Added comments to the data package

src/Notes/app/src/main/java/net/micode/notes/data/Notes.java

@@ -17,9 +17,11 @@
 package net.micode.notes.data;
 
 import android.net.Uri;
+//Notes类就定义了很多常量，是小米便签的数据库
 public class Notes {
     public static final String AUTHORITY = "micode_notes";
     public static final String TAG = "Notes";
+    //三个type
     public static final int TYPE_NOTE     = 0;
     public static final int TYPE_FOLDER   = 1;
     public static final int TYPE_SYSTEM   = 2;
@@ -30,6 +32,7 @@ public class Notes {
      * {@link Notes#ID_TEMPARAY_FOLDER } is for notes belonging no folder
      * {@link Notes#ID_CALL_RECORD_FOLDER} is to store call records
      */
+    //不同种类的文件夹
     public static final int ID_ROOT_FOLDER = 0;
     public static final int ID_TEMPARAY_FOLDER = -1;
     public static final int ID_CALL_RECORD_FOLDER = -2;
@@ -45,12 +48,12 @@ public class Notes {
     public static final int TYPE_WIDGET_INVALIDE      = -1;
     public static final int TYPE_WIDGET_2X            = 0;
     public static final int TYPE_WIDGET_4X            = 1;
-
+    //数据常量 包括普通note和call_note
     public static class DataConstants {
         public static final String NOTE = TextNote.CONTENT_ITEM_TYPE;
         public static final String CALL_NOTE = CallNote.CONTENT_ITEM_TYPE;
     }
-
+    //两个指针，一个找便签和文件夹，一个用来找数据
     /**
      * Uri to query all notes and folders
      */
@@ -59,9 +62,11 @@ public class Notes {
     /**
      * Uri to query data
      */
-    public static final Uri CONTENT_DATA_URI = Uri.parse("content://" + AUTHORITY + "/data");
 
+    public static final Uri CONTENT_DATA_URI = Uri.parse("content://" + AUTHORITY + "/data");
+    //Notecolumns类，用于创建数据库的表头
     public interface NoteColumns {
+        //具体每一项都给了英文注释
         /**
          * The unique ID for a row
          * <P> Type: INTEGER (long) </P>
@@ -169,7 +174,7 @@ public class Notes {
         public static final String PASSWORD = "password";
 
         public static final String IMPORTANCE = "importance";
-    }
+    }//便签的各种属性
     /*
      * 便签数据在数据库中的表头
      */
@@ -245,7 +250,7 @@ public class Notes {
          * <P> Type: TEXT </P>
          */
         public static final String DATA5 = "data5";
-    }
+    }//一个便签内部各种数据类型
 
     public static final class TextNote implements DataColumns {
         /**
@@ -261,7 +266,7 @@ public class Notes {
         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");
-    }
+    }//一种是文本textnote
 
     public static final class CallNote implements DataColumns {
         /**
@@ -281,5 +286,5 @@ public class Notes {
         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");
-    }
+    }//另一种是通话类型的callnote
 }

src/Notes/app/src/main/java/net/micode/notes/data/NotesDatabaseHelper.java

@@ -21,17 +21,17 @@ import android.content.Context;
 import android.database.sqlite.SQLiteDatabase;
 import android.database.sqlite.SQLiteOpenHelper;
 import android.util.Log;
-
+//引用了同一个包中的另一个子包Notes中一些接口
 import net.micode.notes.data.Notes.DataColumns;
 import net.micode.notes.data.Notes.DataConstants;
 import net.micode.notes.data.Notes.NoteColumns;
 
-
+//数据库操作
 public class NotesDatabaseHelper extends SQLiteOpenHelper {
     private static final String DB_NAME = "note.db";
 
     private static final int DB_VERSION = 4;
-
+    //接口两部分一个Note一个DATA
     public interface TABLE {
         public static final String NOTE = "note";
 
@@ -41,7 +41,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
     private static final String TAG = "NotesDatabaseHelper";
 
     private static NotesDatabaseHelper mInstance;
-
+    //基于NoteColumn创建一个NOTE_TABLE表格，并附上初始数据
     private static final String CREATE_NOTE_TABLE_SQL =
         "CREATE TABLE " + TABLE.NOTE + "(" +
             NoteColumns.ID + " INTEGER PRIMARY KEY," +
@@ -62,7 +62,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
             NoteColumns.GTASK_ID + " TEXT NOT NULL DEFAULT ''," +
             NoteColumns.VERSION + " INTEGER NOT NULL DEFAULT 0" +
         ")";
-
+    //主要基于datacolumn来创建DATA_TABLE
     private static final String CREATE_DATA_TABLE_SQL =
         "CREATE TABLE " + TABLE.DATA + "(" +
             DataColumns.ID + " INTEGER PRIMARY KEY," +
@@ -77,7 +77,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
             DataColumns.DATA4 + " TEXT NOT NULL DEFAULT ''," +
             DataColumns.DATA5 + " TEXT NOT NULL DEFAULT ''" +
         ")";
-
+    //这个数据是关于INDEX编号的
     private static final String CREATE_DATA_NOTE_ID_INDEX_SQL =
         "CREATE INDEX IF NOT EXISTS note_id_index ON " +
         TABLE.DATA + "(" + DataColumns.NOTE_ID + ");";
@@ -93,7 +93,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         "   SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + " + 1" +
         "  WHERE " + NoteColumns.ID + "=new." + NoteColumns.PARENT_ID + ";" +
         " END";
-
+    //移入note时触发，修改一系列数据，从哪来之类的
     /**
      * Decrease folder's note count when move note from folder
      */
@@ -106,7 +106,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         "  WHERE " + NoteColumns.ID + "=old." + NoteColumns.PARENT_ID +
         "  AND " + NoteColumns.NOTES_COUNT + ">0" + ";" +
         " END";
-
+    //移除Note时触发，与上面移入对应
     /**
      * Increase folder's note count when insert new note to the folder
      */
@@ -118,7 +118,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         "   SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + " + 1" +
         "  WHERE " + NoteColumns.ID + "=new." + NoteColumns.PARENT_ID + ";" +
         " END";
-
+    //插入Note
     /**
      * Decrease folder's note count when delete note from the folder
      */
@@ -131,7 +131,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         "  WHERE " + NoteColumns.ID + "=old." + NoteColumns.PARENT_ID +
         "  AND " + NoteColumns.NOTES_COUNT + ">0;" +
         " END";
-
+    //删除note
     /**
      * Update note's content when insert data with type {@link DataConstants#NOTE}
      */
@@ -144,7 +144,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         "   SET " + NoteColumns.SNIPPET + "=new." + DataColumns.CONTENT +
         "  WHERE " + NoteColumns.ID + "=new." + DataColumns.NOTE_ID + ";" +
         " END";
-
+    //当给note插入新数据时触发
     /**
      * Update note's content when data with {@link DataConstants#NOTE} type has changed
      */
@@ -156,7 +156,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         "  UPDATE " + TABLE.NOTE +
         "   SET " + NoteColumns.SNIPPET + "=new." + DataColumns.CONTENT +
         "  WHERE " + NoteColumns.ID + "=new." + DataColumns.NOTE_ID + ";" +
-        " END";
+        " END";//note数据被修改update
 
     /**
      * Update note's content when data with {@link DataConstants#NOTE} type has deleted
@@ -169,7 +169,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         "  UPDATE " + TABLE.NOTE +
         "   SET " + NoteColumns.SNIPPET + "=''" +
         "  WHERE " + NoteColumns.ID + "=old." + DataColumns.NOTE_ID + ";" +
-        " END";
+        " END";//更新已经删除的便签的数据
 
     /**
      * Delete datas belong to note which has been deleted
@@ -180,7 +180,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         " BEGIN" +
         "  DELETE FROM " + TABLE.DATA +
         "   WHERE " + DataColumns.NOTE_ID + "=old." + NoteColumns.ID + ";" +
-        " END";
+        " END";//删除 已经被删除的便签的数据
 
     /**
      * Delete notes belong to folder which has been deleted
@@ -191,7 +191,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         " BEGIN" +
         "  DELETE FROM " + TABLE.NOTE +
         "   WHERE " + NoteColumns.PARENT_ID + "=old." + NoteColumns.ID + ";" +
-        " END";
+        " END";//删除 已删除folder文件夹 中的便签要修改的数据
 
     /**
      * Move notes belong to folder which has been moved to trash folder
@@ -204,12 +204,12 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         "  UPDATE " + TABLE.NOTE +
         "   SET " + NoteColumns.PARENT_ID + "=" + Notes.ID_TRASH_FOLER +
         "  WHERE " + NoteColumns.PARENT_ID + "=old." + NoteColumns.ID + ";" +
-        " END";
+        " END";//移动trash_folder中的便签
 
     public NotesDatabaseHelper(Context context) {
         super(context, DB_NAME, null, DB_VERSION);
     }
-
+    //构造函数
     public void createNoteTable(SQLiteDatabase db) {
         db.execSQL(CREATE_NOTE_TABLE_SQL);
         reCreateNoteTableTriggers(db);
@@ -233,7 +233,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         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);
-    }
+    }//数据库操作的API，重新创建
 
     private void createSystemFolder(SQLiteDatabase db) {
         ContentValues values = new ContentValues();
@@ -268,14 +268,14 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         values.put(NoteColumns.ID, Notes.ID_TRASH_FOLER);
         values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
         db.insert(TABLE.NOTE, null, values);
-    }
+    }//创建系统文件夹
 
     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");
-    }
+    }//创建数据表格
 
     private void reCreateDataTableTriggers(SQLiteDatabase db) {
         db.execSQL("DROP TRIGGER IF EXISTS update_note_content_on_insert");
@@ -285,20 +285,20 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         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);
-    }
+    }//类似于recreatenotetable，重新创建触发器
 
     static synchronized NotesDatabaseHelper getInstance(Context context) {
         if (mInstance == null) {
             mInstance = new NotesDatabaseHelper(context);
         }
         return mInstance;
-    }
+    }//sync同步，同一时刻只有一个线程执行
 
     @Override
     public void onCreate(SQLiteDatabase db) {
         createNoteTable(db);
         createDataTable(db);
-    }
+    }//创建Note Data两个表格
 
     @Override
     public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
@@ -331,14 +331,14 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
             throw new IllegalStateException("Upgrade notes database to version " + newVersion
                     + "fails");
         }
-    }
+    }//数据库版本更新
 
     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);
-    }
+    }//更新到V2
 
     private void upgradeToV3(SQLiteDatabase db) {
         // drop unused triggers
@@ -353,10 +353,10 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         values.put(NoteColumns.ID, Notes.ID_TRASH_FOLER);
         values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
         db.insert(TABLE.NOTE, null, values);
-    }
+    }//更新到V3
 
     private void upgradeToV4(SQLiteDatabase db) {
         db.execSQL("ALTER TABLE " + TABLE.NOTE + " ADD COLUMN " + NoteColumns.VERSION
                 + " INTEGER NOT NULL DEFAULT 0");
-    }
+    }//更新到V4
 }

src/Notes/app/src/main/java/net/micode/notes/data/NotesProvider.java

@@ -1,22 +1,5 @@
-/*
- * 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.app.SearchManager;
 import android.content.ContentProvider;
 import android.content.ContentUris;
@@ -33,9 +16,15 @@ import net.micode.notes.R;
 import net.micode.notes.data.Notes.DataColumns;
 import net.micode.notes.data.Notes.NoteColumns;
 import net.micode.notes.data.NotesDatabaseHelper.TABLE;
-
+//为存储和获取数据提供接口。可以在不同的应用程序之间共享数据
-
+//ContentProvider提供的方法
+//query：查询
+//insert：插入
+//update：更新
+//delete：删除
+//getType：得到数据类型
 public class NotesProvider extends ContentProvider {
+    // UriMatcher用于匹配Uri
     private static final UriMatcher mMatcher;
 
     private NotesDatabaseHelper mHelper;
@@ -51,7 +40,9 @@ public class NotesProvider extends ContentProvider {
     private static final int URI_SEARCH_SUGGEST  = 6;
 
     static {
+        // 创建UriMatcher时，调用UriMatcher(UriMatcher.NO_MATCH)表示不匹配任何路径的返回码
         mMatcher = new UriMatcher(UriMatcher.NO_MATCH);
+        // 把需要匹配Uri路径全部给注册上
         mMatcher.addURI(Notes.AUTHORITY, "note", URI_NOTE);
         mMatcher.addURI(Notes.AUTHORITY, "note/#", URI_NOTE_ITEM);
         mMatcher.addURI(Notes.AUTHORITY, "data", URI_DATA);
@@ -65,6 +56,7 @@ public class NotesProvider extends ContentProvider {
      * x'0A' represents the '\n' character in sqlite. For title and content in the search result,
      * we will trim '\n' and white space in order to show more information.
      */
+    // 声明 NOTES_SEARCH_PROJECTION
     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 + ","
@@ -72,7 +64,7 @@ public class NotesProvider extends ContentProvider {
             + 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;
-
+    // 声明NOTES_SNIPPET_SEARCH_QUERY
     private static String NOTES_SNIPPET_SEARCH_QUERY = "SELECT " + NOTES_SEARCH_PROJECTION
             + " FROM " + TABLE.NOTE
             + " WHERE " + NoteColumns.SNIPPET + " LIKE ?"
@@ -80,18 +72,24 @@ public class NotesProvider extends ContentProvider {
             + " AND " + NoteColumns.TYPE + "=" + Notes.TYPE_NOTE;
 
     @Override
+    // Context只有在onCreate()中才被初始化
+    // 对mHelper进行实例化
     public boolean onCreate() {
         mHelper = NotesDatabaseHelper.getInstance(getContext());
         return true;
     }
 
     @Override
+    // 查询uri在数据库中对应的位置
     public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs,
                         String sortOrder) {
         Cursor c = null;
+        // 获取可读数据库
         SQLiteDatabase db = mHelper.getReadableDatabase();
         String id = null;
+        // 匹配查找uri
         switch (mMatcher.match(uri)) {
+            // 对于不同的匹配值，在数据库中查找相应的条目
             case URI_NOTE:
                 c = db.query(TABLE.NOTE, projection, selection, selectionArgs, null, null,
                         sortOrder);
@@ -113,6 +111,7 @@ public class NotesProvider extends ContentProvider {
             case URI_SEARCH:
             case URI_SEARCH_SUGGEST:
                 if (sortOrder != null || projection != null) {
+                    // 不合法的参数异常
                     throw new IllegalArgumentException(
                             "do not specify sortOrder, selection, selectionArgs, or projection" + "with this query");
                 }
@@ -120,6 +119,8 @@ public class NotesProvider extends ContentProvider {
                 String searchString = null;
                 if (mMatcher.match(uri) == URI_SEARCH_SUGGEST) {
                     if (uri.getPathSegments().size() > 1) {
+                        // getPathSegments()方法得到一个String的List，
+                        // 在uri.getPathSegments().get(1)为第2个元素
                         searchString = uri.getPathSegments().get(1);
                     }
                 } else {
@@ -139,6 +140,7 @@ public class NotesProvider extends ContentProvider {
                 }
                 break;
             default:
+                // 抛出异常
                 throw new IllegalArgumentException("Unknown URI " + uri);
         }
         if (c != null) {
@@ -148,13 +150,17 @@ public class NotesProvider extends ContentProvider {
     }
 
     @Override
+    // 插入一个uri
     public Uri insert(Uri uri, ContentValues values) {
+        // 获得可写的数据库
         SQLiteDatabase db = mHelper.getWritableDatabase();
         long dataId = 0, noteId = 0, insertedId = 0;
         switch (mMatcher.match(uri)) {
+            // 新增一个条目
             case URI_NOTE:
                 insertedId = noteId = db.insert(TABLE.NOTE, null, values);
                 break;
+            // 如果存在，查找NOTE_ID
             case URI_DATA:
                 if (values.containsKey(DataColumns.NOTE_ID)) {
                     noteId = values.getAsLong(DataColumns.NOTE_ID);
@@ -167,6 +173,7 @@ public class NotesProvider extends ContentProvider {
                 throw new IllegalArgumentException("Unknown URI " + uri);
         }
         // Notify the note uri
+        // notifyChange获得一个ContextResolver对象并且更新里面的内容
         if (noteId > 0) {
             getContext().getContentResolver().notifyChange(
                     ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId), null);
@@ -178,13 +185,17 @@ public class NotesProvider extends ContentProvider {
                     ContentUris.withAppendedId(Notes.CONTENT_DATA_URI, dataId), null);
         }
 
+        // 返回插入的uri的路径
         return ContentUris.withAppendedId(uri, insertedId);
     }
 
     @Override
+    // 删除一个uri
     public int delete(Uri uri, String selection, String[] selectionArgs) {
+        //Uri代表要操作的数据，Android上可用的每种资源 -包括 图像、视频片段、音频资源等都可以用Uri来表示。
         int count = 0;
         String id = null;
+        // 获得可写的数据库
         SQLiteDatabase db = mHelper.getWritableDatabase();
         boolean deleteData = false;
         switch (mMatcher.match(uri)) {
@@ -228,6 +239,7 @@ public class NotesProvider extends ContentProvider {
     }
 
     @Override
+    // 更新一个uri
     public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
         int count = 0;
         String id = null;
@@ -267,10 +279,12 @@ public class NotesProvider extends ContentProvider {
         return count;
     }
 
+    // 将字符串解析成规定格式
     private String parseSelection(String selection) {
         return (!TextUtils.isEmpty(selection) ? " AND (" + selection + ')' : "");
     }
 
+    //增加一个noteVersion
     private void increaseNoteVersion(long id, String selection, String[] selectionArgs) {
         StringBuilder sql = new StringBuilder(120);
         sql.append("UPDATE ");
@@ -293,6 +307,7 @@ public class NotesProvider extends ContentProvider {
             sql.append(selectString);
         }
 
+        // execSQL()方法可以执行insert、delete、update和CREATE TABLE之类有更改行为的SQL语句
         mHelper.getWritableDatabase().execSQL(sql.toString());
     }