git-xiaomibianqian/other/代码标注/ui/210340167肖凯文代码标注AlarmAlertActivity.java

/*
 * 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.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;


public class AlarmAlertActivity extends Activity implements OnClickListener, OnDismissListener {
    private long mNoteId;//mNoteId可能是笔记的唯一标识符
    private String mSnippet;//mSnippet可能是笔记的摘要或预览
    private static final int SNIPPET_PREW_MAX_LEN = 60;//SNIPPET_PREW_MAX_LEN可能是规定的摘要或预览的最大长度，初值为60
    MediaPlayer mPlayer;//定义了一个名为mPlayer的MediaPlayer对象

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);//调用父类的onCreate
        requestWindowFeature(Window.FEATURE_NO_TITLE);//请求窗口没有标题的特性

        final Window win = getWindow();
        win.addFlags(WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED);//获取当前窗口对象，并添加一个标志，以便在设备被锁定时显示该窗口

        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);
        }//检查屏幕是否已经关闭，如果是，则设置一些标志来保持屏幕开启、打开屏幕并允许在屏幕开启时锁定屏幕，并将布局设置为插入装饰

        Intent intent = getIntent();

        try {
            mNoteId = Long.valueOf(intent.getData().getPathSegments().get(1));
            mSnippet = DataUtils.getSnippetById(this.getContentResolver(), mNoteId);//获取传入的意图并从中获取笔记ID，然后使用该ID从内容提供程序中获取笔记的摘录
            mSnippet = mSnippet.length() > SNIPPET_PREW_MAX_LEN ? mSnippet.substring(0,
                    SNIPPET_PREW_MAX_LEN) + getResources().getString(R.string.notelist_string_info)
                    : mSnippet;//如果摘录超过了预定义的最大长度，则将其截断并附加一些字符串，该代码将截断后的摘录分配给变量mSnippet
        } catch (IllegalArgumentException e) {
            e.printStackTrace();
            return;
        }//从Intent中获取传递的数据，如果数据无效则抛出IllegalArgumentException异常并打印堆栈跟踪信息并返回

        mPlayer = new MediaPlayer();//创建一个MediaPlayer对象
        if (DataUtils.visibleInNoteDatabase(getContentResolver(), mNoteId, Notes.TYPE_NOTE)) {
            showActionDialog();
            playAlarmSound();
        }//检查当前笔记是否可见于笔记数据库，如果是，则显示操作对话框并播放警报声音
        else {
            finish();
        }//如果不是，结束当前活动
    }

    private boolean isScreenOn() {
        PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);//获取 PowerManager 对象，然后调用其 isScreenOn()
        return pm.isScreenOn();//调用其 isScreenOn() 方法，返回当前屏幕是否开启的值
    }//判断屏幕是否开启

    private void playAlarmSound() {// 获取系统当前默认的闹钟铃声的Uri
        Uri url = RingtoneManager.getActualDefaultRingtoneUri(this, RingtoneManager.TYPE_ALARM);// 获取当前静音模式下受影响的流

        int silentModeStreams = Settings.System.getInt(getContentResolver(),
                Settings.System.MODE_RINGER_STREAMS_AFFECTED, 0);// 如果闹钟铃声所在的流也受到了静音模式的影响，则使用受影响的流

        if ((silentModeStreams & (1 << AudioManager.STREAM_ALARM)) != 0) {
            mPlayer.setAudioStreamType(silentModeStreams);
        } else { // 否则使用闹钟铃声所在的流
            mPlayer.setAudioStreamType(AudioManager.STREAM_ALARM);
        }
        try {  // 设置闹钟铃声的Uri并准备播放
            mPlayer.setDataSource(this, url);
            mPlayer.prepare(); // 循环播放闹钟铃声
            mPlayer.setLooping(true);
            mPlayer.start();
        } catch (IllegalArgumentException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (SecurityException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IllegalStateException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

    private void showActionDialog() {  // 创建对话框构建器
        AlertDialog.Builder dialog = new AlertDialog.Builder(this); // 设置对话框标题
        dialog.setTitle(R.string.app_name); // 设置对话框消息内容
        dialog.setMessage(mSnippet);  // 设置对话框确定按钮文本和点击事件监听器
        dialog.setPositiveButton(R.string.notealert_ok, this); // 如果屏幕是开启的，则设置对话框取消按钮文本和点击事件监听器
        if (isScreenOn()) {
            dialog.setNegativeButton(R.string.notealert_enter, this);
        }  // 显示对话框，并设置对话框消失监听器
        dialog.show().setOnDismissListener(this);
    }

    public void onClick(DialogInterface dialog, int which) {
        switch (which) { // 当点击对话框的按钮时触发该方法
            case DialogInterface.BUTTON_NEGATIVE:// 如果点击的是对话框的取消按钮
                Intent intent = new Intent(this, NoteEditActivity.class);// 创建一个新的意图，指定跳转到NoteEditActivity类
                intent.setAction(Intent.ACTION_VIEW); // 设置意图的操作为ACTION_VIEW
                intent.putExtra(Intent.EXTRA_UID, mNoteId);// 将笔记的ID作为额外的信息传递给NoteEditActivity类
                startActivity(intent);// 启动NoteEditActivity类
                break;
            default: // 如果点击的不是对话框的取消按钮，则结束
                break;
        }
    }

    public void onDismiss(DialogInterface dialog) {// 当对话框消失时执行以下代码
        stopAlarmSound();// 停止闹钟声音
        finish(); // 结束当前Activity
    }

    private void stopAlarmSound() {
        if (mPlayer != null) {// 如果音频播放器不为空
            mPlayer.stop();// 停止播放音频
            mPlayer.release();// 释放音频播放器的资源
            mPlayer = null;// 将音频播放器置为空
        }
    }
}