ui-NotesPreferenceActivity注释

src/Notes-master/src/net/micode/notes/ui/NotesPreferenceActivity.java

@@ -48,42 +48,61 @@ import net.micode.notes.data.Notes.NoteColumns;
 import net.micode.notes.gtask.remote.GTaskSyncService;
 
 
+/**
+ * NotesPreferenceActivity是一个用于设置便签应用偏好的Activity
+ * 提供了账户管理、同步设置等功能
+ */
 public class NotesPreferenceActivity extends PreferenceActivity {
+    // 偏好设置的名称
     public static final String PREFERENCE_NAME = "notes_preferences";
     
+    // 存储同步账户名称的键
     public static final String PREFERENCE_SYNC_ACCOUNT_NAME = "pref_key_account_name";
     
+    // 存储上次同步时间的键
     public static final String PREFERENCE_LAST_SYNC_TIME = "pref_last_sync_time";
     
+    // 设置便签背景颜色的键
     public static final String PREFERENCE_SET_BG_COLOR_KEY = "pref_key_bg_random_appear";
     
+    // 同步账户设置的键
     private static final String PREFERENCE_SYNC_ACCOUNT_KEY = "pref_sync_account_key";
     
+    // 账户权限过滤器的键
     private static final String AUTHORITIES_FILTER_KEY = "authorities";
     
+    // 账户设置的分类
     private PreferenceCategory mAccountCategory;
     
+    // 接收同步服务广播的接收器
     private GTaskReceiver mReceiver;
     
+    // 原始账户列表
     private Account[] mOriAccounts;
     
+    // 是否添加了新账户的标志
     private boolean mHasAddedAccount;
 
     @Override
     protected void onCreate(Bundle icicle) {
         super.onCreate(icicle);
 
-        /* using the app icon for navigation */
+        // 设置应用图标可用于导航返回
         getActionBar().setDisplayHomeAsUpEnabled(true);
 
+        // 加载偏好设置布局
         addPreferencesFromResource(R.xml.preferences);
         mAccountCategory = (PreferenceCategory) findPreference(PREFERENCE_SYNC_ACCOUNT_KEY);
         mReceiver = new GTaskReceiver();
+        
+        // 注册广播接收器，监听同步服务的状态变化
         IntentFilter filter = new IntentFilter();
         filter.addAction(GTaskSyncService.GTASK_SERVICE_BROADCAST_NAME);
         registerReceiver(mReceiver, filter);
 
         mOriAccounts = null;
+        
+        // 添加设置页面的头部视图
         View header = LayoutInflater.from(this).inflate(R.layout.settings_header, null);
         getListView().addHeaderView(header, null, true);
     }
@@ -92,8 +111,7 @@ public class NotesPreferenceActivity extends PreferenceActivity {
     protected void onResume() {
         super.onResume();
 
-        // need to set sync account automatically if user has added a new
+        // 如果添加了新账户，自动设置同步账户
-        // account
         if (mHasAddedAccount) {
             Account[] accounts = getGoogleAccounts();
             if (mOriAccounts != null && accounts.length > mOriAccounts.length) {
@@ -113,36 +131,44 @@ public class NotesPreferenceActivity extends PreferenceActivity {
             }
         }
 
+        // 刷新界面
         refreshUI();
     }
 
     @Override
     protected void onDestroy() {
+        // 注销广播接收器，防止内存泄漏
         if (mReceiver != null) {
             unregisterReceiver(mReceiver);
         }
         super.onDestroy();
     }
 
+    /**
+     * 加载账户设置相关的偏好项
+     */
     private void loadAccountPreference() {
+        // 清空账户分类下的所有偏好项
         mAccountCategory.removeAll();
 
+        // 创建账户选择偏好项
         Preference accountPref = new Preference(this);
         final String defaultAccount = getSyncAccountName(this);
         accountPref.setTitle(getString(R.string.preferences_account_title));
         accountPref.setSummary(getString(R.string.preferences_account_summary));
         accountPref.setOnPreferenceClickListener(new OnPreferenceClickListener() {
             public boolean onPreferenceClick(Preference preference) {
+                // 如果当前没有进行同步操作
                 if (!GTaskSyncService.isSyncing()) {
+                    // 如果还没有设置账户，显示选择账户对话框
                     if (TextUtils.isEmpty(defaultAccount)) {
-                        // the first time to set account
                         showSelectAccountAlertDialog();
                     } else {
-                        // if the account has already been set, we need to promp
+                        // 如果已经设置了账户，显示更改账户确认对话框
-                        // user about the risk
                         showChangeAccountConfirmAlertDialog();
                     }
                 } else {
+                    // 同步过程中不能更改账户，提示用户
                     Toast.makeText(NotesPreferenceActivity.this,
                             R.string.preferences_toast_cannot_change_account, Toast.LENGTH_SHORT)
                             .show();
@@ -151,15 +177,20 @@ public class NotesPreferenceActivity extends PreferenceActivity {
             }
         });
 
+        // 将账户偏好项添加到分类中
         mAccountCategory.addPreference(accountPref);
     }
 
+    /**
+     * 加载同步按钮和相关状态显示
+     */
     private void loadSyncButton() {
         Button syncButton = (Button) findViewById(R.id.preference_sync_button);
         TextView lastSyncTimeView = (TextView) findViewById(R.id.prefenerece_sync_status_textview);
 
-        // set button state
+        // 设置同步按钮状态
         if (GTaskSyncService.isSyncing()) {
+            // 当前正在同步，显示取消同步按钮
             syncButton.setText(getString(R.string.preferences_button_sync_cancel));
             syncButton.setOnClickListener(new View.OnClickListener() {
                 public void onClick(View v) {
@@ -167,6 +198,7 @@ public class NotesPreferenceActivity extends PreferenceActivity {
                 }
             });
         } else {
+            // 当前没有同步，显示立即同步按钮
             syncButton.setText(getString(R.string.preferences_button_sync_immediately));
             syncButton.setOnClickListener(new View.OnClickListener() {
                 public void onClick(View v) {
@@ -174,13 +206,16 @@ public class NotesPreferenceActivity extends PreferenceActivity {
                 }
             });
         }
+        // 如果没有设置同步账户，禁用同步按钮
         syncButton.setEnabled(!TextUtils.isEmpty(getSyncAccountName(this)));
 
-        // set last sync time
+        // 设置上次同步时间显示
         if (GTaskSyncService.isSyncing()) {
+            // 显示同步进度
             lastSyncTimeView.setText(GTaskSyncService.getProgressString());
             lastSyncTimeView.setVisibility(View.VISIBLE);
         } else {
+            // 显示上次同步时间
             long lastSyncTime = getLastSyncTime(this);
             if (lastSyncTime != 0) {
                 lastSyncTimeView.setText(getString(R.string.preferences_last_sync_time,
@@ -188,19 +223,27 @@ public class NotesPreferenceActivity extends PreferenceActivity {
                                 lastSyncTime)));
                 lastSyncTimeView.setVisibility(View.VISIBLE);
             } else {
+                // 从未同步过，隐藏时间显示
                 lastSyncTimeView.setVisibility(View.GONE);
             }
         }
     }
 
+    /**
+     * 刷新整个设置界面
+     */
     private void refreshUI() {
         loadAccountPreference();
         loadSyncButton();
     }
 
+    /**
+     * 显示选择账户的对话框
+     */
     private void showSelectAccountAlertDialog() {
         AlertDialog.Builder dialogBuilder = new AlertDialog.Builder(this);
 
+        // 设置对话框标题
         View titleView = LayoutInflater.from(this).inflate(R.layout.account_dialog_title, null);
         TextView titleTextView = (TextView) titleView.findViewById(R.id.account_dialog_title);
         titleTextView.setText(getString(R.string.preferences_dialog_select_account_title));
@@ -210,6 +253,7 @@ public class NotesPreferenceActivity extends PreferenceActivity {
         dialogBuilder.setCustomTitle(titleView);
         dialogBuilder.setPositiveButton(null, null);
 
+        // 获取所有Google账户
         Account[] accounts = getGoogleAccounts();
         String defAccount = getSyncAccountName(this);
 
@@ -217,6 +261,7 @@ public class NotesPreferenceActivity extends PreferenceActivity {
         mHasAddedAccount = false;
 
         if (accounts.length > 0) {
+            // 有可用账户，显示账户列表供用户选择
             CharSequence[] items = new CharSequence[accounts.length];
             final CharSequence[] itemMapping = items;
             int checkedItem = -1;
@@ -230,6 +275,7 @@ public class NotesPreferenceActivity extends PreferenceActivity {
             dialogBuilder.setSingleChoiceItems(items, checkedItem,
                     new DialogInterface.OnClickListener() {
                         public void onClick(DialogInterface dialog, int which) {
+                            // 用户选择了账户，设置为同步账户
                             setSyncAccount(itemMapping[which].toString());
                             dialog.dismiss();
                             refreshUI();
@@ -237,12 +283,14 @@ public class NotesPreferenceActivity extends PreferenceActivity {
                     });
         }
 
+        // 添加"添加账户"选项
         View addAccountView = LayoutInflater.from(this).inflate(R.layout.add_account_text, null);
         dialogBuilder.setView(addAccountView);
 
         final AlertDialog dialog = dialogBuilder.show();
         addAccountView.setOnClickListener(new View.OnClickListener() {
             public void onClick(View v) {
+                // 用户点击添加账户
                 mHasAddedAccount = true;
                 Intent intent = new Intent("android.settings.ADD_ACCOUNT_SETTINGS");
                 intent.putExtra(AUTHORITIES_FILTER_KEY, new String[] {
@@ -254,9 +302,13 @@ public class NotesPreferenceActivity extends PreferenceActivity {
         });
     }
 
+    /**
+     * 显示更改账户确认对话框
+     */
     private void showChangeAccountConfirmAlertDialog() {
         AlertDialog.Builder dialogBuilder = new AlertDialog.Builder(this);
 
+        // 设置对话框标题
         View titleView = LayoutInflater.from(this).inflate(R.layout.account_dialog_title, null);
         TextView titleTextView = (TextView) titleView.findViewById(R.id.account_dialog_title);
         titleTextView.setText(getString(R.string.preferences_dialog_change_account_title,
@@ -265,6 +317,7 @@ public class NotesPreferenceActivity extends PreferenceActivity {
         subtitleTextView.setText(getString(R.string.preferences_dialog_change_account_warn_msg));
         dialogBuilder.setCustomTitle(titleView);
 
+        // 设置选项：更改账户、移除账户、取消
         CharSequence[] menuItemArray = new CharSequence[] {
                 getString(R.string.preferences_menu_change_account),
                 getString(R.string.preferences_menu_remove_account),
@@ -273,8 +326,10 @@ public class NotesPreferenceActivity extends PreferenceActivity {
         dialogBuilder.setItems(menuItemArray, new DialogInterface.OnClickListener() {
             public void onClick(DialogInterface dialog, int which) {
                 if (which == 0) {
+                    // 用户选择更改账户
                     showSelectAccountAlertDialog();
                 } else if (which == 1) {
+                    // 用户选择移除账户
                     removeSyncAccount();
                     refreshUI();
                 }
@@ -283,13 +338,22 @@ public class NotesPreferenceActivity extends PreferenceActivity {
         dialogBuilder.show();
     }
 
+    /**
+     * 获取设备上的Google账户列表
+     */
     private Account[] getGoogleAccounts() {
         AccountManager accountManager = AccountManager.get(this);
         return accountManager.getAccountsByType("com.google");
     }
 
+    /**
+     * 设置同步账户
+     * @param account 要设置的账户名称
+     */
     private void setSyncAccount(String account) {
+        // 如果新设置的账户与当前账户不同
         if (!getSyncAccountName(this).equals(account)) {
+            // 保存新的账户名称到偏好设置
             SharedPreferences settings = getSharedPreferences(PREFERENCE_NAME, Context.MODE_PRIVATE);
             SharedPreferences.Editor editor = settings.edit();
             if (account != null) {
@@ -299,10 +363,10 @@ public class NotesPreferenceActivity extends PreferenceActivity {
             }
             editor.commit();
 
-            // clean up last sync time
+            // 清除上次同步时间
             setLastSyncTime(this, 0);
 
-            // clean up local gtask related info
+            // 清除本地与Google任务相关的信息
             new Thread(new Runnable() {
                 public void run() {
                     ContentValues values = new ContentValues();
@@ -312,13 +376,18 @@ public class NotesPreferenceActivity extends PreferenceActivity {
                 }
             }).start();
 
+            // 提示用户账户设置成功
             Toast.makeText(NotesPreferenceActivity.this,
                     getString(R.string.preferences_toast_success_set_accout, account),
                     Toast.LENGTH_SHORT).show();
         }
     }
 
+    /**
+     * 移除同步账户
+     */
     private void removeSyncAccount() {
+        // 从偏好设置中移除账户信息
         SharedPreferences settings = getSharedPreferences(PREFERENCE_NAME, Context.MODE_PRIVATE);
         SharedPreferences.Editor editor = settings.edit();
         if (settings.contains(PREFERENCE_SYNC_ACCOUNT_NAME)) {
@@ -329,7 +398,7 @@ public class NotesPreferenceActivity extends PreferenceActivity {
         }
         editor.commit();
 
-        // clean up local gtask related info
+        // 清除本地与Google任务相关的信息
         new Thread(new Runnable() {
             public void run() {
                 ContentValues values = new ContentValues();
@@ -340,12 +409,22 @@ public class NotesPreferenceActivity extends PreferenceActivity {
         }).start();
     }
 
+    /**
+     * 获取当前设置的同步账户名称
+     * @param context 上下文对象
+     * @return 同步账户名称，如果没有设置则返回空字符串
+     */
     public static String getSyncAccountName(Context context) {
         SharedPreferences settings = context.getSharedPreferences(PREFERENCE_NAME,
                 Context.MODE_PRIVATE);
         return settings.getString(PREFERENCE_SYNC_ACCOUNT_NAME, "");
     }
 
+    /**
+     * 设置上次同步时间
+     * @param context 上下文对象
+     * @param time 上次同步的时间戳（毫秒）
+     */
     public static void setLastSyncTime(Context context, long time) {
         SharedPreferences settings = context.getSharedPreferences(PREFERENCE_NAME,
                 Context.MODE_PRIVATE);
@@ -354,29 +433,42 @@ public class NotesPreferenceActivity extends PreferenceActivity {
         editor.commit();
     }
 
+    /**
+     * 获取上次同步时间
+     * @param context 上下文对象
+     * @return 上次同步的时间戳（毫秒），如果没有同步过则返回0
+     */
     public static long getLastSyncTime(Context context) {
         SharedPreferences settings = context.getSharedPreferences(PREFERENCE_NAME,
                 Context.MODE_PRIVATE);
         return settings.getLong(PREFERENCE_LAST_SYNC_TIME, 0);
     }
 
+    /**
+     * 广播接收器，用于接收同步服务的状态更新
+     */
     private class GTaskReceiver extends BroadcastReceiver {
 
         @Override
         public void onReceive(Context context, Intent intent) {
+            // 刷新界面
             refreshUI();
+            // 如果正在同步，更新同步状态显示
             if (intent.getBooleanExtra(GTaskSyncService.GTASK_SERVICE_BROADCAST_IS_SYNCING, false)) {
                 TextView syncStatus = (TextView) findViewById(R.id.prefenerece_sync_status_textview);
                 syncStatus.setText(intent
                         .getStringExtra(GTaskSyncService.GTASK_SERVICE_BROADCAST_PROGRESS_MSG));
             }
-
         }
     }
 
+    /**
+     * 处理选项菜单的点击事件
+     */
     public boolean onOptionsItemSelected(MenuItem item) {
         switch (item.getItemId()) {
             case android.R.id.home:
+                // 点击应用图标，返回主界面
                 Intent intent = new Intent(this, NotesListActivity.class);
                 intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                 startActivity(intent);