Android Framework層Power鍵關機流程（一，Power長按鍵操作處理）

一：Android處理Power按鍵長按操作

在Framework層中，Android4.x對Power鍵（KeyEvent.KEYCODE_POWER）的操作，我們從PhoneWindowManager開始分析，在分析前我這裡打印了該方法的堆棧調用信息。大家可以參考一下。

public long interceptKeyBeforeDispatching(WindowState win, KeyEvent event, int policyFlags) {

......

android.util.Log.d("BILL",android.util.Log.getStackTraceString(new Throwable()));

......

}

1-13 19:35:32.458 D/BILL ( 718): java.lang.Throwable

01-13 19:35:32.458 D/BILL ( 718): at com.android.internal.policy.impl.PhoneWindowManager.interceptKeyBeforeDispatching(PhoneWindowManager.java:2224)

01-13 19:35:32.458 D/BILL ( 718): at com.android.server.wm.InputMonitor.interceptKeyBeforeDispatching(InputMonitor.java:501)

01-13 19:35:32.458 D/BILL ( 718): at com.android.server.input.InputManagerService.interceptKeyBeforeDispatching(InputManagerService.java:1383)

01-13 19:35:32.458 D/BILL ( 718): at dalvik.system.NativeStart.run(Native Method)

調用流程如下(只貼出關鍵代碼）：

interceptKeyBeforeDispatching()-->interceptPowerKeyDown()-->mPowerLongPress.run()

1>

public long interceptKeyBeforeDispatching(WindowState win, KeyEvent event, int policyFlags) {

......

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


ITelephony telephonyService = getTelephonyService();
boolean hungUp = false;
if (telephonyService != null) {
try {
if (telephonyService.isRinging()) {
// Pressing Power while there's a ringing incoming
// call should silence the ringer.
telephonyService.silenceRinger();
/// M: [ALPS00093981] @{
} else if ((isScreenOn
|| mScreenOffReason == OFF_BECAUSE_OF_PROX_SENSOR)
/// @}
&& (mIncallPowerBehavior
& Settings.Secure.INCALL_POWER_BUTTON_BEHAVIOR_HANGUP) != 0
&& telephonyService.isOffhook()) {
// Otherwise, if "Power button ends call" is enabled,
// the Power button will hang up any current active call.
hungUp = telephonyService.endCall();
}
} catch (RemoteException ex) {
Log.w(TAG, "ITelephony threw RemoteException", ex);
}
}
interceptPowerKeyDown(!isScreenOn || hungUp
|| mVolumeDownKeyTriggered || mVolumeUpKeyTriggered);
} else {
mPowerKeyTriggered = false;
cancelPendingScreenshotChordAction();
if (interceptPowerKeyUp(canceled || mPendingPowerKeyUpCanceled)) {
result = (result & ~ACTION_WAKE_UP) | ACTION_GO_TO_SLEEP;
}
mPendingPowerKeyUpCanceled = false;
}
break;
}

......

}

注！紅色為判斷長按(down)，藍色為判斷短按(up)。

2>

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

3>

private final Runnable mPowerLongPress = new Runnable() {
......
case LONG_PRESS_POWER_GLOBAL_ACTIONS:
mPowerKeyHandled = true;
if (!performHapticFeedbackLw(null, HapticFeedbackConstants.LONG_PRESS, false)) {
performAuditoryFeedbackForAccessibilityIfNeed();
}
sendCloseSystemWindows(SYSTEM_DIALOG_REASON_GLOBAL_ACTIONS);
showGlobalActionsDialog();
break;
case LONG_PRESS_POWER_SHUT_OFF:
case LONG_PRESS_POWER_SHUT_OFF_NO_CONFIRM:
mPowerKeyHandled = true;
performHapticFeedbackLw(null, HapticFeedbackConstants.LONG_PRESS, false);
sendCloseSystemWindows(SYSTEM_DIALOG_REASON_GLOBAL_ACTIONS);
mWindowManagerFuncs.shutdown(resolvedBehavior == LONG_PRESS_POWER_SHUT_OFF);
break;
......
};

注：上述代碼中下劃線即彈出（關機、重啟、飛行模式等選項）的對話框。