android 6.0 power按键深度解析

主要分析power按键点亮屏幕和灭屏，而且我们主要分析在PhoneWIndowManager的流程。

之前的博客我们分析过按键的流程，当有按键会先到PhoneWindowManager的interceptKeyBeforeQueueing函数，然后再去分析到应用，而power按键也是如此，并且其最后不会分发到应用中去，下面我们看下PhoneWindowManager的interceptKeyBeforeQueueing函数对power按键处理的代码：

顺便说下这个interactive这个变量是从NativeInputManager中传过来的，在NativeInputManager也是有一个mInteractive的成员变量，是PowerManagerService改变状态的时候在Notifier.Java中调用InputManagerService的Native方法，到NativeInputManager的方法nativeSetInteractive方法来设置的mInteractive变量的。所以这个值也可以说是PowerManagerService关于屏幕的状态。

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case KeyEvent.KEYCODE_POWER: {

result &= ~ACTION_PASS_TO_USER;//不分发到应用

isWakeKey = false; // wake-up will be handled separately

if (down) {

Log.i(TAG, “PowerKey down, interactive = ” + interactive);

interceptPowerKeyDown(event, interactive);//按键down

} else {

Log.i(TAG, “PowerKey up.”);

interceptPowerKeyUp(event, interactive, canceled);//按键up

}

break;

}

一、Powerkey down

我们先来看下按键down的interceptPowerKeyDown函数：

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private void interceptPowerKeyDown(KeyEvent event, boolean interactive) {

// Hold a wake lock until the power key is released.

if (!mPowerKeyWakeLock.isHeld()) {//上层持锁

mPowerKeyWakeLock.acquire();

}

// Cancel multi-press detection timeout.
if (mPowerKeyPressCounter != 0) {//在我们的手机不支持这块，统计多次按键
mHandler.removeMessages(MSG_POWER_DELAYED_PRESS);
}

…

if (!mPowerKeyHandled) {

if (interactive) {//亮屏

// When interactive, we’re already awake.

// Wait for a long press or for the button to be released to decide what to do.

if (hasLongPressOnPowerBehavior()) {//是否支持长按键

Message msg = mHandler.obtainMessage(MSG_POWER_LONG_PRESS);

msg.setAsynchronous(true);

mHandler.sendMessageDelayed(msg,

ViewConfiguration.get(mContext).getDeviceGlobalActionKeyTimeout());

}

} else {

wakeUpFromPowerKey(event.getDownTime());

if (mSupportLongPressPowerWhenNonInteractive && hasLongPressOnPowerBehavior()) {
Message msg = mHandler.obtainMessage(MSG_POWER_LONG_PRESS);
msg.setAsynchronous(true);
mHandler.sendMessageDelayed(msg,
ViewConfiguration.get(mContext).getDeviceGlobalActionKeyTimeout());
mBeganFromNonInteractive = true;
} else {
final int maxCount = getMaxMultiPressPowerCount();

if (maxCount <= 1) {
mPowerKeyHandled = true;
} else {
mBeganFromNonInteractive = true;
}
}
}
}

}

1.1 亮屏 长按键处理

我们先来看看hasLongPressOnPowerBehavior函数：

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private boolean hasLongPressOnPowerBehavior() {

return getResolvedLongPressOnPowerBehavior() != LONG_PRESS_POWER_NOTHING;//不为0

}

再来看看getResolvedLongPressOnPowerBehavior函数

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private int getResolvedLongPressOnPowerBehavior() {

if (FactoryTest.isLongPressOnPowerOffEnabled()) {

return LONG_PRESS_POWER_SHUT_OFF_NO_CONFIRM;

}

return mLongPressOnPowerBehavior;

}

其中又调用了isLongPressOnPowerOffEnabled，我们没有支持这个属性。因此只要看mLongPressOnPowerBehavior这个变量

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public static boolean isLongPressOnPowerOffEnabled() {

return SystemProperties.getInt(“factory.long_press_power_off”, 0) != 0;

}

下面再看看mLongPressOnPowerBehavior 这个变量的初始化。

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mLongPressOnPowerBehavior = mContext.getResources().getInteger(

com.android.internal.R.integer.config_longPressOnPowerBehavior);

看资源apk：

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./res/values/config.xml:743: 1
也就是mLongPressOnPowerBehavior = 1，最后hasLongPressOnPowerBehavior返回1.

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if (hasLongPressOnPowerBehavior()) {

Message msg = mHandler.obtainMessage(MSG_POWER_LONG_PRESS);

msg.setAsynchronous(true);

mHandler.sendMessageDelayed(msg,

ViewConfiguration.get(mContext).getDeviceGlobalActionKeyTimeout());

}

然后就发消息，我们再来看处理消息：

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case MSG_POWER_LONG_PRESS:

powerLongPress();

再来看powerLongPress函数

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private void powerLongPress() {

final int behavior = getResolvedLongPressOnPowerBehavior();

switch (behavior) {

case LONG_PRESS_POWER_NOTHING:

break;

case LONG_PRESS_POWER_GLOBAL_ACTIONS://返回1

mPowerKeyHandled = true;

if (!performHapticFeedbackLw(null, HapticFeedbackConstants.LONG_PRESS, false)) {

performAuditoryFeedbackForAccessibilityIfNeed();

}

showGlobalActionsInternal();//下面就是弹出关机，重启之类的对话框了

break;

上面之前我们再添加长按对话框添加重启功能的那篇博客有涉及，这就是在亮屏的时候长按power的流程。

1.2 灭屏 按键down处理

下面我们再来看看，interceptPowerKeyDown的另一个分支，关于现在是灭屏的时候，按键down。

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else {//灭屏

wakeUpFromPowerKey(event.getDownTime());//亮屏

if (mSupportLongPressPowerWhenNonInteractive && hasLongPressOnPowerBehavior()) {
Message msg = mHandler.obtainMessage(MSG_POWER_LONG_PRESS);
msg.setAsynchronous(true);
mHandler.sendMessageDelayed(msg,
ViewConfiguration.get(mContext).getDeviceGlobalActionKeyTimeout());
mBeganFromNonInteractive = true;
} else {
final int maxCount = getMaxMultiPressPowerCount();

if (maxCount <= 1) {
mPowerKeyHandled = true;
} else {
mBeganFromNonInteractive = true;
}
}

第一步直接调用wakeUpFromPowerKey函数，我们看下这个函数：

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private void wakeUpFromPowerKey(long eventTime) {

wakeUp(eventTime, mAllowTheaterModeWakeFromPowerKey, “android.policy:POWER”);//这里mAllowTheaterModeWakeFromPowerKey为true

}

private boolean wakeUp(long wakeTime, boolean wakeInTheaterMode, String reason) {

final boolean theaterModeEnabled = isTheaterModeEnabled();

if (!wakeInTheaterMode && theaterModeEnabled) {

return false;

}

if (theaterModeEnabled) {
Settings.Global.putInt(mContext.getContentResolver(),
Settings.Global.THEATER_MODE_ON, 0);
}

mPolicyLooper.setMessageLogging(mLogPrinter);
mPowerManager.wakeUp(wakeTime, reason);
return true;

}

这里mAllowTheaterModeWakeFromPowerKey为true，因此就直接调用了PowerManager的wakeUp函数了，reason是”Android.policy:POWER”

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else {//灭屏

wakeUpFromPowerKey(event.getDownTime());//亮屏

if (mSupportLongPressPowerWhenNonInteractive && hasLongPressOnPowerBehavior()) {
Message msg = mHandler.obtainMessage(MSG_POWER_LONG_PRESS);
msg.setAsynchronous(true);
mHandler.sendMessageDelayed(msg,
ViewConfiguration.get(mContext).getDeviceGlobalActionKeyTimeout());
mBeganFromNonInteractive = true;
} else {
final int maxCount = getMaxMultiPressPowerCount();//返回为1，不支持多次按钮

if (maxCount <= 1) {
mPowerKeyHandled = true;//走这里
} else {
mBeganFromNonInteractive = true;
}
}

而下面mSupportLongPressPowerWhenNonInteractive 我们配置也是false不支持。多按钮也不支持，因此maxCount为1

二、PowerKey On

PowerKey on 又分为之前down的时候是灭屏还是亮屏处理的，逻辑又不一样。

2.1 之前power按键 down是灭屏的

我们先来看之前Power按键 down的时候手机是灭屏的情况下，下面我们分析PowerKey on的interceptPowerKeyUp函数：

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private void interceptPowerKeyUp(KeyEvent event, boolean interactive, boolean canceled) {

final boolean handled = canceled || mPowerKeyHandled;//记得之前灭屏按键down的时候，mPowerKeyHandled = true

mScreenshotChordPowerKeyTriggered = false;

cancelPendingScreenshotChordAction();

cancelPendingPowerKeyAction();

if (!handled) {
// Figure out how to handle the key now that it has been released.
mPowerKeyPressCounter += 1;

final int maxCount = getMaxMultiPressPowerCount();
final long eventTime = event.getDownTime();
if (mPowerKeyPressCounter < maxCount) {
// This could be a multi-press.  Wait a little bit longer to confirm.
// Continue holding the wake lock.
Message msg = mHandler.obtainMessage(MSG_POWER_DELAYED_PRESS,
interactive ? 1 : 0, mPowerKeyPressCounter, eventTime);
msg.setAsynchronous(true);
mHandler.sendMessageDelayed(msg, ViewConfiguration.getDoubleTapTimeout());
return;
}

// No other actions.  Handle it immediately.
powerPress(eventTime, interactive, mPowerKeyPressCounter);
}

// Done.  Reset our state.
finishPowerKeyPress();

}

之前在手机灭屏我们按power键down的时候，最后mPowerKeyHandled = true，这里handled = true，最后直接调用

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private void finishPowerKeyPress() {

mBeganFromNonInteractive = false;//我们手机不支持

mPowerKeyPressCounter = 0;//多按键，不支持

if (mPowerKeyWakeLock.isHeld()) {

mPowerKeyWakeLock.release();//之前按power键down时候的锁释放

}

}

2.2 之前power按键 down是亮屏的

之前power按键 down的时候手机亮屏，power down又分为长按和短按。我们先来看之前power down亮屏，down是长按的情况下，现在是power up的情况：

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private void powerLongPress() {

final int behavior = getResolvedLongPressOnPowerBehavior();

switch (behavior) {

case LONG_PRESS_POWER_NOTHING:

break;

case LONG_PRESS_POWER_GLOBAL_ACTIONS://为1

mPowerKeyHandled = true;

if (!performHapticFeedbackLw(null, HapticFeedbackConstants.LONG_PRESS, false)) {

performAuditoryFeedbackForAccessibilityIfNeed();

}

showGlobalActionsInternal();

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(behavior == LONG_PRESS_POWER_SHUT_OFF);

break;

}

}

之前看过这函数，长按mPowerKeyHandled = true，和上面一样。直接最后interceptPowerKeyUp函数就调用finishPowerKeyPress函数了。

然后我们再来看之前powerKey Down的时候是亮屏的，又是短按的情况，我们再来看interceptPowerKeyUp函数：

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private void interceptPowerKeyUp(KeyEvent event, boolean interactive, boolean canceled) {

final boolean handled = canceled || mPowerKeyHandled;//这个实收handled为false了

mScreenshotChordPowerKeyTriggered = false;

cancelPendingScreenshotChordAction();

cancelPendingPowerKeyAction();

if (!handled) {
// Figure out how to handle the key now that it has been released.
mPowerKeyPressCounter += 1;

final int maxCount = getMaxMultiPressPowerCount();//这个返回为1，本来是多次按钮的。这里没有配置
final long eventTime = event.getDownTime();
if (mPowerKeyPressCounter < maxCount) {
// This could be a multi-press.  Wait a little bit longer to confirm.
// Continue holding the wake lock.
Message msg = mHandler.obtainMessage(MSG_POWER_DELAYED_PRESS,
interactive ? 1 : 0, mPowerKeyPressCounter, eventTime);
msg.setAsynchronous(true);
mHandler.sendMessageDelayed(msg, ViewConfiguration.getDoubleTapTimeout());
return;
}

// No other actions.  Handle it immediately.
powerPress(eventTime, interactive, mPowerKeyPressCounter);
}

// Done.  Reset our state.
finishPowerKeyPress();

}

我们先看看getMaxMultiPressPowerCount函数：

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private int getMaxMultiPressPowerCount() {

if (mTriplePressOnPowerBehavior != MULTI_PRESS_POWER_NOTHING) {// 为0

return 3;

}

if (mDoublePressOnPowerBehavior != MULTI_PRESS_POWER_NOTHING) {//为0

return 2;

}

return 1;

}

最后这个函数返回为1，因此上面函数就直接调用powerPress函数了。

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private void powerPress(long eventTime, boolean interactive, int count) {

if (mScreenOnEarly && !mScreenOnFully) {

Slog.i(TAG, “Suppressed redundant power key press while ”

+ “already in the process of turning the screen on.”);

return;

}

if (count == 2) {
powerMultiPressAction(eventTime, interactive, mDoublePressOnPowerBehavior);
} else if (count == 3) {
powerMultiPressAction(eventTime, interactive, mTriplePressOnPowerBehavior);
} else if (interactive && !mBeganFromNonInteractive) {//之前我们只支持1，必须亮屏，另一个参数这里为false
switch (mShortPressOnPowerBehavior) {// 这个参数也是资源apk中配置的，为1
case SHORT_PRESS_POWER_NOTHING:
break;
case SHORT_PRESS_POWER_GO_TO_SLEEP://直接调用PowerManager的goToSleep函数了
mPowerManager.goToSleep(eventTime,
PowerManager.GO_TO_SLEEP_REASON_POWER_BUTTON, 0);
break;
case SHORT_PRESS_POWER_REALLY_GO_TO_SLEEP:
mPowerManager.goToSleep(eventTime,
PowerManager.GO_TO_SLEEP_REASON_POWER_BUTTON,
PowerManager.GO_TO_SLEEP_FLAG_NO_DOZE);
break;
case SHORT_PRESS_POWER_REALLY_GO_TO_SLEEP_AND_GO_HOME:
mPowerManager.goToSleep(eventTime,
PowerManager.GO_TO_SLEEP_REASON_POWER_BUTTON,
PowerManager.GO_TO_SLEEP_FLAG_NO_DOZE);
launchHomeFromHotKey();
break;
case SHORT_PRESS_POWER_GO_HOME:
launchHomeFromHotKey(true /* awakenFromDreams */, false /*respectKeyguard*/);
break;
}
}

}

因为我们没有配置多次power按钮，mShortPressOnPowerBehavior配置为1，所以就直接调用了PowerManager的goToSleep函数了。

三、总结

这篇博客我们主要分析了，power按键在PhoneWindowManager的处理。

power按键down：

1.down又分长按亮屏 弹出关闭重启对话框

2. 短按灭屏 调用wakeup

power按键on：

1.之前down的时候亮屏短按才会调用goToSleep

2.之前down的时候亮屏长按不作处理

3.之前down的时候灭屏不作处理