README.md

@@ -1,2 +0,0 @@
-# xiaomi
-

src/model/Note.java

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+
+
+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

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+
+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) {//定义了一个私有构造函数，接受context和long类型的folderid作为参数。
+        mContext = context;//将传入的上下文赋值给类的成员变量mcontext
+        mAlertDate = 0;//将提醒日期初始化为0，表示当前没有设置提醒。
+        mModifiedDate = System.currentTimeMillis();//获取当前时间戳，并赋值给mmodifieddate，用于记录笔记的修改时间
+        mFolderId = folderId;
+        mNote = new Note();//创建一个类的实例并赋值
+        mNoteId = 0;//初始化为零
+        mIsDeleted = false;
+        mMode = 0;
+        mWidgetType = Notes.TYPE_WIDGET_INVALIDE;//将小部件类型设置为无效类型，表明当前笔记关联的小部件状态无效。
+    }
+
+    // Existing note construct
+    private WorkingNote(Context context, long noteId, long folderId) {
+        mContext = context;
+        mNoteId = noteId;//明确初始化
+        mFolderId = folderId;
+        mIsDeleted = false;
+        mNote = new Note();
+        loadNote();//此时mnoteid已可用
+    }
+
+    private void loadNote() {//定义了一个私有的方法
+        Cursor cursor = mContext.getContentResolver().query(
+                ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, mNoteId), NOTE_PROJECTION, null,
+                null, null);//定义好的表示笔记数据的内容URI，将mnoteid附加到该URI上，形成一个特定笔记的查询URI，都设null表示不指定额外条件和排序，查询结果会返回一个cursor对象，用于遍历查询得到的数据行
+
+        if (cursor != null) {//判断查询结果
+            if (cursor.moveToFirst()) {//将游标移动到查询结果集的第一行，若成功则进入这个if块执行后续操作
+                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);//从查询结果的当前行中获取不同属性的值，并赋值给类的相应成员变量
+            }
+            cursor.close();
+        } else {
+            Log.e(TAG, "No note with id:" + mNoteId);
+            throw new IllegalArgumentException("Unable to find note with id " + mNoteId);//若返回说明查询结果集为空，此时通过Log.e方法打印错误日志，然后抛出异常，提示找不到指定的ID笔记
+        }
+        loadNoteData();
+    }
+
+    private void loadNoteData() {//定义了一个私有方法
+        Cursor cursor = mContext.getContentResolver().query(Notes.CONTENT_DATA_URI, DATA_PROJECTION,
+                DataColumns.NOTE_ID + "=?", new String[] {
+                    String.valueOf(mNoteId)
+                }, null);//表示数据所在的位置，指定要从查询结果中返回的列，查询NOTE-ID列等于某个值的记录，？会被后面的参数替换
+
+        if (cursor != null) {//查询是否为空
+            if (cursor.moveToFirst()) {
+                do {
+                    String type = cursor.getString(DATA_MIME_TYPE_COLUMN);//从当前行获取数据的MIME类型，存储在type变量中
+                    if (DataConstants.NOTE.equals(type)) {
+                        mContent = cursor.getString(DATA_CONTENT_COLUMN);//获取笔记内容并赋值给mcontent
+                        mMode = cursor.getInt(DATA_MODE_COLUMN);//获取笔记内容并赋值
+                        mNote.setTextDataId(cursor.getLong(DATA_ID_COLUMN));//从当前行获取数据ID并设置到mnote对象中
+                    } else if (DataConstants.CALL_NOTE.equals(type)) {
+                        mNote.setCallDataId(cursor.getLong(DATA_ID_COLUMN));//判断如果是通话笔记类型，则获取数据ID并设置到mnote对象的数据ID属性中
+                    } 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);
+        }
+    }//若查询结果集为空，没有找到对性的mnoteid的数据，此时提示找不到指定的ID的笔记数据
+
+    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;
+    }//创建一个空的workingnote对象分别调用三种方法，设置笔记的背景颜色ID,小部件ID和小部件类型
+
+    public static WorkingNote load(Context context, long id) {
+        return new WorkingNote(context, id, 0);
+    }//接收context和id作为参数，直接通过调用对应的构造函数创建并返回一个working note对象，这三个参数含义需结合构造函数具体逻辑确定，推测可能是默认的文件夹id或其他默认标识
+
+    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;
+        }//判断笔记是否值得保存，接着判断笔记是否已存在于数据库中，如果不存在，调用函数获取一个新的笔记ID，并赋值给mnoteid，若获取id为0，说明创建笔记id失败，之后并将笔记数据同步到数据库
+        
+    }
+
+    public boolean existInDatabase() {
+        return mNoteId > 0;
+    }//判断成员变量mnotedid是否大于0来确定，大于0则认为存在于数据库，直接返回该判断结果
+
+    private boolean isWorthSaving() {
+        if (mIsDeleted || (!existInDatabase() && TextUtils.isEmpty(mContent))
+                || (existInDatabase() && !mNote.isLocalModified())) {
+            return false;
+        } else {
+            return true;
+        }
+    }//通过多个条件组合判断，若满足任一条件则返回false，表示不值得保存
+
+    public void setOnSettingStatusChangedListener(NoteSettingChangedListener l) {
+        mNoteSettingStatusListener = l;
+    }//接受一个类型的参数1，并将其赋值给成员变量，以便在相关设置状态改变时出发监听器的方法
+
+    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);
+        }
+    }//判断传入日期与当前记录的提醒日期是否不同，若不同，将提醒日期更新传入date，检查是否为空，若不为空调用其方法，通过监听器提醒日期已改变，并传入新日期和设置标识
+
+    public void markDeleted(boolean mark) {
+        mIsDeleted = mark;
+        if (mWidgetId != AppWidgetManager.INVALID_APPWIDGET_ID
+                && mWidgetType != Notes.TYPE_WIDGET_INVALIDE && mNoteSettingStatusListener != null) {
+                mNoteSettingStatusListener.onWidgetChanged();
+        }
+    }//用于标识笔记是否已删除，并在满足特定条件时通知监听器
+
+
+    public void setBgColorId(int id) {
+        if (id != mBgColorId) {
+            mBgColorId = id;
+            if (mNoteSettingStatusListener != null) {
+                mNoteSettingStatusListener.onBackgroundColorChanged();
+            }
+            mNote.setNoteValue(NoteColumns.BG_COLOR_ID, String.valueOf(id));
+        }
+    }//用于设置笔记的背景ID并在必要时通知监听器以及更新笔记数据
+    public void setCheckListMode(int mode) {
+        if (mMode != mode) {
+            if (mNoteSettingStatusListener != null) {
+                mNoteSettingStatusListener.onCheckListModeChanged(mMode, mode);
+            }
+            mMode = mode;
+            mNote.setTextData(TextNote.MODE, String.valueOf(mMode));
+        }
+    }//用于设置笔记的清单模式，并在必要时通知监听器以及更新笔记数据
+
+    public void setWidgetType(int type) {
+        if (type != mWidgetType) {
+            mWidgetType = type;
+            mNote.setNoteValue(NoteColumns.WIDGET_TYPE, String.valueOf(mWidgetType));
+        }
+    }//用于设置笔记关联小部件的类型
+
+    public void setWidgetId(int id) {
+        if (id != mWidgetId) {
+            mWidgetId = id;
+            mNote.setNoteValue(NoteColumns.WIDGET_ID, String.valueOf(mWidgetId));
+        }
+    }//用于设置笔记关联小部件的ID
+
+    public void setWorkingText(String text) {
+        if (!TextUtils.equals(mContent, text)) {
+            mContent = text;
+            mNote.setTextData(DataColumns.CONTENT, mContent);
+        }
+    }//用于设置笔记的文本内容
+
+    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));
+    }//将当前笔记转换为通话笔记设置相关通话信息
+
+    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/widget/NoteWidgetProvider.java

@@ -0,0 +1,137 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ 
+ *        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.
+ */
+//这段代码是一个Android App Widget的抽象基类NotewidgetProvider,用于管理笔记类小部件的通用逻辑，支持不同尺寸和样式的小部件2x、4x
+/*这段代码是笔记类小部件的核心实现，通过抽象基类统一管理数据绑定和交互逻辑，
+子类只需关注布局和资源的差异化。其设计体现了高内聚、低耦合的原则，
+适合扩展多尺寸小部件。实际使用时需确保数据库查询的效率和线程安全。*/
+package net.micode.notes.widget;
+import android.app.PendingIntent;
+import android.appwidget.AppWidgetManager;
+import android.appwidget.AppWidgetProvider;
+import android.content.ContentValues;
+import android.content.Context;
+import android.content.Intent;
+import android.database.Cursor;
+import android.util.Log;
+import android.widget.RemoteViews;
+
+import net.micode.notes.R;
+import net.micode.notes.data.Notes;
+import net.micode.notes.data.Notes.NoteColumns;
+import net.micode.notes.tool.ResourceParser;
+import net.micode.notes.ui.NoteEditActivity;
+import net.micode.notes.ui.NotesListActivity;
+
+public abstract class NoteWidgetProvider extends AppWidgetProvider {
+    public static final String [] PROJECTION = new String [] {
+        NoteColumns.ID,
+        NoteColumns.BG_COLOR_ID,
+        NoteColumns.SNIPPET
+    };
+
+    public static final int COLUMN_ID           = 0;
+    public static final int COLUMN_BG_COLOR_ID  = 1;
+    public static final int COLUMN_SNIPPET      = 2;
+
+    private static final String TAG = "NoteWidgetProvider";
+
+    @Override
+    public void onDeleted(Context context, int[] appWidgetIds) {
+        ContentValues values = new ContentValues();
+        values.put(NoteColumns.WIDGET_ID, AppWidgetManager.INVALID_APPWIDGET_ID);
+        for (int i = 0; i < appWidgetIds.length; i++) {
+            context.getContentResolver().update(Notes.CONTENT_NOTE_URI,
+                    values,
+                    NoteColumns.WIDGET_ID + "=?",
+                    new String[] { String.valueOf(appWidgetIds[i])});
+        }
+    }//当小部件删除时，清除数据库中关联的widgetId
+
+    private Cursor getNoteWidgetInfo(Context context, int widgetId) {
+        return context.getContentResolver().query(Notes.CONTENT_NOTE_URI,
+                PROJECTION,
+                NoteColumns.WIDGET_ID + "=? AND " + NoteColumns.PARENT_ID + "<>?",
+                new String[] { String.valueOf(widgetId), String.valueOf(Notes.ID_TRASH_FOLER) },
+                null);
+    }//根据widgetId查询关联的笔记数据，排除已放入垃圾桶的笔记
+
+    protected void update(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
+        update(context, appWidgetManager, appWidgetIds, false);
+    }
+
+    private void update(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds,
+            boolean privacyMode) {
+        for (int i = 0; i < appWidgetIds.length; i++) {
+            if (appWidgetIds[i] != AppWidgetManager.INVALID_APPWIDGET_ID) {
+                //初始化默认值
+                int bgId = ResourceParser.getDefaultBgId(context);
+                String snippet = "";
+                Intent intent = new Intent(context, NoteEditActivity.class);
+                intent.setFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP);
+                intent.putExtra(Notes.INTENT_EXTRA_WIDGET_ID, appWidgetIds[i]);
+                intent.putExtra(Notes.INTENT_EXTRA_WIDGET_TYPE, getWidgetType());
+                //查询数据库获取笔记数据
+                Cursor c = getNoteWidgetInfo(context, appWidgetIds[i]);
+                if (c != null && c.moveToFirst()) {
+                    if (c.getCount() > 1) {
+                        Log.e(TAG, "Multiple message with same widget id:" + appWidgetIds[i]);
+                        c.close();
+                        return;
+                    }
+                    snippet = c.getString(COLUMN_SNIPPET);
+                    bgId = c.getInt(COLUMN_BG_COLOR_ID);
+                    intent.putExtra(Intent.EXTRA_UID, c.getLong(COLUMN_ID));
+                    intent.setAction(Intent.ACTION_VIEW);
+                } else {
+                    snippet = context.getResources().getString(R.string.widget_havenot_content);
+                    intent.setAction(Intent.ACTION_INSERT_OR_EDIT);
+                }
+
+                if (c != null) {
+                    c.close();
+                }
+                //构建RemoteViews
+                RemoteViews rv = new RemoteViews(context.getPackageName(), getLayoutId());
+                rv.setImageViewResource(R.id.widget_bg_image, getBgResourceId(bgId));
+                intent.putExtra(Notes.INTENT_EXTRA_BACKGROUND_ID, bgId);
+                /**
+                 * Generate the pending intent to start host for the widget
+                 */
+                //设置点击事件
+                PendingIntent pendingIntent = null;
+                if (privacyMode) {
+                    rv.setTextViewText(R.id.widget_text,
+                            context.getString(R.string.widget_under_visit_mode));
+                    pendingIntent = PendingIntent.getActivity(context, appWidgetIds[i], new Intent(
+                            context, NotesListActivity.class), PendingIntent.FLAG_UPDATE_CURRENT);
+                } else {
+                    rv.setTextViewText(R.id.widget_text, snippet);
+                    pendingIntent = PendingIntent.getActivity(context, appWidgetIds[i], intent,
+                            PendingIntent.FLAG_UPDATE_CURRENT);
+                }
+
+                rv.setOnClickPendingIntent(R.id.widget_text, pendingIntent);
+                //更新小部件
+                appWidgetManager.updateAppWidget(appWidgetIds[i], rv);
+            }
+        }
+    }
+
+    protected abstract int getBgResourceId(int bgId);
+    //获取背景资源
+    protected abstract int getLayoutId();
+    //获取布局文件
+    protected abstract int getWidgetType();
+    //获取小部件类型
+}

src/widget/NoteWidgetProvider_2x.java

@@ -0,0 +1,37 @@
+
+//主要功能包括：
+//指定2x小部件使用布局
+//提供2x小部件专用的背景资源
+//标识小部件类型为2x尺寸
+//处理小部件更新逻辑
+package net.micode.notes.widget;
+
+import android.appwidget.AppWidgetManager;
+import android.content.Context;
+
+import net.micode.notes.R;
+import net.micode.notes.data.Notes;
+import net.micode.notes.tool.ResourceParser;
+
+
+public class NoteWidgetProvider_2x extends NoteWidgetProvider {//继承自NotewidgetProvider，专门处理2x尺寸的小部件
+    @Override
+    public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
+        super.update(context, appWidgetManager, appWidgetIds);
+    }//这是APP widget 的核心方法，当小部件需要更新时调用，直接调用父类的update方法更新逻辑
+
+    @Override
+    protected int getLayoutId() {
+        return R.layout.widget_2x;
+    }//返回2x尺寸小部件使用布局资源ID（R.layout.widget_2x)
+
+    @Override
+    protected int getBgResourceId(int bgId) {
+        return ResourceParser.WidgetBgResources.getWidget2xBgResource(bgId);
+    }//根据背景ID返回对应的2X尺寸资源
+
+    @Override
+    protected int getWidgetType() {
+        return Notes.TYPE_WIDGET_2X;
+    }//用于标识这个2x尺寸的小部件
+}

src/widget/NoteWidgetProvider_4x.java

@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+
+ *
+ * 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.
+ */
+//这段代码是一个 Android App Widget （应用小部件）的提供者类，专门用于处理 4x 尺寸的笔记小部件
+//(NotewidgetProvider_4x)。它是NotewidgetProvider 的子类，主要功能是为 4x 尺寸的小部件提供特定的布局、背景资源和类型标识
+package net.micode.notes.widget;
+
+import android.appwidget.AppWidgetManager;
+import android.content.Context;
+
+import net.micode.notes.R;
+import net.micode.notes.data.Notes;
+import net.micode.notes.tool.ResourceParser;
+
+
+public class NoteWidgetProvider_4x extends NoteWidgetProvider {
+    @Override
+    public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
+        super.update(context, appWidgetManager, appWidgetIds);
+    }//当小部件需要更新时调用，直接委托父类处理逻辑
+
+    protected int getLayoutId() {
+        return R.layout.widget_4x;
+    }//返回4x小部件的布局文件R.layout.widget_4x,定义界面结构
+
+    @Override
+    protected int getBgResourceId(int bgId) {
+        return ResourceParser.WidgetBgResources.getWidget4xBgResource(bgId);
+    }//根据背景ID返回对应的4X尺寸背景资源
+
+    @Override
+    protected int getWidgetType() {
+        return Notes.TYPE_WIDGET_4X;
+    }//返回常量Notes.TYPE_WIDGET_4x
+}