代码注释

AlarmAlertActivity.java

@@ -0,0 +1,169 @@
+/*
+ * 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;
+
+// 定义一个名为 AlarmAlertActivity 的 Activity
+public class AlarmAlertActivity extends Activity implements OnClickListener, OnDismissListener {
+// 用于存储笔记的 ID
+    private long mNoteId;
+    private String mSnippet;
+// 定义片段预览的最大长度
+    private static final int SNIPPET_PREW_MAX_LEN = 60;
+// 定义媒体播放器，用于播放闹钟声音
+    MediaPlayer mPlayer;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        requestWindowFeature(Window.FEATURE_NO_TITLE);
+	// 获取窗口对象
+        final Window win = getWindow();
+// 设置在锁屏状态下也能显示该窗口
+        win.addFlags(WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED);
+	// 如果屏幕没有点亮
+        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);
+        }
+	// 获取启动该 Activity 的 Intent
+        Intent intent = getIntent();
+
+        try {
+	// 从 Intent 的数据中获取路径片段中的第二个元素作为笔记 ID
+            mNoteId = Long.valueOf(intent.getData().getPathSegments().get(1));
+// 根据笔记 ID 获取笔记片段
+            mSnippet = DataUtils.getSnippetById(this.getContentResolver(), mNoteId);
+// 如果片段长度超过最大长度，则截断并添加提示信息
+            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();
+            return;
+        }
+	// 创建媒体播放器对象
+        mPlayer = new MediaPlayer();
+        if (DataUtils.visibleInNoteDatabase(getContentResolver(), mNoteId, Notes.TYPE_NOTE)) {
+            showActionDialog();
+            playAlarmSound();
+        } else {
+            finish();
+        }
+    }
+	// 判断屏幕是否点亮
+    private boolean isScreenOn() {
+        PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
+        return pm.isScreenOn();
+    }
+	// 播放闹钟声音
+    private void playAlarmSound() {
+// 获取默认闹钟铃声的 Uri
+        Uri url = RingtoneManager.getActualDefaultRingtoneUri(this, RingtoneManager.TYPE_ALARM);
+	// 获取系统设置中铃声流的静音模式状态
+        int silentModeStreams = Settings.System.getInt(getContentResolver(),
+                Settings.System.MODE_RINGER_STREAMS_AFFECTED, 0);
+
+        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为闹钟铃声的 Uri
+            mPlayer.setDataSource(this, url);
+            mPlayer.prepare();
+            mPlayer.setLooping(true);
+/ 开始播放
+            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();
+        }
+    }
+ // 显示操作对话框
+    private void showActionDialog() {
+        AlertDialog.Builder dialog = new AlertDialog.Builder(this);
+        dialog.setTitle(R.string.app_name);
+        dialog.setMessage(mSnippet);
+
+        dialog.setPositiveButton(R.string.notealert_ok, this);
+        if (isScreenOn()) {
+            dialog.setNegativeButton(R.string.notealert_enter, this);
+        }
+        dialog.show().setOnDismissListener(this);
+    }
+ // 对话框关闭事件处理方法
+    public void onClick(DialogInterface dialog, int which) {
+        switch (which) {s
+            case DialogInterface.BUTTON_NEGATIVE:
+                Intent intent = new Intent(this, NoteEditActivity.class);
+                intent.setAction(Intent.ACTION_VIEW);
+                intent.putExtra(Intent.EXTRA_UID, mNoteId);
+                startActivity(intent);
+                break;
+            default:
+                break;
+        }
+    }
+// 对话框关闭事件处理方法
+    public void onDismiss(DialogInterface dialog) {
+        stopAlarmSound();
+        finish();
+    }
+ // 停止闹钟声音的方法
+    private void stopAlarmSound() {
+        if (mPlayer != null) {
+            mPlayer.stop();
+            mPlayer.release();
+            mPlayer = null;
+        }
+    }
+}