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Android 长按电源键和短按电源键的详细处理流程

时间:2024-3-2 19:22     作者:韩俊     分类: Android


1 Android
Android4.x在Framework的PhoneWindowManager对Power(KeyEvent.KEYCODE_POWER)和Home(KeyEvent.KEYCODE_HOME)键做了处理,不会把这些键传送上层应用程序。如需要把这些键发送给Activity和Service,需要在PhoneWindowManager处理这些键时“发送一个广播出去,然后在应用程序接收到广播后做处理”。

如果应用程序只需要获取获取待机、唤醒、关机、网络状态变化消息,则可监听以下广播消息:
1) 待机:
广播消息:android.intent.action.SCREEN_OFF (代码)
2) 唤醒:
广播消息:android.intent.action.SCREEN_ON (代码)
3) 关机:
广播消息:android.intent.action.ACTION_SHUTDOWN (XML或代码)
4) 网络状态变化:
广播消息:android.net.conn.CONNECTIVITY_CHANGE (XML或代码)
然后调用下面的isNetworkAvailable获取当前网络状态。
public static boolean isNetworkAvailable(Context context) {

ConnectivityManager mgr = (ConnectivityManager) context
.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo[] info = mgr.getAllNetworkInfo();
if (info != null) {
for (int i = 0; i < info.length; i++) {
if (info[i].getState() == NetworkInfo.State.CONNECTED) {
return true;
}
}
}
return false;
}

2.
短按Power键处理流程

短按Power键处理流程如下图所示:

3.
长按Power键处理流程

长按Power键处理流程如下图所示:

3.1
Message超时处理流程

如果长按Power键(超过500ms),则此消息(Message.callback为mPowerLongPress)将被执行。mPowerLongPress (PhoneWindowManager.java)定义如下:

[java] view
plaincopy

private final Runnable mPowerLongPress = new Runnable() {
public void run() {
// The context isn't read
if (mLongPressOnPowerBehavior < 0) {
mLongPressOnPowerBehavior = mContext.getResources().getInteger(
com.android.internal.R.integer.config_longPressOnPowerBehavior);
}
switch (mLongPressOnPowerBehavior) {
case LONG_PRESS_POWER_NOTHING:
break;
case LONG_PRESS_POWER_GLOBAL_ACTIONS:
mPowerKeyHandled = true;
performHapticFeedbackLw(null, HapticFeedbackConstants.LONG_PRESS, false);
sendCloseSystemWindows(SYSTEM_DIALOG_REASON_GLOBAL_ACTIONS);
showGlobalActionsDialog();
break;
case LONG_PRESS_POWER_SHUT_OFF:
mPowerKeyHandled = true;
performHapticFeedbackLw(null, HapticFeedbackConstants.LONG_PRESS, false);
sendCloseSystemWindows(SYSTEM_DIALOG_REASON_GLOBAL_ACTIONS);
ShutdownThread.shutdown(mContext, true);
break;
}
}
};

它是一个匿名内部类,它是一个实现Runnable的类的对象引用,因此

new Runnable() {

public void run(){

...

}

};

它包括了定义这个类(只不过这个类没有名字)和实例化这个类的对象。

当超时时,其执行流程如下图所示:

3.2
reboot系统调用流程

reboot系统调用流程如下图所示:

4.
如何处理短按和长按电源键

长按电源键:弹出关机确认对话框(KeyDown之后,如果 500ms之内,没有收到KeyUp则弹出关机确认对话框)

短按电源键:执行待机(KeyUp时执行<wmActions=4>)或唤醒(KeyDown时执行<wmActions=2>)

对于长按电源键,在PhoneWindowManager.java的interceptKeyBeforeQueueing函数中进行处理,其相关代码如下 :

[java] view
plaincopy

case KeyEvent.KEYCODE_POWER: {
result &= ~ACTION_PASS_TO_USER;
if (down) {
if (isScreenOn && !mPowerKeyTriggered
&& (event.getFlags() & KeyEvent.FLAG_FALLBACK) == 0) {
mPowerKeyTriggered = true;
mPowerKeyTime = event.getDownTime();
interceptScreenshotChord();
}

    ...    
    // Power Key down, set mPowerLongPress executing after 500ms    
    interceptPowerKeyDown(!isScreenOn || hungUp    
            || mVolumeDownKeyTriggered || mVolumeUpKeyTriggered);    
} else {    
    mPowerKeyTriggered = false;    
    cancelPendingScreenshotChordAction();    
    if (interceptPowerKeyUp(canceled || mPendingPowerKeyUpCanceled)) {    
        result = (result &amp; ~ACTION_POKE_USER_ACTIVITY) | ACTION_GO_TO_SLEEP;    
    }    
    // Power key up, remove the mPowerLongPress, that is, if user release    
    // power key during 500ms, mPowerLongPress will not be execute, then execute sleep    
    mPendingPowerKeyUpCanceled = false;    
}    
break;    

}

[java] view
plaincopy

private void interceptPowerKeyDown(boolean handled) {
mPowerKeyHandled = handled;
if (!handled) {
mHandler.postDelayed(mPowerLongPress, ViewConfiguration.getGlobalActionKeyTimeout()/500ms/);
}
}

private boolean interceptPowerKeyUp(boolean canceled) {
if (!mPowerKeyHandled) {
mHandler.removeCallbacks(mPowerLongPress);
return !canceled;
}
return false;
}

标签: android

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