Android O關(guān)機(jī)流程

問題起因

*今天測試提出了一個(gè)問題缨叫，關(guān)機(jī)過程中（播放關(guān)機(jī)動畫)按Power鍵可以熄屏卒煞、亮屏狸驳。

解決方案

*首先我想應(yīng)該從關(guān)機(jī)流程開始吧藕咏，然后自己一步步跟進(jìn)代碼，修改framework代碼邏輯贸铜，在關(guān)機(jī)時(shí)堡纬，禁用Power鍵

關(guān)機(jī)流程

想必都很清楚正常關(guān)機(jī)是如何操作的，按Power鍵來確定關(guān)機(jī)蒿秦，這里首先來分析一下PhoneWindowManager這個(gè)類隐轩，這個(gè)類Power、volum等事件處理
PhoneWindowManager.java

public int interceptKeyBeforeQueueing(KeyEvent event, int policyFlags) { 
    ...
    switch (keyCode) {
    ...
        case KeyEvent.KEYCODE_POWER: {
            // Any activity on the power button stops the accessibility shortcut
            cancelPendingAccessibilityShortcutAction();
            result &= ~ACTION_PASS_TO_USER;
            isWakeKey = false; // wake-up will be handled separately
            if (down) {
                interceptPowerKeyDown(event, interactive);
            } else {
                interceptPowerKeyUp(event, interactive, canceled);
            }
            break;
        }
     ...
     }
 }

因?yàn)槭前聪翽ower走的interceptPowerKeyDown這個(gè)函數(shù)渤早。

private void interceptPowerKeyDown(KeyEvent event, boolean interactive) {
    ...
    if (!mPowerKeyHandled) {
        if (interactive) {
            // 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()) {
                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;
                }
            }
        }
    }
}

直接看關(guān)鍵部分,判斷是否是LongPress职车，是的話就通過Handler發(fā)送消息處理，追蹤到mHandler鹊杖，handlemessage里面調(diào)用powerLongPress()這個(gè)私有函數(shù)來處理長按power悴灵。

private void powerLongPress() {
    final int behavior = getResolvedLongPressOnPowerBehavior();
    switch (behavior) {
    case LONG_PRESS_POWER_NOTHING:
        break;
    case LONG_PRESS_POWER_GLOBAL_ACTIONS:
        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;
    }
}

將mPowerKeyHandled設(shè)置為true表示這個(gè)行為已經(jīng)被處理了，其實(shí)是正在處理骂蓖。showGlobalActionsInternal()這個(gè)函數(shù)我想應(yīng)該就是處理長按power顯示的對話框吧积瞒。

void showGlobalActionsInternal() {
    sendCloseSystemWindows(SYSTEM_DIALOG_REASON_GLOBAL_ACTIONS);
    if (mGlobalActions == null) {
        mGlobalActions = new GlobalActions(mContext, mWindowManagerFuncs);
    }
    final boolean keyguardShowing = isKeyguardShowingAndNotOccluded();
    mGlobalActions.showDialog(keyguardShowing, isDeviceProvisioned());
    if (keyguardShowing) {
        // since it took two seconds of long press to bring this up,
        // poke the wake lock so they have some time to see the dialog.
        mPowerManager.userActivity(SystemClock.uptimeMillis(), false);
    }
}

果不其然，創(chuàng)建了GlobalActions類對象登下，而從注釋該類介紹來看是一個(gè)創(chuàng)建全局對話框的幫助類茫孔，構(gòu)造方法中獲得各種系統(tǒng)服務(wù)，其中有AudioManager被芳、WindowManagerFuncs缰贝，其中關(guān)機(jī)我們應(yīng)該看的是WindowManagerFuncs這個(gè)服務(wù)，他獲取的是WindowManagerService畔濒。再來看showDialog這個(gè)方法剩晴。

public void showDialog(boolean keyguardShowing, boolean isDeviceProvisioned) {
    mKeyguardShowing = keyguardShowing;
    mDeviceProvisioned = isDeviceProvisioned;
    if (mDialog != null) {
        mDialog.dismiss();
        mDialog = null;
        // Show delayed, so that the dismiss of the previous dialog completes
        mHandler.sendEmptyMessage(MESSAGE_SHOW);
    } else {
        handleShow();
    }
}

private GlobalActionsDialog createDialog() {
    ...
    if (GLOBAL_ACTION_KEY_POWER.equals(actionKey)) {
            mItems.add(new PowerAction());
        } else if (GLOBAL_ACTION_KEY_REBOOT.equals(actionKey)) {
            mItems.add(new RebootAction());
        } 
    ...
}

其中handleShow方法最終調(diào)用createDialog();這個(gè)方法來創(chuàng)建GlobalActionsDialog這個(gè)對話框?qū)ο螅渲欣酶鞣N參數(shù)Action來控制item的各種行為侵状，我們這里要看的就是PowerAction

private final class PowerAction extends SinglePressAction implements LongPressAction {
    ...
    @Override
    public void onPress() {         
       mWindowManagerFuncs.shutdown(true/* confirm */);      
    }
}

看到這里就都明白了赞弥，通過對話框關(guān)機(jī)，這里調(diào)用的是mWindowManagerFuncs.shutdown趣兄，這個(gè)方法绽左，這里mWindowManagerFuncs也就是WindowManagerService這個(gè)服務(wù)

@Override
public void shutdown(boolean confirm) {
    ShutdownThread.shutdown(mContext, PowerManager.SHUTDOWN_USER_REQUESTED, confirm);
}

其中通過名字可以知道調(diào)用了一個(gè)關(guān)機(jī)線程來處理，簡單點(diǎn)的話就可以直接追蹤到run方法艇潭。這里就不知道看代碼了拼窥，通過打印信息來看看做了什么

11-18 20:00:17.061 1361-5920/system_process I/ShutdownThread: Sending shutdown broadcast...
11-18 20:00:18.710 1361-5920/system_process I/ShutdownThread: Shutting down activity manager...
11-18 20:00:18.913 1361-5920/system_process I/ShutdownThread: Shutting down package manager...
11-18 20:00:18.937 1361-6051/system_process W/ShutdownThread: Turning off cellular radios...
11-18 20:00:18.953 1361-6051/system_process I/ShutdownThread: Waiting for NFC, Bluetooth and Radio...
11-18 20:00:19.455 1361-6051/system_process I/ShutdownThread: Radio turned off.
11-18 20:00:19.455 1361-6051/system_process I/ShutdownThread: NFC, Radio and Bluetooth shutdown complete.
11-18 20:00:19.459 1361-5920/system_process I/ShutdownThread: Shutting down MountService
11-18 20:00:20.461 1361-5920/system_process W/ShutdownThread: Shutdown wait timed out
11-18 20:00:20.504 1361-5920/system_process I/ShutdownThread: waitShutdownAnimation true
11-18 20:00:20.510 1361-5920/system_process I/ShutdownThread: wait SHUTDOWN_ANIMATION_SERVICE completed. time out 14
11-18 20:00:20.836 1361-1712/system_process W/ShutdownThread: Result code 0 from MountService.shutdown
11-18 20:00:21.510 1361-5920/system_process I/ShutdownThread: wait SHUTDOWN_ANIMATION_SERVICE completed. time out 13
11-18 20:00:22.511 1361-5920/system_process I/ShutdownThread: wait SHUTDOWN_ANIMATION_SERVICE completed. time out 12
11-18 20:00:23.511 1361-5920/system_process I/ShutdownThread: wait SHUTDOWN_ANIMATION_SERVICE completed. time out 11
11-18 20:00:24.512 1361-5920/system_process I/ShutdownThread: wait SHUTDOWN_ANIMATION_SERVICE completed. time out 10
11-18 20:00:26.014 1361-5920/system_process I/ShutdownThread: Performing low-level shutdown...

首先發(fā)送關(guān)機(jī)廣播承粤，關(guān)閉一系列服務(wù)AMS、PKMS闯团、radio、NFC等等等仙粱，等待關(guān)機(jī)動畫完成房交。

• 流程理清楚了，解決起來就很簡單了伐割，在ShutdownThread設(shè)置一個(gè)靜態(tài)成員變量 public static boolean isShutDowning = false; 候味，執(zhí)行run方法就將這個(gè)標(biāo)示設(shè)為true
• 然后在PhoneWindowManager的powerPress函數(shù)中添加判斷是否禁用Power。

驗(yàn)證了也確實(shí)OK