XiaoMi/app/src/main/java/net/micode/notes/ui/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;   //文本再数据库存储中的id号
    private String mSnippet;    //闹钟提醒时的文字
    private static final int SNIPPET_PREW_MAX_LEN = 60;
    MediaPlayer mPlayer;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);  //界面显示无标题

        final Window win = getWindow();
        win.addFlags(WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED);

        if (!isScreenOn()) {      //锁屏后到了提示时间点亮屏幕，
            win.addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON //保持屏幕亮着
                    | WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON    //点亮屏幕
                    | WindowManager.LayoutParams.FLAG_ALLOW_LOCK_WHILE_SCREEN_ON    //允许点亮时锁屏
                    | WindowManager.LayoutParams.FLAG_LAYOUT_INSET_DECOR);
        }

        Intent intent = getIntent();

        try {
            mNoteId = Long.valueOf(intent.getData().getPathSegments().get(1));//获取ID
            mSnippet = DataUtils.getSnippetById(this.getContentResolver(), mNoteId);//根据ID获取标签的内容，利用getContentResolver()可以得到当前应用的实例

            /*判断标签是否达到符合的长度*/
            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) { //处理异常，显示异常信息
            e.printStackTrace();
            return;
        }

        mPlayer = new MediaPlayer();
        if (DataUtils.visibleInNoteDatabase(getContentResolver(), mNoteId, Notes.TYPE_NOTE)) {
            showActionDialog(); //弹出对话框
            playAlarmSound();   //响起提示音
        } else {
            finish();   //完成闹钟
        }
    }

    private boolean isScreenOn() {  //判断是否锁屏
        PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
        return pm.isScreenOn();
    }

    private void playAlarmSound() { //响起提示音
        Uri url = RingtoneManager.getActualDefaultRingtoneUri(this, RingtoneManager.TYPE_ALARM);    //获取系统默认铃声

        int silentModeStreams = Settings.System.getInt(getContentResolver(),    //通过settings这个类来获取数据库中的数据
                Settings.System.MODE_RINGER_STREAMS_AFFECTED, 0);

        if ((silentModeStreams & (1 << AudioManager.STREAM_ALARM)) != 0) {
            mPlayer.setAudioStreamType(silentModeStreams);
        } else {
            mPlayer.setAudioStreamType(AudioManager.STREAM_ALARM);
        }
        try {
            mPlayer.setDataSource(this, url);   //设置数据来源url
            mPlayer.prepare();  //准备同步
            mPlayer.setLooping(true);   //设置循环播放
            mPlayer.start();    //开始播放
        } catch (IllegalArgumentException e) { //传递了一个不合法或不正确的参数时出现异常
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (SecurityException e) { //程序使用不当存在某些危险的操作引发安全问题
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IllegalStateException e) { //在不合理或不正确时间内唤醒一方法时出现异常
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) { //文件读取异常
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

    private void showActionDialog() {
        AlertDialog.Builder dialog = new AlertDialog.Builder(this); //创建对象
        dialog.setTitle(R.string.app_name); //对话框设置标题
        dialog.setMessage(mSnippet);    //对话框设置内容
        dialog.setPositiveButton(R.string.notealert_ok, this);  //设置确定按钮
        if (isScreenOn()) {
            dialog.setNegativeButton(R.string.notealert_enter, this); //设置取消按钮
        }
        dialog.show().setOnDismissListener(this);
    }

    public void onClick(DialogInterface dialog, int which) {
        switch (which) {    //选择下一步的操作
            case DialogInterface.BUTTON_NEGATIVE:   //取消
                /*实现两个类的跳转*/
                Intent intent = new Intent(this, NoteEditActivity.class);   //创建intent对象
                intent.setAction(Intent.ACTION_VIEW);   //调用隐式intent调用
                intent.putExtra(Intent.EXTRA_UID, mNoteId); //Intent.EXTRA_UID为键名，mNoteId为键对应的值，把想要传递的数据暂存在intent中，当另一个活动启动后，再把这些数据从intent缓存中取出
                startActivity(intent);  //开始跳转
                break;

            default:
                break;  //确定
        }
    }

    public void onDismiss(DialogInterface dialog) {
        stopAlarmSound();   //停止闹钟声音
        finish();   //完成动作
    }

    private void stopAlarmSound() {
        if (mPlayer != null) {
            mPlayer.stop(); //停止播放
            mPlayer.release();  //释放对象
            mPlayer = null;
        }
    }
}