diff --git a/src/Notes-master/AndroidManifest.xml b/src/Notes-master/AndroidManifest.xml
index e5c7d47..d28261b 100644
--- a/src/Notes-master/AndroidManifest.xml
+++ b/src/Notes-master/AndroidManifest.xml
@@ -1,27 +1,20 @@
 <?xml version="1.0" encoding="utf-8"?>
-
 <!-- 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.
 -->
-
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
-    package="net.micode.notes"
     android:versionCode="1"
     android:versionName="0.1" >
-
-    <uses-sdk android:minSdkVersion="14" />
-
+    <!-- 已移除package属性，已注释minSdkVersion（可选删除） -->
+    <!-- <uses-sdk android:minSdkVersion="14" /> -->
     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
     <uses-permission android:name="com.android.launcher.permission.INSTALL_SHORTCUT" />
     <uses-permission android:name="android.permission.INTERNET" />
@@ -30,8 +23,7 @@
     <uses-permission android:name="android.permission.AUTHENTICATE_ACCOUNTS" />
     <uses-permission android:name="android.permission.GET_ACCOUNTS" />
     <uses-permission android:name="android.permission.USE_CREDENTIALS" />
-    <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
-
+    <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" /> 
     <application
         android:icon="@drawable/icon_app"
         android:label="@string/app_name" >
@@ -42,107 +34,103 @@
             android:launchMode="singleTop"
             android:theme="@style/NoteTheme"
             android:uiOptions="splitActionBarWhenNarrow"
-            android:windowSoftInputMode="adjustPan" >
-
+            android:windowSoftInputMode="adjustPan"
+            android:exported="true" > <!-- 新增 -->
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
-
         <activity
             android:name=".ui.NoteEditActivity"
             android:configChanges="keyboardHidden|orientation|screenSize"
             android:launchMode="singleTop"
-            android:theme="@style/NoteTheme" >
-
+            android:theme="@style/NoteTheme"
+            android:exported="true" > <!-- 新增 -->
             <intent-filter>
                 <action android:name="android.intent.action.VIEW" />
                 <category android:name="android.intent.category.DEFAULT" />
                 <data android:mimeType="vnd.android.cursor.item/text_note" />
                 <data android:mimeType="vnd.android.cursor.item/call_note" />
             </intent-filter>
-
             <intent-filter>
                 <action android:name="android.intent.action.INSERT_OR_EDIT" />
                 <category android:name="android.intent.category.DEFAULT" />
                 <data android:mimeType="vnd.android.cursor.item/text_note" />
                 <data android:mimeType="vnd.android.cursor.item/call_note" />
             </intent-filter>
-
             <intent-filter>
                 <action android:name="android.intent.action.SEARCH" />
                 <category android:name="android.intent.category.DEFAULT" />
             </intent-filter>
-
             <meta-data
                 android:name="android.app.searchable"
                 android:resource="@xml/searchable" />
         </activity>
-
         <provider
             android:name="net.micode.notes.data.NotesProvider"
             android:authorities="micode_notes"
             android:multiprocess="true" />
-
         <receiver
             android:name=".widget.NoteWidgetProvider_2x"
-            android:label="@string/app_widget2x2" >
+            android:label="@string/app_widget2x2"
+            android:exported="false" > <!-- 新增 -->
             <intent-filter>
                 <action android:name="android.appwidget.action.APPWIDGET_UPDATE" />
                 <action android:name="android.appwidget.action.APPWIDGET_DELETED" />
                 <action android:name="android.intent.action.PRIVACY_MODE_CHANGED" />
             </intent-filter>
-
             <meta-data
                 android:name="android.appwidget.provider"
                 android:resource="@xml/widget_2x_info" />
         </receiver>
         <receiver
             android:name=".widget.NoteWidgetProvider_4x"
-            android:label="@string/app_widget4x4" >
-
+            android:label="@string/app_widget4x4"
+            android:exported="false" > <!-- 新增 -->
             <intent-filter>
                 <action android:name="android.appwidget.action.APPWIDGET_UPDATE" />
                 <action android:name="android.appwidget.action.APPWIDGET_DELETED" />
                 <action android:name="android.intent.action.PRIVACY_MODE_CHANGED" />
             </intent-filter>
-
             <meta-data
                 android:name="android.appwidget.provider"
                 android:resource="@xml/widget_4x_info" />
         </receiver>
-
-        <receiver android:name=".ui.AlarmInitReceiver" >
+        <receiver
+            android:name=".ui.AlarmInitReceiver"
+            android:exported="true" > <!-- 新增 -->
             <intent-filter>
                 <action android:name="android.intent.action.BOOT_COMPLETED" />
             </intent-filter>
         </receiver>
-
         <receiver
             android:name="net.micode.notes.ui.AlarmReceiver"
             android:process=":remote" >
         </receiver>
-
         <activity
             android:name=".ui.AlarmAlertActivity"
             android:label="@string/app_name"
             android:launchMode="singleInstance"
             android:theme="@android:style/Theme.Holo.Wallpaper.NoTitleBar" >
         </activity>
-
         <activity
             android:name="net.micode.notes.ui.NotesPreferenceActivity"
             android:label="@string/preferences_title"
             android:launchMode="singleTop"
             android:theme="@android:style/Theme.Holo.Light" >
         </activity>
-
+        <activity
+            android:name=".ui.TrashActivity"
+            android:label="@string/menu_trash"
+            android:launchMode="singleTop"
+            android:theme="@style/NoteTheme"
+            android:exported="true" >
+        </activity>
         <service
             android:name="net.micode.notes.gtask.remote.GTaskSyncService"
             android:exported="false" >
         </service>
-
         <meta-data
             android:name="android.app.default_searchable"
             android:value=".ui.NoteEditActivity" />
diff --git a/src/Notes-master/res/layout/activity_trash.xml b/src/Notes-master/res/layout/activity_trash.xml
new file mode 100644
index 0000000..2099f3a
--- /dev/null
+++ b/src/Notes-master/res/layout/activity_trash.xml
@@ -0,0 +1,71 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!-- 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.
+-->
+
+<FrameLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="fill_parent"
+    android:layout_height="fill_parent"
+    android:background="@drawable/list_background">
+
+    <LinearLayout
+        android:layout_width="fill_parent"
+        android:layout_height="fill_parent"
+        android:orientation="vertical">
+
+        <LinearLayout
+            android:layout_width="fill_parent"
+            android:layout_height="wrap_content"
+            android:orientation="horizontal"
+            android:gravity="center_vertical"
+            android:padding="8dp">
+
+            <Button
+                android:id="@+id/btn_clean_all"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:text="@string/button_clean_all"
+                android:minWidth="120dp"
+                android:padding="16dp" />
+
+            <View
+                android:layout_width="0dp"
+                android:layout_height="1dp"
+                android:layout_weight="1" />
+
+            <Button
+                android:id="@+id/btn_return"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:text="@string/button_return"
+                android:minWidth="120dp"
+                android:padding="16dp" />
+
+        </LinearLayout>
+
+        <ListView
+            android:id="@+id/trash_list"
+            android:layout_width="fill_parent"
+            android:layout_height="0dip"
+            android:layout_weight="1"
+            android:cacheColorHint="@null"
+            android:listSelector="@android:color/transparent"
+            android:divider="@null"
+            android:fadingEdge="@null" />
+
+    </LinearLayout>
+
+</FrameLayout>
\ No newline at end of file
diff --git a/src/Notes-master/res/menu/note_list.xml b/src/Notes-master/res/menu/note_list.xml
index 42ea736..a2e8b6e 100644
--- a/src/Notes-master/res/menu/note_list.xml
+++ b/src/Notes-master/res/menu/note_list.xml
@@ -36,4 +36,8 @@
     <item
         android:id="@+id/menu_search"
         android:title="@string/menu_search"/>
+
+    <item
+        android:id="@+id/menu_trash"
+        android:title="@string/menu_trash"/>
 </menu>
diff --git a/src/Notes-master/res/values-zh-rCN/strings.xml b/src/Notes-master/res/values-zh-rCN/strings.xml
index 09f75ed..2cf7c76 100644
--- a/src/Notes-master/res/values-zh-rCN/strings.xml
+++ b/src/Notes-master/res/values-zh-rCN/strings.xml
@@ -42,6 +42,11 @@
     <string name="menu_sync_cancel">取消同步</string>
     <string name="menu_setting">设置</string>
     <string name="menu_search">搜索</string>
+    <string name="menu_trash">回收站</string>
+    <string name="button_return">返回</string>
+    <string name="button_clean_all">清空</string>
+    <string name="button_recovery">恢复</string>
+    <string name="menu_success">成功</string>
     <string name="menu_delete">删除</string>
     <string name="menu_move">移动到文件夹</string>
     <string name="menu_select_title">选中了 %d 项</string>
@@ -70,6 +75,7 @@
     <string name="alert_message_delete_notes">确认要删除所选的 %d 条便签吗?</string>
     <string name="alert_message_delete_note">确认要删除该条便签吗?</string>
     <string name="alert_message_delete_folder">确认删除文件夹及所包含的便签吗？</string>
+    <string name="alert_message_clear_all_trash">确认清空回收站中的所有便签吗？此操作无法撤销。</string>
     <string name="format_move_notes_to_folder">已将所选 %1$d 条便签移到 %2$s 文件夹</string>
     <!-- export text -->
     <string name="error_sdcard_unmounted">SD卡被占用，不能操作</string>
diff --git a/src/Notes-master/res/values/strings.xml b/src/Notes-master/res/values/strings.xml
index 55df868..5a013df 100644
--- a/src/Notes-master/res/values/strings.xml
+++ b/src/Notes-master/res/values/strings.xml
@@ -46,6 +46,11 @@
     <string name="menu_sync_cancel">Cancel syncing</string>
     <string name="menu_setting">Settings</string>
     <string name="menu_search">Search</string>
+    <string name="menu_trash">Trash</string>
+    <string name="button_return">Return</string>
+    <string name="button_clean_all">Clean All</string>
+    <string name="button_recovery">Recovery</string>
+    <string name="menu_success">Success</string>
     <string name="menu_delete">Delete</string>
     <string name="menu_move">Move to folder</string>
     <string name="menu_select_title">%d selected</string>
@@ -72,6 +77,7 @@
     <string name="info_note_enter_desktop">Note added to home</string>
     <string name="alert_message_delete_folder">Confirm to delete folder and its notes?</string>
     <string name="alert_title_delete">Delete selected notes</string>
+    <string name="alert_message_clear_all_trash">Confirm to clear all notes from trash? This action cannot be undone.</string>
     <string name="alert_message_delete_notes">Confirm to delete the selected %d notes?</string>
     <string name="alert_message_delete_note">Confirm to delete this note?</string>
     <string name="format_move_notes_to_folder">Have moved selected %1$d notes to %2$s folder</string>
diff --git a/src/Notes-master/src/net/micode/notes/data/Notes.java b/src/Notes-master/src/net/micode/notes/data/Notes.java
index 5b309f9..d1519c7 100644
--- a/src/Notes-master/src/net/micode/notes/data/Notes.java
+++ b/src/Notes-master/src/net/micode/notes/data/Notes.java
@@ -17,43 +17,24 @@
 package net.micode.notes.data;
 
 import android.net.Uri;
-
-/**
- * 笔记应用的数据结构定义
- * 包含所有笔记相关的常量、接口和内部类定义
- * 纯定义类，不包含函数实现
- */
 public class Notes {
-    // ContentProvider的授权标识 
     public static final String AUTHORITY = "micode_notes";
-    // 日志标签
     public static final String TAG = "Notes";
-    // 0类型：普通笔记
     public static final int TYPE_NOTE     = 0;
-    // 1类型：文件夹 
     public static final int TYPE_FOLDER   = 1;
-    // 2类型：系统文件夹 
     public static final int TYPE_SYSTEM   = 2;
 
-    // 系统文件夹的 ID 定义。
-    // #ID_ROOT_FOLDER 默认根文件夹
-    // #ID_TEMPARAY_FOLDER 临时文件夹，移动笔记时的中转
-    // #ID_CALL_RECORD_FOLDER 通话记录专用文件夹
-    // #ID_TRASH_FOLER 回收站
-    public static final int ID_ROOT_FOLDER = 0;              // 默认根文件夹
-    public static final int ID_TEMPARAY_FOLDER = -1;         // 临时文件夹（用于无归属的笔记）
-    public static final int ID_CALL_RECORD_FOLDER = -2;      // 通话记录文件夹
-    public static final int ID_TRASH_FOLER = -3;             // 回收站文件夹
-
     /**
-     * Intent Extra 键常量，用于在 Android 组件间通过 Intent 传递数据，包括：
-     * 1. 提醒日期 
-     * 2. 背景颜色ID
-     * 3. 小部件ID
-     * 4. 小部件类型
-     * 5. 文件夹ID
-     * 6. 通话日期
+     * Following IDs are system folders' identifiers
+     * {@link Notes#ID_ROOT_FOLDER } is default folder
+     * {@link Notes#ID_TEMPARAY_FOLDER } is for notes belonging no folder
+     * {@link Notes#ID_CALL_RECORD_FOLDER} is to store call records
      */
+    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;
+    public static final int ID_TRASH_FOLER = -3;
+
     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";
@@ -61,176 +42,251 @@ public class Notes {
     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";
 
-    // 无效的小部件类型 -1
     public static final int TYPE_WIDGET_INVALIDE      = -1;
-    // 2x2小部件类型 0
     public static final int TYPE_WIDGET_2X            = 0;
-    // 4x4小部件类型 1
     public static final int TYPE_WIDGET_4X            = 1;
 
-    /**
-     * 数据类型常量定义
-     */
     public static class DataConstants {
-        // 普通笔记的MIME类型
         public static final String NOTE = TextNote.CONTENT_ITEM_TYPE;
-        // 通话记录笔记的MIME类型
         public static final String CALL_NOTE = CallNote.CONTENT_ITEM_TYPE;
     }
 
-    //  URI 是 ContentProvider 的标准访问入口，用于统一访问应用的数据。
-    // 查询所有笔记和文件夹的URI
+    /**
+     * Uri to query all notes and folders
+     */
     public static final Uri CONTENT_NOTE_URI = Uri.parse("content://" + AUTHORITY + "/note");
 
-    // 查询数据表的URI
-    public static final Uri CONTENT_DATA_URI = Uri.parse("content://" + AUTHORITY + "/data");
-
     /**
-     * NoteColumns 接口 - 便签表(notes表)列定义
-     * 定义了便签和文件夹数据库表的所有列名和类型
+     * Uri to query data
      */
+    public static final Uri CONTENT_DATA_URI = Uri.parse("content://" + AUTHORITY + "/data");
+
     /**
-     * 笔记表的列名定义接口
+     * Uri to query trash notes
      */
+    public static final Uri CONTENT_TRASH_URI = Uri.parse("content://" + AUTHORITY + "/trash");
+
     public interface NoteColumns {
-        
-        // 行的唯一ID
+        /**
+         * The unique ID for a row
+         * <P> Type: INTEGER (long) </P>
+         */
         public static final String ID = "_id";
 
-        // 笔记或文件夹的父ID
+        /**
+         * The parent's id for note or folder
+         * <P> Type: INTEGER (long) </P>
+         */
         public static final String PARENT_ID = "parent_id";
 
-        // 笔记或文件夹的创建日期
+        /**
+         * Created data for note or folder
+         * <P> Type: INTEGER (long) </P>
+         */
         public static final String CREATED_DATE = "created_date";
 
-        // 最后修改日期
+        /**
+         * Latest modified date
+         * <P> Type: INTEGER (long) </P>
+         */
         public static final String MODIFIED_DATE = "modified_date";
 
-        // 提醒日期
+
+        /**
+         * Alert date
+         * <P> Type: INTEGER (long) </P>
+         */
         public static final String ALERTED_DATE = "alert_date";
 
-        // 文件夹名称或笔记的文本内容摘要
+        /**
+         * Folder's name or text content of note
+         * <P> Type: TEXT </P>
+         */
         public static final String SNIPPET = "snippet";
 
-        // 笔记的小部件ID
+        /**
+         * Note's widget id
+         * <P> Type: INTEGER (long) </P>
+         */
         public static final String WIDGET_ID = "widget_id";
 
-        // 笔记的小部件类型
+        /**
+         * Note's widget type
+         * <P> Type: INTEGER (long) </P>
+         */
         public static final String WIDGET_TYPE = "widget_type";
 
-        // 笔记的背景颜色ID
+        /**
+         * Note's background color's id
+         * <P> Type: INTEGER (long) </P>
+         */
         public static final String BG_COLOR_ID = "bg_color_id";
 
-        // 是否有附件；对于文本笔记没有附件，多媒体笔记至少有一个附件
+        /**
+         * For text note, it doesn't has attachment, for multi-media
+         * note, it has at least one attachment
+         * <P> Type: INTEGER </P>
+         */
         public static final String HAS_ATTACHMENT = "has_attachment";
 
-        // 文件夹中的笔记数量
+        /**
+         * Folder's count of notes
+         * <P> Type: INTEGER (long) </P>
+         */
         public static final String NOTES_COUNT = "notes_count";
 
-        // 文件类型：文件夹或笔记
+        /**
+         * The file type: folder or note
+         * <P> Type: INTEGER </P>
+         */
         public static final String TYPE = "type";
 
-        // 最后一次同步的ID
+        /**
+         * The last sync id
+         * <P> Type: INTEGER (long) </P>
+         */
         public static final String SYNC_ID = "sync_id";
 
-        // 标记是否在本地被修改
+        /**
+         * Sign to indicate local modified or not
+         * <P> Type: 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
+        /**
+         * Original parent id before moving into temporary folder
+         * <P> Type : INTEGER </P>
+         */
         public static final String ORIGIN_PARENT_ID = "origin_parent_id";
 
-        // Google Task的ID
+        /**
+         * The gtask id
+         * <P> Type : TEXT </P>
+         */
         public static final String GTASK_ID = "gtask_id";
 
-        // 版本号
+        /**
+         * The version code
+         * <P> Type : INTEGER (long) </P>
+         */
         public static final String VERSION = "version";
     }
 
-     /**
-     * DataColumns 接口 - 便签数据表(data表)列定义
-     * 定义了便签详细内容的数据表列名和类型
-     * 使用MIME_TYPE字段区分不同类型的便签数据（文本便签、通话记录等）
-     */
+    public interface TrashColumns extends NoteColumns {
+        /**
+         * Deleted date for trash note
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String DELETED_DATE = "deleted_date";
+    }
+
     public interface DataColumns {
-        // 行的唯一ID
+        /**
+         * The unique ID for a row
+         * <P> Type: INTEGER (long) </P>
+         */
         public static final String ID = "_id";
 
-        // 该行数据项的MIME类型
+        /**
+         * The MIME type of the item represented by this row.
+         * <P> Type: Text </P>
+         */
         public static final String MIME_TYPE = "mime_type";
 
-        // 该数据所属笔记的引用ID
+        /**
+         * The reference id to note that this data belongs to
+         * <P> Type: INTEGER (long) </P>
+         */
         public static final String NOTE_ID = "note_id";
 
-        // 笔记或文件夹的创建日期
+        /**
+         * Created data for note or folder
+         * <P> Type: INTEGER (long) </P>
+         */
         public static final String CREATED_DATE = "created_date";
 
-        // 最后修改日期
+        /**
+         * Latest modified date
+         * <P> Type: INTEGER (long) </P>
+         */
         public static final String MODIFIED_DATE = "modified_date";
 
-        // 数据内容
+        /**
+         * Data's content
+         * <P> Type: TEXT </P>
+         */
         public static final String CONTENT = "content";
 
-        // 通用数据列1
+
+        /**
+         * Generic data column, the meaning is {@link #MIMETYPE} specific, used for
+         * integer data type
+         * <P> Type: INTEGER </P>
+         */
         public static final String DATA1 = "data1";
 
-        // 通用数据列2
+        /**
+         * Generic data column, the meaning is {@link #MIMETYPE} specific, used for
+         * integer data type
+         * <P> Type: INTEGER </P>
+         */
         public static final String DATA2 = "data2";
 
-        // 通用数据列3
+        /**
+         * Generic data column, the meaning is {@link #MIMETYPE} specific, used for
+         * TEXT data type
+         * <P> Type: TEXT </P>
+         */
         public static final String DATA3 = "data3";
 
-        // 通用数据列4
+        /**
+         * Generic data column, the meaning is {@link #MIMETYPE} specific, used for
+         * TEXT data type
+         * <P> Type: TEXT </P>
+         */
         public static final String DATA4 = "data4";
 
-        // 通用数据列5
+        /**
+         * Generic data column, the meaning is {@link #MIMETYPE} specific, used for
+         * TEXT data type
+         * <P> Type: TEXT </P>
+         */
         public static final String DATA5 = "data5";
     }
 
-    /**
-     * TextNote 类 - 文本便签数据定义
-     * 定义了文本便签特有的数据列和URI
-     */
     public static final class TextNote implements DataColumns {
-        // 模式标识：文本是否为清单模式
+        /**
+         * Mode to indicate the text in check list mode or not
+         * <P> Type: Integer 1:check list mode 0: normal mode </P>
+         */
         public static final String MODE = DATA1;
 
-        // 清单模式常量
         public static final int MODE_CHECK_LIST = 1;
-        
-        // 普通模式常量
-        public static final int MODE_NORMAL = 0;
 
-        // 文本笔记的目录MIME类型
         public static final String CONTENT_TYPE = "vnd.android.cursor.dir/text_note";
 
-        // 文本笔记的单项MIME类型
         public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/text_note";
 
-        // 文本笔记的URI
         public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/text_note");
     }
 
-    /**
-     * CallNote 类 - 通话记录便签数据定义
-     * 定义了通话记录便签特有的数据列和URI
-     */
     public static final class CallNote implements DataColumns {
-        // 通话日期
+        /**
+         * Call date for this record
+         * <P> Type: INTEGER (long) </P>
+         */
         public static final String CALL_DATE = DATA1;
 
-        // 电话号码
+        /**
+         * Phone number for this record
+         * <P> Type: TEXT </P>
+         */
         public static final String PHONE_NUMBER = DATA3;
 
-        // 联系人姓名
-        public static final String CONTACT_NAME = DATA4;
-
-        // 通话记录笔记的目录MIME类型
         public static final String CONTENT_TYPE = "vnd.android.cursor.dir/call_note";
 
-        // 通话记录笔记的单项MIME类型
         public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/call_note";
 
-        // 通话记录笔记的URI
         public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/call_note");
     }
 }
diff --git a/src/Notes-master/src/net/micode/notes/data/NotesDatabaseHelper.java b/src/Notes-master/src/net/micode/notes/data/NotesDatabaseHelper.java
index c41a420..427f3c5 100644
--- a/src/Notes-master/src/net/micode/notes/data/NotesDatabaseHelper.java
+++ b/src/Notes-master/src/net/micode/notes/data/NotesDatabaseHelper.java
@@ -26,31 +26,23 @@ import net.micode.notes.data.Notes.DataColumns;
 import net.micode.notes.data.Notes.DataConstants;
 import net.micode.notes.data.Notes.NoteColumns;
 
-/**
- * 笔记数据库帮助
- * 负责数据库的创建、升级和维护
- */
+
 public class NotesDatabaseHelper extends SQLiteOpenHelper {
-    private static final String DB_NAME = "note.db";  // 数据库名称
-    private static final int DB_VERSION = 4;          // 数据库版本
-;
-    /**
-     * 数据库表名定义接口
-     */
+    private static final String DB_NAME = "note.db";
+
+    private static final int DB_VERSION = 5;
+
     public interface TABLE {
-        /** 笔记表名 */
         public static final String NOTE = "note";
 
-        /** 数据表名 */
         public static final String DATA = "data";
-    }
-
 
-    private static final String TAG = "NotesDatabaseHelper";  // 日志标签
-    private static NotesDatabaseHelper mInstance;              // 单例实例
+        public static final String TRASH = "trash_note";
+    }
 
-    /** 数据库帮助类的单例实例 */
+    private static final String TAG = "NotesDatabaseHelper";
 
+    private static NotesDatabaseHelper mInstance;
 
     private static final String CREATE_NOTE_TABLE_SQL =
         "CREATE TABLE " + TABLE.NOTE + "(" +
@@ -73,7 +65,6 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
             NoteColumns.VERSION + " INTEGER NOT NULL DEFAULT 0" +
         ")";
 
-    // 创建笔记数据表的SQL语句
     private static final String CREATE_DATA_TABLE_SQL =
         "CREATE TABLE " + TABLE.DATA + "(" +
             DataColumns.ID + " INTEGER PRIMARY KEY," +
@@ -89,18 +80,46 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
             DataColumns.DATA5 + " TEXT NOT NULL DEFAULT ''" +
         ")";
 
-    // 创建笔记数据表中note_id列的索引
     private static final String CREATE_DATA_NOTE_ID_INDEX_SQL =
         "CREATE INDEX IF NOT EXISTS note_id_index ON " +
         TABLE.DATA + "(" + DataColumns.NOTE_ID + ");";
 
+    private static final String CREATE_TRASH_TABLE_SQL =
+        "CREATE TABLE " + TABLE.TRASH + "(" +
+            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," +
+            "deleted_date INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)" +
+        ")";
+
     /**
-     * 当笔记移动到文件夹时增加文件夹的笔记计数
+     * Increase folder's note count when move note to the folder
      */
-    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";
+    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";
 
     /**
-     * 当笔记从文件夹移走时减少文件夹的笔记计数
+     * Decrease folder's note count when move note from folder
      */
     private static final String NOTE_DECREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER =
         "CREATE TRIGGER decrease_folder_count_on_update " +
@@ -113,7 +132,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         " END";
 
     /**
-     * 当向文件夹中插入新笔记时增加文件夹的笔记计数
+     * Increase folder's note count when insert new note to the folder
      */
     private static final String NOTE_INCREASE_FOLDER_COUNT_ON_INSERT_TRIGGER =
         "CREATE TRIGGER increase_folder_count_on_insert " +
@@ -125,7 +144,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         " END";
 
     /**
-     * 当从文件夹中删除笔记时减少文件夹的笔记计数
+     * Decrease folder's note count when delete note from the folder
      */
     private static final String NOTE_DECREASE_FOLDER_COUNT_ON_DELETE_TRIGGER =
         "CREATE TRIGGER decrease_folder_count_on_delete " +
@@ -137,7 +156,9 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         "  AND " + NoteColumns.NOTES_COUNT + ">0;" +
         " END";
 
-    /**插入 TEXT_NOTE 类型的数据行时，用数据内容刷新 note.snippet */
+    /**
+     * Update note's content when insert data with type {@link DataConstants#NOTE}
+     */
     private static final String DATA_UPDATE_NOTE_CONTENT_ON_INSERT_TRIGGER =
         "CREATE TRIGGER update_note_content_on_insert " +
         " AFTER INSERT ON " + TABLE.DATA +
@@ -148,7 +169,9 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         "  WHERE " + NoteColumns.ID + "=new." + DataColumns.NOTE_ID + ";" +
         " END";
 
-    /**更新 TEXT_NOTE 数据行时，同步更新 note.snippet */
+    /**
+     * Update note's content when data with {@link DataConstants#NOTE} type has changed
+     */
     private static final String DATA_UPDATE_NOTE_CONTENT_ON_UPDATE_TRIGGER =
         "CREATE TRIGGER update_note_content_on_update " +
         " AFTER UPDATE ON " + TABLE.DATA +
@@ -159,7 +182,9 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         "  WHERE " + NoteColumns.ID + "=new." + DataColumns.NOTE_ID + ";" +
         " END";
 
-    /** 删除 TEXT_NOTE 数据行时，清空 note.snippet */
+    /**
+     * Update note's content when data with {@link DataConstants#NOTE} type has deleted
+     */
     private static final String DATA_UPDATE_NOTE_CONTENT_ON_DELETE_TRIGGER =
         "CREATE TRIGGER update_note_content_on_delete " +
         " AFTER delete ON " + TABLE.DATA +
@@ -171,7 +196,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         " END";
 
     /**
-     * 删除已删除笔记的数据
+     * Delete datas belong to note which has been deleted
      */
     private static final String NOTE_DELETE_DATA_ON_DELETE_TRIGGER =
         "CREATE TRIGGER delete_data_on_delete " +
@@ -182,7 +207,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         " END";
 
     /**
-     * 删除已删除文件夹下的所有笔记
+     * Delete notes belong to folder which has been deleted
      */
     private static final String FOLDER_DELETE_NOTES_ON_DELETE_TRIGGER =
         "CREATE TRIGGER folder_delete_notes_on_delete " +
@@ -193,7 +218,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         " END";
 
     /**
-     * 当文件夹被移到回收站时，将其所有笔记也移到回收站
+     * Move notes belong to folder which has been moved to trash folder
      */
     private static final String FOLDER_MOVE_NOTES_ON_TRASH_TRIGGER =
         "CREATE TRIGGER folder_move_notes_on_trash " +
@@ -205,31 +230,18 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         "  WHERE " + NoteColumns.PARENT_ID + "=old." + NoteColumns.ID + ";" +
         " END";
 
-    /**
-     * 构造方法
-     * @param context 上下文对象
-     */
     public NotesDatabaseHelper(Context context) {
         super(context, DB_NAME, null, DB_VERSION);
     }
 
-    /**
-     * 创建笔记表
-     * @param db 数据库对象
-     */
     public void createNoteTable(SQLiteDatabase db) {
-        db.execSQL(CREATE_NOTE_TABLE_SQL);  // 创建笔记表结构
-        reCreateNoteTableTriggers(db);      // 重建笔记表触发器
-        createSystemFolder(db);             // 创建系统文件夹
+        db.execSQL(CREATE_NOTE_TABLE_SQL);
+        reCreateNoteTableTriggers(db);
+        createSystemFolder(db);
         Log.d(TAG, "note table has been created");
     }
 
-    /**
-     * 重建笔记表的触发器
-     * @param db 数据库对象
-     */
     private void reCreateNoteTableTriggers(SQLiteDatabase db) {
-        // 删除现有触发器
         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");
@@ -238,7 +250,6 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         db.execSQL("DROP TRIGGER IF EXISTS folder_delete_notes_on_delete");
         db.execSQL("DROP TRIGGER IF EXISTS folder_move_notes_on_trash");
 
-        // 创建新触发器
         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);
@@ -248,71 +259,63 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         db.execSQL(FOLDER_MOVE_NOTES_ON_TRASH_TRIGGER);
     }
 
-    /**
-     * 创建系统文件夹
-     * @param db 数据库对象
-     */
     private void createSystemFolder(SQLiteDatabase db) {
         ContentValues values = new ContentValues();
 
         /**
-         * 通话记录文件夹，用于存储通话记录笔记
+         * call record foler for call notes
          */
         values.put(NoteColumns.ID, Notes.ID_CALL_RECORD_FOLDER);
         values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
         db.insert(TABLE.NOTE, null, values);
 
-        // 创建根文件夹（默认文件夹）
+        /**
+         * root folder which is default folder
+         */
         values.clear();
         values.put(NoteColumns.ID, Notes.ID_ROOT_FOLDER);
         values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
         db.insert(TABLE.NOTE, null, values);
 
-        // 创建临时文件夹（用于移动笔记）
+        /**
+         * temporary folder which is used for moving note
+         */
         values.clear();
         values.put(NoteColumns.ID, Notes.ID_TEMPARAY_FOLDER);
         values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
         db.insert(TABLE.NOTE, null, values);
 
-        // 创建回收站文件夹
+        /**
+         * create trash folder
+         */
         values.clear();
         values.put(NoteColumns.ID, Notes.ID_TRASH_FOLER);
         values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
         db.insert(TABLE.NOTE, null, values);
     }
 
-    /**
-     * 创建笔记数据表
-     * @param db 数据库对象
-     */
     public void createDataTable(SQLiteDatabase db) {
-        db.execSQL(CREATE_DATA_TABLE_SQL);           // 创建笔记数据表结构
-        reCreateDataTableTriggers(db);               // 重建笔记数据表触发器
-        db.execSQL(CREATE_DATA_NOTE_ID_INDEX_SQL);    // 创建note_id列索引
+        db.execSQL(CREATE_DATA_TABLE_SQL);
+        reCreateDataTableTriggers(db);
+        db.execSQL(CREATE_DATA_NOTE_ID_INDEX_SQL);
         Log.d(TAG, "data table has been created");
     }
 
-    /**
-     * 重建笔记数据表的触发器
-     * @param db 数据库对象
-     */
+    public void createTrashTable(SQLiteDatabase db) {
+        db.execSQL(CREATE_TRASH_TABLE_SQL);
+        Log.d(TAG, "trash_note table has been created");
+    }
+
     private void reCreateDataTableTriggers(SQLiteDatabase db) {
-        // 删除现有触发器
         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");
 
-        // 创建新触发器
         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NotesDatabaseHelper的单例实例
-     * @param context 上下文对象
-     * @return NotesDatabaseHelper的单例实例
-     */
     static synchronized NotesDatabaseHelper getInstance(Context context) {
         if (mInstance == null) {
             mInstance = new NotesDatabaseHelper(context);
@@ -320,99 +323,80 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         return mInstance;
     }
 
-    /** 创建数据库：依次创建 note 表与 data 表 */
     @Override
     public void onCreate(SQLiteDatabase db) {
-
-        createNoteTable(db);   // 创建笔记表
-        createDataTable(db);   // 创建笔记数据表
+        createNoteTable(db);
+        createDataTable(db);
+        createTrashTable(db);
     }
 
-    /**
-     * 当数据库版本需要更新时调用
-     * @param db 数据库对象
-     * @param oldVersion 旧版本号
-     * @param newVersion 新版本号
-     */
     @Override
     public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
-      
-        boolean reCreateTriggers = false;  // 是否需要重建触发器
-        boolean skipV2 = false;            // 是否跳过版本2的升级
+        boolean reCreateTriggers = false;
+        boolean skipV2 = false;
 
-        // 从版本1升级
         if (oldVersion == 1) {
             upgradeToV2(db);
-
+            skipV2 = true; // this upgrade including the upgrade from v2 to v3
             oldVersion++;
         }
 
-        // 从版本2升级（跳过已在版本1升级中处理的情况）
         if (oldVersion == 2 && !skipV2) {
             upgradeToV3(db);
             reCreateTriggers = true;
             oldVersion++;
         }
 
-        // 从版本3升级
         if (oldVersion == 3) {
             upgradeToV4(db);
             oldVersion++;
         }
 
-        // 如果需要，重建触发器
+        if (oldVersion == 4) {
+            upgradeToV5(db);
+            oldVersion++;
+        }
+
         if (reCreateTriggers) {
             reCreateNoteTableTriggers(db);
             reCreateDataTableTriggers(db);
         }
 
-        // 检查升级是否成功
         if (oldVersion != newVersion) {
-            throw new IllegalStateException("Upgrade notes database to version " + newVersion);
-
+            throw new IllegalStateException("Upgrade notes database to version " + newVersion
+                    + "fails");
         }
     }
 
-    /**
-     * 将数据库升级到版本2
-     * @param db 数据库对象
-     */
     private void upgradeToV2(SQLiteDatabase db) {
-        // 删除旧表
         db.execSQL("DROP TABLE IF EXISTS " + TABLE.NOTE);
         db.execSQL("DROP TABLE IF EXISTS " + TABLE.DATA);
-        // 创建新表
         createNoteTable(db);
         createDataTable(db);
     }
 
-    /**
-     * 将数据库升级到版本3
-     * @param db 数据库对象
-     */
     private void upgradeToV3(SQLiteDatabase db) {
-        // 删除不再使用的触发器
+        // drop unused triggers
         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列用于同步
+        // add a column for gtask id
         db.execSQL("ALTER TABLE " + TABLE.NOTE + " ADD COLUMN " + NoteColumns.GTASK_ID
                 + " TEXT NOT NULL DEFAULT ''");
-        
-        // 添加回收站系统文件夹
+        // add a trash system folder
         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);
     }
 
-    /**
-     * 将数据库升级到版本4
-     * @param db 数据库对象
-     */
     private void upgradeToV4(SQLiteDatabase db) {
         db.execSQL("ALTER TABLE " + TABLE.NOTE + " ADD COLUMN " + NoteColumns.VERSION
                 + " INTEGER NOT NULL DEFAULT 0");
     }
+
+    private void upgradeToV5(SQLiteDatabase db) {
+        createTrashTable(db);
+        Log.d(TAG, "Upgraded to version 5: created trash_note table");
+    }
 }
diff --git a/src/Notes-master/src/net/micode/notes/data/NotesProvider.java b/src/Notes-master/src/net/micode/notes/data/NotesProvider.java
index 3949f8c..b4f6a7a 100644
--- a/src/Notes-master/src/net/micode/notes/data/NotesProvider.java
+++ b/src/Notes-master/src/net/micode/notes/data/NotesProvider.java
@@ -35,58 +35,39 @@ import net.micode.notes.data.Notes.NoteColumns;
 import net.micode.notes.data.NotesDatabaseHelper.TABLE;
 
 
-/**
- * 笔记内容提供者
- * 负责处理笔记和数据的CRUD操作，提供ContentProvider接口
- * 支持搜索和搜索建议功能
- */
 public class NotesProvider extends ContentProvider {
+    private static final UriMatcher mMatcher;
 
-    private static final UriMatcher mMatcher;  // URI匹配器，用于解析不同类型的URI请求
-
-    // 数据库帮助类实例，负责获取读写数据库
     private NotesDatabaseHelper mHelper;
 
-    private static final String TAG = "NotesProvider";  // 日志标签
+    private static final String TAG = "NotesProvider";
 
-    // URI匹配码：笔记列表
     private static final int URI_NOTE            = 1;
-    // URI匹配码：单个笔记
     private static final int URI_NOTE_ITEM       = 2;
-    // URI匹配码：数据列表
     private static final int URI_DATA            = 3;
-    // URI匹配码：单个数据项
     private static final int URI_DATA_ITEM       = 4;
 
-
-    // URI匹配码：搜索
     private static final int URI_SEARCH          = 5;
-    // URI匹配码：搜索建议
     private static final int URI_SEARCH_SUGGEST  = 6;
+    private static final int URI_TRASH           = 7;
+    private static final int URI_TRASH_ITEM      = 8;
 
-    /**
-     * 静态初始化块 - 配置URI匹配规则
-     */
     static {
         mMatcher = new UriMatcher(UriMatcher.NO_MATCH);
-        // 笔记集合URI
         mMatcher.addURI(Notes.AUTHORITY, "note", URI_NOTE);
-        // 单个笔记URI（带ID）
         mMatcher.addURI(Notes.AUTHORITY, "note/#", URI_NOTE_ITEM);
-        // 笔记数据集合URI
         mMatcher.addURI(Notes.AUTHORITY, "data", URI_DATA);
-        // 单个笔记数据URI（带ID）
         mMatcher.addURI(Notes.AUTHORITY, "data/#", URI_DATA_ITEM);
-        // 搜索URI
         mMatcher.addURI(Notes.AUTHORITY, "search", URI_SEARCH);
-        // 搜索建议URI（两种形式）
         mMatcher.addURI(Notes.AUTHORITY, SearchManager.SUGGEST_URI_PATH_QUERY, URI_SEARCH_SUGGEST);
         mMatcher.addURI(Notes.AUTHORITY, SearchManager.SUGGEST_URI_PATH_QUERY + "/*", URI_SEARCH_SUGGEST);
+        mMatcher.addURI(Notes.AUTHORITY, "trash", URI_TRASH);
+        mMatcher.addURI(Notes.AUTHORITY, "trash/#", URI_TRASH_ITEM);
     }
 
     /**
-     * 笔记搜索投影字段。
-     * x'0A' 代表 SQLite 中的换行符；搜索时去掉换行与空格，便于列表展示更多内容。
+     * 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.
      */
     private static final String NOTES_SEARCH_PROJECTION = NoteColumns.ID + ","
         + NoteColumns.ID + " AS " + SearchManager.SUGGEST_COLUMN_INTENT_EXTRA_DATA + ","
@@ -96,35 +77,18 @@ public class NotesProvider extends ContentProvider {
         + "'" + Intent.ACTION_VIEW + "' AS " + SearchManager.SUGGEST_COLUMN_INTENT_ACTION + ","
         + "'" + Notes.TextNote.CONTENT_TYPE + "' AS " + SearchManager.SUGGEST_COLUMN_INTENT_DATA;
 
-    /**
-     * 笔记片段搜索查询语句
-     * 只搜索非回收站中的普通笔记，根据内容片段进行模糊匹配
-     */
     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;
 
-    /**
-     * 内容提供者创建时调用
-     * 初始化数据库帮助类实例
-     */
     @Override
     public boolean onCreate() {
         mHelper = NotesDatabaseHelper.getInstance(getContext());
         return true;
     }
 
-    /**
-     * 查询方法 - 处理对笔记和数据的查询请求
-     * @param uri 请求的URI
-     * @param projection 查询的列
-     * @param selection 查询条件
-     * @param selectionArgs 查询条件参数
-     * @param sortOrder 排序方式
-     * @return 查询结果游标
-     */
     @Override
     public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs,
             String sortOrder) {
@@ -132,27 +96,35 @@ public class NotesProvider extends ContentProvider {
         SQLiteDatabase db = mHelper.getReadableDatabase();
         String id = null;
         switch (mMatcher.match(uri)) {
-            case URI_NOTE:  // 查询笔记集合
+            case URI_NOTE:
                 c = db.query(TABLE.NOTE, projection, selection, selectionArgs, null, null,
                         sortOrder);
                 break;
-
-            case URI_NOTE_ITEM:  // 查询单个笔记
+            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;
-            case URI_DATA:  // 查询笔记数据集合
+            case URI_DATA:
                 c = db.query(TABLE.DATA, projection, selection, selectionArgs, null, null,
                         sortOrder);
                 break;
-            case URI_DATA_ITEM:  // 查询单个笔记数据
+            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;
-            case URI_SEARCH:  // 搜索请求
-            case URI_SEARCH_SUGGEST:  // 搜索建议请求
+            case URI_TRASH:
+                c = db.query(TABLE.TRASH, projection, selection, selectionArgs, null, null,
+                        sortOrder);
+                break;
+            case URI_TRASH_ITEM:
+                id = uri.getPathSegments().get(1);
+                c = db.query(TABLE.TRASH, projection, NoteColumns.ID + "=" + id
+                        + parseSelection(selection), selectionArgs, null, null, sortOrder);
+                break;
+            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");
@@ -183,27 +155,20 @@ public class NotesProvider extends ContentProvider {
                 throw new IllegalArgumentException("Unknown URI " + uri);
         }
         if (c != null) {
-            // 通知游标所关联的 URI，用于后续数据变更时自动刷新
             c.setNotificationUri(getContext().getContentResolver(), uri);
         }
         return c;
     }
 
-    /**
-     * 插入方法 - 处理对笔记和数据的插入请求
-     * @param uri 请求的URI
-     * @param values 要插入的数据
-     * @return 插入后的资源URI
-     */
     @Override
     public Uri insert(Uri uri, ContentValues values) {
         SQLiteDatabase db = mHelper.getWritableDatabase();
         long dataId = 0, noteId = 0, insertedId = 0;
         switch (mMatcher.match(uri)) {
-            case URI_NOTE:  // 插入笔记
+            case URI_NOTE:
                 insertedId = noteId = db.insert(TABLE.NOTE, null, values);
                 break;
-            case URI_DATA:  // 插入笔记数据
+            case URI_DATA:
                 if (values.containsKey(DataColumns.NOTE_ID)) {
                     noteId = values.getAsLong(DataColumns.NOTE_ID);
                 } else {
@@ -211,31 +176,32 @@ public class NotesProvider extends ContentProvider {
                 }
                 insertedId = dataId = db.insert(TABLE.DATA, null, values);
                 break;
+            case URI_TRASH:
+                insertedId = noteId = db.insert(TABLE.TRASH, null, values);
+                break;
             default:
                 throw new IllegalArgumentException("Unknown URI " + uri);
         }
-        // 通知笔记 URI 变化（noteId>0 时）
-        if (noteId > 0) {
+        // Notify the note uri
+        if (noteId > 0 && mMatcher.match(uri) != URI_TRASH) {
             getContext().getContentResolver().notifyChange(
                     ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId), null);
         }
 
-        // 通知数据 URI 变化（dataId>0 时）
+        // Notify the data uri
         if (dataId > 0) {
             getContext().getContentResolver().notifyChange(
                     ContentUris.withAppendedId(Notes.CONTENT_DATA_URI, dataId), null);
         }
 
+        // Notify the trash uri
+        if (mMatcher.match(uri) == URI_TRASH) {
+            getContext().getContentResolver().notifyChange(Notes.CONTENT_TRASH_URI, null);
+        }
+
         return ContentUris.withAppendedId(uri, insertedId);
     }
 
-    /**
-     * 删除方法 - 处理对笔记和数据的删除请求
-     * @param uri 请求的URI
-     * @param selection 删除条件
-     * @param selectionArgs 删除条件参数
-     * @return 删除的行数
-     */
     @Override
     public int delete(Uri uri, String selection, String[] selectionArgs) {
         int count = 0;
@@ -252,7 +218,6 @@ public class NotesProvider extends ContentProvider {
                 /**
                  * ID that smaller than 0 is system folder which is not allowed to
                  * trash
-                 * ID小于0的是系统文件夹，不允许删除
                  */
                 long noteId = Long.valueOf(id);
                 if (noteId <= 0) {
@@ -271,50 +236,60 @@ public class NotesProvider extends ContentProvider {
                         DataColumns.ID + "=" + id + parseSelection(selection), selectionArgs);
                 deleteData = true;
                 break;
+            case URI_TRASH:
+                if (TextUtils.isEmpty(selection)) {
+                    selection = NoteColumns.ID + ">0";
+                } else {
+                    selection = "(" + selection + ") AND " + NoteColumns.ID + ">0 ";
+                }
+                count = db.delete(TABLE.TRASH, selection, selectionArgs);
+                break;
+            case URI_TRASH_ITEM:
+                id = uri.getPathSegments().get(1);
+                long trashId = Long.valueOf(id);
+                if (trashId <= 0) {
+                    break;
+                }
+                count = db.delete(TABLE.TRASH,
+                        NoteColumns.ID + "=" + id + parseSelection(selection), selectionArgs);
+                break;
             default:
                 throw new IllegalArgumentException("Unknown URI " + uri);
         }
         if (count > 0) {
             if (deleteData) {
-                // 数据行删除会影响笔记摘要，通知笔记 URI
                 getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null);
             }
+            if (mMatcher.match(uri) == URI_TRASH || mMatcher.match(uri) == URI_TRASH_ITEM) {
+                getContext().getContentResolver().notifyChange(Notes.CONTENT_TRASH_URI, null);
+            }
             getContext().getContentResolver().notifyChange(uri, null);
         }
         return count;
     }
 
-    /**
-     * 更新数据库中的数据
-     * @param uri 要更新的内容URI
-     * @param values 要更新的列值
-     * @param selection 更新条件
-     * @param selectionArgs 更新条件参数
-     * @return 更新的行数
-     */
     @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;  // 是否更新了数据内容
-        
+        boolean updateData = false;
         switch (mMatcher.match(uri)) {
-            case URI_NOTE:  // 更新所有笔记
-                increaseNoteVersion(-1, selection, selectionArgs);  // 增加笔记版本号
+            case URI_NOTE:
+                increaseNoteVersion(-1, selection, selectionArgs);
                 count = db.update(TABLE.NOTE, values, selection, selectionArgs);
                 break;
-            case URI_NOTE_ITEM:  // 更新单个笔记
+            case URI_NOTE_ITEM:
                 id = uri.getPathSegments().get(1);
-                increaseNoteVersion(Long.valueOf(id), selection, selectionArgs);  // 增加笔记版本号
+                increaseNoteVersion(Long.valueOf(id), selection, selectionArgs);
                 count = db.update(TABLE.NOTE, values, NoteColumns.ID + "=" + id
                         + parseSelection(selection), selectionArgs);
                 break;
-            case URI_DATA:  // 更新所有笔记数据
+            case URI_DATA:
                 count = db.update(TABLE.DATA, values, selection, selectionArgs);
                 updateData = true;
                 break;
-            case URI_DATA_ITEM:  // 更新单个笔记数据
+            case URI_DATA_ITEM:
                 id = uri.getPathSegments().get(1);
                 count = db.update(TABLE.DATA, values, DataColumns.ID + "=" + id
                         + parseSelection(selection), selectionArgs);
@@ -326,32 +301,17 @@ public class NotesProvider extends ContentProvider {
 
         if (count > 0) {
             if (updateData) {
-                // 数据行更新影响笔记摘要，通知笔记 URI
                 getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null);
             }
-            // 通知URI的观察者数据已更改
             getContext().getContentResolver().notifyChange(uri, null);
         }
         return count;
     }
 
-    /**
-     * 拼接 WHERE 子句，如果传入 selection 非空则加上 AND (...)。
-     *
-     * @param selection 选择条件
-     * @return 格式化后的选择条件
-     */
     private String parseSelection(String selection) {
-        return (!TextUtils.isEmpty(selection) ? " AND (" + selection + ")" : "");
+        return (!TextUtils.isEmpty(selection) ? " AND (" + selection + ')' : "");
     }
 
-    /**
-     * 增加笔记版本号，用于标记被修改过。
-     * 用于记录笔记的修改版本，支持并发更新场景
-     * @param id 笔记ID；小于0表示不按ID过滤，仅使用 selection
-     * @param selection 选择条件
-     * @param selectionArgs 选择参数
-     */
     private void increaseNoteVersion(long id, String selection, String[] selectionArgs) {
         StringBuilder sql = new StringBuilder(120);
         sql.append("UPDATE ");
@@ -377,11 +337,6 @@ public class NotesProvider extends ContentProvider {
         mHelper.getWritableDatabase().execSQL(sql.toString());
     }
 
-    /**
-     * 获取内容URI对应的MIME类型
-     * @param uri 内容URI
-     * @return MIME类型 - 目前未完全实现，返回null
-     */
     @Override
     public String getType(Uri uri) {
         // TODO Auto-generated method stub
diff --git a/src/Notes-master/src/net/micode/notes/tool/DataUtils.java b/src/Notes-master/src/net/micode/notes/tool/DataUtils.java
index d10fa87..5cab067 100644
--- a/src/Notes-master/src/net/micode/notes/tool/DataUtils.java
+++ b/src/Notes-master/src/net/micode/notes/tool/DataUtils.java
@@ -29,75 +29,95 @@ 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.data.Notes.TrashColumns;
 import net.micode.notes.ui.NotesListAdapter.AppWidgetAttribute;
 
 import java.util.ArrayList;
 import java.util.HashSet;
 
-/**
- * 数据工具类。
- * <p>职责：封装常用的数据库批量操作（删除、移动、查询校验等），统一错误处理与日志。</p>
- * <p>使用场景：列表/编辑/同步等需要对 note 表或 data 表做批量操作时复用。</p>
- */
-/**
- * 数据工具 - 提供笔记数据的各种操作工具方法
- * 包含批量删除、移动笔记、文件夹管理、小部件处理等功能
- */
+
 public class DataUtils {
-    /**
-     * 日志标签
-     */
     public static final String TAG = "DataUtils";
-    
     /**
-     * 批量删除笔记。
-     *
-     * @param resolver ContentResolver对象
-     * @param ids 要删除的笔记ID集合
-     * @return 删除成功返回true，否则返回false
+     * Move notes to trash table instead of directly deleting them
      */
-    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");
+    public static boolean batchMoveToTrash(ContentResolver resolver, HashSet<Long> ids) {
+        if (ids == null || ids.size() == 0) {
+            Log.d(TAG, "the ids is null or empty");
             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());
-        }
+        Cursor cursor = null;
         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;
+            for (long id : ids) {
+                if(id == Notes.ID_ROOT_FOLDER || id <= 0) {
+                    Log.e(TAG, "Don't move system folder root or invalid id: " + id);
+                    continue;
+                }
+
+                // Query the note from note table
+                cursor = resolver.query(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, id),
+                        null, null, null, null);
+                
+                if (cursor != null && cursor.moveToFirst()) {
+                    // Read all columns from the note
+                    ContentValues trashValues = new ContentValues();
+                    
+                    // Copy all columns from note to trash
+                    for (String column : cursor.getColumnNames()) {
+                        int columnIndex = cursor.getColumnIndex(column);
+                        if (columnIndex >= 0) {
+                            int type = cursor.getType(columnIndex);
+                            switch (type) {
+                                case android.database.Cursor.FIELD_TYPE_NULL:
+                                    break;
+                                case android.database.Cursor.FIELD_TYPE_INTEGER:
+                                    trashValues.put(column, cursor.getLong(columnIndex));
+                                    break;
+                                case android.database.Cursor.FIELD_TYPE_FLOAT:
+                                    trashValues.put(column, cursor.getDouble(columnIndex));
+                                    break;
+                                case android.database.Cursor.FIELD_TYPE_STRING:
+                                    trashValues.put(column, cursor.getString(columnIndex));
+                                    break;
+                                case android.database.Cursor.FIELD_TYPE_BLOB:
+                                    trashValues.put(column, cursor.getBlob(columnIndex));
+                                    break;
+                            }
+                        }
+                    }
+                    
+                    // Set deleted_date to current time
+                    trashValues.put("deleted_date", System.currentTimeMillis());
+                    
+                    // Insert into trash table
+                    resolver.insert(Notes.CONTENT_TRASH_URI, trashValues);
+                    
+                    // Delete from note table
+                    resolver.delete(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, id), null, null);
+                }
+                
+                if (cursor != null) {
+                    cursor.close();
+                    cursor = null;
+                }
             }
             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()));
+        } catch (Exception e) {
+            Log.e(TAG, String.format("Move to trash failed: %s", e.toString()));
+            return false;
+        } finally {
+            if (cursor != null) {
+                cursor.close();
+            }
         }
-        return false;
     }
 
-    /**
-     * 将单个笔记从源文件夹移动到目标文件夹
-     * @param resolver 内容解析器
-     * @param id 笔记ID
-     * @param srcFolderId 源文件夹ID
-     * @param desFolderId 目标文件夹ID
-     */
+    public static boolean batchDeleteNotes(ContentResolver resolver, HashSet<Long> ids) {
+        // Instead of directly deleting, move to trash
+        return batchMoveToTrash(resolver, ids);
+    }
+
     public static void moveNoteToFoler(ContentResolver resolver, long id, long srcFolderId, long desFolderId) {
         ContentValues values = new ContentValues();
         values.put(NoteColumns.PARENT_ID, desFolderId);
@@ -106,13 +126,6 @@ public class DataUtils {
         resolver.update(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, id), values, null, null);
     }
 
-    /**
-     * 批量将笔记移动到指定文件夹
-     * @param resolver 内容解析器
-     * @param ids 要移动的笔记ID集合
-     * @param folderId 目标文件夹ID
-     * @return 是否移动成功
-     */
     public static boolean batchMoveToFolder(ContentResolver resolver, HashSet<Long> ids,
             long folderId) {
         if (ids == null) {
@@ -145,9 +158,7 @@ public class DataUtils {
     }
 
     /**
-     * 获取用户创建的文件夹数量（不包括系统文件夹）
-     * @param resolver 内容解析器
-     * @return 用户文件夹数量
+     * 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,
@@ -171,13 +182,6 @@ public class DataUtils {
         return count;
     }
 
-    /**
-     * 检查指定ID和类型的笔记是否在数据库中可见（不在垃圾桶中）
-     * @param resolver 内容解析器
-     * @param noteId 笔记ID
-     * @param type 笔记类型
-     * @return 是否可见
-     */
     public static boolean visibleInNoteDatabase(ContentResolver resolver, long noteId, int type) {
         Cursor cursor = resolver.query(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId),
                 null,
@@ -195,12 +199,6 @@ public class DataUtils {
         return exist;
     }
 
-    /**
-     * 检查指定ID的笔记是否存在于数据库中
-     * @param resolver 内容解析器
-     * @param noteId 笔记ID
-     * @return 是否存在
-     */
     public static boolean existInNoteDatabase(ContentResolver resolver, long noteId) {
         Cursor cursor = resolver.query(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId),
                 null, null, null, null);
@@ -215,12 +213,6 @@ public class DataUtils {
         return exist;
     }
 
-    /**
-     * 检查指定ID的笔记数据是否存在于数据库中
-     * @param resolver 内容解析器
-     * @param dataId 数据ID
-     * @return 是否存在
-     */
     public static boolean existInDataDatabase(ContentResolver resolver, long dataId) {
         Cursor cursor = resolver.query(ContentUris.withAppendedId(Notes.CONTENT_DATA_URI, dataId),
                 null, null, null, null);
@@ -235,12 +227,6 @@ public class DataUtils {
         return exist;
     }
 
-    /**
-     * 检查指定名称的可见文件夹是否存在（不在垃圾桶中）
-     * @param resolver 内容解析器
-     * @param name 文件夹名称
-     * @return 是否存在
-     */
     public static boolean checkVisibleFolderName(ContentResolver resolver, String name) {
         Cursor cursor = resolver.query(Notes.CONTENT_NOTE_URI, null,
                 NoteColumns.TYPE + "=" + Notes.TYPE_FOLDER +
@@ -257,12 +243,6 @@ public class DataUtils {
         return exist;
     }
 
-    /**
-     * 获取与指定文件夹关联的所有应用小部件
-     * @param resolver 内容解析器
-     * @param folderId 文件夹ID
-     * @return 应用小部件属性集合
-     */
     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 },
@@ -290,13 +270,6 @@ public class DataUtils {
         return set;
     }
 
-    /**
-     * 通过笔记ID获取电话号码
-     * 用于通话记录笔记的电话号码获取
-     * @param resolver 内容解析器
-     * @param noteId 笔记ID
-     * @return 电话号码
-     */
     public static String getCallNumberByNoteId(ContentResolver resolver, long noteId) {
         Cursor cursor = resolver.query(Notes.CONTENT_DATA_URI,
                 new String [] { CallNote.PHONE_NUMBER },
@@ -317,13 +290,93 @@ public class DataUtils {
     }
 
     /**
-     * 通过电话号码和通话日期获取笔记ID
-     * 用于通话记录笔记的查询
-     * @param resolver 内容解析器
-     * @param phoneNumber 电话号码
-     * @param callDate 通话日期时间戳
-     * @return 笔记ID
+     * Restore note from trash table back to note table
      */
+    public static boolean restoreNoteFromTrash(ContentResolver resolver, long trashId) {
+        Cursor cursor = null;
+        try {
+            // Query the note from trash table
+            cursor = resolver.query(ContentUris.withAppendedId(Notes.CONTENT_TRASH_URI, trashId),
+                    null, null, null, null);
+            
+            if (cursor != null && cursor.moveToFirst()) {
+                // Read all columns from the trash note
+                ContentValues noteValues = new ContentValues();
+                
+                // Copy all columns from trash to note (except deleted_date)
+                for (String column : cursor.getColumnNames()) {
+                    if ("deleted_date".equals(column)) {
+                        continue; // Skip deleted_date column
+                    }
+                    int columnIndex = cursor.getColumnIndex(column);
+                    if (columnIndex >= 0) {
+                        int type = cursor.getType(columnIndex);
+                        switch (type) {
+                            case android.database.Cursor.FIELD_TYPE_NULL:
+                                break;
+                            case android.database.Cursor.FIELD_TYPE_INTEGER:
+                                noteValues.put(column, cursor.getLong(columnIndex));
+                                break;
+                            case android.database.Cursor.FIELD_TYPE_FLOAT:
+                                noteValues.put(column, cursor.getDouble(columnIndex));
+                                break;
+                            case android.database.Cursor.FIELD_TYPE_STRING:
+                                noteValues.put(column, cursor.getString(columnIndex));
+                                break;
+                            case android.database.Cursor.FIELD_TYPE_BLOB:
+                                noteValues.put(column, cursor.getBlob(columnIndex));
+                                break;
+                        }
+                    }
+                }
+                
+                // Insert back to note table
+                resolver.insert(Notes.CONTENT_NOTE_URI, noteValues);
+                
+                // Delete from trash table
+                resolver.delete(ContentUris.withAppendedId(Notes.CONTENT_TRASH_URI, trashId), null, null);
+                
+                return true;
+            }
+            return false;
+        } catch (Exception e) {
+            Log.e(TAG, String.format("Restore from trash failed: %s", e.toString()));
+            return false;
+        } finally {
+            if (cursor != null) {
+                cursor.close();
+            }
+        }
+    }
+
+    /**
+     * Permanently delete note from trash table
+     */
+    public static boolean permanentlyDeleteFromTrash(ContentResolver resolver, long trashId) {
+        try {
+            int count = resolver.delete(ContentUris.withAppendedId(Notes.CONTENT_TRASH_URI, trashId), null, null);
+            return count > 0;
+        } catch (Exception e) {
+            Log.e(TAG, String.format("Permanently delete from trash failed: %s", e.toString()));
+            return false;
+        }
+    }
+
+    /**
+     * Clear all notes from trash table
+     */
+    public static boolean clearAllTrash(ContentResolver resolver) {
+        try {
+            int count = resolver.delete(Notes.CONTENT_TRASH_URI, null, null);
+            Log.d(TAG, "Cleared " + count + " notes from trash");
+            // Return true even if count is 0, as it might mean the trash was already empty
+            return true;
+        } catch (Exception e) {
+            Log.e(TAG, String.format("Clear all trash failed: %s", e.toString()));
+            return false;
+        }
+    }
+
     public static long getNoteIdByPhoneNumberAndCallDate(ContentResolver resolver, String phoneNumber, long callDate) {
         Cursor cursor = resolver.query(Notes.CONTENT_DATA_URI,
                 new String [] { CallNote.NOTE_ID },
@@ -345,13 +398,6 @@ public class DataUtils {
         return 0;
     }
 
-    /**
-     * 通过笔记ID获取笔记摘要
-     * @param resolver 内容解析器
-     * @param noteId 笔记ID
-     * @return 笔记摘要
-     * @throws IllegalArgumentException 如果笔记不存在
-     */
     public static String getSnippetById(ContentResolver resolver, long noteId) {
         Cursor cursor = resolver.query(Notes.CONTENT_NOTE_URI,
                 new String [] { NoteColumns.SNIPPET },
@@ -370,12 +416,6 @@ public class DataUtils {
         throw new IllegalArgumentException("Note is not found with id: " + noteId);
     }
 
-    /**
-     * 格式化笔记摘要
-     * 去除首尾空格并只保留第一行内容
-     * @param snippet 原始笔记摘要
-     * @return 格式化后的笔记摘要
-     */
     public static String getFormattedSnippet(String snippet) {
         if (snippet != null) {
             snippet = snippet.trim();
diff --git a/src/Notes-master/src/net/micode/notes/ui/NotesListActivity.java b/src/Notes-master/src/net/micode/notes/ui/NotesListActivity.java
index 31b61b7..0478bbd 100644
--- a/src/Notes-master/src/net/micode/notes/ui/NotesListActivity.java
+++ b/src/Notes-master/src/net/micode/notes/ui/NotesListActivity.java
@@ -78,90 +78,85 @@ import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.util.HashSet;
 
-/**
- * 笔记列表活动 - 负责显示和管理笔记列表
- * 提供笔记的创建、编辑、删除、移动等功能
- * 支持文件夹管理和多选操作模式
- */
 public class NotesListActivity extends Activity implements OnClickListener, OnItemLongClickListener {
-    // 异步查询处理的标记常量
-    private static final int FOLDER_NOTE_LIST_QUERY_TOKEN = 0; // 查询笔记列表的标记
-    private static final int FOLDER_LIST_QUERY_TOKEN      = 1; // 查询文件夹列表的标记
+    private static final int FOLDER_NOTE_LIST_QUERY_TOKEN = 0;
+
+    private static final int FOLDER_LIST_QUERY_TOKEN      = 1;
+
+    private static final int MENU_FOLDER_DELETE = 0;
 
-    // 文件夹上下文菜单的菜单项ID
-    private static final int MENU_FOLDER_DELETE = 0;         // 删除文件夹
-    private static final int MENU_FOLDER_VIEW = 1;           // 查看文件夹
-    private static final int MENU_FOLDER_CHANGE_NAME = 2;    // 修改文件夹名称
+    private static final int MENU_FOLDER_VIEW = 1;
+
+    private static final int MENU_FOLDER_CHANGE_NAME = 2;
 
-    // 用于存储应用介绍是否已添加的偏好设置键
     private static final String PREFERENCE_ADD_INTRODUCTION = "net.micode.notes.introduction";
 
-    /**
-     * 列表所处的编辑状态：
-     * NOTE_LIST 根目录；SUB_FOLDER 子文件夹；CALL_RECORD_FOLDER 通话记录专用文件夹。
-     */
     private enum ListEditState {
-        NOTE_LIST,            // 笔记列表状态
-        SUB_FOLDER,           // 子文件夹状态
-        CALL_RECORD_FOLDER    // 通话记录文件夹状态
+        NOTE_LIST, SUB_FOLDER, CALL_RECORD_FOLDER
     };
 
-    // 成员变量
-    private ListEditState mState;                           // 当前列表编辑状态
-    private BackgroundQueryHandler mBackgroundQueryHandler; // 异步查询处理器
-    private NotesListAdapter mNotesListAdapter;             // 笔记列表适配器
-    private ListView mNotesListView;                        // 笔记列表视图
-    private Button mAddNewNote;                             // 新建笔记按钮
-    private boolean mDispatch;                              // 是否分发触摸事件给列表视图
-    private int mOriginY;                                   // 原始触摸Y坐标
-    private int mDispatchY;                                 // 分发触摸Y坐标
-    private TextView mTitleBar;                             // 标题栏
-    private long mCurrentFolderId;                          // 当前文件夹ID
-    private ContentResolver mContentResolver;               // 内容解析器
-    private ModeCallback mModeCallBack;                     // 多选模式回调
-
-    private static final String TAG = "NotesListActivity";  // 日志标签
-    public static final int NOTES_LISTVIEW_SCROLL_RATE = 30;// 笔记列表滚动速率
-
-    private NoteItemData mFocusNoteDataItem;                // 当前焦点的笔记数据项
-
-    // 查询条件常量
-    private static final String NORMAL_SELECTION = NoteColumns.PARENT_ID + "=?"; // 普通文件夹查询条件
+    private ListEditState mState;
+
+    private BackgroundQueryHandler mBackgroundQueryHandler;
+
+    private NotesListAdapter mNotesListAdapter;
+
+    private ListView mNotesListView;
+
+    private Button mAddNewNote;
+
+    private boolean mDispatch;
+
+    private int mOriginY;
+
+    private int mDispatchY;
+
+    private TextView mTitleBar;
+
+    private long mCurrentFolderId;
+
+    private ContentResolver mContentResolver;
+
+    private ModeCallback mModeCallBack;
+
+    private static final String TAG = "NotesListActivity";
+
+    public static final int NOTES_LISTVIEW_SCROLL_RATE = 30;
+
+    private NoteItemData mFocusNoteDataItem;
+
+    private static final String NORMAL_SELECTION = NoteColumns.PARENT_ID + "=?";
+
     private static final String ROOT_FOLDER_SELECTION = "(" + NoteColumns.TYPE + "<>"
             + Notes.TYPE_SYSTEM + " AND " + NoteColumns.PARENT_ID + "=?)" + " OR ("
             + NoteColumns.ID + "=" + Notes.ID_CALL_RECORD_FOLDER + " AND "
-            + NoteColumns.NOTES_COUNT + ">0)"; // 根文件夹查询条件（显示非系统文件夹和非空通话记录文件夹）
+            + NoteColumns.NOTES_COUNT + ">0)";
 
-    // 请求码常量
-    private final static int REQUEST_CODE_OPEN_NODE = 102; // 打开笔记的请求码
-    private final static int REQUEST_CODE_NEW_NODE  = 103; // 新建笔记的请求码
+    private final static int REQUEST_CODE_OPEN_NODE = 102;
+    private final static int REQUEST_CODE_NEW_NODE  = 103;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
-        setContentView(R.layout.note_list); // 设置布局
-        initResources(); // 初始化资源
+        setContentView(R.layout.note_list);
+        initResources();
 
-        // 首次进入时插入“介绍”笔记
-        setAppInfoFromRawRes(); // 设置应用信息（首次使用时添加介绍笔记）
+        /**
+         * Insert an introduction when user firstly use this application
+         */
+        setAppInfoFromRawRes();
     }
 
     @Override
     protected void onActivityResult(int requestCode, int resultCode, Intent data) {
-        // 处理从NoteEditActivity返回的结果
         if (resultCode == RESULT_OK
                 && (requestCode == REQUEST_CODE_OPEN_NODE || requestCode == REQUEST_CODE_NEW_NODE)) {
-            // 如果是打开或新建笔记的请求返回成功，刷新列表
             mNotesListAdapter.changeCursor(null);
         } else {
             super.onActivityResult(requestCode, resultCode, data);
         }
     }
 
-/**
-     * 从原始资源文件中设置应用介绍信息
-     * 当用户首次使用应用时，添加介绍笔记
-     */
     private void setAppInfoFromRawRes() {
         SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(this);
         if (!sp.getBoolean(PREFERENCE_ADD_INTRODUCTION, false)) {
@@ -208,20 +203,12 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
         }
     }
 
-    /**
-     * 当活动开始时调用
-     * 启动异步查询笔记列表
-     */
     @Override
     protected void onStart() {
         super.onStart();
         startAsyncNotesListQuery();
     }
 
-/**
-     * 初始化资源
-     * 设置内容解析器、异步查询处理器、列表适配器等
-     */
     private void initResources() {
         mContentResolver = this.getContentResolver();
         mBackgroundQueryHandler = new BackgroundQueryHandler(this.getContentResolver());
@@ -244,19 +231,11 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
         mModeCallBack = new ModeCallback();
     }
 
-/**
-     * 多选模式回调类 - 处理笔记的多选操作
-     * 实现了多选模式下的菜单创建、选择状态变化等功能
-     */
     private class ModeCallback implements ListView.MultiChoiceModeListener, OnMenuItemClickListener {
         private DropdownMenu mDropDownMenu;
         private ActionMode mActionMode;
         private MenuItem mMoveMenu;
 
-        /**
-         * 创建操作模式时调用
-         * 设置多选模式下的菜单和视图
-         */
         public boolean onCreateActionMode(ActionMode mode, Menu menu) {
             getMenuInflater().inflate(R.menu.note_list_options, menu);
             menu.findItem(R.id.delete).setOnMenuItemClickListener(this);
@@ -290,10 +269,6 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
             return true;
         }
 
-        /**
-         * 更新菜单状态
-         * 根据选择的笔记数量更新下拉菜单标题和全选状态
-         */
         private void updateMenu() {
             int selectedCount = mNotesListAdapter.getSelectedCount();
             // Update dropdown menu
@@ -321,37 +296,22 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
             return false;
         }
 
-        /**
-         * 销毁操作模式时调用
-         * 恢复普通模式下的视图状态
-         */
         public void onDestroyActionMode(ActionMode mode) {
             mNotesListAdapter.setChoiceMode(false);
             mNotesListView.setLongClickable(true);
             mAddNewNote.setVisibility(View.VISIBLE);
         }
 
-        /**
-         * 结束操作模式
-         */
         public void finishActionMode() {
             mActionMode.finish();
         }
 
-        /**
-         * 当列表项的选择状态改变时调用
-         * 更新适配器中的选择状态并刷新菜单
-         */
         public void onItemCheckedStateChanged(ActionMode mode, int position, long id,
                 boolean checked) {
             mNotesListAdapter.setCheckedItem(position, checked);
             updateMenu();
         }
 
-        /**
-         * 处理菜单项点击事件
-         * 支持删除和移动操作
-         */
         public boolean onMenuItemClick(MenuItem item) {
             if (mNotesListAdapter.getSelectedCount() == 0) {
                 Toast.makeText(NotesListActivity.this, getString(R.string.menu_select_none),
@@ -361,7 +321,6 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
 
             switch (item.getItemId()) {
                 case R.id.delete:
-                    // 显示删除确认对话框
                     AlertDialog.Builder builder = new AlertDialog.Builder(NotesListActivity.this);
                     builder.setTitle(getString(R.string.alert_title_delete));
                     builder.setIcon(android.R.drawable.ic_dialog_alert);
@@ -371,14 +330,13 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
                                              new DialogInterface.OnClickListener() {
                                                  public void onClick(DialogInterface dialog,
                                                          int which) {
-                                                     batchDelete(); // 执行批量删除
+                                                     batchDelete();
                                                  }
                                              });
                     builder.setNegativeButton(android.R.string.cancel, null);
                     builder.show();
                     break;
                 case R.id.move:
-                    // 查询目标文件夹列表
                     startQueryDestinationFolders();
                     break;
                 default:
@@ -388,10 +346,6 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
         }
     }
 
-/**
-     * 新建笔记按钮的触摸监听器
-     * 处理特殊的触摸事件分发逻辑
-     */
     private class NewNoteOnTouchListener implements OnTouchListener {
 
         public boolean onTouch(View v, MotionEvent event) {
@@ -402,13 +356,22 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
                     int newNoteViewHeight = mAddNewNote.getHeight();
                     int start = screenHeight - newNoteViewHeight;
                     int eventY = start + (int) event.getY();
-                    // 子文件夹状态需减去标题栏高度
+                    /**
+                     * Minus TitleBar's height
+                     */
                     if (mState == ListEditState.SUB_FOLDER) {
                         eventY -= mTitleBar.getHeight();
                         start -= mTitleBar.getHeight();
                     }
-                    // HACKME: 点击“新建”按钮透明区时，将事件派发给下方列表。
-                    // 透明区近似线性公式 y = -0.12x + 94（px），背景改动需同步更新该公式。
+                    /**
+                     * HACKME:When click the transparent part of "New Note" button, dispatch
+                     * the event to the list view behind this button. The transparent part of
+                     * "New Note" button could be expressed by formula y=-0.12x+94（Unit:pixel）
+                     * and the line top of the button. The coordinate based on left of the "New
+                     * Note" button. The 94 represents maximum height of the transparent part.
+                     * Notice that, if the background of the button changes, the formula should
+                     * also change. This is very bad, just for the UI designer's strong requirement.
+                     */
                     if (event.getY() < (event.getX() * (-0.12) + 94)) {
                         View view = mNotesListView.getChildAt(mNotesListView.getChildCount() - 1
                                 - mNotesListView.getFooterViewsCount());
@@ -445,10 +408,6 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
 
     };
 
-/**
-     * 开始异步查询笔记列表
-     * 根据当前文件夹ID选择不同的查询条件
-     */
     private void startAsyncNotesListQuery() {
         String selection = (mCurrentFolderId == Notes.ID_ROOT_FOLDER) ? ROOT_FOLDER_SELECTION
                 : NORMAL_SELECTION;
@@ -458,27 +417,18 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
                 }, NoteColumns.TYPE + " DESC," + NoteColumns.MODIFIED_DATE + " DESC");
     }
 
-/**
-     * 后台查询处理器 - 处理异步数据库查询
-     */
     private final class BackgroundQueryHandler extends AsyncQueryHandler {
         public BackgroundQueryHandler(ContentResolver contentResolver) {
             super(contentResolver);
         }
 
-        /**
-         * 查询完成时调用
-         * 根据不同的查询标记处理查询结果
-         */
         @Override
         protected void onQueryComplete(int token, Object cookie, Cursor cursor) {
             switch (token) {
                 case FOLDER_NOTE_LIST_QUERY_TOKEN:
-                    // 查询笔记列表完成，更新适配器
                     mNotesListAdapter.changeCursor(cursor);
                     break;
                 case FOLDER_LIST_QUERY_TOKEN:
-                    // 查询文件夹列表完成，显示文件夹菜单
                     if (cursor != null && cursor.getCount() > 0) {
                         showFolderListMenu(cursor);
                     } else {
@@ -491,10 +441,6 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
         }
     }
 
-/**
-     * 显示文件夹列表菜单
-     * 用于选择移动笔记的目标文件夹
-     */
     private void showFolderListMenu(Cursor cursor) {
         AlertDialog.Builder builder = new AlertDialog.Builder(NotesListActivity.this);
         builder.setTitle(R.string.menu_title_select_folder);
@@ -516,10 +462,6 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
         builder.show();
     }
 
-/**
-     * 创建新笔记
-     * 跳转到笔记编辑界面
-     */
     private void createNewNote() {
         Intent intent = new Intent(this, NoteEditActivity.class);
         intent.setAction(Intent.ACTION_INSERT_OR_EDIT);
@@ -527,10 +469,6 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
         this.startActivityForResult(intent, REQUEST_CODE_NEW_NODE);
     }
 
-/**
-     * 批量删除笔记
-     * 在同步模式下将笔记移动到回收站，非同步模式下直接删除
-     */
     private void batchDelete() {
         new AsyncTask<Void, Void, HashSet<AppWidgetAttribute>>() {
             protected HashSet<AppWidgetAttribute> doInBackground(Void... unused) {
@@ -568,10 +506,6 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
         }.execute();
     }
 
-/**
-     * 删除文件夹
-     * 在同步模式下将文件夹移动到回收站，非同步模式下直接删除
-     */
     private void deleteFolder(long folderId) {
         if (folderId == Notes.ID_ROOT_FOLDER) {
             Log.e(TAG, "Wrong folder id, should not happen " + folderId);
@@ -599,10 +533,6 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
         }
     }
 
-/**
-     * 打开笔记
-     * 跳转到笔记编辑界面查看/编辑笔记
-     */
     private void openNode(NoteItemData data) {
         Intent intent = new Intent(this, NoteEditActivity.class);
         intent.setAction(Intent.ACTION_VIEW);
@@ -610,10 +540,6 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
         this.startActivityForResult(intent, REQUEST_CODE_OPEN_NODE);
     }
 
-/**
-     * 打开文件夹
-     * 更新当前文件夹ID并重新查询笔记列表
-     */
     private void openFolder(NoteItemData data) {
         mCurrentFolderId = data.getId();
         startAsyncNotesListQuery();
@@ -631,10 +557,6 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
         mTitleBar.setVisibility(View.VISIBLE);
     }
 
-/**
-     * 处理点击事件
-     * 当前只处理新建笔记按钮的点击
-     */
     public void onClick(View v) {
         switch (v.getId()) {
             case R.id.btn_new_note:
@@ -645,9 +567,6 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
         }
     }
 
-/**
-     * 显示软键盘
-     */
     private void showSoftInput() {
         InputMethodManager inputMethodManager = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
         if (inputMethodManager != null) {
@@ -655,18 +574,11 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
         }
     }
 
-/**
-     * 隐藏软键盘
-     */
     private void hideSoftInput(View view) {
         InputMethodManager inputMethodManager = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
         inputMethodManager.hideSoftInputFromWindow(view.getWindowToken(), 0);
     }
 
-/**
-     * 显示创建或修改文件夹的对话框
-     * @param create 是否为创建文件夹模式
-     */
     private void showCreateOrModifyFolderDialog(final boolean create) {
         final AlertDialog.Builder builder = new AlertDialog.Builder(this);
         View view = LayoutInflater.from(this).inflate(R.layout.dialog_edit_text, null);
@@ -752,10 +664,6 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
         });
     }
 
-    /**
-     * 处理返回键按下事件
-     * 根据当前状态返回到上一级菜单或退出应用
-     */
     @Override
     public void onBackPressed() {
         switch (mState) {
@@ -780,10 +688,6 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
         }
     }
 
-/**
-     * 更新小部件
-     * 根据小部件类型发送相应的广播更新
-     */
     private void updateWidget(int appWidgetId, int appWidgetType) {
         Intent intent = new Intent(AppWidgetManager.ACTION_APPWIDGET_UPDATE);
         if (appWidgetType == Notes.TYPE_WIDGET_2X) {
@@ -803,10 +707,6 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
         setResult(RESULT_OK, intent);
     }
 
-/**
-     * 文件夹上下文菜单监听器
-     * 创建文件夹的上下文菜单
-     */
     private final OnCreateContextMenuListener mFolderOnCreateContextMenuListener = new OnCreateContextMenuListener() {
         public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) {
             if (mFocusNoteDataItem != null) {
@@ -818,10 +718,6 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
         }
     };
 
-    /**
-     * 上下文菜单关闭时调用
-     * 清除列表视图的上下文菜单监听器
-     */
     @Override
     public void onContextMenuClosed(Menu menu) {
         if (mNotesListView != null) {
@@ -830,10 +726,6 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
         super.onContextMenuClosed(menu);
     }
 
-    /**
-     * 处理上下文菜单项的选择
-     * 支持查看、删除、重命名文件夹操作
-     */
     @Override
     public boolean onContextItemSelected(MenuItem item) {
         if (mFocusNoteDataItem == null) {
@@ -868,10 +760,6 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
         return true;
     }
 
-    /**
-     * 准备选项菜单
-     * 根据当前状态加载不同的菜单布局
-     */
     @Override
     public boolean onPrepareOptionsMenu(Menu menu) {
         menu.clear();
@@ -890,10 +778,6 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
         return true;
     }
 
-    /**
-     * 处理选项菜单项的选择
-     * 支持新建文件夹、导出文本、同步等操作
-     */
     @Override
     public boolean onOptionsItemSelected(MenuItem item) {
         switch (item.getItemId()) {
@@ -928,6 +812,11 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
             case R.id.menu_search:
                 onSearchRequested();
                 break;
+            case R.id.menu_trash: {
+                Intent intent = new Intent(this, TrashActivity.class);
+                startActivity(intent);
+                break;
+            }
             default:
                 break;
         }
diff --git a/src/Notes-master/src/net/micode/notes/ui/TrashActivity.java b/src/Notes-master/src/net/micode/notes/ui/TrashActivity.java
new file mode 100644
index 0000000..cf07235
--- /dev/null
+++ b/src/Notes-master/src/net/micode/notes/ui/TrashActivity.java
@@ -0,0 +1,203 @@
+/*
+ * 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.ui;
+
+import android.app.Activity;
+import android.app.AlertDialog;
+import android.content.AsyncQueryHandler;
+import android.content.ContentResolver;
+import android.content.DialogInterface;
+import android.database.Cursor;
+import android.os.Bundle;
+import android.util.Log;
+import android.view.View;
+import android.view.View.OnClickListener;
+import android.widget.AdapterView;
+import android.widget.AdapterView.OnItemClickListener;
+import android.widget.Button;
+import android.widget.ListView;
+import android.widget.Toast;
+
+import net.micode.notes.R;
+import net.micode.notes.data.Notes;
+import net.micode.notes.data.Notes.NoteColumns;
+import net.micode.notes.tool.DataUtils;
+
+public class TrashActivity extends Activity implements OnClickListener {
+    private static final String TAG = "TrashActivity";
+    
+    private static final int TRASH_LIST_QUERY_TOKEN = 0;
+    
+    private Button mReturnButton;
+    private Button mCleanAllButton;
+    private ListView mTrashListView;
+    private NotesListAdapter mTrashListAdapter;
+    private ContentResolver mContentResolver;
+    private BackgroundQueryHandler mBackgroundQueryHandler;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.activity_trash);
+        initResources();
+    }
+
+    @Override
+    protected void onStart() {
+        super.onStart();
+        startAsyncTrashListQuery();
+    }
+
+    private void initResources() {
+        mContentResolver = this.getContentResolver();
+        mBackgroundQueryHandler = new BackgroundQueryHandler(mContentResolver);
+        
+        mReturnButton = (Button) findViewById(R.id.btn_return);
+        if (mReturnButton != null) {
+            mReturnButton.setOnClickListener(this);
+        }
+        
+        mCleanAllButton = (Button) findViewById(R.id.btn_clean_all);
+        if (mCleanAllButton != null) {
+            mCleanAllButton.setOnClickListener(this);
+        }
+        
+        mTrashListView = (ListView) findViewById(R.id.trash_list);
+        if (mTrashListView != null) {
+            mTrashListAdapter = new NotesListAdapter(this);
+            mTrashListView.setAdapter(mTrashListAdapter);
+            mTrashListView.setOnItemClickListener(new OnTrashItemClickListener());
+        }
+    }
+
+    private void startAsyncTrashListQuery() {
+        mBackgroundQueryHandler.startQuery(TRASH_LIST_QUERY_TOKEN, null,
+                Notes.CONTENT_TRASH_URI, NoteItemData.PROJECTION, null, null,
+                NoteColumns.MODIFIED_DATE + " DESC");
+    }
+
+    private final class BackgroundQueryHandler extends AsyncQueryHandler {
+        public BackgroundQueryHandler(ContentResolver contentResolver) {
+            super(contentResolver);
+        }
+
+        @Override
+        protected void onQueryComplete(int token, Object cookie, Cursor cursor) {
+            switch (token) {
+                case TRASH_LIST_QUERY_TOKEN:
+                    mTrashListAdapter.changeCursor(cursor);
+                    break;
+                default:
+                    break;
+            }
+        }
+    }
+
+    private class OnTrashItemClickListener implements OnItemClickListener {
+        @Override
+        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
+            if (view instanceof NotesListItem) {
+                NoteItemData item = ((NotesListItem) view).getItemData();
+                showTrashItemDialog(item);
+            }
+        }
+    }
+
+    private void showTrashItemDialog(final NoteItemData item) {
+        AlertDialog.Builder builder = new AlertDialog.Builder(this);
+        builder.setTitle(item.getSnippet());
+        builder.setItems(new String[] {
+                getString(R.string.menu_delete),
+                getString(R.string.button_recovery)
+        }, new DialogInterface.OnClickListener() {
+            @Override
+            public void onClick(DialogInterface dialog, int which) {
+                switch (which) {
+                    case 0: // Delete - 彻底删除
+                        permanentlyDeleteNote(item.getId());
+                        break;
+                    case 1: // Recovery - 恢复
+                        recoverNote(item.getId());
+                        break;
+                }
+            }
+        });
+        builder.show();
+    }
+
+    private void permanentlyDeleteNote(long noteId) {
+        if (DataUtils.permanentlyDeleteFromTrash(mContentResolver, noteId)) {
+            Toast.makeText(this, getString(R.string.menu_delete) + " " + getString(R.string.menu_success), 
+                    Toast.LENGTH_SHORT).show();
+            startAsyncTrashListQuery(); // Refresh list
+        } else {
+            Toast.makeText(this, getString(R.string.menu_delete) + " " + getString(R.string.failed_sdcard_export), 
+                    Toast.LENGTH_SHORT).show();
+        }
+    }
+
+    private void recoverNote(long noteId) {
+        if (DataUtils.restoreNoteFromTrash(mContentResolver, noteId)) {
+            Toast.makeText(this, getString(R.string.button_recovery) + " " + getString(R.string.menu_success), 
+                    Toast.LENGTH_SHORT).show();
+            startAsyncTrashListQuery(); // Refresh list
+        } else {
+            Toast.makeText(this, getString(R.string.button_recovery) + " " + getString(R.string.failed_sdcard_export), 
+                    Toast.LENGTH_SHORT).show();
+        }
+    }
+
+    private void showClearAllTrashDialog() {
+        AlertDialog.Builder builder = new AlertDialog.Builder(this);
+        builder.setTitle(getString(R.string.button_clean_all));
+        builder.setMessage(getString(R.string.alert_message_clear_all_trash));
+        builder.setPositiveButton(android.R.string.ok,
+                new DialogInterface.OnClickListener() {
+                    @Override
+                    public void onClick(DialogInterface dialog, int which) {
+                        clearAllTrash();
+                    }
+                });
+        builder.setNegativeButton(android.R.string.cancel, null);
+        builder.show();
+    }
+
+    private void clearAllTrash() {
+        if (DataUtils.clearAllTrash(mContentResolver)) {
+            Toast.makeText(this, getString(R.string.button_clean_all) + " " + getString(R.string.menu_success), 
+                    Toast.LENGTH_SHORT).show();
+            startAsyncTrashListQuery(); // Refresh list to clear UI
+        } else {
+            Toast.makeText(this, getString(R.string.button_clean_all) + " " + getString(R.string.failed_sdcard_export), 
+                    Toast.LENGTH_SHORT).show();
+        }
+    }
+
+    @Override
+    public void onClick(View v) {
+        switch (v.getId()) {
+            case R.id.btn_return:
+                finish();
+                break;
+            case R.id.btn_clean_all:
+                showClearAllTrashDialog();
+                break;
+            default:
+                break;
+        }
+    }
+}
\ No newline at end of file