注释

AlarmAlertActivity.java

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+/*
+ * 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;// 活动的基类
+import android.app.AlertDialog;// 用于创建警告对话框
+import android.content.Context; // 提供访问应用程序特定资源的上下文
+import android.content.DialogInterface; // 对话框交互接口
+import android.content.Intent; // 创建启动新活动的意图
+import android.media.AudioManager; // 管理音频设置
+import android.media.MediaPlayer; // 播放音频文件
+import android.media.RingtoneManager; // 访问系统铃声
+import android.net.Uri; // 表示URI
+import android.os.Bundle;// 在活动之间传递数据
+import android.os.PowerManager; // 管理电源状态
+import android.provider.Settings; // 系统设置
+import android.view.Window; // 窗口管理
+import android.view.WindowManager;// 管理窗口
+
+import net.micode.notes.R; // 导入资源引用
+import net.micode.notes.data.Notes; // 导入笔记数据模型
+import net.micode.notes.tool.DataUtils; // 数据操作的工具函数
+
+import java.io.IOException; // 处理IO异常
+
+
+public class AlarmAlertActivity extends Activity implements OnClickListener, OnDismissListener {
+    private long mNoteId;
+     // 笔记的唯一标识
+    private String mSnippet;
+     // 笔记的内容片段
+    private static final int SNIPPET_PREW_MAX_LEN = 60;
+     // 内容片段的最大长度
+    MediaPlayer mPlayer;
+    // 媒体播放器，用于播放警报音
+
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        requestWindowFeature(Window.FEATURE_NO_TITLE);
+        // 请求无标题窗口
+
+        final Window win = getWindow();
+         // 设置窗口标志，使其在锁屏时可见
+        win.addFlags(WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED);
+
+          // 如果屏幕未亮，则设置相关标志
+        if (!isScreenOn()) {
+            win.addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON 
+            // 保持屏幕常亮
+                    | WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON 
+                    // 打开屏幕
+                    | WindowManager.LayoutParams.FLAG_ALLOW_LOCK_WHILE_SCREEN_ON 
+                    // 允许锁定屏幕
+                    | WindowManager.LayoutParams.FLAG_LAYOUT_INSET_DECOR); 
+                    // 窗口布局插入装饰
+        }
+
+        Intent intent = getIntent();
+        // 获取启动活动的意图
+
+       try {
+            // 从意图中提取笔记ID
+            mNoteId = Long.valueOf(intent.getData().getPathSegments().get(1));
+            // 根据笔记ID获取内容片段
+            mSnippet = DataUtils.getSnippetById(this.getContentResolver(), mNoteId);
+            // 如果内容片段超过最大长度，则进行截断处理
+            mSnippet = mSnippet.length() > SNIPPET_PREW_MAX_LEN ? mSnippet.substring(0,
+                    SNIPPET_PREW_MAX_LEN) + getResources().getString(R.string.notelist_string_info)
+                    : mSnippet;
+        } catch (IllegalArgumentException e) {
+            e.printStackTrace(); // 打印异常堆栈信息
+            return; // 发生异常时返回
+        }
+
+      mPlayer = new MediaPlayer(); // 初始化媒体播放器
+        // 检查笔记是否在数据库中可见
+        if (DataUtils.visibleInNoteDatabase(getContentResolver(), mNoteId, Notes.TYPE_NOTE)) {
+            showActionDialog(); // 显示操作对话框
+            playAlarmSound(); // 播放警报声音
+        } else {
+            finish(); 
+            // 如果不可见，则结束活动
+        }
+    }
+
+    // 检查屏幕是否开启的方法
+    private boolean isScreenOn() {
+        PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
+        return pm.isScreenOn(); 
+        // 返回屏幕状态
+    }
+}
+
+    private void playAlarmSound() {
+    // 获取默认的闹钟铃声URI
+    Uri url = RingtoneManager.getActualDefaultRingtoneUri(this, RingtoneManager.TYPE_ALARM);
+
+    // 获取影响静音模式的流类型
+    int silentModeStreams = Settings.System.getInt(getContentResolver(),
+            Settings.System.MODE_RINGER_STREAMS_AFFECTED, 0);
+
+    // 检查静音模式下是否包括闹钟流
+    if ((silentModeStreams & (1 << AudioManager.STREAM_ALARM)) != 0) {
+        mPlayer.setAudioStreamType(silentModeStreams); 
+        // 设置音频流类型为静音模式
+    } else {
+        mPlayer.setAudioStreamType(AudioManager.STREAM_ALARM);
+         // 设置为闹钟流
+    }
+    
+    try {
+        // 设置数据源为铃声URI
+        mPlayer.setDataSource(this, url);
+        mPlayer.prepare(); 
+        // 准备播放器
+        mPlayer.setLooping(true); 
+        // 设置循环播放
+        mPlayer.start(); 
+        // 开始播放
+    } catch (IllegalArgumentException e) {
+        e.printStackTrace(); // 打印异常信息
+    } catch (SecurityException e) {
+        e.printStackTrace(); // 打印异常信息
+    } catch (IllegalStateException e) {
+        e.printStackTrace(); // 打印异常信息
+    } catch (IOException e) {
+        e.printStackTrace(); // 打印异常信息
+    }
+}
+
+private void showActionDialog() {
+    AlertDialog.Builder dialog = new AlertDialog.Builder(this);
+    dialog.setTitle(R.string.app_name); 
+    // 设置对话框标题
+    dialog.setMessage(mSnippet); 
+    // 设置对话框消息内容
+    dialog.setPositiveButton(R.string.notealert_ok, this); 
+    // 设置确认按钮
+
+    // 如果屏幕已开启，设置取消按钮
+    if (isScreenOn()) {
+        dialog.setNegativeButton(R.string.notealert_enter, this);
+    }
+    
+    dialog.show().setOnDismissListener(this); 
+    // 显示对话框并设置消失监听器
+}
+
+public void onClick(DialogInterface dialog, int which) {
+    switch (which) {
+        case DialogInterface.BUTTON_NEGATIVE:
+            // 点击取消按钮时，启动编辑笔记活动
+            Intent intent = new Intent(this, NoteEditActivity.class);
+            intent.setAction(Intent.ACTION_VIEW);
+            intent.putExtra(Intent.EXTRA_UID, mNoteId); 
+            // 传递笔记ID
+            startActivity(intent); 
+            // 启动活动
+            break;
+        default:
+            break; // 默认情况不处理
+    }
+}
+
+public void onDismiss(DialogInterface dialog) {
+    stopAlarmSound(); 
+    // 停止播放警报声音
+    finish(); 
+    // 结束当前活动
+}
+
+private void stopAlarmSound() {
+    if (mPlayer != null) {
+        mPlayer.stop(); 
+        // 停止播放
+        mPlayer.release();
+         // 释放媒体播放器资源
+        mPlayer = null; 
+        // 清空播放器引用
+    }
+}

AlarmInitReceiver.java

@@ -0,0 +1,81 @@
+/*
+ * 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;
+
+// 导入所需的Android类
+import android.app.AlarmManager; // 用于管理闹钟服务
+import android.app.PendingIntent; // 用于延迟执行的意图
+import android.content.BroadcastReceiver; // 广播接收器基类
+import android.content.ContentUris; // 用于处理内容URI
+import android.content.Context; // 上下文类
+import android.content.Intent; // 意图类
+import android.database.Cursor; // 数据库结果集游标
+
+// 导入笔记相关的数据类
+import net.micode.notes.data.Notes; // 笔记数据类
+import net.micode.notes.data.Notes.NoteColumns; // 笔记列定义类
+
+
+public class AlarmInitReceiver extends BroadcastReceiver {
+
+    // 定义要查询的列
+    private static final String [] PROJECTION = new String [] {
+        NoteColumns.ID,            
+        // 笔记ID
+        NoteColumns.ALERTED_DATE   
+        // 警报日期
+    };
+
+    // 列索引
+    private static final int COLUMN_ID                = 0; 
+    // ID列索引
+    private static final int COLUMN_ALERTED_DATE      = 1;
+     // 警报日期列索引
+
+    @Override
+    public void onReceive(Context context, Intent intent) {
+        long currentDate = System.currentTimeMillis(); // 获取当前时间戳
+        // 查询提醒日期大于当前时间的笔记
+        Cursor c = context.getContentResolver().query(Notes.CONTENT_NOTE_URI,
+                PROJECTION,
+                NoteColumns.ALERTED_DATE + ">? AND " + NoteColumns.TYPE + "=" + Notes.TYPE_NOTE,
+                new String[] { String.valueOf(currentDate) },
+                null);
+
+        if (c != null) {
+            // 如果结果集不为空
+            if (c.moveToFirst()) {
+                do {
+                    long alertDate = c.getLong(COLUMN_ALERTED_DATE); 
+                    // 获取警报日期
+                    Intent sender = new Intent(context, AlarmReceiver.class); // 创建意图，用于发送警报
+                    // 设置数据为对应的笔记URI
+                    sender.setData(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, c.getLong(COLUMN_ID)));
+                    // 创建PendingIntent，注册广播接收器
+                    PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, sender, 0);
+                    // 获取AlarmManager服务
+                    AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
+                    // 设置闹钟
+                    alarmManager.set(AlarmManager.RTC_WAKEUP, alertDate, pendingIntent);
+                } while (c.moveToNext()); 
+                // 遍历结果集
+            }
+            c.close(); 
+            // 关闭Cursor
+        }
+    }
+}

AlarmReceiver.java

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+/*
+ * 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; 
+// 指定当前类所在的包名
+
+import android.content.BroadcastReceiver; // 导入广播接收器基类
+import android.content.Context; // 导入上下文类
+import android.content.Intent; // 导入意图类
+
+// 定义AlarmReceiver类，继承自BroadcastReceiver
+public class AlarmReceiver extends BroadcastReceiver {
+    @Override
+    // 当接收到广播时调用的方法
+    public void onReceive(Context context, Intent intent) {
+        // 设置要启动的活动为AlarmAlertActivity
+        intent.setClass(context, AlarmAlertActivity.class);
+        // 添加标志，使新的活动在新的任务中启动
+        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+        // 启动AlarmAlertActivity
+        context.startActivity(intent);
+    }
+}