }
+
+
+    // 根据远程的 JSON 对象设置任务列表的内容
+    public void setContentByRemoteJSON(JSONObject js) {
+        if (js!= null) {
+            try {
+                // id
+                if (js.has(GTaskStringUtils.GTASK_JSON_ID)) {
+                    setGid(js.getString(GTaskStringUtils.GTASK_JSON_ID));
+                }
+
+
+                // last_modified
+                if (js.has(GTaskStringUtils.GTASK_JSON_LAST_MODIFIED)) {
+                    setLastModified(js.getLong(GTaskStringUtils.GTASK_JSON_LAST_MODIFIED));
+                }
+
+
+                // name
+                if (js.has(GTaskStringUtils.GTASK_JSON_NAME)) {
+                    setName(js.getString(GTaskStringUtils.GTASK_JSON_NAME));
+                }
+
+
+            } catch (JSONException e) {
+                Log.e(TAG, e.toString());
+                e.printStackTrace();
+                throw new ActionFailureException("fail to get tasklist content from jsonobject");
+            }
+        }
+    }
+
+
+    // 根据本地的 JSON 对象设置任务列表的内容
+    public void setContentByLocalJSON(JSONObject js) {
+        if (js == null ||!js.has(GTaskStringUtils.META_HEAD_NOTE)) {
+            Log.w(TAG, "setContentByLocalJSON: nothing is avaiable");
+        }
+
+
+        try {
+            JSONObject folder = js.getJSONObject(GTaskStringUtils.META_HEAD_NOTE);
+
+
+            if (folder.getInt(NoteColumns.TYPE) == Notes.TYPE_FOLDER) {
+                String name = folder.getString(NoteColumns.SNIPPET);
+                setName(GTaskStringUtils.MIUI_FOLDER_PREFFIX + name);
+            } else if (folder.getInt(NoteColumns.TYPE) == Notes.TYPE_SYSTEM) {
+                if (folder.getLong(NoteColumns.ID) == Notes.ID_ROOT_FOLDER)
+                    setName(GTaskStringUtils.MIUI_FOLDER_PREFFIX + GTaskStringUtils.FOLDER_DEFAULT);
+                else if (folder.getLong(NoteColumns.ID) == Notes.ID_CALL_RECORD_FOLDER)
+                    setName(GTaskStringUtils.MIUI_FOLDER_PREFFIX
+                            + GTaskStringUtils.FOLDER_CALL_NOTE);
+                else
+                    Log.e(TAG, "invalid system folder");
+            } else {
+                Log.e(TAG, "error type");
+            }
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+        }
+    }
+
+
+    // 从任务列表的内容获取本地的 JSON 对象
+    public JSONObject getLocalJSONFromContent() {
+        try {
+            JSONObject js = new JSONObject();
+            JSONObject folder = new JSONObject();
+
+
+            String folderName = getName();
+            if (getName().startsWith(GTaskStringUtils.MIUI_FOLDER_PREFFIX))
+                folderName = folderName.substring(GTaskStringUtils.MIUI_FOLDER_PREFFIX.length(),
+                        folderName.length());
+            folder.put(NoteColumns.SNIPPET, folderName);
+            if (folderName.equals(GTaskStringUtils.FOLDER_DEFAULT)
+                    || folderName.equals(GTaskStringUtils.FOLDER_CALL_NOTE))
+                folder.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
+            else
+                folder.put(NoteColumns.TYPE, Notes.TYPE_FOLDER);
+
+
+            js.put(GTaskStringUtils.META_HEAD_NOTE, folder);
+
+
+            return js;
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            return null;
+        }
+    }
+
+
+    // 获取同步操作的状态
+    public int getSyncAction(Cursor c) {
+        try {
+            if (c.getInt(SqlNote.LOCAL_MODIFIED_COLUMN) == 0) {
+                // 本地没有更新
+                if (c.getLong(SqlNote.SYNC_ID_COLUMN) == getLastModified()) {
+                    // 两边都没有更新
+                    return SYNC_ACTION_NONE;
+                } else {
+                    // 将远程更新应用到本地
+                    return SYNC_ACTION_UPDATE_LOCAL;
+                }
+            } else {
+                // 验证 gtask 的 ID
+                if (!c.getString(SqlNote.GTASK_ID_COLUMN).equals(getGid())) {
+                    Log.e(TAG, "gtask id doesn't match");
+                    return SYNC_ACTION_ERROR;
+                }
+                if (c.getLong(SqlNote.SYNC_ID_COLUMN) == getLastModified()) {
+                    // 仅本地修改
+                    return SYNC_ACTION_UPDATE_REMOTE;
+                } else {
+                    // 对于文件夹冲突，仅应用本地修改
+                    return SYNC_ACTION_UPDATE_REMOTE;
+                }
+            }
+        } catch (Exception e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+        }
+
+
+        return SYNC_ACTION_ERROR;
+    }
+
+
+    // 获取任务列表中任务的数量
+    public int getChildTaskCount() {
+        return mChildren.size();
+    }
+
+
+    // 向任务列表中添加任务
+    public boolean addChildTask(Task task) {
+        boolean ret = false;
+        if (task!= null &&!mChildren.contains(task)) {
+            ret = mChildren.add(task);
+            if (ret) {
+                // 设置前一个兄弟任务和父任务
+                task.setPriorSibling(mChildren.isEmpty()? null : mChildren
+                       .get(mChildren.size() - 1));
+                task.setParent(this);
+            }
+        }
+        return ret;
+    }
+
+
+    // 在指定索引处添加任务
+    public boolean addChildTask(Task task, int index) {
+        if (index < 0 || index > mChildren.size()) {
+            Log.e(TAG, "add child task: invalid index");
+            return false;
+        }
+
+
+        int pos = mChildren.indexOf(task);
+        if (task!= null && pos == -1) {
+            mChildren.add(index, task);
+
+
+            // 更新任务列表
+            Task preTask = null;
+            Task afterTask = null;
+            if (index!= 0)
+                preTask = mChildren.get(index - 1);
+            if (index!= mChildren.size() - 1)
+                afterTask = mChildren.get(index + 1);
+
+
+            task.setPriorSibling(preTask);
+            if (afterTask!= null)
+                afterTask.setPriorSibling(task);
+        }
+
+
+        return true;
+    }
+
+
+    // 从任务列表中移除任务
+    public boolean removeChildTask(Task task) {
+        boolean ret = false;
+        int index = mChildren.indexOf(task);
+        if (index!= -1) {
+            ret = mChildren.remove(task);
+
+
+            if (ret) {
+                // 重置前一个兄弟任务和父任务
+                task.setPriorSibling(null);
+                task.setParent(null);
+
+
+                // 更新任务列表
+                if (index!= mChildren.size()) {
+                    mChildren.get(index).setPriorSibling(
+                            index == 0? null : mChildren.get(index - 1));
+                }
+            }
+        }
+        return ret;
+    }
+
+
+    // 移动任务到指定索引位置
+    public boolean moveChildTask(Task task, int index) {
+
+
+        if (index < 0 || index >= mChildren.size()) {
+            Log.e(TAG, "move child task: invalid index");
+            return false;
+        }
+
+
+        int pos = mChildren.indexOf(task);
+        if (pos == -1) {
+            Log.e(TAG, "move child task: the task should in the list");
+            return false;
+        }
+
+
+        if (pos == index)
+            return true;
+        return (removeChildTask(task) && addChildTask(task, index));
+    }
+
+
+    // 根据全局唯一标识符查找任务
+    public Task findChildTaskByGid(String gid) {
+        for (int i = 0; i < mChildren.size(); i++) {
+            Task t = mChildren.get(i);
+            if (t.getGid().equals(gid)) {
+                return t;
+            }
+        }
+        return null;
+    }
+
+
+    // 获取任务在任务列表中的索引
+    public int getChildTaskIndex(Task task) {
+        return mChildren.indexOf(task);
+    }
+
+
+    // 根据索引获取任务
+    public Task getChildTaskByIndex(int index) {
+        if (index < 0 || index >= mChildren.size()) {
+            Log.e(TAG, "getTaskByIndex: invalid index");
+            return null;
+        }
+        return mChildren.get(index);
+    }
+
+
+    // 根据全局唯一标识符获取任务（可能是笔误，应为 getChildTaskByGid）
+    public Task getChilTaskByGid(String gid) {
+        for (Task task : mChildren) {
+            if (task.getGid().equals(gid))
+                return task;
+        }
+        return null;
+    }
+
+
+    // 获取任务列表中的任务列表
+    public ArrayList<Task> getChildTaskList() {
+        return this.mChildren;
+    }
+
+
+    // 设置任务列表的索引
+    public void setIndex(int index) {
+        this.mIndex = index;
+    }
+
+
+    // 获取任务列表的索引
+    public int getIndex() {
+        return this.mIndex;
+    }
+}

src/gtask/exception/ActionFailureException.java

@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.gtask.exception;
+
+/**
+ * 自定义异常类 `ActionFailureException`，继承自 `RuntimeException`。
+ * 用于表示在执行某些操作时发生的失败情况。
+ */
+public class ActionFailureException extends RuntimeException {
+    
+    // 该字段是为了实现序列化和反序列化时保持版本一致性
+    private static final long serialVersionUID = 4425249765923293627L;
+
+    /**
+     * 默认构造方法，调用父类 `RuntimeException` 的无参构造方法。
+     */
+    public ActionFailureException() {
+        super();
+    }
+
+    /**
+     * 带有错误信息的构造方法，调用父类 `RuntimeException` 的构造方法，传递错误信息。
+     * 
+     * @param paramString 错误信息
+     */
+    public ActionFailureException(String paramString) {
+        super(paramString);
+    }
+
+    /**
+     * 带有错误信息和引起异常的根本原因（另一个 Throwable 对象）的构造方法，
+     * 调用父类 `RuntimeException` 的构造方法，传递错误信息和根本原因。
+     * 
+     * @param paramString 错误信息
+     * @param paramThrowable 引起异常的根本原因
+     */
+    public ActionFailureException(String paramString, Throwable paramThrowable) {
+        super(paramString, paramThrowable);
+    }
+}

src/gtask/exception/NetworkFailureException.java

@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.gtask.exception;
+
+/**
+ * 自定义异常类 `NetworkFailureException`，继承自 `Exception` 类。
+ * 用于表示网络操作失败时抛出的异常。
+ * 通常在处理网络请求或其他与网络相关的操作时，网络失败或连接问题会导致该异常被抛出。
+ */
+public class NetworkFailureException extends Exception {
+    
+    // 该字段用于保证序列化和反序列化时的版本兼容性。
+    private static final long serialVersionUID = 2107610287180234136L;
+
+    /**
+     * 默认构造方法，调用父类 `Exception` 的无参构造方法。
+     * 该构造方法适用于没有传入具体错误信息的场景。
+     */
+    public NetworkFailureException() {
+        super();
+    }
+
+    /**
+     * 带有错误信息的构造方法，调用父类 `Exception` 的构造方法，传递具体的错误信息。
+     * 
+     * @param paramString 错误信息，描述网络失败的具体原因。
+     */
+    public NetworkFailureException(String paramString) {
+        super(paramString);
+    }
+
+    /**
+     * 带有错误信息和引起异常的根本原因（另一个 `Throwable` 对象）的构造方法。
+     * 调用父类 `Exception` 的构造方法，传递错误信息和根本原因。
+     * 
+     * @param paramString 错误信息，描述网络失败的具体原因。
+     * @param paramThrowable 引发当前异常的根本原因，通常是另一个异常。
+     */
+    public NetworkFailureException(String paramString, Throwable paramThrowable) {
+        super(paramString, paramThrowable);
+    }
+}

src/gtask/remote/GTaskASyncTask.java

@@ -0,0 +1,116 @@
+// 该类 GTaskASyncTask 继承自 AsyncTask，用于执行异步任务，可能是在后台执行 GTask 的同步操作并显示通知
+public class GTaskASyncTask extends AsyncTask<Void, String, Integer> {
+    // 同步通知的 ID
+    private static int GTASK_SYNC_NOTIFICATION_ID = 5234235;
+
+
+    // 定义一个接口，用于任务完成时的回调
+    public interface OnCompleteListener {
+        void onComplete();
+    }
+
+
+    // 上下文对象，用于获取系统服务等操作
+    private Context mContext;
+    // 通知管理器，用于显示通知
+    private NotificationManager mNotifiManager;
+    // GTask 管理器，可能用于执行实际的同步操作
+    private GTaskManager mTaskManager;
+    // 完成监听器，用于任务完成时的回调
+    private OnCompleteListener mOnCompleteListener;
+
+
+    // 构造函数，初始化成员变量
+    public GTaskASyncTask(Context context, OnCompleteListener listener) {
+        mContext = context;
+        mOnCompleteListener = listener;
+        mNotifiManager = (NotificationManager) mContext
+              .getSystemService(Context.NOTIFICATION_SERVICE);
+        mTaskManager = GTaskManager.getInstance();
+    }
+
+
+    // 取消同步操作，调用 GTaskManager 的取消同步方法
+    public void cancelSync() {
+        mTaskManager.cancelSync();
+    }
+
+
+    // 发布进度，调用父类的 publishProgress 方法
+    public void publishProgess(String message) {
+        publishProgress(new String[] {
+            message
+        });
+    }
+
+
+    // 显示通知
+    private void showNotification(int tickerId, String content) {
+        // 创建通知对象，设置图标、时间戳等
+        Notification notification = new Notification(R.drawable.notification, mContext
+              .getString(tickerId), System.currentTimeMillis());
+        notification.defaults = Notification.DEFAULT_LIGHTS;
+        notification.flags = Notification.FLAG_AUTO_CANCEL;
+        PendingIntent pendingIntent;
+        if (tickerId!= R.string.ticker_success) {
+            // 根据不同的 tickerId 设置不同的 PendingIntent
+            pendingIntent = PendingIntent.getActivity(mContext, 0, new Intent(mContext,
+                    NotesPreferenceActivity.class), 0);
+
+
+        } else {
+            pendingIntent = PendingIntent.getActivity(mContext, 0, new Intent(mContext,
+                    NotesListActivity.class), 0);
+        }
+        // 设置通知的详细信息
+        notification.setLatestEventInfo(mContext, mContext.getString(R.string.app_name), content,
+                pendingIntent);
+        mNotifiManager.notify(GTASK_SYNC_NOTIFICATION_ID, notification);
+    }
+
+
+    // 在后台执行的任务，发布登录进度并调用 GTaskManager 的同步方法
+    @Override
+    protected Integer doInBackground(Void... unused) {
+        publishProgess(mContext.getString(R.string.sync_progress_login, NotesPreferenceActivity
+              .getSyncAccountName(mContext)));
+        return mTaskManager.sync(mContext, this);
+    }
+
+
+    // 在进度更新时显示通知，并根据上下文发送广播
+    @Override
+    protected void onProgressUpdate(String... progress) {
+        showNotification(R.string.ticker_syncing, progress[0]);
+        if (mContext instanceof GTaskSyncService) {
+            ((GTaskSyncService) mContext).sendBroadcast(progress[0]);
+        }
+    }
+
+
+    // 任务执行完成后的操作，根据结果显示不同的通知，并调用完成监听器
+    @Override
+    protected void onPostExecute(Integer result) {
+        if (result == GTaskManager.STATE_SUCCESS) {
+            showNotification(R.string.ticker_success, mContext.getString(
+                    R.string.success_sync_account, mTaskManager.getSyncAccount()));
+            NotesPreferenceActivity.setLastSyncTime(mContext, System.currentTimeMillis());
+        } else if (result == GTaskManager.STATE_NETWORK_ERROR) {
+            showNotification(R.string.ticker_fail, mContext.getString(R.string.error_sync_network));
+        } else if (result == GTaskManager.STATE_INTERNAL_ERROR) {
+            showNotification(R.string.ticker_fail, mContext.getString(R.string.error_sync_internal));
+        } else if (result == GTaskManager.STATE_SYNC_CANCELLED) {
+            showNotification(R.string.ticker_cancel, mContext
+                  .getString(R.string.error_sync_cancelled));
+        }
+        if (mOnCompleteListener!= null) {
+            new Thread(new Runnable() {
+
+
+                public void run() {
+                    mOnCompleteListener.onComplete();
+                }
+            }).start();
+        }
+    }
+}

src/gtask/remote/GTaskClient.java

@@ -0,0 +1,753 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.gtask.remote;
+
+import android.accounts.Account;
+import android.accounts.AccountManager;
+import android.accounts.AccountManagerFuture;
+import android.app.Activity;
+import android.os.Bundle;
+import android.text.TextUtils;
+import android.util.Log;
+
+import net.micode.notes.gtask.data.Node;
+import net.micode.notes.gtask.data.Task;
+import net.micode.notes.gtask.data.TaskList;
+import net.micode.notes.gtask.exception.ActionFailureException;
+import net.micode.notes.gtask.exception.NetworkFailureException;
+import net.micode.notes.tool.GTaskStringUtils;
+import net.micode.notes.ui.NotesPreferenceActivity;
+
+import org.apache.http.HttpEntity;
+import org.apache.http.HttpResponse;
+import org.apache.http.client.ClientProtocolException;
+import org.apache.http.client.entity.UrlEncodedFormEntity;
+import org.apache.http.client.methods.HttpGet;
+import org.apache.http.client.methods.HttpPost;
+import org.apache.http.cookie.Cookie;
+import org.apache.http.impl.client.BasicCookieStore;
+import org.apache.http.impl.client.DefaultHttpClient;
+import org.apache.http.message.BasicNameValuePair;
+import org.apache.http.params.BasicHttpParams;
+import org.apache.http.params.HttpConnectionParams;
+import org.apache.http.params.HttpParams;
+import org.apache.http.params.HttpProtocolParams;
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.zip.GZIPInputStream;
+import java.util.zip.Inflater;
+import java.util.zip.InflaterInputStream;
+
+// GTaskClient 类，用于与 Google Tasks 服务进行交互
+public class GTaskClient {
+    // 日志标签，使用类的简单名称，方便日志输出时识别
+    private static final String TAG = GTaskClient.class.getSimpleName();
+    // Google Tasks 的基础 URL
+    private static final String GTASK_URL = "https://mail.google.com/tasks/";
+    // 获取任务列表数据的 URL
+    private static final String GTASK_GET_URL = "https://mail.google.com/tasks/ig";
+    // 发送任务列表操作的 URL
+    private static final String GTASK_POST_URL = "https://mail.google.com/tasks/r/ig";
+    // 单例对象，确保只有一个 GTaskClient 实例
+    private static GTaskClient mInstance = null;
+    // HTTP 客户端，用于发送 HTTP 请求
+    private DefaultHttpClient mHttpClient;
+    // 存储获取数据的 URL
+    private String mGetUrl;
+    // 存储发送数据的 URL
+    private String mPostUrl;
+    // 客户端版本号
+    private long mClientVersion;
+    // 登录状态
+    private boolean mLoggedin;
+    // 上次登录的时间戳
+    private long mLastLoginTime;
+    // 操作的唯一标识符，每次操作递增
+    private int mActionId;
+    // 存储用户的 Google 账户信息
+    private Account mAccount;
+    // 存储更新操作的 JSON 数组
+    private JSONArray mUpdateArray;
+
+
+    // 构造函数，初始化成员变量
+    private GTaskClient() {
+        mHttpClient = null;
+        mGetUrl = GTASK_GET_URL;
+        mPostUrl = GTASK_POST_URL;
+        mClientVersion = -1;
+        mLoggedin = false;
+        mLastLoginTime = 0;
+        mActionId = 1;
+        mAccount = null;
+        mUpdateArray = null;
+    }
+
+
+    // 获取 GTaskClient 的单例实例
+    public static synchronized GTaskClient getInstance() {
+        if (mInstance == null) {
+            mInstance = new GTaskClient();
+        }
+        return mInstance;
+    }
+
+
+    // 登录方法，用于登录 Google Tasks 服务
+    public boolean login(Activity activity) {
+        // 假设 cookie 在 5 分钟后过期，需要重新登录
+        final long interval = 1000 * 60 * 5;
+        if (mLastLoginTime + interval < System.currentTimeMillis()) {
+            mLoggedin = false;
+        }
+
+
+        // 账户切换后需要重新登录
+        if (mLoggedin &&!TextUtils.equals(getSyncAccount().name, NotesPreferenceActivity.getSyncAccountName(activity))) {
+            mLoggedin = false;
+        }
+
+
+        if (mLoggedin) {
+            Log.d(TAG, "already logged in");
+            return true;
+        }
+
+
+        mLastLoginTime = System.currentTimeMillis();
+        // 调用 loginGoogleAccount 方法获取认证令牌
+        String authToken = loginGoogleAccount(activity, false);
+        if (authToken == null) {
+            Log.e(TAG, "login google account failed");
+            return false;
+        }
+
+
+        // 如果账户不是以 gmail.com 或 googlemail.com 结尾，使用自定义域名登录
+        if (!(mAccount.name.toLowerCase().endsWith("gmail.com") || mAccount.name.toLowerCase().endsWith("googlemail.com"))) {
+            StringBuilder url = new StringBuilder(GTASK_URL).append("a/");
+            int index = mAccount.name.indexOf('@') + 1;
+            String suffix = mAccount.name.substring(index);
+            url.append(suffix + "/");
+            mGetUrl = url.toString() + "ig";
+            mPostUrl = url.toString() + "r/ig";
+
+
+            if (tryToLoginGtask(activity, authToken)) {
+                mLoggedin = true;
+            }
+        }
+
+
+        // 尝试使用谷歌官方 URL 登录
+        if (!mLoggedin) {
+            mGetUrl = GTASK_GET_URL;
+            mPostUrl = GTASK_POST_URL;
+            if (!tryToLoginGtask(activity, authToken)) {
+                return false;
+            }
+        }
+
+
+        mLoggedin = true;
+        return true;
+    }
+
+
+    // 登录 Google 账户
+    private String loginGoogleAccount(Activity activity, boolean invalidateToken) {
+        String authToken;
+        // 获取账户管理器
+        AccountManager accountManager = AccountManager.get(activity);
+        // 获取所有 Google 账户
+        Account[] accounts = accountManager.getAccountsByType("com.google");
+
+
+        if (accounts.length == 0) {
+            Log.e(TAG, "there is no available google account");
+            return null;
+        }
+
+
+        // 获取同步账户的名称
+        String accountName = NotesPreferenceActivity.getSyncAccountName(activity);
+        Account account = null;
+        for (Account a : accounts) {
+            if (a.name.equals(accountName)) {
+                account = a;
+                break;
+            }
+        }
+        if (account!= null) {
+            mAccount = account;
+        } else {
+            Log.e(TAG, "unable to get an account with the same name in the settings");
+            return null;
+        }
+
+
+        // 获取账户的认证令牌
+        AccountManagerFuture<Bundle> accountManagerFuture = accountManager.getAuthToken(account, "goanna_mobile", null, activity, null, null);
+        try {
+            Bundle authTokenBundle = accountManagerFuture.getResult();
+            authToken = authTokenBundle.getString(AccountManager.KEY_AUTHTOKEN);
+            if (invalidateToken) {
+                // 使令牌失效并重新登录
+                accountManager.invalidateAuthToken("com.google", authToken);
+                loginGoogleAccount(activity, false);
+            }
+        } catch (Exception e) {
+            Log.e(TAG, "get auth token failed");
+            authToken = null;
+        }
+
+
+        return authToken;
+    }
+
+
+    // 尝试登录 GTask 服务
+    private boolean tryToLoginGtask(Activity activity, String authToken) {
+        if (!loginGtask(authToken)) {
+            // 令牌可能过期，重新获取令牌并再次尝试登录
+            authToken = loginGoogleAccount(activity, true);
+            if (authToken == null) {
+                Log.e(TAG, "login google account failed");
+                return false;
+            }
+
+
+            if (!loginGtask(authToken)) {
+                Log.e(TAG, "login gtask failed");
+                return false;
+            }
+        }
+        return true;
+    }
+
+
+    // 执行 GTask 服务的登录操作
+    private boolean loginGtask(String authToken) {
+        int timeoutConnection = 10000;
+        int timeoutSocket = 15000;
+        // 设置 HTTP 请求的参数，包括连接超时和套接字超时
+        HttpParams httpParameters = new BasicHttpParams();
+        HttpConnectionParams.setConnectionTimeout(httpParameters, timeoutConnection);
+        HttpConnectionParams.setSoTimeout(httpParameters, timeoutSocket);
+        mHttpClient = new DefaultHttpClient(httpParameters);
+        BasicCookieStore localBasicCookieStore = new BasicCookieStore();
+        mHttpClient.setCookieStore(localBasicCookieStore);
+        HttpProtocolParams.setUseExpectContinue(mHttpClient.getParams(), false);
+
+
+        // 执行登录请求
+        try {
+            String loginUrl = mGetUrl + "?auth=" + authToken;
+            HttpGet httpGet = new HttpGet(loginUrl);
+            HttpResponse response = null;
+            response = mHttpClient.execute(httpGet);
+
+
+            // 检查是否获得认证 cookie
+            List<Cookie> cookies = mHttpClient.getCookieStore().getCookies();
+            boolean hasAuthCookie = false;
+            for (Cookie cookie : cookies) {
+                if (cookie.getName().contains("GTL")) {
+                    hasAuthCookie = true;
+                }
+            }
+            if (!hasAuthCookie) {
+                Log.w(TAG, "it seems that there is no auth cookie");
+            }
+
+
+            // 获取响应内容并解析客户端版本号
+            String resString = getResponseContent(response.getEntity());
+            String jsBegin = "_setup(";
+            String jsEnd = ")}</script>";
+            int begin = resString.indexOf(jsBegin);
+            int end = resString.lastIndexOf(jsEnd);
+            String jsString = null;
+            if (begin!= -1 && end!= -1 && begin < end) {
+                jsString = resString.substring(begin + jsBegin.length(), end);
+            }
+            JSONObject js = new JSONObject(jsString);
+            mClientVersion = js.getLong("v");
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            return false;
+        } catch (Exception e) {
+            Log.e(TAG, "httpget gtask_url failed");
+            return false;
+        }
+
+
+        return true;
+    }
+
+
+    // 获取下一个操作的唯一标识符
+    private int getActionId() {
+        return mActionId++;
+    }
+
+
+    // 创建 HTTP POST 请求
+    private HttpPost createHttpPost() {
+        HttpPost httpPost = new HttpPost(mPostUrl);
+        // 设置请求头，指定内容类型和其他属性
+        httpPost.setHeader("Content-Type", "application/x-www-form-urlencoded;charset=utf-8");
+        httpPost.setHeader("AT", "1");
+        return httpPost;
+    }
+
+
+    // 获取 HTTP 响应的内容
+    private String getResponseContent(HttpEntity entity) throws IOException {
+        String contentEncoding = null;
+        if (entity.getContentEncoding()!= null) {
+            contentEncoding = entity.getContentEncoding().getValue();
+            Log.d(TAG, "encoding: " + contentEncoding);
+        }
+
+
+        InputStream input = entity.getContent();
+        if (contentEncoding!= null && contentEncoding.equalsIgnoreCase("gzip")) {
+            input = new GZIPInputStream(entity.getContent());
+        } else if (contentEncoding!= null && contentEncoding.equalsIgnoreCase("deflate")) {
+            Inflater inflater = new Inflater(true);
+            input = new InflaterInputStream(entity.getContent(), inflater);
+        }
+
+
+        try {
+            InputStreamReader isr = new InputStreamReader(input);
+            BufferedReader br = new BufferedReader(isr);
+            StringBuilder sb = new StringBuilder();
+
+
+            // 逐行读取响应内容
+            while (true) {
+                String buff = br.readLine();
+                if (buff == null) {
+                    return sb.toString();
+                }
+                sb = sb.append(buff);
+            }
+        } finally {
+            input.close();
+        }
+    }
+
+
+    // 发送 POST 请求
+    private JSONObject postRequest(JSONObject js) throws NetworkFailureException {
+        if (!mLoggedin) {
+            Log.e(TAG, "please login first");
+            throw new ActionFailureException("not logged in");
+        }
+
+
+        HttpPost httpPost = createHttpPost();
+        try {
+            LinkedList<BasicNameValuePair> list = new LinkedList<BasicNameValuePair>();
+            list.add(new BasicNameValuePair("r", js.toString()));
+            // 创建 URL 编码的表单实体
+            UrlEncodedFormEntity entity = new UrlEncodedFormEntity(list, "UTF-8");
+            httpPost.setEntity(entity);
+
+
+            // 执行 POST 请求
+            HttpResponse response = mHttpClient.execute(httpPost);
+            String jsString = getResponseContent(response.getEntity());
+            return new JSONObject(jsString);
+
+
+        } catch (ClientProtocolException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new NetworkFailureException("postRequest failed");
+        } catch (IOException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new NetworkFailureException("postRequest failed");
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new ActionFailureException("unable to convert response content to jsonobject");
+        } catch (Exception e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new ActionFailureException("error occurs when posting request");
+        }
+    }
+
+
+    // 创建任务
+    public void createTask(Task task) throws NetworkFailureException {
+        commitUpdate();
+        try {
+            JSONObject jsPost = new JSONObject();
+            JSONArray actionList = new JSONArray();
+
+
+            // 将任务的创建操作添加到动作列表中
+            actionList.put(task.getCreateAction(getActionId()));
+            jsPost.put(GTaskStringUtils.GTASK_JSON_ACTION_LIST, actionList);
+
+
+            // 包含客户端版本号
+            jsPost.put(GTaskStringUtils.GTASK_JSON_CLIENT_VERSION, mClientVersion);
+
+
+            // 发送请求并处理响应
+            JSONObject jsResponse = postRequest(jsPost);
+            JSONObject jsResult = (JSONObject) jsResponse.getJSONArray(GTaskStringUtils.GTASK_JSON_RESULTS).get(0);
+            task.setGid(jsResult.getString(GTaskStringUtils.GTASK_JSON_NEW_ID));
+
+
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new ActionFailureException("create task: handing jsonobject failed");
+        }
+    }
+
+
+    // 创建任务列表
+    public void createTaskList(TaskList tasklist) throws NetworkFailureException {
+        commitUpdate();
+        try {
+            JSONObject jsPost = new JSONObject();
+            JSONArray actionList = new JSONArray();
+
+
+            // 将任务列表的创建操作添加到动作列表中
+            actionList.put(tasklist.getCreateAction(getActionId()));
+            jsPost.put(GTaskStringUtils.GTASK_JSON_ACTION_LIST, actionList);
+
+
+            // 包含客户端版本号
+            jsPost.put(GTaskStringUtils.GTASK_JSON_CLIENT_VERSION, mClientVersion);
+
+
+            // 发送请求并处理响应
+            JSONObject jsResponse = postRequest(jsPost);
+            JSONObject jsResult = (JSONObject) jsResponse.getJSONArray(GTaskStringUtils.GTASK_JSON_RESULTS).get(0);
+            tasklist.setGid(jsResult.getString(GTaskStringUtils.GTASK_JSON_NEW_ID));
+
+
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new ActionFailureException("create tasklist: handing jsonobject failed");
+        }
+    }
+
+
+    // 提交更新操作
+    public void commitUpdate() throws NetworkFailureException {
+        if (mUpdateArray!= null) {
+            try {
+                JSONObject jsPost = new JSONObject();
+
+
+                // 将更新操作列表添加到请求中
+                jsPost.put(GTaskStringUtils.GTASK_JSON_ACTION_LIST, mUpdateArray);
+
+
+                // 包含客户端版本号
+                jsPost.put(GTaskStringUtils.GTASK_JSON_CLIENT_VERSION, mClientVersion);
+
+
+                postRequest(jsPost);
+                mUpdateArray = null;
+            } catch (JSONException e) {
+                Log.e(TAG, e.toString());
+                e.printStackTrace();
+                throw new ActionFailureException("commit update: handing jsonobject failed");
+            }
+        }
+    }
+
+
+    // 添加节点更新操作
+    public void addUpdateNode(Node node) throws NetworkFailureException {
+        if (node!= null) {
+            // 为了避免过多更新操作，最多存储 10 个更新项
+            if (mUpdateArray!= null && mUpdateArray.length() > 10) {
+                commitUpdate();
+            }
+
+
+            if (mUpdateArray == null)
+                mUpdateArray = new JSONArray();
+            mUpdateArray.put(node.getUpdateAction(getActionId()));
+        }
+    }
+
+
+    // 移动任务
+    public void moveTask(Task task, TaskList preParent, TaskList curParent) throws NetworkFailureException {
+        commitUpdate();
+        try {
+            JSONObject jsPost = new JSONObject();
+            JSONArray actionList = new JSONArray();
+            JSONObject action = new JSONObject();
+
+
+            // 配置移动任务的操作信息
+            action.put(GTaskStringUtils.GTASK_JSON_ACTION_TYPE, GTaskStringUtils.GTASK_JSON_ACTION_TYPE_MOVE);
+            action.put(GTaskStringUtils.GTASK_JSON_ACTION_ID, getActionId());
+            action.put(GTaskStringUtils.GTASK_JSON_ID, task.getGid());
+            if (preParent == curParent && task.getPriorSibling()!= null) {
+                // 仅在任务列表内移动且不是第一个任务时添加前置兄弟任务的信息
+                action.put(GTaskStringUtils.GTASK_JSON_PRIOR_SIBLING_ID, task.getPriorSibling());
+            }
+            action.put(GTaskStringUtils.GTASK_JSON_SOURCE_LIST, preParent.getGid());
+            action.put(GTaskStringUtils.GTASK_JSON_DEST_PARENT, curParent.getGid());
+            if (preParent!= curParent) {
+                // 仅在任务列表间移动时添加目标列表信息
+                action.put(GTaskStringUtils.GTASK_JSON_DEST_LIST, curParent.getGid());
+            }
+            actionList.put(action);
+            jsPost.put(GTaskStringUtils.GTASK_JSON_ACTION_LIST, actionList);
+
+
+            // 包含客户端版本号
+            jsPost.put(GTaskStringUtils.GTASK_JSON_CLIENT_VERSION, mClientVersion);
+
+
+            postRequest(jsPost);
+
+
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new ActionFailureException("move task: handing jsonobject failed");
+        }
+    }
+
+
+    // 该部分代码是 GTaskClient 类的部分方法，主要涉及节点删除、任务列表获取以及一些相关操作
+
+// 删除节点的方法
+public void deleteNode(Node node) throws NetworkFailureException {
+    // 首先调用 commitUpdate 方法，可能是为了提交之前的更新操作
+    commitUpdate();
+    try {
+        // 创建一个新的 JSON 对象用于存储要发送给服务器的请求信息
+        JSONObject jsPost = new JSONObject();
+        // 创建一个 JSON 数组，用于存储操作列表
+        JSONArray actionList = new JSONArray();
+
+        // action_list
+        // 将节点标记为已删除
+        node.setDeleted(true);
+        // 将节点的更新操作添加到操作列表中，getActionId() 可能是获取一个唯一的操作 ID
+        actionList.put(node.getUpdateAction(getActionId()));
+        // 将操作列表添加到 JSON 对象中，使用了一个常量作为键，可能是约定的键名
+        jsPost.put(GTaskStringUtils.GTASK_JSON_ACTION_LIST, actionList);
+
+        // client_version
+        // 将客户端版本添加到 JSON 对象中，可能是为了服务器端进行兼容性检查等操作
+        jsPost.put(GTaskStringUtils.GTASK_JSON_CLIENT_VERSION, mClientVersion);
+
+        // 调用 postRequest 方法发送请求，将创建的 JSON 对象作为请求参数
+        postRequest(jsPost);
+        // 将更新数组置为 null，可能是清空之前的更新操作
+        mUpdateArray = null;
+    } catch (JSONException e) {
+        // 发生 JSON 异常时的处理，输出错误日志并抛出自定义异常
+        Log.e(TAG, e.toString());
+        e.printStackTrace();
+        throw new ActionFailureException("delete node: handing jsonobject failed");
+    }
+}
+
+// 获取任务列表的方法
+public JSONArray getTaskLists() throws NetworkFailureException {
+    // 如果未登录，则输出错误日志并抛出异常
+    if (!mLoggedin) {
+        Log.e(TAG, "please login first");
+        throw new ActionFailureException("not logged in");
+    }
+
+    try {
+        // 创建一个 HTTP GET 请求
+        HttpGet httpGet = new HttpGet(mGetUrl);
+        HttpResponse response = null;
+        // 执行请求并获取响应
+        response = mHttpClient.execute(httpGet);
+
+        // get the task list
+        // 获取响应内容
+        String resString = getResponseContent(response.getEntity());
+        // 定义 JSON 数据的起始和结束标记，可能是为了提取有效 JSON 数据
+        String jsBegin = "_setup(";
+        String jsEnd = ")}</script>";
+        int begin = resString.indexOf(jsBegin);
+        int end = resString.lastIndexOf(jsEnd);
+        String jsString = null;
+        // 提取有效的 JSON 字符串
+        if (begin!= -1 && end!= -1 && begin < end) {
+            jsString = resString.substring(begin + jsBegin.length(), end);
+        }
+        // 将 JSON 字符串解析为 JSON 对象
+        JSONObject js = new JSONObject(jsString);
+        // 从 JSON 对象中获取任务列表数据，使用了一个常量作为键，可能是约定的键名
+        return js.getJSONObject("t").getJSONArray(GTaskStringUtils.GTASK_JSON_LISTS);
+    } catch (ClientProtocolException e) {
+        // 客户端协议异常处理，输出错误日志并抛出网络异常
+        Log.e(TAG, e.toString());
+        e.printStackTrace();
+        throw new NetworkFailureException("gettasklists: httpget failed");
+    } catch (IOException e) {
+        // IO 异常处理，输出错误日志并抛出网络异常
+        Log.e(TAG, e.toString());
+        e.printStackTrace();
+        throw new NetworkFailureException("gettasklists: httpget failed");
+    } catch (JSONException e) {
+        // JSON 异常处理，输出错误日志并抛出自定义异常
+        Log.e(TAG, e.toString());
+        e.printStackTrace();
+        throw new ActionFailureException("get task lists: handing jasonobject failed");
+    }
+}
+
+// 根据列表 GID 获取任务列表的方法
+public JSONArray getTaskList(String listGid) throws NetworkFailureException {
+    // 调用 commitUpdate 方法，可能是为了提交之前的更新操作
+    commitUpdate();
+    try {
+        // 创建一个新的 JSON 对象用于存储请求信息
+        JSONObject jsPost = new JSONObject();
+        // 创建一个操作列表的 JSON 数组
+        JSONArray actionList = new JSONArray();
+        // 创建一个操作的 JSON 对象
+        JSONObject action = new JSONObject();
+
+        // action_list
+        // 设置操作类型，使用了一个常量作为操作类型，可能是约定的操作类型
+        action.put(GTaskStringUtils.GTASK_JSON_ACTION_TYPE,
+                GTaskStringUtils.GTASK_JSON_ACTION_TYPE_GETALL);
+        // 设置操作的 ID，使用 getActionId() 获取唯一操作 ID
+        action.put(GTaskStringUtils.GTASK_JSON_ACTION_ID, getActionId());
+        // 设置列表的 GID
+        action.put(GTaskStringUtils.GTASK_JSON_LIST_ID, listGid);
+        // 设置是否获取已删除的任务，这里设置为 false
+        action.put(GTaskStringUtils.GTASK_JSON_GET_DELET OF_NODE);
+            Log.e(TAG, "delete node: handing jsonobject failed");
+        }
+    }
+
+
+    // 获取任务列表
+    public JSONArray getTaskLists() throws NetworkFailureException {
+        if (!mLoggedin) {
+            Log.e(TAG, "please login first");
+            throw new ActionFailureException("not logged in");
+        }
+
+
+        try {
+            HttpGet httpGet = new HttpGet(mGetUrl);
+            HttpResponse response = null;
+            response = mHttpClient.execute(httpGet);
+
+
+            // 获取任务列表
+            String resString = getResponseContent(response.getEntity());
+            String jsBegin = "_setup(";
+            String jsEnd = ")}</script>";
+            int begin = resString.indexOf(jsBegin);
+            int end = resString.lastIndexOf(jsEnd);
+            String jsString = null;
+            if (begin!= -1 && end!= -1 && begin < end) {
+                jsString = resString.substring(begin + jsBegin.length(), end);
+            }
+            JSONObject js = new JSONObject(jsString);
+            return js.getJSONObject("t").getJSONArray(GTaskStringUtils.GTASK_JSON_LISTS);
+        } catch (ClientProtocolException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new NetworkFailureException("gettasklists: httpget failed");
+        } catch (IOException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new NetworkFailureException("gettasklists: httpget failed");
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new ActionFailureException("get task lists: handing jasonobject failed");
+        }
+    }
+
+
+    // 根据列表 GID 获取任务列表
+    public JSONArray getTaskList(String listGid) throws NetworkFailureException {
+        commitUpdate();
+        try {
+            JSONObject jsPost = new JSONObject();
+            JSONArray actionList = new JSONArray();
+            JSONObject action = new JSONObject();
+
+
+            // 配置操作列表
+            action.put(GTaskStringUtils.GTASK_JSON_ACTION_TYPE,
+                    GTaskStringUtils.GTASK_JSON_ACTION_TYPE_GETALL);
+            action.put(GTaskStringUtils.GTASK_JSON_ACTION_ID, getActionId());
+            action.put(GTaskStringUtils.GTASK_JSON_LIST_ID, listGid);
+            action.put(GTaskStringUtils.GTASK_JSON_GET_DELETED, false);
+            actionList.put(action);
+            jsPost.put(GTaskStringUtils.GTASK_JSON_ACTION_LIST, actionList);
+
+
+            // 包含客户端版本号
+            jsPost.put(GTaskStringUtils.GTASK_JSON_CLIENT_VERSION, mClientVersion);
+
+
+            JSONObject jsResponse = postRequest(jsPost);
+            return jsResponse.getJSONArray(GTaskStringUtils.GTASK_JSON_TASKS);
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new ActionFailureException("get task list: handing jsonobject failed");
+        }
+    }
+
+
+    // 获取同步账户
+    public Account getSyncAccount() {
+        return mAccount;
+    }
+
+
+    // 重置更新数组
+    public void resetUpdateArray() {
+        mUpdateArray = null;
+    }
+}

src/gtask/remote/GTaskManager.java

@@ -0,0 +1,918 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.gtask.remote;
+
+import android.app.Activity;
+import android.content.ContentResolver;
+import android.content.ContentUris;
+import android.content.ContentValues;
+import android.content.Context;
+import android.database.Cursor;
+import android.util.Log;
+
+import net.micode.notes.R;
+import net.micode.notes.data.Notes;
+import net.micode.notes.data.Notes.DataColumns;
+import net.micode.notes.data.Notes.NoteColumns;
+import net.micode.notes.gtask.data.MetaData;
+import net.micode.notes.gtask.data.Node;
+import net.micode.notes.gtask.data.SqlNote;
+import net.micode.notes.gtask.data.Task;
+import net.micode.notes.gtask.data.TaskList;
+import net.micode.notes.gtask.exception.ActionFailureException;
+import net.micode.notes.gtask.exception.NetworkFailureException;
+import net.micode.notes.tool.DataUtils;
+import net.micode.notes.tool.GTaskStringUtils;
+
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.Map;
+
+// GTaskManager 类，用于管理 GTask 的同步操作
+public class GTaskManager {
+    // 日志标签，使用类的简单名称
+    private static final String TAG = GTaskManager.class.getSimpleName();
+    // 同步成功的状态码
+    public static final int STATE_SUCCESS = 0;
+    // 网络错误的状态码
+    public static final int STATE_NETWORK_ERROR = 1;
+    // 内部错误的状态码
+    public static final int STATE_INTERNAL_ERROR = 2;
+    // 同步正在进行的状态码
+    public static final int STATE_SYNC_IN_PROGRESS = 3;
+    // 同步已取消的状态码
+    public static final int STATE_SYNC_CANCELLED = 4;
+
+
+    // 单例实例
+    private static GTaskManager mInstance = null;
+    // 关联的 Activity，可能用于执行一些与 UI 或账户认证相关的操作
+    private Activity mActivity;
+    // 上下文对象，用于访问系统资源
+    private Context mContext;
+    // 内容解析器，用于操作内容提供器的数据
+    private ContentResolver mContentResolver;
+    // 标记是否正在同步
+    private boolean mSyncing;
+    // 标记是否已取消同步
+    private boolean mCancelled;
+    // 存储任务列表的映射，键为字符串，值为 TaskList 对象
+    private HashMap<String, TaskList> mGTaskListHashMap;
+    // 存储节点的映射，键为字符串，值为 Node 对象
+    private HashMap<String, Node> mGTaskHashMap;
+    // 存储元数据的映射，键为字符串，值为 MetaData 对象
+    private HashMap<String, MetaData> mMetaHashMap;
+    // 元数据列表
+    private TaskList mMetaList;
+    // 存储本地删除的 ID 集合
+    private HashSet<Long> mLocalDeleteIdMap;
+    // 存储 GID 到 NID 的映射，键为字符串（GID），值为 Long（NID）
+    private HashMap<String, Long> mGidToNid;
+    // 存储 NID 到 GID 的映射，键为 Long（NID），值为字符串（GID）
+    private HashMap<Long, String> mNidToGid;
+
+
+    // 私有构造函数，用于初始化成员变量
+    private GTaskManager() {
+        mSyncing = false;
+        mCancelled = false;
+        mGTaskListHashMap = new HashMap<String, TaskList>();
+        mGTaskHashMap = new HashMap<String, Node>();
+        mMetaHashMap = new HashMap<String, MetaData>();
+        mMetaList = null;
+        mLocalDeleteIdMap = new HashSet<Long>();
+        mGidToNid = new HashMap<String, Long>();
+        mNidToGid = new HashMap<Long, String>();
+    }
+
+
+    // 获取 GTaskManager 的单例实例
+    public static synchronized GTaskManager getInstance() {
+        if (mInstance == null) {
+            mInstance = new GTaskManager();
+        }
+        return mInstance;
+    }
+
+
+    // 设置活动上下文，可能用于获取认证令牌等操作
+    public synchronized void setActivityContext(Activity activity) {
+        // used for getting authtoken
+        mActivity = activity;
+    }
+
+
+    // 执行同步操作的方法
+    public int sync(Context context, GTaskASyncTask asyncTask) {
+        // 如果正在同步，输出日志信息并返回正在同步的状态码
+        if (mSyncing) {
+            Log.d(TAG, "Sync is in progress");
+            return STATE_SYNC_IN_PROGRESS;
+        }
+        mContext = context;
+        mContentResolver = mContext.getContentResolver();
+        mSyncing = true;
+        mCancelled = false;
+        // 清空各种映射和集合，为同步操作做准备
+        mGTaskListHashMap.clear();
+        mGTaskHashMap.clear();
+        mMetaHashMap.clear();
+        mLocalDeleteIdMap.clear();
+        mGidToNid.clear();
+        mNidToGid.clear();
+
+
+        try {
+            GTaskClient client = GTaskClient.getInstance();
+            // 重置 GTaskClient 的更新数组
+            client.resetUpdateArray();
+
+
+            // 登录 Google 任务，如果未取消且登录失败则抛出异常
+            if (!mCancelled) {
+                if (!client.login(mActivity)) {
+                    throw new NetworkFailureException("login google task failed");
+                }
+            }
+
+
+            // 通知异步任务同步进度，开始初始化任务列表
+            asyncTask.publishProgess(mContext.getString(R.string.sync_progress_init_list));
+            initGTaskList();
+
+
+            // 通知异步任务同步进度，开始进行内容同步操作
+            asyncTask.publishProgess(mContext.getString(R.string.sync_progress_syncing));
+            syncContent();
+        } catch (NetworkFailureException e) {
+            Log.e(TAG, e.toString());
+            return STATE_NETWORK_ERROR;
+        } catch (ActionFailureException e) {
+            Log.e(TAG, e.toString());
+            return STATE_INTERNAL_ERROR;
+        } catch (Exception e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            return STATE_INTERNAL_ERROR;
+        } finally {
+            // 无论是否发生异常，最终都清空各种映射和集合，并标记同步结束
+            mGTaskListHashMap.clear();
+            mGTaskHashMap.clear();
+            mMetaHashMap.clear();
+            mLocalDeleteIdMap.clear();
+            mGidToNid.clear();
+            mNidToGid.clear();
+            mSyncing = false;
+        }
+
+
+        // 根据是否取消返回相应的状态码
+        return mCancelled? STATE_SYNC_CANCELLED : STATE_SUCCESS;
+    }
+}
+
+    // 该方法用于初始化 GTask 列表
+private void initGTaskList() throws NetworkFailureException {
+    // 如果同步操作已被取消，则直接返回
+    if (mCancelled)
+        return;
+    // 获取 GTaskClient 的实例
+    GTaskClient client = GTaskClient.getInstance();
+    try {
+        // 从 GTaskClient 获取任务列表的 JSON 数组
+        JSONArray jsTaskLists = client.getTaskLists();
+
+        // 首先将元数据列表初始化为 null
+        mMetaList = null;
+        // 遍历任务列表的 JSON 数组
+        for (int i = 0; i < jsTaskLists.length(); i++) {
+            // 从 JSON 数组中获取每个任务列表的 JSONObject 表示
+            JSONObject object = jsTaskLists.getJSONObject(i);
+            // 获取任务列表的 GID 和名称
+            String gid = object.getString(GTaskStringUtils.GTASK_JSON_ID);
+            String name = object.getString(GTaskStringUtils.GTASK_JSON_NAME);
+
+            // 检查任务列表的名称是否是元数据文件夹
+            if (name.equals(GTaskStringUtils.MIUI_FOLDER_PREFFIX + GTaskStringUtils.FOLDER_META)) {
+                // 创建一个新的任务列表对象，并根据远程 JSON 内容设置其内容
+                mMetaList = new TaskList();
+                mMetaList.setContentByRemoteJSON(object);
+
+                // 加载元数据
+                JSONArray jsMetas = client.getTaskList(gid);
+                for (int j = 0; j < jsMetas.length(); j++) {
+                    // 获取元数据的 JSONObject 表示
+                    object = (JSONObject) jsMetas.getJSONObject(j);
+                    // 创建元数据对象并根据远程 JSON 内容设置其内容
+                    MetaData metaData = new MetaData();
+                    metaData.setContentByRemoteJSON(object);
+                    // 如果元数据值得保存
+                    if (metaData.isWorthSaving()) {
+                        // 将元数据添加为元数据列表的子任务
+                        mMetaList.addChildTask(metaData);
+                        if (metaData.getGid()!= null) {
+                            // 将元数据添加到元数据映射中
+                            mMetaHashMap.put(metaData.getRelatedGid(), metaData);
+                        }
+                    }
+                }
+            }
+        }
+
+        // 如果元数据列表不存在，则创建一个新的元数据列表
+        if (mMetaList == null) {
+            mMetaList = new TaskList();
+            mMetaList.setName(GTaskStringUtils.MIUI_FOLDER_PREFFIX + GTaskStringUtils.FOLDER_META);
+            GTaskClient.getInstance().createTaskList(mMetaList);
+        }
+
+        // 初始化任务列表
+        for (int i = 0; i < jsTaskLists.length(); i++) {
+            // 获取任务列表的 JSONObject 表示
+            JSONObject object = jsTaskLists.getJSONObject(i);
+            // 获取任务列表的 GID 和名称
+            String gid = object.getString(GTaskStringUtils.GTASK_JSON_ID);
+            String name = object.getString(GTaskStringUtils.GTASK_JSON_NAME);
+
+            // 检查任务列表名称是否以特定前缀开头且不是元数据文件夹
+            if (name.startsWith(GTaskStringUtils.MIUI_FOLDER_PREFFIX) &&
+                   !name.equals(GTaskStringUtils.MIUI_FOLDER_PREFFIX + GTaskStringUtils.FOLDER_META)) {
+                // 创建新的任务列表对象并根据远程 JSON 内容设置其内容
+                TaskList tasklist = new TaskList();
+                tasklist.setContentByRemoteJSON(object);
+                // 将任务列表添加到任务列表映射中
+                mGTaskListHashMap.put(gid, tasklist);
+                mGTaskHashMap.put(gid, tasklist);
+
+                // 加载任务
+                JSONArray jsTasks = client.getTaskList(gid);
+                for (int j = 0; j < jsTasks.length(); j++) {
+                    // 获取任务的 JSONObject 表示
+                    object = (JSONObject) jsTasks.getJSONObject(j);
+                    gid = object.getString(GTaskStringUtils.GTASK_JSON_ID);
+                    // 创建新的任务对象并根据远程 JSON 内容设置其内容
+                    Task task = new Task();
+                    task.setContentByRemoteJSON(object);
+                    // 如果任务值得保存
+                    if (task.isWorthSaving()) {
+                        // 设置任务的元信息
+                        task.setMetaInfo(mMetaHashMap.get(gid));
+                        // 将任务添加为任务列表的子任务
+                        tasklist.addChildTask(task);
+                        // 将任务添加到任务映射中
+                        mGTaskHashMap.put(gid, task);
+                    }
+                }
+            }
+        }
+    } catch (JSONException e) {
+        // 打印日志并抛出操作失败异常
+        Log.e(TAG, e.toString());
+        e.printStackTrace();
+        throw new ActionFailureException("initGTaskList: handing JSONObject failed");
+    }
+}
+
+
+// 该方法用于同步内容
+private void syncContent() throws NetworkFailureException {
+    int syncType;
+    Cursor c = null;
+    String gid;
+    Node node;
+
+    // 清空本地删除 ID 映射
+    mLocalDeleteIdMap.clear();
+
+    // 如果同步操作已取消，直接返回
+    if (mCancelled) {
+        return;
+    }
+
+    // 处理本地删除的笔记
+    try {
+        // 查询垃圾桶文件夹中的笔记
+        c = mContentResolver.query(Notes.CONTENT_NOTE_URI, SqlNote.PROJECTION_NOTE,
+                "(type<>? AND parent_id=?)", new String[] {
+                        String.valueOf(Notes.TYPE_SYSTEM), String.valueOf(Notes.ID_TRASH_FOLER)
+                }, null);
+        if (c!= null) {
+            while (c.moveToNext()) {
+                // 获取笔记的 GID
+                gid = c.getString(SqlNote.GTASK_ID_COLUMN);
+                // 根据 GID 获取节点
+                node = mGTaskHashMap.get(gid);
+                if (node!= null) {
+                    // 从任务映射中移除该节点
+                    mGTaskHashMap.remove(gid);
+                    // 执行远程删除操作
+                    doContentSync(Node.SYNC_ACTION_DEL_REMOTE, node, c);
+                }
+                // 将笔记的本地 ID 添加到本地删除 ID 集合中
+                mLocalDeleteIdMap.add(c.getLong(SqlNote.ID_COLUMN));
+            }
+        } else {
+            Log.w(TAG, "failed to query trash folder");
+        }
+    } finally {
+        // 关闭游标
+        if (c!= null) {
+            c.close();
+            c = null;
+        }
+    }
+
+    // 先同步文件夹
+    syncFolder();
+
+    // 处理数据库中存在的笔记
+    try {
+        // 查询数据库中的笔记
+        c = mContentResolver.query(Notes.CONTENT_NOTE_URI, SqlNote.PROJECTION_NOTE,
+                "(type=? AND parent_id<>?)", new String[] {
+                        String.valueOf(Notes.TYPE_NOTE), String.valueOf(Notes.ID_TRASH_FOLER)
+                }, NoteColumns.TYPE + " DESC");
+        if (c!= null) {
+            while (c.moveToNext()) {
+                // 获取笔记的 GID
+                gid = c.getString(SqlNote.GTASK_ID_COLUMN);
+                // 根据 GID 获取节点
+                node = mGTaskHashMap.get(gid);
+                if (node!= null) {
+                    mGTaskHashMap.remove(gid);
+                    mGidToNid.put(gid, c.getLong(SqlNote.ID_COLUMN));
+                    mNidToGid.put(c.getLong(SqlNote.ID_COLUMN), gid);
+                    // 获取同步类型
+                    syncType = node.getSyncAction(c);
+                } else {
+                    if (c.getString(SqlNote.GTASK_ID_COLUMN).trim().length() == 0) {
+                        // 本地添加
+                        syncType = Node.SYNC_ACTION_ADD_REMOTE;
+                    } else {
+                        // 远程删除
+                        syncType = Node.SYNC_ACTION_DEL_LOCAL;
+                    }
+                }
+                // 执行内容同步操作
+                doContentSync(syncType, node, c);
+            }
+        } else {
+            Log.w(TAG, "failed to query existing note in database");
+        }
+    } finally {
+        // 关闭游标
+        if (c!= null) {
+            c.close();
+            c = null;
+        }
+    }
+// 该部分代码是 GTaskManager 类的一部分，涉及同步操作的进一步处理，包括处理剩余项、同步文件夹等操作
+
+// 遍历 mGTaskHashMap 中剩余的项
+// go through remaining items
+Iterator<Map.Entry<String, Node>> iter = mGTaskHashMap.entrySet().iterator();
+while (iter.hasNext()) {
+    // 获取下一个映射项
+    Map.Entry<String, Node> entry = iter.next();
+    // 获取节点
+    node = entry.getValue();
+    // 调用 doContentSync 方法进行本地添加操作，传入的参数为 Node.SYNC_ACTION_ADD_LOCAL，表示本地添加操作，节点和空的 Cursor（可能表示不需要数据库信息）
+    doContentSync(Node.SYNC_ACTION_ADD_LOCAL, node, null);
+}
+
+// mCancelled 可以被另一个线程设置，所以需要逐个检查
+// clear local delete table
+// 如果同步未被取消
+if (!mCancelled) {
+    // 尝试批量删除本地已删除的笔记，如果失败则抛出 ActionFailureException
+    if (!DataUtils.batchDeleteNotes(mContentResolver, mLocalDeleteIdMap)) {
+        throw new ActionFailureException("failed to batch-delete local deleted notes");
+    }
+}
+
+// refresh local sync id
+// 如果同步未被取消
+if (!mCancelled) {
+    // 调用 GTaskClient 的 commitUpdate 方法提交更新
+    GTaskClient.getInstance().commitUpdate();
+    // 调用 refreshLocalSyncId 方法刷新本地同步 ID
+    refreshLocalSyncId();
+}
+
+
+// 同步文件夹的方法，可能会抛出 NetworkFailureException 异常
+private void syncFolder() throws NetworkFailureException {
+    // 定义游标、GID、节点和同步类型变量
+    Cursor c = null;
+    String gid;
+    Node node;
+    int syncType;
+
+    // 如果同步操作已取消，直接返回
+    if (mCancelled) {
+        return;
+    }
+
+    // for root folder
+    try {
+        // 查询根文件夹的信息
+        c = mContentResolver.query(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI,
+                Notes.ID_ROOT_FOLDER), SqlNote.PROJECTION_NOTE, null, null, null);
+        if (c!= null) {
+            // 将游标移动到下一个位置
+            c.moveToNext();
+            // 获取 GID
+            gid = c.getString(SqlNote.GTASK_ID_COLUMN);
+            // 从 mGTaskHashMap 中获取节点
+            node = mGTaskHashMap.get(gid);
+            if (node!= null) {
+                // 从映射中移除该节点
+                mGTaskHashMap.remove(gid);
+                // 将 GID 和根文件夹的 ID 映射存储到 mGidToNid 和 mNidToGid 中
+                mGidToNid.put(gid, (long) Notes.ID_ROOT_FOLDER);
+                mNidToGid.put((long) Notes.ID_ROOT_FOLDER, gid);
+                // 对于系统文件夹，如果节点的名称不等于特定的系统文件夹名称，调用 doContentSync 进行远程更新操作
+                if (!node.getName().equals(
+                        GTaskStringUtils.MIUI_FOLDER_PREFFIX + GTaskStringUtils.FOLDER_DEFAULT))
+                    doContentSync(Node.SYNC_ACTION_UPDATE_REMOTE, node, c);
+            } else {
+                // 如果节点不存在，调用 doContentSync 进行远程添加操作
+                doContentSync(Node.SYNC_ACTION_ADD_REMOTE, node, c);
+            }
+        } else {
+            Log.w(TAG, "failed to query root folder");
+        }
+    } finally {
+        // 确保游标被关闭
+        if (c!= null) {
+            c.close();
+            c = null;
+        }
+    }
+
+    // for call-note folder
+    try {
+        // 查询通话记录文件夹的信息
+        c = mContentResolver.query(Notes.CONTENT_NOTE_URI, SqlNote.PROJECTION_NOTE, "(_id=?)",
+                new String[] {
+                    String.valueOf(Notes.ID_CALL_RECORD_FOLDER)
+                }, null);
+        if (c!= null) {
+            if (c.moveToNext()) {
+                // 获取 GID
+                gid = c.getString(SqlNote.GTASK_ID_COLUMN);
+                // 从 mGTaskHashMap 中获取节点
+                node = mGTaskHashMap.get(gid);
+                if (node!= null) {
+                    // 从映射中移除该节点
+                    mGTaskHashMap.remove(gid);
+                    // 将 GID 和通话记录文件夹的 ID 映射存储到 mGidToNid 和 mNidToGid 中
+                    mGidToNid.put(gid, (long) Notes.ID_CALL_RECORD_FOLDER);
+                    mNidToGid.put((long) Notes.ID_CALL_RECORD_FOLDER, gid);
+                    // 对于系统文件夹，如果节点的名称不等于特定的通话记录文件夹名称，调用 doContentSync 进行远程更新操作
+                    if (!node.getName().equals(
+                            GTaskStringUtils.MIUI_FOLDER_PREFFIX + GTaskStringUtils.FOLDER_CALL_NOTE))
+                        doContentSync(Node.SYNC_ACTION_UPDATE_REMOTE, node, c);
+                } else {
+                    // 如果节点不存在，调用 doContentSync 进行远程添加操作
+                    doContentSync(Node.SYNC_ACTION_ADD_REMOTE, node, c);
+                }
+            }
+        } else {
+            Log.w(TAG, "failed to query call note folder");
+        }
+    } finally {
+        // 确保游标被关闭
+        if (c!= null) {
+            c.close();
+            c = null;
+        }
+    }
+
+    // for local existing folders
+    try {
+        // 查询本地存在的文件夹信息
+        c = mContentResolver.query(Notes.CONTENT_NOTE_URI, SqlNote.PROJECTION_NOTE,
+                "(type=? AND parent_id<>?)", new String[] {
+                        String.valueOf(Notes.TYPE_FOLDER), String.valueOf(Notes.ID_TRASH_FOLER)
+                }, NoteColumns.TYPE + " DESC");
+        if (c!= null) {
+            while (c.moveToNext()) {
+                // 获取 GID
+                gid = c.getString(SqlNote.GTASK_ID_COLUMN);
+                // 从 mGTaskHashMap 中获取节点
+                node = mGTaskHashMap.get(gid);
+                if (node!= null) {
+                    // 从映射中移除该节点
+                    mGTaskHashMap.remove(gid);
+                    // 将 GID 和当前文件夹的 ID 映射存储到 mGidToNid 和 mNidToGid 中
+                    mGidToNid.put(gid, c.getLong(SqlNote.ID_COLUMN));
+                    mNidToGid.put(c.getLong(SqlNote.ID_COLUMN), gid);
+                    // 获取同步类型
+                    syncType = node.getSyncAction(c);
+                } else {
+                    // 如果 GID 长度为 0，说明是本地添加操作
+                    if (c.getString(SqlNote.GTASK_ID_COLUMN).trim().length() == 0) {
+                        syncType = Node.SYNC_ACTION_ADD_REMOTE;
+                    } else {
+                        // 否则是远程删除操作
+                        syncType = Node.SYNC_ACTION_DEL_LOCAL;
+                    }
+                }
+                // 调用 doContentSync 进行相应的同步操作
+                doContentSync(syncType, node, c);
+            }
+        } else {
+            Log.w(TAG, "failed to query existing folder");
+        }
+    } finally {
+        // 确保游标被关闭
+        if (c!= null) {
+            c.close();
+            c = null;
+        }
+    }
+
+        // for remote add folders
+        // 遍历任务列表的 HashMap 的迭代器
+Iterator<Map.Entry<String, TaskList>> iter = mGTaskListHashMap.entrySet().iterator();
+while (iter.hasNext()) {
+    // 获取迭代器的下一个元素
+    Map.Entry<String, TaskList> entry = iter.next();
+    // 获取任务列表的 GID
+    gid = entry.getKey();
+    // 获取任务列表的节点
+    node = entry.getValue();
+    // 检查 GTaskHashMap 是否包含该 GID
+    if (mGTaskHashMap.containsKey(gid)) {
+        // 从 GTaskHashMap 中移除该 GID
+        mGTaskHashMap.remove(gid);
+        // 执行内容同步操作，同步类型为本地添加
+        doContentSync(Node.SYNC_ACTION_ADD_LOCAL, node, null);
+    }
+}
+// 如果同步操作未取消
+if (!mCancelled)
+    // 调用 GTaskClient 的 commitUpdate 方法
+    GTaskClient.getInstance().commitUpdate();
+
+
+// 执行内容同步操作的方法，根据不同的同步类型进行不同的操作
+private void doContentSync(int syncType, Node node, Cursor c) throws NetworkFailureException {
+    if (mCancelled) {
+        return;
+    }
+    MetaData meta;
+    switch (syncType) {
+        // 本地添加节点
+        case Node.SYNC_ACTION_ADD_LOCAL:
+            addLocalNode(node);
+            break;
+        // 远程添加节点
+        case Node.SYNC_ACTION_ADD_REMOTE:
+            addRemoteNode(node, c);
+            break;
+        // 本地删除节点
+        case Node.SYNC_ACTION_DEL_LOCAL:
+            // 从元数据映射中获取元数据
+            meta = mMetaHashMap.get(c.getString(SqlNote.GTASK_ID_COLUMN));
+            if (meta!= null) {
+                // 调用 GTaskClient 的 deleteNode 方法删除元数据
+                GTaskClient.getInstance().deleteNode(meta);
+            }
+            // 将本地删除的节点 ID 添加到本地删除集合中
+            mLocalDeleteIdMap.add(c.getLong(SqlNote.ID_COLUMN));
+            break;
+        // 远程删除节点
+        case Node.SYNC_ACTION_DEL_REMOTE:
+            // 从元数据映射中获取元数据
+            meta = mMetaHashMap.get(node.getGid());
+            if (meta!= null) {
+                // 调用 GTaskClient 的 deleteNode 方法删除元数据
+                GTaskClient.getInstance().deleteNode(meta);
+            }
+            // 调用 GTaskClient 的 deleteNode 方法删除节点
+            GTaskClient.getInstance().deleteNode(node);
+            break;
+        // 本地更新节点
+        case Node.SYNC_ACTION_UPDATE_LOCAL:
+            updateLocalNode(node, c);
+            break;
+        // 远程更新节点
+        case Node.SYNC_ACTION_UPDATE_REMOTE:
+            updateRemoteNode(node, c);
+            break;
+        // 同步冲突
+        case Node.SYNC_ACTION_UPDATE_CONFLICT:
+            // 合并修改，目前只是简单地使用远程更新
+            updateRemoteNode(node, c);
+            break;
+        // 无同步操作
+        case Node.SYNC_ACTION_NONE:
+            break;
+        // 同步操作错误
+        case Node.SYNC_ACTION_ERROR:
+        default:
+            // 抛出异常，因为同步操作类型未知
+            throw new ActionFailureException("unkown sync action type");
+    }
+}
+
+
+// 本地添加节点的方法
+private void addLocalNode(Node node) throws NetworkFailureException {
+    if (mCancelled) {
+        return;
+    }
+    SqlNote sqlNote;
+    if (node instanceof TaskList) {
+        // 根据节点名称创建不同的 SqlNote 对象
+        if (node.getName().equals(
+                GTaskStringUtils.MIUI_FOLDER_PREFFIX + GTaskStringUtils.FOLDER_DEFAULT)) {
+            sqlNote = new SqlNote(mContext, Notes.ID_ROOT_FOLDER);
+        } else if (node.getName().equals(
+                GTaskStringUtils.MIUI_FOLDER_PREFFIX + GTaskStringUtils.FOLDER_CALL_NOTE)) {
+            sqlNote = new SqlNote(mContext, Notes.ID_CALL_RECORD_FOLDER);
+        } else {
+            sqlNote = new SqlNote(mContext);
+            // 设置 SqlNote 的内容
+            sqlNote.setContent(node.getLocalJSONFromContent());
+            // 设置父节点 ID
+            sqlNote.setParentId(Notes.ID_ROOT_FOLDER);
+        }
+    } else {
+        sqlNote = new SqlNote(mContext);
+        JSONObject js = node.getLocalJSONFromContent();
+        try {
+            if (js.has(GTaskStringUtils.META_HEAD_NOTE)) {
+                JSONObject note = js.getJSONObject(GTaskStringUtils.META_HEAD_NOTE);
+                if (note.has(NoteColumns.ID)) {
+                    long id = note.getLong(NoteColumns.ID);
+                    if (DataUtils.existInNoteDatabase(mContentResolver, id)) {
+                        // 如果 ID 已存在，移除 ID
+                        note.remove(NoteColumns.ID);
+                    }
+                }
+            }
+            if (js.has(GTaskStringUtils.META_HEAD_DATA)) {
+                JSONArray dataArray = js.getJSONArray(GTaskStringUtils.META_HEAD_DATA);
+                for (int i = 0; i < dataArray.length(); i++) {
+                    JSONObject data = dataArray.getJSONObject(i);
+                    if (data.has(DataColumns.ID)) {
+                        long dataId = data.getLong(DataColumns.ID);
+                        if (DataUtils.existInDataDatabase(mContentResolver, dataId)) {
+                            // 如果数据 ID 已存在，移除数据 ID
+                            data.remove(DataColumns.ID);
+                        }
+                    }
+                }
+            }
+        } catch (JSONException e) {
+            Log.w(TAG, e.toString());
+            e.printStackTrace();
+        }
+        // 设置 SqlNote 的内容
+        sqlNote.setContent(js);
+        // 获取父节点的 GID 对应的本地 ID
+        Long parentId = mGidToNid.get(((Task) node).getParent().getGid());
+        if (parentId == null) {
+            Log.e(TAG, "cannot find task's parent id locally");
+            throw new ActionFailureException("cannot add local node");
+        }
+        // 设置父节点 ID
+        sqlNote.setParentId(parentId.longValue());
+    }
+    // 创建本地节点
+    sqlNote.setGtaskId(node.getGid());
+    sqlNote.commit(false);
+    // 更新 GID 到 NID 的映射和 NID 到 GID 的映射
+    mGidToNid.put(node.getGid(), sqlNote.getId());
+    mNidToGid.put(sqlNote.getId(), node.getGid());
+    // 更新远程元数据
+    updateRemoteMeta(node.getGid(), sqlNote);
+}
+
+
+// 本地更新节点的方法
+private void updateLocalNode(Node node, Cursor c) throws NetworkFailureException {
+    if (mCancelled) {
+        return;
+    }
+    SqlNote sqlNote;
+    // 本地更新笔记
+    sqlNote = new SqlNote(mContext, c);
+    sqlNote.setContent(node.getLocalJSONFromContent());
+    // 获取父节点的 GID 对应的本地 ID
+    Long parentId = (node instanceof Task)? mGidToNid.get(((Task) node).getParent().getGid())
+            : new Long(Notes.ID_ROOT_FOLDER);
+    if (parentId == null) {
+        Log.e(TAG, "cannot find task's parent id locally");
+        throw new ActionFailureException("cannot update local node");
+    }
+    // 设置父节点 ID
+    sqlNote.setParentId(parentId.longValue());
+    sqlNote.commit(true);
+    // 更新元数据信息
+    updateRemoteMeta(node.getGid(), sqlNote);
+}
+
+
+// 远程添加节点的方法
+private void addRemoteNode(Node node, Cursor c) throws NetworkFailureException {
+    if (mCancelled) {
+        return;
+    }
+    SqlNote sqlNote = new SqlNote(mContext, c);
+    Node n;
+    // 远程更新
+    if (sqlNote.isNoteType()) {
+        Task task = new Task();
+        // 设置任务的内容
+        task.setContentByLocalJSON(sqlNote.getContent());
+        // 获取父任务列表的 GID
+        String parentGid = mNidToGid.get(sqlNote.getParentId());
+        if (parentGid == null) {
+            Log.e(TAG, "cannot find task's parent tasklist");
+            throw new ActionFailureException("cannot add remote task");
+        }
+        // 将任务添加到父任务列表中
+        mGTaskListHashMap.get(parentGid).addChildTask(task);
+        // 调用 GTaskClient 的 createTask 方法创建任务
+        GTaskClient.getInstance().createTask(task);
+        n = (Node) task;
+        // 添加元数据
+        updateRemoteMeta(task.getGid(), sqlNote);
+    } else {
+        TaskList tasklist = null;
+        // 构建文件夹名称
+        String folderName = GTaskStringUtils.MIUI_FOLDER_PREFFIX;
+        if (sqlNote.getId() == Notes.ID_ROOT_FOLDER)
+            folderName += GTaskStringUtils.FOLDER_DEFAULT;
+        else if (sqlNote.getId() == Notes.ID_CALL_RECORD_FOLDER)
+            folderName += GTaskStringUtils.FOLDER_CALL_NOTE;
+        else
+            folderName += sqlNote.getSnippet();
+        // 遍历任务列表的 HashMap，查找是否已存在该文件夹
+        Iterator<Map.Entry<String, TaskList>> iter = mGTaskListHashMap.entrySet().iterator();
+        while (iter.hasNext()) {
+            Map.Entry<String, TaskList> entry = iter.next();
+            String gid = entry.getKey();
+            TaskList list = entry.getValue();
+            if (list.getName().equals(folderName)) {
+                tasklist = list;
+                if (mGTaskHashMap.containsKey(gid)) {
+                    mGTaskHashMap.remove(gid);
+                }
+                break;
+            }
+        }
+        // 如果不存在，创建新的任务列表
+        if (tasklist == null) {
+            tasklist = new TaskList();
+            tasklist.setContentByLocalJSON(sqlNote.getContent());
+            GTaskClient.getInstance().createTaskList(tasklist);
+            mGTaskListHashMap.put(tasklist.getGid(), tasklist);
+        }
+        n = (Node) tasklist;
+    }
+    // 更新本地笔记
+    sqlNote.setGtaskId(n.getGid());
+    sqlNote.commit(false);
+    sqlNote.resetLocalModified();
+    sqlNote.commit(true);
+    // 更新 GID 到 NID 的映射和 NID 到 GID 的映射
+    mGidToNid.put(n.getGid(), sqlNote.getId());
+    mNidToGid.put(sqlNote.getId(), n.getGid());
+}
+
+
+// 远程更新节点的方法
+private void updateRemoteNode(Node node, Cursor c) throws NetworkFailureException {
+    if (mCancelled) {
+        return;
+    }
+    SqlNote sqlNote = new SqlNote(mContext, c);
+    // 远程更新
+    node.setContentByLocalJSON(sqlNote.getContent());
+    GTaskClient.getInstance().addUpdateNode(node);
+    // 更新元数据
+    updateRemoteMeta(node.getGid(), sqlNote);
+    // 如果是任务，可能需要移动任务
+    if (sqlNote.isNoteType()) {
+        Task task = (Task) node;
+        TaskList preParentList = task.getParent();
+        // 获取当前父任务列表的 GID
+        String curParentGid = mNidToGid.get(sqlNote.getParentId());
+        if (curParentGid == null) {
+            Log.e(TAG, "cannot find task's parent tasklist");
+            throw new ActionFailureException("cannot update remote task");
+        }
+        TaskList curParentList = mGTaskListHashMap.get(curParentGid);
+        if (preParentList!= curParentList) {
+            // 移除任务从原父任务列表，并添加到新父任务列表
+            preParentList.removeChildTask(task);
+            curParentList.addChildTask(task);
+            // 调用 GTaskClient 的 moveTask 方法移动任务
+            GTaskClient.getInstance().moveTask(task, preParentList, curParentList);
+        }
+    }
+    // 清除本地修改标志
+    sqlNote.resetLocalModified();
+    sqlNote.commit(true);
+}
+
+
+// 更新远程元数据的方法
+private void updateRemoteMeta(String gid, SqlNote sqlNote) throws NetworkFailureException {
+    if (sqlNote!= null && sqlNote.isNoteType()) {
+        MetaData metaData = mMetaHashMap.get(gid);
+        if (metaData!= null) {
+            // 更新元数据
+            metaData.setMeta(gid, sqlNote.getContent());
+            GTaskClient.getInstance().addUpdateNode(metaData);
+        } else {
+            metaData = new MetaData();
+            metaData.setMeta(gid, sqlNote.getContent());
+            mMetaList.addChildTask(metaData);
+            mMetaHashMap.put(gid, metaData);
+            GTaskClient.getInstance().createTask(metaData);
+        }
+    }
+}
+
+
+// 刷新本地同步 ID 的方法
+private void refreshLocalSyncId() throws NetworkFailureException {
+    if (mCancelled) {
+        return;
+    }
+    // 获取最新的 GTask 列表
+    mGTaskHashMap.clear();
+    mGTaskListHashMap.clear();
+    mMetaHashMap.clear();
+    initGTaskList();
+    Cursor c = null;
+    try {
+        // 查询本地笔记
+        c = mContentResolver.query(Notes.CONTENT_NOTE_URI, SqlNote.PROJECTION_NOTE,
+                "(type<>? AND parent_id<>?)", new String[] {
+                        String.valueOf(Notes.TYPE_SYSTEM), String.valueOf(Notes.ID_TRASH_FOLER)
+                }, NoteColumns.TYPE + " DESC");
+        if (c!= null) {
+            while (c.moveToNext()) {
+                String gid = c.getString(SqlNote.GTASK_ID_COLUMN);
+                Node node = mGTaskHashMap.get(gid);
+                if (node!= null) {
+                    mGTaskHashMap.remove(gid);
+                    ContentValues values = new ContentValues();
+                    // 更新同步 ID
+                    values.put(NoteColumns.SYNC_ID, node.getLastModified());
+                    mContentResolver.update(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI,
+                            c.getLong(SqlNote.ID_COLUMN)), values, null, null);
+                } else {
+                    Log.e(TAG, "something is missed");
+                    throw new ActionFailureException(
+                            "some local items don't have gid after sync");
+                }
+            }
+        } else {
+            Log.w(TAG, "failed to query local note to refresh sync id");
+        }
+    } finally {
+        if (c!= null) {
+            c.close();
+            c = null;
+        }
+    }
+}
+
+
+// 获取同步账户的方法
+public String getSyncAccount() {
+    return GTaskClient.getInstance().getSyncAccount().name;
+}
+
+
+// 取消同步的方法
+public void cancelSync() {
+    mCancelled = true;
+}

src/gtask/remote/GTaskSyncService.java

@@ -0,0 +1,155 @@
+/*
+ * 版权信息：
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ * 遵循 Apache License, Version 2.0 许可证
+ * http://www.apache.org/licenses/LICENSE-2.0
+ */
+
+package net.micode.notes.gtask.remote;
+
+import android.app.Activity;
+import android.app.Service;
+import android.content.Context;
+import android.content.Intent;
+import android.os.Bundle;
+import android.os.IBinder;
+
+
+// GTaskSyncService 类，用于实现 GTask 的同步服务
+public class GTaskSyncService extends Service {
+    // 定义同步操作类型的字符串名称
+    public final static String ACTION_STRING_NAME = "sync_action_type";
+    // 开始同步操作的常量
+    public final static int ACTION_START_SYNC = 0;
+    // 取消同步操作的常量
+    public final static int ACTION_CANCEL_SYNC = 1;
+    // 无效操作的常量
+    public final static int ACTION_INVALID = 2;
+    // 服务广播的名称
+    public final static String GTASK_SERVICE_BROADCAST_NAME = "net.micode.notes.gtask.remote.gtask_sync_service";
+    // 广播中表示是否正在同步的键
+    public final static String GTASK_SERVICE_BROADCAST_IS_SYNCING = "isSyncing";
+    // 广播中表示同步进度消息的键
+    public final static String GTASK_SERVICE_BROADCAST_PROGRESS_MSG = "progressMsg";
+
+
+    // 存储同步任务的静态变量
+    private static GTaskASyncTask mSyncTask = null;
+    // 存储同步进度消息的静态变量
+    private static String mSyncProgress = "";
+
+
+    // 开始同步的方法
+    private void startSync() {
+        // 如果同步任务为空，则创建一个新的同步任务
+        if (mSyncTask == null) {
+            mSyncTask = new GTaskASyncTask(this, new GTaskASyncTask.OnCompleteListener() {
+                // 同步任务完成后的回调方法
+                public void onComplete() {
+                    mSyncTask = null;
+                    sendBroadcast("");
+                    stopSelf();
+                }
+            });
+            sendBroadcast("");
+            // 执行同步任务
+            mSyncTask.execute();
+        }
+    }
+
+
+    // 取消同步的方法
+    private void cancelSync() {
+        // 如果同步任务不为空，则取消同步任务
+        if (mSyncTask!= null) {
+            mSyncTask.cancelSync();
+        }
+    }
+
+
+    // 服务创建时调用的方法
+    @Override
+    public void onCreate() {
+        mSyncTask = null;
+    }
+
+
+    // 服务启动时调用的方法，根据传入的意图执行不同的操作
+    @Override
+    public int onStartCommand(Intent intent, int flags, int startId) {
+        Bundle bundle = intent.getExtras();
+        if (bundle!= null && bundle.containsKey(ACTION_STRING_NAME)) {
+            switch (bundle.getInt(ACTION_STRING_NAME, ACTION_INVALID)) {
+                // 开始同步操作
+                case ACTION_START_SYNC:
+                    startSync();
+                    break;
+                // 取消同步操作
+                case ACTION_CANCEL_SYNC:
+                    cancelSync();
+                    break;
+                default:
+                    break;
+            }
+            // 服务被杀死后会自动重启
+            return START_STICKY;
+        }
+        // 调用父类的 onStartCommand 方法
+        return super.onStartCommand(intent, flags, startId);
+    }
+
+
+    // 内存不足时调用的方法，如果有同步任务则取消同步任务
+    @Override
+    public void onLowMemory() {
+        if (mSyncTask!= null) {
+            mSyncTask.cancelSync();
+        }
+    }
+
+
+    // 服务绑定方法，返回 null 表示不支持绑定
+    @Override
+    public IBinder onBind(Intent intent) {
+        return null;
+    }
+
+
+    // 发送广播的方法
+    public void sendBroadcast(String msg) {
+        mSyncProgress = msg;
+        Intent intent = new Intent(GTASK_SERVICE_BROADCAST_NAME);
+        intent.putExtra(GTASK_SERVICE_BROADCAST_IS_SYNCING, mSyncTask!= null);
+        intent.putExtra(GTASK_SERVICE_BROADCAST_PROGRESS_MSG, msg);
+        sendBroadcast(intent);
+    }
+
+
+    // 静态方法，开始同步操作，设置活动上下文并启动服务
+    public static void startSync(Activity activity) {
+        GTaskManager.getInstance().setActivityContext(activity);
+        Intent intent = new Intent(activity, GTaskSyncService.class);
+        intent.putExtra(GTaskSyncService.ACTION_STRING_NAME, GTaskSyncService.ACTION_START_SYNC);
+        activity.startService(intent);
+    }
+
+
+    // 静态方法，取消同步操作，发送取消同步的意图并启动服务
+    public static void cancelSync(Context context) {
+        Intent intent = new Intent(context, GTaskSyncService.class);
+        intent.putExtra(GTaskSyncService.ACTION_STRING_NAME, GTaskSyncService.ACTION_CANCEL_SYNC);
+        context.startService(intent);
+    }
+
+
+    // 静态方法，检查是否正在同步
+    public static boolean isSyncing() {
+        return mSyncTask!= null;
+    }
+
+
+    // 静态方法，获取同步进度字符串
+    public static String getProgressString() {
+        return mSyncProgress;
+    }
+}

src/model/Note.java

@@ -0,0 +1,253 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.model;
+import android.content.ContentProviderOperation;
+import android.content.ContentProviderResult;
+import android.content.ContentUris;
+import android.content.ContentValues;
+import android.content.Context;
+import android.content.OperationApplicationException;
+import android.net.Uri;
+import android.os.RemoteException;
+import android.util.Log;
+
+import net.micode.notes.data.Notes;
+import net.micode.notes.data.Notes.CallNote;
+import net.micode.notes.data.Notes.DataColumns;
+import net.micode.notes.data.Notes.NoteColumns;
+import net.micode.notes.data.Notes.TextNote;
+
+import java.util.ArrayList;
+
+
+public class Note {
+    private ContentValues mNoteDiffValues;
+    private NoteData mNoteData;
+    private static final String TAG = "Note";
+    /**
+     * Create a new note id for adding a new note to databases
+     */
+    public static synchronized long getNewNoteId(Context context, long folderId) {
+        // Create a new note in the database
+        ContentValues values = new ContentValues();
+        long createdTime = System.currentTimeMillis();
+        values.put(NoteColumns.CREATED_DATE, createdTime);
+        values.put(NoteColumns.MODIFIED_DATE, createdTime);
+        values.put(NoteColumns.TYPE, Notes.TYPE_NOTE);
+        values.put(NoteColumns.LOCAL_MODIFIED, 1);
+        values.put(NoteColumns.PARENT_ID, folderId);
+        Uri uri = context.getContentResolver().insert(Notes.CONTENT_NOTE_URI, values);
+
+        long noteId = 0;
+        try {
+            noteId = Long.valueOf(uri.getPathSegments().get(1));
+        } catch (NumberFormatException e) {
+            Log.e(TAG, "Get note id error :" + e.toString());
+            noteId = 0;
+        }
+        if (noteId == -1) {
+            throw new IllegalStateException("Wrong note id:" + noteId);
+        }
+        return noteId;
+    }
+
+    public Note() {
+        mNoteDiffValues = new ContentValues();
+        mNoteData = new NoteData();
+    }
+
+    public void setNoteValue(String key, String value) {
+        mNoteDiffValues.put(key, value);
+        mNoteDiffValues.put(NoteColumns.LOCAL_MODIFIED, 1);
+        mNoteDiffValues.put(NoteColumns.MODIFIED_DATE, System.currentTimeMillis());
+    }
+
+    public void setTextData(String key, String value) {
+        mNoteData.setTextData(key, value);
+    }
+
+    public void setTextDataId(long id) {
+        mNoteData.setTextDataId(id);
+    }
+
+    public long getTextDataId() {
+        return mNoteData.mTextDataId;
+    }
+
+    public void setCallDataId(long id) {
+        mNoteData.setCallDataId(id);
+    }
+
+    public void setCallData(String key, String value) {
+        mNoteData.setCallData(key, value);
+    }
+
+    public boolean isLocalModified() {
+        return mNoteDiffValues.size() > 0 || mNoteData.isLocalModified();
+    }
+
+    public boolean syncNote(Context context, long noteId) {
+        if (noteId <= 0) {
+            throw new IllegalArgumentException("Wrong note id:" + noteId);
+        }
+
+        if (!isLocalModified()) {
+            return true;
+        }
+
+        /**
+         * In theory, once data changed, the note should be updated on {@link NoteColumns#LOCAL_MODIFIED} and
+         * {@link NoteColumns#MODIFIED_DATE}. For data safety, though update note fails, we also update the
+         * note data info
+         */
+        if (context.getContentResolver().update(
+                ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId), mNoteDiffValues, null,
+                null) == 0) {
+            Log.e(TAG, "Update note error, should not happen");
+            // Do not return, fall through
+        }
+        mNoteDiffValues.clear();
+
+        if (mNoteData.isLocalModified()
+                && (mNoteData.pushIntoContentResolver(context, noteId) == null)) {
+            return false;
+        }
+
+        return true;
+    }
+
+    private class NoteData {
+        private long mTextDataId;
+
+        private ContentValues mTextDataValues;
+
+        private long mCallDataId;
+
+        private ContentValues mCallDataValues;
+
+        private static final String TAG = "NoteData";
+
+        public NoteData() {
+            mTextDataValues = new ContentValues();
+            mCallDataValues = new ContentValues();
+            mTextDataId = 0;
+            mCallDataId = 0;
+        }
+
+        boolean isLocalModified() {
+            return mTextDataValues.size() > 0 || mCallDataValues.size() > 0;
+        }
+
+        void setTextDataId(long id) {
+            if(id <= 0) {
+                throw new IllegalArgumentException("Text data id should larger than 0");
+            }
+            mTextDataId = id;
+        }
+
+        void setCallDataId(long id) {
+            if (id <= 0) {
+                throw new IllegalArgumentException("Call data id should larger than 0");
+            }
+            mCallDataId = id;
+        }
+
+        void setCallData(String key, String value) {
+            mCallDataValues.put(key, value);
+            mNoteDiffValues.put(NoteColumns.LOCAL_MODIFIED, 1);
+            mNoteDiffValues.put(NoteColumns.MODIFIED_DATE, System.currentTimeMillis());
+        }
+
+        void setTextData(String key, String value) {
+            mTextDataValues.put(key, value);
+            mNoteDiffValues.put(NoteColumns.LOCAL_MODIFIED, 1);
+            mNoteDiffValues.put(NoteColumns.MODIFIED_DATE, System.currentTimeMillis());
+        }
+
+        Uri pushIntoContentResolver(Context context, long noteId) {
+            /**
+             * Check for safety
+             */
+            if (noteId <= 0) {
+                throw new IllegalArgumentException("Wrong note id:" + noteId);
+            }
+
+            ArrayList<ContentProviderOperation> operationList = new ArrayList<ContentProviderOperation>();
+            ContentProviderOperation.Builder builder = null;
+
+            if(mTextDataValues.size() > 0) {
+                mTextDataValues.put(DataColumns.NOTE_ID, noteId);
+                if (mTextDataId == 0) {
+                    mTextDataValues.put(DataColumns.MIME_TYPE, TextNote.CONTENT_ITEM_TYPE);
+                    Uri uri = context.getContentResolver().insert(Notes.CONTENT_DATA_URI,
+                            mTextDataValues);
+                    try {
+                        setTextDataId(Long.valueOf(uri.getPathSegments().get(1)));
+                    } catch (NumberFormatException e) {
+                        Log.e(TAG, "Insert new text data fail with noteId" + noteId);
+                        mTextDataValues.clear();
+                        return null;
+                    }
+                } else {
+                    builder = ContentProviderOperation.newUpdate(ContentUris.withAppendedId(
+                            Notes.CONTENT_DATA_URI, mTextDataId));
+                    builder.withValues(mTextDataValues);
+                    operationList.add(builder.build());
+                }
+                mTextDataValues.clear();
+            }
+
+            if(mCallDataValues.size() > 0) {
+                mCallDataValues.put(DataColumns.NOTE_ID, noteId);
+                if (mCallDataId == 0) {
+                    mCallDataValues.put(DataColumns.MIME_TYPE, CallNote.CONTENT_ITEM_TYPE);
+                    Uri uri = context.getContentResolver().insert(Notes.CONTENT_DATA_URI,
+                            mCallDataValues);
+                    try {
+                        setCallDataId(Long.valueOf(uri.getPathSegments().get(1)));
+                    } catch (NumberFormatException e) {
+                        Log.e(TAG, "Insert new call data fail with noteId" + noteId);
+                        mCallDataValues.clear();
+                        return null;
+                    }
+                } else {
+                    builder = ContentProviderOperation.newUpdate(ContentUris.withAppendedId(
+                            Notes.CONTENT_DATA_URI, mCallDataId));
+                    builder.withValues(mCallDataValues);
+                    operationList.add(builder.build());
+                }
+                mCallDataValues.clear();
+            }
+
+            if (operationList.size() > 0) {
+                try {
+                    ContentProviderResult[] results = context.getContentResolver().applyBatch(
+                            Notes.AUTHORITY, operationList);
+                    return (results == null || results.length == 0 || results[0] == null) ? null
+                            : ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId);
+                } catch (RemoteException e) {
+                    Log.e(TAG, String.format("%s: %s", e.toString(), e.getMessage()));
+                    return null;
+                } catch (OperationApplicationException e) {
+                    Log.e(TAG, String.format("%s: %s", e.toString(), e.getMessage()));
+                    return null;
+                }
+            }
+            return null;
+        }
+    }
+}

src/model/WorkingNote.java

@@ -0,0 +1,368 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.model;
+
+import android.appwidget.AppWidgetManager;
+import android.content.ContentUris;
+import android.content.Context;
+import android.database.Cursor;
+import android.text.TextUtils;
+import android.util.Log;
+
+import net.micode.notes.data.Notes;
+import net.micode.notes.data.Notes.CallNote;
+import net.micode.notes.data.Notes.DataColumns;
+import net.micode.notes.data.Notes.DataConstants;
+import net.micode.notes.data.Notes.NoteColumns;
+import net.micode.notes.data.Notes.TextNote;
+import net.micode.notes.tool.ResourceParser.NoteBgResources;
+
+
+public class WorkingNote {
+    // Note for the working note
+    private Note mNote;
+    // Note Id
+    private long mNoteId;
+    // Note content
+    private String mContent;
+    // Note mode
+    private int mMode;
+
+    private long mAlertDate;
+
+    private long mModifiedDate;
+
+    private int mBgColorId;
+
+    private int mWidgetId;
+
+    private int mWidgetType;
+
+    private long mFolderId;
+
+    private Context mContext;
+
+    private static final String TAG = "WorkingNote";
+
+    private boolean mIsDeleted;
+
+    private NoteSettingChangedListener mNoteSettingStatusListener;
+
+    public static final String[] DATA_PROJECTION = new String[] {
+            DataColumns.ID,
+            DataColumns.CONTENT,
+            DataColumns.MIME_TYPE,
+            DataColumns.DATA1,
+            DataColumns.DATA2,
+            DataColumns.DATA3,
+            DataColumns.DATA4,
+    };
+
+    public static final String[] NOTE_PROJECTION = new String[] {
+            NoteColumns.PARENT_ID,
+            NoteColumns.ALERTED_DATE,
+            NoteColumns.BG_COLOR_ID,
+            NoteColumns.WIDGET_ID,
+            NoteColumns.WIDGET_TYPE,
+            NoteColumns.MODIFIED_DATE
+    };
+
+    private static final int DATA_ID_COLUMN = 0;
+
+    private static final int DATA_CONTENT_COLUMN = 1;
+
+    private static final int DATA_MIME_TYPE_COLUMN = 2;
+
+    private static final int DATA_MODE_COLUMN = 3;
+
+    private static final int NOTE_PARENT_ID_COLUMN = 0;
+
+    private static final int NOTE_ALERTED_DATE_COLUMN = 1;
+
+    private static final int NOTE_BG_COLOR_ID_COLUMN = 2;
+
+    private static final int NOTE_WIDGET_ID_COLUMN = 3;
+
+    private static final int NOTE_WIDGET_TYPE_COLUMN = 4;
+
+    private static final int NOTE_MODIFIED_DATE_COLUMN = 5;
+
+    // New note construct
+    private WorkingNote(Context context, long folderId) {
+        mContext = context;
+        mAlertDate = 0;
+        mModifiedDate = System.currentTimeMillis();
+        mFolderId = folderId;
+        mNote = new Note();
+        mNoteId = 0;
+        mIsDeleted = false;
+        mMode = 0;
+        mWidgetType = Notes.TYPE_WIDGET_INVALIDE;
+    }
+
+    // Existing note construct
+    private WorkingNote(Context context, long noteId, long folderId) {
+        mContext = context;
+        mNoteId = noteId;
+        mFolderId = folderId;
+        mIsDeleted = false;
+        mNote = new Note();
+        loadNote();
+    }
+
+    private void loadNote() {
+        Cursor cursor = mContext.getContentResolver().query(
+                ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, mNoteId), NOTE_PROJECTION, null,
+                null, null);
+
+        if (cursor != null) {
+            if (cursor.moveToFirst()) {
+                mFolderId = cursor.getLong(NOTE_PARENT_ID_COLUMN);
+                mBgColorId = cursor.getInt(NOTE_BG_COLOR_ID_COLUMN);
+                mWidgetId = cursor.getInt(NOTE_WIDGET_ID_COLUMN);
+                mWidgetType = cursor.getInt(NOTE_WIDGET_TYPE_COLUMN);
+                mAlertDate = cursor.getLong(NOTE_ALERTED_DATE_COLUMN);
+                mModifiedDate = cursor.getLong(NOTE_MODIFIED_DATE_COLUMN);
+            }
+            cursor.close();
+        } else {
+            Log.e(TAG, "No note with id:" + mNoteId);
+            throw new IllegalArgumentException("Unable to find note with id " + mNoteId);
+        }
+        loadNoteData();
+    }
+
+    private void loadNoteData() {
+        Cursor cursor = mContext.getContentResolver().query(Notes.CONTENT_DATA_URI, DATA_PROJECTION,
+                DataColumns.NOTE_ID + "=?", new String[] {
+                    String.valueOf(mNoteId)
+                }, null);
+
+        if (cursor != null) {
+            if (cursor.moveToFirst()) {
+                do {
+                    String type = cursor.getString(DATA_MIME_TYPE_COLUMN);
+                    if (DataConstants.NOTE.equals(type)) {
+                        mContent = cursor.getString(DATA_CONTENT_COLUMN);
+                        mMode = cursor.getInt(DATA_MODE_COLUMN);
+                        mNote.setTextDataId(cursor.getLong(DATA_ID_COLUMN));
+                    } else if (DataConstants.CALL_NOTE.equals(type)) {
+                        mNote.setCallDataId(cursor.getLong(DATA_ID_COLUMN));
+                    } else {
+                        Log.d(TAG, "Wrong note type with type:" + type);
+                    }
+                } while (cursor.moveToNext());
+            }
+            cursor.close();
+        } else {
+            Log.e(TAG, "No data with id:" + mNoteId);
+            throw new IllegalArgumentException("Unable to find note's data with id " + mNoteId);
+        }
+    }
+
+    public static WorkingNote createEmptyNote(Context context, long folderId, int widgetId,
+            int widgetType, int defaultBgColorId) {
+        WorkingNote note = new WorkingNote(context, folderId);
+        note.setBgColorId(defaultBgColorId);
+        note.setWidgetId(widgetId);
+        note.setWidgetType(widgetType);
+        return note;
+    }
+
+    public static WorkingNote load(Context context, long id) {
+        return new WorkingNote(context, id, 0);
+    }
+
+    public synchronized boolean saveNote() {
+        if (isWorthSaving()) {
+            if (!existInDatabase()) {
+                if ((mNoteId = Note.getNewNoteId(mContext, mFolderId)) == 0) {
+                    Log.e(TAG, "Create new note fail with id:" + mNoteId);
+                    return false;
+                }
+            }
+
+            mNote.syncNote(mContext, mNoteId);
+
+            /**
+             * Update widget content if there exist any widget of this note
+             */
+            if (mWidgetId != AppWidgetManager.INVALID_APPWIDGET_ID
+                    && mWidgetType != Notes.TYPE_WIDGET_INVALIDE
+                    && mNoteSettingStatusListener != null) {
+                mNoteSettingStatusListener.onWidgetChanged();
+            }
+            return true;
+        } else {
+            return false;
+        }
+    }
+
+    public boolean existInDatabase() {
+        return mNoteId > 0;
+    }
+
+    private boolean isWorthSaving() {
+        if (mIsDeleted || (!existInDatabase() && TextUtils.isEmpty(mContent))
+                || (existInDatabase() && !mNote.isLocalModified())) {
+            return false;
+        } else {
+            return true;
+        }
+    }
+
+    public void setOnSettingStatusChangedListener(NoteSettingChangedListener l) {
+        mNoteSettingStatusListener = l;
+    }
+
+    public void setAlertDate(long date, boolean set) {
+        if (date != mAlertDate) {
+            mAlertDate = date;
+            mNote.setNoteValue(NoteColumns.ALERTED_DATE, String.valueOf(mAlertDate));
+        }
+        if (mNoteSettingStatusListener != null) {
+            mNoteSettingStatusListener.onClockAlertChanged(date, set);
+        }
+    }
+
+    public void markDeleted(boolean mark) {
+        mIsDeleted = mark;
+        if (mWidgetId != AppWidgetManager.INVALID_APPWIDGET_ID
+                && mWidgetType != Notes.TYPE_WIDGET_INVALIDE && mNoteSettingStatusListener != null) {
+                mNoteSettingStatusListener.onWidgetChanged();
+        }
+    }
+
+    public void setBgColorId(int id) {
+        if (id != mBgColorId) {
+            mBgColorId = id;
+            if (mNoteSettingStatusListener != null) {
+                mNoteSettingStatusListener.onBackgroundColorChanged();
+            }
+            mNote.setNoteValue(NoteColumns.BG_COLOR_ID, String.valueOf(id));
+        }
+    }
+
+    public void setCheckListMode(int mode) {
+        if (mMode != mode) {
+            if (mNoteSettingStatusListener != null) {
+                mNoteSettingStatusListener.onCheckListModeChanged(mMode, mode);
+            }
+            mMode = mode;
+            mNote.setTextData(TextNote.MODE, String.valueOf(mMode));
+        }
+    }
+
+    public void setWidgetType(int type) {
+        if (type != mWidgetType) {
+            mWidgetType = type;
+            mNote.setNoteValue(NoteColumns.WIDGET_TYPE, String.valueOf(mWidgetType));
+        }
+    }
+
+    public void setWidgetId(int id) {
+        if (id != mWidgetId) {
+            mWidgetId = id;
+            mNote.setNoteValue(NoteColumns.WIDGET_ID, String.valueOf(mWidgetId));
+        }
+    }
+
+    public void setWorkingText(String text) {
+        if (!TextUtils.equals(mContent, text)) {
+            mContent = text;
+            mNote.setTextData(DataColumns.CONTENT, mContent);
+        }
+    }
+
+    public void convertToCallNote(String phoneNumber, long callDate) {
+        mNote.setCallData(CallNote.CALL_DATE, String.valueOf(callDate));
+        mNote.setCallData(CallNote.PHONE_NUMBER, phoneNumber);
+        mNote.setNoteValue(NoteColumns.PARENT_ID, String.valueOf(Notes.ID_CALL_RECORD_FOLDER));
+    }
+
+    public boolean hasClockAlert() {
+        return (mAlertDate > 0 ? true : false);
+    }
+
+    public String getContent() {
+        return mContent;
+    }
+
+    public long getAlertDate() {
+        return mAlertDate;
+    }
+
+    public long getModifiedDate() {
+        return mModifiedDate;
+    }
+
+    public int getBgColorResId() {
+        return NoteBgResources.getNoteBgResource(mBgColorId);
+    }
+
+    public int getBgColorId() {
+        return mBgColorId;
+    }
+
+    public int getTitleBgResId() {
+        return NoteBgResources.getNoteTitleBgResource(mBgColorId);
+    }
+
+    public int getCheckListMode() {
+        return mMode;
+    }
+
+    public long getNoteId() {
+        return mNoteId;
+    }
+
+    public long getFolderId() {
+        return mFolderId;
+    }
+
+    public int getWidgetId() {
+        return mWidgetId;
+    }
+
+    public int getWidgetType() {
+        return mWidgetType;
+    }
+
+    public interface NoteSettingChangedListener {
+        /**
+         * Called when the background color of current note has just changed
+         */
+        void onBackgroundColorChanged();
+
+        /**
+         * Called when user set clock
+         */
+        void onClockAlertChanged(long date, boolean set);
+
+        /**
+         * Call when user create note from widget
+         */
+        void onWidgetChanged();
+
+        /**
+         * Call when switch between check list mode and normal mode
+         * @param oldMode is previous mode before change
+         * @param newMode is new mode
+         */
+        void onCheckListModeChanged(int oldMode, int newMode);
+    }
+}

src/tool/BackupUtils.java

@@ -0,0 +1,344 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.tool;
+
+import android.content.Context;
+import android.database.Cursor;
+import android.os.Environment;
+import android.text.TextUtils;
+import android.text.format.DateFormat;
+import android.util.Log;
+
+import net.micode.notes.R;
+import net.micode.notes.data.Notes;
+import net.micode.notes.data.Notes.DataColumns;
+import net.micode.notes.data.Notes.DataConstants;
+import net.micode.notes.data.Notes.NoteColumns;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.PrintStream;
+
+
+public class BackupUtils {
+    private static final String TAG = "BackupUtils";
+    // Singleton stuff
+    private static BackupUtils sInstance;
+
+    public static synchronized BackupUtils getInstance(Context context) {
+        if (sInstance == null) {
+            sInstance = new BackupUtils(context);
+        }
+        return sInstance;
+    }
+
+    /**
+     * Following states are signs to represents backup or restore
+     * status
+     */
+    // Currently, the sdcard is not mounted
+    public static final int STATE_SD_CARD_UNMOUONTED           = 0;
+    // The backup file not exist
+    public static final int STATE_BACKUP_FILE_NOT_EXIST        = 1;
+    // The data is not well formated, may be changed by other programs
+    public static final int STATE_DATA_DESTROIED               = 2;
+    // Some run-time exception which causes restore or backup fails
+    public static final int STATE_SYSTEM_ERROR                 = 3;
+    // Backup or restore success
+    public static final int STATE_SUCCESS                      = 4;
+
+    private TextExport mTextExport;
+
+    private BackupUtils(Context context) {
+        mTextExport = new TextExport(context);
+    }
+
+    private static boolean externalStorageAvailable() {
+        return Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState());
+    }
+
+    public int exportToText() {
+        return mTextExport.exportToText();
+    }
+
+    public String getExportedTextFileName() {
+        return mTextExport.mFileName;
+    }
+
+    public String getExportedTextFileDir() {
+        return mTextExport.mFileDirectory;
+    }
+
+    private static class TextExport {
+        private static final String[] NOTE_PROJECTION = {
+                NoteColumns.ID,
+                NoteColumns.MODIFIED_DATE,
+                NoteColumns.SNIPPET,
+                NoteColumns.TYPE
+        };
+
+        private static final int NOTE_COLUMN_ID = 0;
+
+        private static final int NOTE_COLUMN_MODIFIED_DATE = 1;
+
+        private static final int NOTE_COLUMN_SNIPPET = 2;
+
+        private static final String[] DATA_PROJECTION = {
+                DataColumns.CONTENT,
+                DataColumns.MIME_TYPE,
+                DataColumns.DATA1,
+                DataColumns.DATA2,
+                DataColumns.DATA3,
+                DataColumns.DATA4,
+        };
+
+        private static final int DATA_COLUMN_CONTENT = 0;
+
+        private static final int DATA_COLUMN_MIME_TYPE = 1;
+
+        private static final int DATA_COLUMN_CALL_DATE = 2;
+
+        private static final int DATA_COLUMN_PHONE_NUMBER = 4;
+
+        private final String [] TEXT_FORMAT;
+        private static final int FORMAT_FOLDER_NAME          = 0;
+        private static final int FORMAT_NOTE_DATE            = 1;
+        private static final int FORMAT_NOTE_CONTENT         = 2;
+
+        private Context mContext;
+        private String mFileName;
+        private String mFileDirectory;
+
+        public TextExport(Context context) {
+            TEXT_FORMAT = context.getResources().getStringArray(R.array.format_for_exported_note);
+            mContext = context;
+            mFileName = "";
+            mFileDirectory = "";
+        }
+
+        private String getFormat(int id) {
+            return TEXT_FORMAT[id];
+        }
+
+        /**
+         * Export the folder identified by folder id to text
+         */
+        private void exportFolderToText(String folderId, PrintStream ps) {
+            // Query notes belong to this folder
+            Cursor notesCursor = mContext.getContentResolver().query(Notes.CONTENT_NOTE_URI,
+                    NOTE_PROJECTION, NoteColumns.PARENT_ID + "=?", new String[] {
+                        folderId
+                    }, null);
+
+            if (notesCursor != null) {
+                if (notesCursor.moveToFirst()) {
+                    do {
+                        // Print note's last modified date
+                        ps.println(String.format(getFormat(FORMAT_NOTE_DATE), DateFormat.format(
+                                mContext.getString(R.string.format_datetime_mdhm),
+                                notesCursor.getLong(NOTE_COLUMN_MODIFIED_DATE))));
+                        // Query data belong to this note
+                        String noteId = notesCursor.getString(NOTE_COLUMN_ID);
+                        exportNoteToText(noteId, ps);
+                    } while (notesCursor.moveToNext());
+                }
+                notesCursor.close();
+            }
+        }
+
+        /**
+         * Export note identified by id to a print stream
+         */
+        private void exportNoteToText(String noteId, PrintStream ps) {
+            Cursor dataCursor = mContext.getContentResolver().query(Notes.CONTENT_DATA_URI,
+                    DATA_PROJECTION, DataColumns.NOTE_ID + "=?", new String[] {
+                        noteId
+                    }, null);
+
+            if (dataCursor != null) {
+                if (dataCursor.moveToFirst()) {
+                    do {
+                        String mimeType = dataCursor.getString(DATA_COLUMN_MIME_TYPE);
+                        if (DataConstants.CALL_NOTE.equals(mimeType)) {
+                            // Print phone number
+                            String phoneNumber = dataCursor.getString(DATA_COLUMN_PHONE_NUMBER);
+                            long callDate = dataCursor.getLong(DATA_COLUMN_CALL_DATE);
+                            String location = dataCursor.getString(DATA_COLUMN_CONTENT);
+
+                            if (!TextUtils.isEmpty(phoneNumber)) {
+                                ps.println(String.format(getFormat(FORMAT_NOTE_CONTENT),
+                                        phoneNumber));
+                            }
+                            // Print call date
+                            ps.println(String.format(getFormat(FORMAT_NOTE_CONTENT), DateFormat
+                                    .format(mContext.getString(R.string.format_datetime_mdhm),
+                                            callDate)));
+                            // Print call attachment location
+                            if (!TextUtils.isEmpty(location)) {
+                                ps.println(String.format(getFormat(FORMAT_NOTE_CONTENT),
+                                        location));
+                            }
+                        } else if (DataConstants.NOTE.equals(mimeType)) {
+                            String content = dataCursor.getString(DATA_COLUMN_CONTENT);
+                            if (!TextUtils.isEmpty(content)) {
+                                ps.println(String.format(getFormat(FORMAT_NOTE_CONTENT),
+                                        content));
+                            }
+                        }
+                    } while (dataCursor.moveToNext());
+                }
+                dataCursor.close();
+            }
+            // print a line separator between note
+            try {
+                ps.write(new byte[] {
+                        Character.LINE_SEPARATOR, Character.LETTER_NUMBER
+                });
+            } catch (IOException e) {
+                Log.e(TAG, e.toString());
+            }
+        }
+
+        /**
+         * Note will be exported as text which is user readable
+         */
+        public int exportToText() {
+            if (!externalStorageAvailable()) {
+                Log.d(TAG, "Media was not mounted");
+                return STATE_SD_CARD_UNMOUONTED;
+            }
+
+            PrintStream ps = getExportToTextPrintStream();
+            if (ps == null) {
+                Log.e(TAG, "get print stream error");
+                return STATE_SYSTEM_ERROR;
+            }
+            // First export folder and its notes
+            Cursor folderCursor = mContext.getContentResolver().query(
+                    Notes.CONTENT_NOTE_URI,
+                    NOTE_PROJECTION,
+                    "(" + NoteColumns.TYPE + "=" + Notes.TYPE_FOLDER + " AND "
+                            + NoteColumns.PARENT_ID + "<>" + Notes.ID_TRASH_FOLER + ") OR "
+                            + NoteColumns.ID + "=" + Notes.ID_CALL_RECORD_FOLDER, null, null);
+
+            if (folderCursor != null) {
+                if (folderCursor.moveToFirst()) {
+                    do {
+                        // Print folder's name
+                        String folderName = "";
+                        if(folderCursor.getLong(NOTE_COLUMN_ID) == Notes.ID_CALL_RECORD_FOLDER) {
+                            folderName = mContext.getString(R.string.call_record_folder_name);
+                        } else {
+                            folderName = folderCursor.getString(NOTE_COLUMN_SNIPPET);
+                        }
+                        if (!TextUtils.isEmpty(folderName)) {
+                            ps.println(String.format(getFormat(FORMAT_FOLDER_NAME), folderName));
+                        }
+                        String folderId = folderCursor.getString(NOTE_COLUMN_ID);
+                        exportFolderToText(folderId, ps);
+                    } while (folderCursor.moveToNext());
+                }
+                folderCursor.close();
+            }
+
+            // Export notes in root's folder
+            Cursor noteCursor = mContext.getContentResolver().query(
+                    Notes.CONTENT_NOTE_URI,
+                    NOTE_PROJECTION,
+                    NoteColumns.TYPE + "=" + +Notes.TYPE_NOTE + " AND " + NoteColumns.PARENT_ID
+                            + "=0", null, null);
+
+            if (noteCursor != null) {
+                if (noteCursor.moveToFirst()) {
+                    do {
+                        ps.println(String.format(getFormat(FORMAT_NOTE_DATE), DateFormat.format(
+                                mContext.getString(R.string.format_datetime_mdhm),
+                                noteCursor.getLong(NOTE_COLUMN_MODIFIED_DATE))));
+                        // Query data belong to this note
+                        String noteId = noteCursor.getString(NOTE_COLUMN_ID);
+                        exportNoteToText(noteId, ps);
+                    } while (noteCursor.moveToNext());
+                }
+                noteCursor.close();
+            }
+            ps.close();
+
+            return STATE_SUCCESS;
+        }
+
+        /**
+         * Get a print stream pointed to the file {@generateExportedTextFile}
+         */
+        private PrintStream getExportToTextPrintStream() {
+            File file = generateFileMountedOnSDcard(mContext, R.string.file_path,
+                    R.string.file_name_txt_format);
+            if (file == null) {
+                Log.e(TAG, "create file to exported failed");
+                return null;
+            }
+            mFileName = file.getName();
+            mFileDirectory = mContext.getString(R.string.file_path);
+            PrintStream ps = null;
+            try {
+                FileOutputStream fos = new FileOutputStream(file);
+                ps = new PrintStream(fos);
+            } catch (FileNotFoundException e) {
+                e.printStackTrace();
+                return null;
+            } catch (NullPointerException e) {
+                e.printStackTrace();
+                return null;
+            }
+            return ps;
+        }
+    }
+
+    /**
+     * Generate the text file to store imported data
+     */
+    private static File generateFileMountedOnSDcard(Context context, int filePathResId, int fileNameFormatResId) {
+        StringBuilder sb = new StringBuilder();
+        sb.append(Environment.getExternalStorageDirectory());
+        sb.append(context.getString(filePathResId));
+        File filedir = new File(sb.toString());
+        sb.append(context.getString(
+                fileNameFormatResId,
+                DateFormat.format(context.getString(R.string.format_date_ymd),
+                        System.currentTimeMillis())));
+        File file = new File(sb.toString());
+
+        try {
+            if (!filedir.exists()) {
+                filedir.mkdir();
+            }
+            if (!file.exists()) {
+                file.createNewFile();
+            }
+            return file;
+        } catch (SecurityException e) {
+            e.printStackTrace();
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+
+        return null;
+    }
+}
+
+

src/tool/DataUtils.java

@@ -0,0 +1,295 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.tool;
+
+import android.content.ContentProviderOperation;
+import android.content.ContentProviderResult;
+import android.content.ContentResolver;
+import android.content.ContentUris;
+import android.content.ContentValues;
+import android.content.OperationApplicationException;
+import android.database.Cursor;
+import android.os.RemoteException;
+import android.util.Log;
+
+import net.micode.notes.data.Notes;
+import net.micode.notes.data.Notes.CallNote;
+import net.micode.notes.data.Notes.NoteColumns;
+import net.micode.notes.ui.NotesListAdapter.AppWidgetAttribute;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+
+
+public class DataUtils {
+    public static final String TAG = "DataUtils";
+    public static boolean batchDeleteNotes(ContentResolver resolver, HashSet<Long> ids) {
+        if (ids == null) {
+            Log.d(TAG, "the ids is null");
+            return true;
+        }
+        if (ids.size() == 0) {
+            Log.d(TAG, "no id is in the hashset");
+            return true;
+        }
+
+        ArrayList<ContentProviderOperation> operationList = new ArrayList<ContentProviderOperation>();
+        for (long id : ids) {
+            if(id == Notes.ID_ROOT_FOLDER) {
+                Log.e(TAG, "Don't delete system folder root");
+                continue;
+            }
+            ContentProviderOperation.Builder builder = ContentProviderOperation
+                    .newDelete(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, id));
+            operationList.add(builder.build());
+        }
+        try {
+            ContentProviderResult[] results = resolver.applyBatch(Notes.AUTHORITY, operationList);
+            if (results == null || results.length == 0 || results[0] == null) {
+                Log.d(TAG, "delete notes failed, ids:" + ids.toString());
+                return false;
+            }
+            return true;
+        } catch (RemoteException e) {
+            Log.e(TAG, String.format("%s: %s", e.toString(), e.getMessage()));
+        } catch (OperationApplicationException e) {
+            Log.e(TAG, String.format("%s: %s", e.toString(), e.getMessage()));
+        }
+        return false;
+    }
+
+    public static void moveNoteToFoler(ContentResolver resolver, long id, long srcFolderId, long desFolderId) {
+        ContentValues values = new ContentValues();
+        values.put(NoteColumns.PARENT_ID, desFolderId);
+        values.put(NoteColumns.ORIGIN_PARENT_ID, srcFolderId);
+        values.put(NoteColumns.LOCAL_MODIFIED, 1);
+        resolver.update(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, id), values, null, null);
+    }
+
+    public static boolean batchMoveToFolder(ContentResolver resolver, HashSet<Long> ids,
+            long folderId) {
+        if (ids == null) {
+            Log.d(TAG, "the ids is null");
+            return true;
+        }
+
+        ArrayList<ContentProviderOperation> operationList = new ArrayList<ContentProviderOperation>();
+        for (long id : ids) {
+            ContentProviderOperation.Builder builder = ContentProviderOperation
+                    .newUpdate(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, id));
+            builder.withValue(NoteColumns.PARENT_ID, folderId);
+            builder.withValue(NoteColumns.LOCAL_MODIFIED, 1);
+            operationList.add(builder.build());
+        }
+
+        try {
+            ContentProviderResult[] results = resolver.applyBatch(Notes.AUTHORITY, operationList);
+            if (results == null || results.length == 0 || results[0] == null) {
+                Log.d(TAG, "delete notes failed, ids:" + ids.toString());
+                return false;
+            }
+            return true;
+        } catch (RemoteException e) {
+            Log.e(TAG, String.format("%s: %s", e.toString(), e.getMessage()));
+        } catch (OperationApplicationException e) {
+            Log.e(TAG, String.format("%s: %s", e.toString(), e.getMessage()));
+        }
+        return false;
+    }
+
+    /**
+     * Get the all folder count except system folders {@link Notes#TYPE_SYSTEM}}
+     */
+    public static int getUserFolderCount(ContentResolver resolver) {
+        Cursor cursor =resolver.query(Notes.CONTENT_NOTE_URI,
+                new String[] { "COUNT(*)" },
+                NoteColumns.TYPE + "=? AND " + NoteColumns.PARENT_ID + "<>?",
+                new String[] { String.valueOf(Notes.TYPE_FOLDER), String.valueOf(Notes.ID_TRASH_FOLER)},
+                null);
+
+        int count = 0;
+        if(cursor != null) {
+            if(cursor.moveToFirst()) {
+                try {
+                    count = cursor.getInt(0);
+                } catch (IndexOutOfBoundsException e) {
+                    Log.e(TAG, "get folder count failed:" + e.toString());
+                } finally {
+                    cursor.close();
+                }
+            }
+        }
+        return count;
+    }
+
+    public static boolean visibleInNoteDatabase(ContentResolver resolver, long noteId, int type) {
+        Cursor cursor = resolver.query(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId),
+                null,
+                NoteColumns.TYPE + "=? AND " + NoteColumns.PARENT_ID + "<>" + Notes.ID_TRASH_FOLER,
+                new String [] {String.valueOf(type)},
+                null);
+
+        boolean exist = false;
+        if (cursor != null) {
+            if (cursor.getCount() > 0) {
+                exist = true;
+            }
+            cursor.close();
+        }
+        return exist;
+    }
+
+    public static boolean existInNoteDatabase(ContentResolver resolver, long noteId) {
+        Cursor cursor = resolver.query(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId),
+                null, null, null, null);
+
+        boolean exist = false;
+        if (cursor != null) {
+            if (cursor.getCount() > 0) {
+                exist = true;
+            }
+            cursor.close();
+        }
+        return exist;
+    }
+
+    public static boolean existInDataDatabase(ContentResolver resolver, long dataId) {
+        Cursor cursor = resolver.query(ContentUris.withAppendedId(Notes.CONTENT_DATA_URI, dataId),
+                null, null, null, null);
+
+        boolean exist = false;
+        if (cursor != null) {
+            if (cursor.getCount() > 0) {
+                exist = true;
+            }
+            cursor.close();
+        }
+        return exist;
+    }
+
+    public static boolean checkVisibleFolderName(ContentResolver resolver, String name) {
+        Cursor cursor = resolver.query(Notes.CONTENT_NOTE_URI, null,
+                NoteColumns.TYPE + "=" + Notes.TYPE_FOLDER +
+                " AND " + NoteColumns.PARENT_ID + "<>" + Notes.ID_TRASH_FOLER +
+                " AND " + NoteColumns.SNIPPET + "=?",
+                new String[] { name }, null);
+        boolean exist = false;
+        if(cursor != null) {
+            if(cursor.getCount() > 0) {
+                exist = true;
+            }
+            cursor.close();
+        }
+        return exist;
+    }
+
+    public static HashSet<AppWidgetAttribute> getFolderNoteWidget(ContentResolver resolver, long folderId) {
+        Cursor c = resolver.query(Notes.CONTENT_NOTE_URI,
+                new String[] { NoteColumns.WIDGET_ID, NoteColumns.WIDGET_TYPE },
+                NoteColumns.PARENT_ID + "=?",
+                new String[] { String.valueOf(folderId) },
+                null);
+
+        HashSet<AppWidgetAttribute> set = null;
+        if (c != null) {
+            if (c.moveToFirst()) {
+                set = new HashSet<AppWidgetAttribute>();
+                do {
+                    try {
+                        AppWidgetAttribute widget = new AppWidgetAttribute();
+                        widget.widgetId = c.getInt(0);
+                        widget.widgetType = c.getInt(1);
+                        set.add(widget);
+                    } catch (IndexOutOfBoundsException e) {
+                        Log.e(TAG, e.toString());
+                    }
+                } while (c.moveToNext());
+            }
+            c.close();
+        }
+        return set;
+    }
+
+    public static String getCallNumberByNoteId(ContentResolver resolver, long noteId) {
+        Cursor cursor = resolver.query(Notes.CONTENT_DATA_URI,
+                new String [] { CallNote.PHONE_NUMBER },
+                CallNote.NOTE_ID + "=? AND " + CallNote.MIME_TYPE + "=?",
+                new String [] { String.valueOf(noteId), CallNote.CONTENT_ITEM_TYPE },
+                null);
+
+        if (cursor != null && cursor.moveToFirst()) {
+            try {
+                return cursor.getString(0);
+            } catch (IndexOutOfBoundsException e) {
+                Log.e(TAG, "Get call number fails " + e.toString());
+            } finally {
+                cursor.close();
+            }
+        }
+        return "";
+    }
+
+    public static long getNoteIdByPhoneNumberAndCallDate(ContentResolver resolver, String phoneNumber, long callDate) {
+        Cursor cursor = resolver.query(Notes.CONTENT_DATA_URI,
+                new String [] { CallNote.NOTE_ID },
+                CallNote.CALL_DATE + "=? AND " + CallNote.MIME_TYPE + "=? AND PHONE_NUMBERS_EQUAL("
+                + CallNote.PHONE_NUMBER + ",?)",
+                new String [] { String.valueOf(callDate), CallNote.CONTENT_ITEM_TYPE, phoneNumber },
+                null);
+
+        if (cursor != null) {
+            if (cursor.moveToFirst()) {
+                try {
+                    return cursor.getLong(0);
+                } catch (IndexOutOfBoundsException e) {
+                    Log.e(TAG, "Get call note id fails " + e.toString());
+                }
+            }
+            cursor.close();
+        }
+        return 0;
+    }
+
+    public static String getSnippetById(ContentResolver resolver, long noteId) {
+        Cursor cursor = resolver.query(Notes.CONTENT_NOTE_URI,
+                new String [] { NoteColumns.SNIPPET },
+                NoteColumns.ID + "=?",
+                new String [] { String.valueOf(noteId)},
+                null);
+
+        if (cursor != null) {
+            String snippet = "";
+            if (cursor.moveToFirst()) {
+                snippet = cursor.getString(0);
+            }
+            cursor.close();
+            return snippet;
+        }
+        throw new IllegalArgumentException("Note is not found with id: " + noteId);
+    }
+
+    public static String getFormattedSnippet(String snippet) {
+        if (snippet != null) {
+            snippet = snippet.trim();
+            int index = snippet.indexOf('\n');
+            if (index != -1) {
+                snippet = snippet.substring(0, index);
+            }
+        }
+        return snippet;
+    }
+}

src/tool/GTaskStringUtils.java

@@ -0,0 +1,113 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.tool;
+
+public class GTaskStringUtils {
+
+    public final static String GTASK_JSON_ACTION_ID = "action_id";
+
+    public final static String GTASK_JSON_ACTION_LIST = "action_list";
+
+    public final static String GTASK_JSON_ACTION_TYPE = "action_type";
+
+    public final static String GTASK_JSON_ACTION_TYPE_CREATE = "create";
+
+    public final static String GTASK_JSON_ACTION_TYPE_GETALL = "get_all";
+
+    public final static String GTASK_JSON_ACTION_TYPE_MOVE = "move";
+
+    public final static String GTASK_JSON_ACTION_TYPE_UPDATE = "update";
+
+    public final static String GTASK_JSON_CREATOR_ID = "creator_id";
+
+    public final static String GTASK_JSON_CHILD_ENTITY = "child_entity";
+
+    public final static String GTASK_JSON_CLIENT_VERSION = "client_version";
+
+    public final static String GTASK_JSON_COMPLETED = "completed";
+
+    public final static String GTASK_JSON_CURRENT_LIST_ID = "current_list_id";
+
+    public final static String GTASK_JSON_DEFAULT_LIST_ID = "default_list_id";
+
+    public final static String GTASK_JSON_DELETED = "deleted";
+
+    public final static String GTASK_JSON_DEST_LIST = "dest_list";
+
+    public final static String GTASK_JSON_DEST_PARENT = "dest_parent";
+
+    public final static String GTASK_JSON_DEST_PARENT_TYPE = "dest_parent_type";
+
+    public final static String GTASK_JSON_ENTITY_DELTA = "entity_delta";
+
+    public final static String GTASK_JSON_ENTITY_TYPE = "entity_type";
+
+    public final static String GTASK_JSON_GET_DELETED = "get_deleted";
+
+    public final static String GTASK_JSON_ID = "id";
+
+    public final static String GTASK_JSON_INDEX = "index";
+
+    public final static String GTASK_JSON_LAST_MODIFIED = "last_modified";
+
+    public final static String GTASK_JSON_LATEST_SYNC_POINT = "latest_sync_point";
+
+    public final static String GTASK_JSON_LIST_ID = "list_id";
+
+    public final static String GTASK_JSON_LISTS = "lists";
+
+    public final static String GTASK_JSON_NAME = "name";
+
+    public final static String GTASK_JSON_NEW_ID = "new_id";
+
+    public final static String GTASK_JSON_NOTES = "notes";
+
+    public final static String GTASK_JSON_PARENT_ID = "parent_id";
+
+    public final static String GTASK_JSON_PRIOR_SIBLING_ID = "prior_sibling_id";
+
+    public final static String GTASK_JSON_RESULTS = "results";
+
+    public final static String GTASK_JSON_SOURCE_LIST = "source_list";
+
+    public final static String GTASK_JSON_TASKS = "tasks";
+
+    public final static String GTASK_JSON_TYPE = "type";
+
+    public final static String GTASK_JSON_TYPE_GROUP = "GROUP";
+
+    public final static String GTASK_JSON_TYPE_TASK = "TASK";
+
+    public final static String GTASK_JSON_USER = "user";
+
+    public final static String MIUI_FOLDER_PREFFIX = "[MIUI_Notes]";
+
+    public final static String FOLDER_DEFAULT = "Default";
+
+    public final static String FOLDER_CALL_NOTE = "Call_Note";
+
+    public final static String FOLDER_META = "METADATA";
+
+    public final static String META_HEAD_GTASK_ID = "meta_gid";
+
+    public final static String META_HEAD_NOTE = "meta_note";
+
+    public final static String META_HEAD_DATA = "meta_data";
+
+    public final static String META_NOTE_NAME = "[META INFO] DON'T UPDATE AND DELETE";
+
+}

src/tool/ResourceParser.java

@@ -0,0 +1,181 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.tool;
+
+import android.content.Context;
+import android.preference.PreferenceManager;
+
+import net.micode.notes.R;
+import net.micode.notes.ui.NotesPreferenceActivity;
+
+public class ResourceParser {
+
+    public static final int YELLOW           = 0;
+    public static final int BLUE             = 1;
+    public static final int WHITE            = 2;
+    public static final int GREEN            = 3;
+    public static final int RED              = 4;
+
+    public static final int BG_DEFAULT_COLOR = YELLOW;
+
+    public static final int TEXT_SMALL       = 0;
+    public static final int TEXT_MEDIUM      = 1;
+    public static final int TEXT_LARGE       = 2;
+    public static final int TEXT_SUPER       = 3;
+
+    public static final int BG_DEFAULT_FONT_SIZE = TEXT_MEDIUM;
+
+    public static class NoteBgResources {
+        private final static int [] BG_EDIT_RESOURCES = new int [] {
+            R.drawable.edit_yellow,
+            R.drawable.edit_blue,
+            R.drawable.edit_white,
+            R.drawable.edit_green,
+            R.drawable.edit_red
+        };
+
+        private final static int [] BG_EDIT_TITLE_RESOURCES = new int [] {
+            R.drawable.edit_title_yellow,
+            R.drawable.edit_title_blue,
+            R.drawable.edit_title_white,
+            R.drawable.edit_title_green,
+            R.drawable.edit_title_red
+        };
+
+        public static int getNoteBgResource(int id) {
+            return BG_EDIT_RESOURCES[id];
+        }
+
+        public static int getNoteTitleBgResource(int id) {
+            return BG_EDIT_TITLE_RESOURCES[id];
+        }
+    }
+
+    public static int getDefaultBgId(Context context) {
+        if (PreferenceManager.getDefaultSharedPreferences(context).getBoolean(
+                NotesPreferenceActivity.PREFERENCE_SET_BG_COLOR_KEY, false)) {
+            return (int) (Math.random() * NoteBgResources.BG_EDIT_RESOURCES.length);
+        } else {
+            return BG_DEFAULT_COLOR;
+        }
+    }
+
+    public static class NoteItemBgResources {
+        private final static int [] BG_FIRST_RESOURCES = new int [] {
+            R.drawable.list_yellow_up,
+            R.drawable.list_blue_up,
+            R.drawable.list_white_up,
+            R.drawable.list_green_up,
+            R.drawable.list_red_up
+        };
+
+        private final static int [] BG_NORMAL_RESOURCES = new int [] {
+            R.drawable.list_yellow_middle,
+            R.drawable.list_blue_middle,
+            R.drawable.list_white_middle,
+            R.drawable.list_green_middle,
+            R.drawable.list_red_middle
+        };
+
+        private final static int [] BG_LAST_RESOURCES = new int [] {
+            R.drawable.list_yellow_down,
+            R.drawable.list_blue_down,
+            R.drawable.list_white_down,
+            R.drawable.list_green_down,
+            R.drawable.list_red_down,
+        };
+
+        private final static int [] BG_SINGLE_RESOURCES = new int [] {
+            R.drawable.list_yellow_single,
+            R.drawable.list_blue_single,
+            R.drawable.list_white_single,
+            R.drawable.list_green_single,
+            R.drawable.list_red_single
+        };
+
+        public static int getNoteBgFirstRes(int id) {
+            return BG_FIRST_RESOURCES[id];
+        }
+
+        public static int getNoteBgLastRes(int id) {
+            return BG_LAST_RESOURCES[id];
+        }
+
+        public static int getNoteBgSingleRes(int id) {
+            return BG_SINGLE_RESOURCES[id];
+        }
+
+        public static int getNoteBgNormalRes(int id) {
+            return BG_NORMAL_RESOURCES[id];
+        }
+
+        public static int getFolderBgRes() {
+            return R.drawable.list_folder;
+        }
+    }
+
+    public static class WidgetBgResources {
+        private final static int [] BG_2X_RESOURCES = new int [] {
+            R.drawable.widget_2x_yellow,
+            R.drawable.widget_2x_blue,
+            R.drawable.widget_2x_white,
+            R.drawable.widget_2x_green,
+            R.drawable.widget_2x_red,
+        };
+
+        public static int getWidget2xBgResource(int id) {
+            return BG_2X_RESOURCES[id];
+        }
+
+        private final static int [] BG_4X_RESOURCES = new int [] {
+            R.drawable.widget_4x_yellow,
+            R.drawable.widget_4x_blue,
+            R.drawable.widget_4x_white,
+            R.drawable.widget_4x_green,
+            R.drawable.widget_4x_red
+        };
+
+        public static int getWidget4xBgResource(int id) {
+            return BG_4X_RESOURCES[id];
+        }
+    }
+
+    public static class TextAppearanceResources {
+        private final static int [] TEXTAPPEARANCE_RESOURCES = new int [] {
+            R.style.TextAppearanceNormal,
+            R.style.TextAppearanceMedium,
+            R.style.TextAppearanceLarge,
+            R.style.TextAppearanceSuper
+        };
+
+        public static int getTexAppearanceResource(int id) {
+            /**
+             * HACKME: Fix bug of store the resource id in shared preference.
+             * The id may larger than the length of resources, in this case,
+             * return the {@link ResourceParser#BG_DEFAULT_FONT_SIZE}
+             */
+            if (id >= TEXTAPPEARANCE_RESOURCES.length) {
+                return BG_DEFAULT_FONT_SIZE;
+            }
+            return TEXTAPPEARANCE_RESOURCES[id];
+        }
+
+        public static int getResourcesSize() {
+            return TEXTAPPEARANCE_RESOURCES.length;
+        }
+    }
+}