添加注释

src/net/micode/notes/gtask/data/SqlNote.java

@@ -123,34 +123,35 @@ public class SqlNote {
     private ArrayList<SqlData> mDataList;
 
     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>();
+        //初始化成员变量
+        mContext = context;// 上下文
+        mContentResolver = context.getContentResolver();// 获取内容解析器
+        mIsCreate = true; // 是否为新建笔记
+        mId = INVALID_ID; // 笔记ID
+        mAlertDate = 0; // 提醒时间
+        mBgColorId = ResourceParser.getDefaultBgId(context); // 背景颜色ID
+        mCreatedDate = System.currentTimeMillis(); // 创建时间
+        mHasAttachment = 0; // 是否有附件
+        mModifiedDate = System.currentTimeMillis(); // 修改时间
+        mParentId = 0; // 所属父笔记ID
+        mSnippet = ""; // 笔记摘要
+        mType = Notes.TYPE_NOTE; // 笔记类型
+        mWidgetId = AppWidgetManager.INVALID_APPWIDGET_ID; // 小部件ID
+        mWidgetType = Notes.TYPE_WIDGET_INVALIDE; // 小部件类型
+        mOriginParent = 0; // 原始的父笔记ID
+        mVersion = 0; // 笔记版本
+        mDiffNoteValues = new ContentValues(); // 存储笔记差异内容的 ContentValues 对象
+        mDataList = new ArrayList<SqlData>(); // 存储笔记数据的 ArrayList
     }
 
     public SqlNote(Context context, Cursor c) {
         mContext = context;
         mContentResolver = context.getContentResolver();
         mIsCreate = false;
-        loadFromCursor(c);
+        loadFromCursor(c); // 从Cursor加载笔记数据
         mDataList = new ArrayList<SqlData>();
         if (mType == Notes.TYPE_NOTE)
-            loadDataContent();
+            loadDataContent(); // 加载笔记内容
         mDiffNoteValues = new ContentValues();
     }
 
@@ -158,10 +159,10 @@ public class SqlNote {
         mContext = context;
         mContentResolver = context.getContentResolver();
         mIsCreate = false;
-        loadFromCursor(id);
+        loadFromCursor(id); // 根据ID从数据库中加载笔记数据
         mDataList = new ArrayList<SqlData>();
         if (mType == Notes.TYPE_NOTE)
-            loadDataContent();
+            loadDataContent(); // 加载笔记内容
         mDiffNoteValues = new ContentValues();
 
     }
@@ -175,7 +176,7 @@ public class SqlNote {
                     }, null);
             if (c != null) {
                 c.moveToNext();
-                loadFromCursor(c);
+                loadFromCursor(c);// 从Cursor加载笔记数据
             } else {
                 Log.w(TAG, "loadFromCursor: cursor = null");
             }
@@ -186,43 +187,45 @@ public class SqlNote {
     }
 
     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);
+        mId = c.getLong(ID_COLUMN);                 // 加载ID数据
+        mAlertDate = c.getLong(ALERTED_DATE_COLUMN); // 加载提醒日期数据
+        mBgColorId = c.getInt(BG_COLOR_ID_COLUMN);   // 加载背景颜色ID数据
+        mCreatedDate = c.getLong(CREATED_DATE_COLUMN); // 加载创建日期数据
+        mHasAttachment = c.getInt(HAS_ATTACHMENT_COLUMN); // 加载附件存在标记数据
+        mModifiedDate = c.getLong(MODIFIED_DATE_COLUMN); // 加载修改日期数据
+        mParentId = c.getLong(PARENT_ID_COLUMN); // 加载父级ID数据
+        mSnippet = c.getString(SNIPPET_COLUMN); // 加载摘要数据
+        mType = c.getInt(TYPE_COLUMN); // 加载类型数据
+        mWidgetId = c.getInt(WIDGET_ID_COLUMN); // 加载小部件ID数据
+        mWidgetType = c.getInt(WIDGET_TYPE_COLUMN); // 加载小部件类型数据
+        mVersion = c.getLong(VERSION_COLUMN); // 加载版本号数据
     }
 
     private void loadDataContent() {
         Cursor c = null;
-        mDataList.clear();
+        mDataList.clear();// 清空数据列表
         try {
+            // 通过ContentResolver从Content Provider查询数据内容
             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) {
+                    // 数据内容为空
                     Log.w(TAG, "it seems that the note has not data");
                     return;
                 }
-                while (c.moveToNext()) {
+                while (c.moveToNext()) {// 遍历Cursor，创建SqlData对象并添加到数据列表中
                     SqlData data = new SqlData(mContext, c);
                     mDataList.add(data);
                 }
             } else {
                 Log.w(TAG, "loadDataContent: cursor = null");
             }
-        } finally {
+        } finally { // Cursor为空
             if (c != null)
-                c.close();
+                c.close();// 关闭Cursor
         }
     }
 
@@ -441,22 +444,25 @@ public class SqlNote {
     }
 
     public void commit(boolean validateVersion) {
-        if (mIsCreate) {
+        if (mIsCreate) {// 判断当前对象是否为新建对象。如果是，则执行以下代码块。
             if (mId == INVALID_ID && mDiffNoteValues.containsKey(NoteColumns.ID)) {
+            // 如果当前对象的id为无效id，并且mDiffNoteValues中包含NoteColumns.ID这个键，则移除该键值对。
                 mDiffNoteValues.remove(NoteColumns.ID);
             }
-
+            // 通过ContentResolver向Notes表中插入一条记录，第一部分是插入的uri。  
             Uri uri = mContentResolver.insert(Notes.CONTENT_NOTE_URI, mDiffNoteValues);
-            try {
+            try {// 试图从uri的路径段中获取note的id。
+                // 将获取到的id转换为long类型并赋值给mId。如果转换失败，会抛出NumberFormatException异常。
                 mId = Long.valueOf(uri.getPathSegments().get(1));
             } catch (NumberFormatException e) {
+                // 记录错误日志，创建note失败。抛出ActionFailureException异常，异常信息为create note failed。
                 Log.e(TAG, "Get note id error :" + e.toString());
                 throw new ActionFailureException("create note failed");
             }
-            if (mId == 0) {
+            if (mId == 0) {// 如果mId仍然为0，抛出一个IllegalStateException异常，创建thread id失败。  
                 throw new IllegalStateException("Create thread id failed");
             }
-
+            // 如果mType等于Notes.TYPE_NOTE，执行以下代码块。  
             if (mType == Notes.TYPE_NOTE) {
                 for (SqlData sqlData : mDataList) {
                     sqlData.commit(mId, false, -1);
@@ -464,24 +470,28 @@ public class SqlNote {
             }
         } else {
             if (mId <= 0 && mId != Notes.ID_ROOT_FOLDER && mId != Notes.ID_CALL_RECORD_FOLDER) {
-                Log.e(TAG, "No such note");
+                Log.e(TAG, "No such note");// 打印错误日志"No such note
+                 // 抛出异常IllegalStateException
                 throw new IllegalStateException("Try to update note with invalid id");
             }
             if (mDiffNoteValues.size() > 0) {
                 mVersion ++;
                 int result = 0;
                 if (!validateVersion) {
+                    //更新Notes表中的记录，将mDiffNoteValues中的键值对更新到Notes表中
                     result = mContentResolver.update(Notes.CONTENT_NOTE_URI, mDiffNoteValues, "("
                             + NoteColumns.ID + "=?)", new String[] {
                         String.valueOf(mId)
                     });
                 } else {
+                     // 更新Notes表中的记录，将mDiffNoteValues中的键值对更新到Notes表中
                     result = mContentResolver.update(Notes.CONTENT_NOTE_URI, mDiffNoteValues, "("
                             + NoteColumns.ID + "=?) AND (" + NoteColumns.VERSION + "<=?)",
                             new String[] {
                                     String.valueOf(mId), String.valueOf(mVersion)
                             });
                 }
+                // 如果result为0，即没有更新记录，则打印警告日志
                 if (result == 0) {
                     Log.w(TAG, "there is no update. maybe user updates note when syncing");
                 }