注释代码

AlarmAlertActivity.java

@@ -0,0 +1,313 @@
+/*
+ * 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.
+ */
+
+// 导入所需的Android和Java类
+
+package net.micode.notes.ui;
+
+ 
+
+import android.app.Activity;
+
+import android.app.AlertDialog;
+
+import android.content.Context;
+
+import android.content.DialogInterface;
+
+import android.content.DialogInterface.OnClickListener;
+
+import android.content.DialogInterface.OnDismissListener;
+
+import android.content.Intent;
+
+import android.media.AudioManager;
+
+import android.media.MediaPlayer;
+
+import android.media.RingtoneManager;
+
+import android.net.Uri;
+
+import android.os.Bundle;
+
+import android.os.PowerManager;
+
+import android.provider.Settings;
+
+import android.view.Window;
+
+import android.view.WindowManager;
+
+ 
+
+import net.micode.notes.R;
+
+import net.micode.notes.data.Notes;
+
+import net.micode.notes.tool.DataUtils;
+
+ 
+
+import java.io.IOException;
+
+ 
+
+// 声明AlarmAlertActivity类，继承自Activity，并实现OnClickListener和OnDismissListener接口
+
+public class AlarmAlertActivity extends Activity implements OnClickListener, OnDismissListener {
+
+    // 声明成员变量
+
+    private long mNoteId; // 笔记ID
+
+    private String mSnippet; // 笔记摘要
+
+    private static final int SNIPPET_PREW_MAX_LEN = 60; // 摘要最大长度
+
+    MediaPlayer mPlayer; // 媒体播放器，用于播放闹钟声音
+
+ 
+
+    // onCreate方法，Activity创建时调用
+
+    @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(); // 获取当前窗口
+
+        win.addFlags(WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED); // 允许在锁屏时显示
+
+ 
+
+        // 如果屏幕未点亮，则添加一系列标志以点亮屏幕并保持其开启
+
+        if (!isScreenOn()) {
+
+            win.addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON
+
+                    | WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON
+
+                    | WindowManager.LayoutParams.FLAG_ALLOW_LOCK_WHILE_SCREEN_ON
+
+                    | WindowManager.LayoutParams.FLAG_LAYOUT_INSET_DECOR);
+
+        }
+
+ 
+
+        Intent intent = getIntent(); // 获取启动此Activity的Intent
+
+ 
+
+        try {
+
+            // 从Intent中提取笔记ID
+
+            mNoteId = Long.valueOf(intent.getData().getPathSegments().get(1));
+
+            // 从数据库中获取笔记摘要
+
+            mSnippet = DataUtils.getSnippetById(this.getContentResolver(), mNoteId);
+
+            // 如果摘要长度超过最大长度，则截断并添加省略号
+
+            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(); // 捕获异常并打印堆栈跟踪
+
+            return; // 如果发生异常，则退出方法
+
+        }
+
+ 
+
+        mPlayer = new MediaPlayer(); // 初始化媒体播放器
+
+        // 检查笔记是否在数据库中且类型为普通笔记
+
+        if (DataUtils.visibleInNoteDatabase(getContentResolver(), mNoteId, Notes.TYPE_NOTE)) {
+
+            showActionDialog(); // 显示操作对话框
+
+            playAlarmSound(); // 播放闹钟声音
+
+        } else {
+
+            finish(); // 如果笔记不存在，则结束Activity
+
+        }
+
+    }
+
+ 
+
+    // 检查屏幕是否点亮
+
+    private boolean isScreenOn() {
+
+        PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
+
+        return pm.isScreenOn();
+
+    }
+
+ 
+
+    // 播放闹钟声音
+
+    private void playAlarmSound() {
+
+        Uri url = RingtoneManager.getActualDefaultRingtoneUri(this, RingtoneManager.TYPE_ALARM); // 获取默认的闹钟铃声URI
+
+ 
+
+        // 获取静音模式下受影响的音频流类型
+
+        int silentModeStreams = Settings.System.getInt(getContentResolver(),
+
+                Settings.System.MODE_RINGER_STREAMS_AFFECTED, 0);
+
+ 
+
+        // 根据静音模式设置音频流类型
+
+        if ((silentModeStreams & (1 << AudioManager.STREAM_ALARM)) != 0) {
+
+            mPlayer.setAudioStreamType(silentModeStreams);
+
+        } else {
+
+            mPlayer.setAudioStreamType(AudioManager.STREAM_ALARM);
+
+        }
+
+        try {
+
+            // 设置媒体播放器的数据源并开始播放
+
+            mPlayer.setDataSource(this, url);
+
+            mPlayer.prepare();
+
+            mPlayer.setLooping(true);
+
+            mPlayer.start();
+
+        } catch (IllegalArgumentException | SecurityException | IllegalStateException | IOException e) {
+
+            e.printStackTrace(); // 捕获并打印各种异常
+
+        }
+
+    }
+
+ 
+
+    // 显示操作对话框
+
+    private void showActionDialog() {
+
+        AlertDialog.Builder dialog = new AlertDialog.Builder(this); // 创建对话框构建器
+
+        dialog.setTitle(R.string.app_name); // 设置对话框标题
+
+        dialog.setMessage(mSnippet); // 设置对话框消息
+
+        dialog.setPositiveButton(R.string.notealert_ok, this); // 设置正面按钮及其点击事件监听器
+
+        if (isScreenOn()) {
+
+            dialog.setNegativeButton(R.string.notealert_enter, this); // 如果屏幕点亮，则设置负面按钮及其点击事件监听器
+
+        }
+
+        dialog.show().setOnDismissListener(this); // 显示对话框并设置其关闭事件监听器
+
+    }
+
+ 
+
+    // 点击对话框按钮时调用
+
+    public void onClick(DialogInterface dialog, int which) {
+
+        switch (which) {
+
+            case DialogInterface.BUTTON_NEGATIVE: // 如果点击的是负面按钮
+
+                Intent intent = new Intent(this, NoteEditActivity.class); // 创建跳转到NoteEditActivity的Intent
+
+                intent.setAction(Intent.ACTION_VIEW); // 设置Intent动作为查看
+
+                intent.putExtra(Intent.EXTRA_UID, mNoteId); // 将笔记ID作为额外数据添加到Intent中
+
+                startActivity(intent); // 启动NoteEditActivity
+
+                break;
+
+            default:
+
+                break;
+
+        }
+
+    }
+
+ 
+
+    // 对话框关闭时调用
+
+    public void onDismiss(DialogInterface dialog) {
+
+        stopAlarmSound(); // 停止播放闹钟声音
+
+        finish(); // 结束Activity
+
+    }
+
+ 
+
+    // 停止播放闹钟声音
+
+    private void stopAlarmSound() {
+
+        if (mPlayer != null) {
+
+            mPlayer.stop(); // 停止媒体播放器
+
+            mPlayer.release(); // 释放媒体播放器资源
+
+            mPlayer = null; // 将媒体播放器引用置为空
+
+        }
+
+    }
+
+}

AlarmInitReceiver.java

@@ -0,0 +1,131 @@
+/*
+ * 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.
+ */
+
+// 导入所需的Android和应用程序特定的包
+
+package net.micode.notes.ui;
+
+ 
+
+import android.app.AlarmManager; // 导入AlarmManager类，用于设置闹钟
+
+import android.app.PendingIntent; // 导入PendingIntent类，用于表示一个将要执行的操作
+
+import android.content.BroadcastReceiver; // 导入BroadcastReceiver类，用于接收广播消息
+
+import android.content.ContentUris; // 导入ContentUris类，用于生成内容URI
+
+import android.content.Context; // 导入Context类，表示应用程序环境的全局信息
+
+import android.content.Intent; // 导入Intent类，用于不同组件之间的通信
+
+import android.database.Cursor; // 导入Cursor类，用于遍历查询结果
+
+ 
+
+import net.micode.notes.data.Notes; // 导入Notes类，包含NoteProvider的相关常量
+
+import net.micode.notes.data.Notes.NoteColumns; // 导入NoteColumns接口，包含Note表的列名
+
+ 
+
+// 定义一个继承自BroadcastReceiver的类，用于初始化闹钟
+
+public class AlarmInitReceiver extends BroadcastReceiver {
+
+ 
+
+    // 定义要从Note表中查询的列
+
+    private static final String [] PROJECTION = new String [] {
+
+        NoteColumns.ID, // Note的ID
+
+        NoteColumns.ALERTED_DATE // Note的提醒日期
+
+    };
+
+ 
+
+    // 定义查询结果集中列的索引
+
+    private static final int COLUMN_ID                = 0; // ID列的索引
+
+    private static final int COLUMN_ALERTED_DATE      = 1; // 提醒日期列的索引
+
+ 
+
+    // 当接收到广播时调用的方法
+
+    @Override
+
+    public void onReceive(Context context, Intent intent) {
+
+        long currentDate = System.currentTimeMillis(); // 获取当前时间（毫秒）
+
+        // 从Note表中查询提醒日期大于当前时间且类型为Note的记录
+
+        Cursor c = context.getContentResolver().query(Notes.CONTENT_NOTE_URI,
+
+                PROJECTION,
+
+                NoteColumns.ALERTED_DATE + ">? AND " + NoteColumns.TYPE + "=" + Notes.TYPE_NOTE,
+
+                new String[] { String.valueOf(currentDate) }, // 替换查询语句中的?为当前时间的字符串表示
+
+                null); // 不对结果进行排序
+
+ 
+
+        if (c != null) { // 如果查询结果不为空
+
+            if (c.moveToFirst()) { // 移动到查询结果的第一条记录
+
+                do {
+
+                    long alertDate = c.getLong(COLUMN_ALERTED_DATE); // 获取当前记录的提醒日期
+
+                    Intent sender = new Intent(context, AlarmReceiver.class); // 创建一个Intent，指向AlarmReceiver
+
+                    // 设置Intent的数据为Note的URI，并附加Note的ID
+
+                    sender.setData(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, c.getLong(COLUMN_ID)));
+
+                    // 创建一个PendingIntent，表示在指定时间执行的操作
+
+                    PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, sender, 0);
+
+                    // 获取AlarmManager实例，用于设置闹钟
+
+                    AlarmManager alermManager = (AlarmManager) context
+
+                            .getSystemService(Context.ALARM_SERVICE);
+
+                    // 设置一个闹钟，在指定的提醒日期（alertDate）触发AlarmReceiver
+
+                    alermManager.set(AlarmManager.RTC_WAKEUP, alertDate, pendingIntent);
+
+                } while (c.moveToNext()); // 移动到下一条记录，直到遍历完所有结果
+
+            }
+
+            c.close(); // 关闭Cursor，释放资源
+
+        }
+
+    }
+
+}

AlarmReceiver.java

@@ -0,0 +1,65 @@
+/*
+ * 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.
+ */
+
+// 导入必要的Android框架类
+
+package net.micode.notes.ui; // 指定这个类所在的包名
+
+ 
+
+import android.content.BroadcastReceiver; // 导入BroadcastReceiver类，用于接收广播
+
+import android.content.Context; // 导入Context类，代表应用的当前状态，包括资源和类以及调用应用级操作
+
+import android.content.Intent; // 导入Intent类，用于不同组件之间的通信
+
+ 
+
+// 定义一个名为AlarmReceiver的类，它继承自BroadcastReceiver
+
+public class AlarmReceiver extends BroadcastReceiver {
+
+    
+
+    // 重写onReceive方法，这是BroadcastReceiver的核心方法，用于接收广播
+
+    @Override
+
+    public void onReceive(Context context, Intent intent) {
+
+        // 设置Intent的目标Activity为AlarmAlertActivity，这意味着当广播被接收时，将启动这个Activity
+
+        intent.setClass(context, AlarmAlertActivity.class);
+
+        
+
+        // 添加一个标志，指定这个Activity应该在一个新的任务中启动
+
+        // 这对于从非Activity的上下文中启动Activity（如BroadcastReceiver）是必要的
+
+        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+
+        
+
+        // 使用上下文（context）启动Intent指定的Activity
+
+        // 这将导致AlarmAlertActivity被创建并显示在屏幕上
+
+        context.startActivity(intent);
+
+    }
+
+}