void InputDispatcher::notifyKey(const NotifyKeyArgs* args) {
#if DEBUG_INBOUND_EVENT_DETAILSALOGD("notifyKey - eventTime=%lld, deviceId=%d, source=0x%x, policyFlags=0x%x, action=0x%x, ""flags=0x%x, keyCode=0x%x, scanCode=0x%x, metaState=0x%x, downTime=%lld",args->eventTime, args->deviceId, args->source, args->policyFlags,args->action, args->flags, args->keyCode, args->scanCode,args->metaState, args->downTime);
#endifif (!validateKeyEvent(args->action)) {return;}uint32_t policyFlags = args->policyFlags;int32_t flags = args->flags;int32_t metaState = args->metaState;if ((policyFlags & POLICY_FLAG_VIRTUAL) || (flags & AKEY_EVENT_FLAG_VIRTUAL_HARD_KEY)) {policyFlags |= POLICY_FLAG_VIRTUAL;flags |= AKEY_EVENT_FLAG_VIRTUAL_HARD_KEY;}if (policyFlags & POLICY_FLAG_FUNCTION) {metaState |= AMETA_FUNCTION_ON;}policyFlags |= POLICY_FLAG_TRUSTED;int32_t keyCode = args->keyCode;if (metaState & AMETA_META_ON && args->action == AKEY_EVENT_ACTION_DOWN) {int32_t newKeyCode = AKEYCODE_UNKNOWN;if (keyCode == AKEYCODE_DEL) {newKeyCode = AKEYCODE_BACK;} else if (keyCode == AKEYCODE_ENTER) {newKeyCode = AKEYCODE_HOME;}if (newKeyCode != AKEYCODE_UNKNOWN) {AutoMutex _l(mLock);struct KeyReplacement replacement = {keyCode, args->deviceId};mReplacedKeys.add(replacement, newKeyCode);keyCode = newKeyCode;metaState &= ~AMETA_META_ON;}} else if (args->action == AKEY_EVENT_ACTION_UP) {// In order to maintain a consistent stream of up and down events, check to see if the key// going up is one we've replaced in a down event and haven't yet replaced in an up event,// even if the modifier was released between the down and the up events.AutoMutex _l(mLock);struct KeyReplacement replacement = {keyCode, args->deviceId};ssize_t index = mReplacedKeys.indexOfKey(replacement);if (index >= 0) {keyCode = mReplacedKeys.valueAt(index);mReplacedKeys.removeItemsAt(index);metaState &= ~AMETA_META_ON;}}KeyEvent event;event.initialize(args->deviceId, args->source, args->action,flags, keyCode, args->scanCode, metaState, 0,args->downTime, args->eventTime);mPolicy->interceptKeyBeforeQueueing(&event, /*byref*/ policyFlags);bool needWake;{ // acquire lockmLock.lock();if (shouldSendKeyToInputFilterLocked(args)) {mLock.unlock();policyFlags |= POLICY_FLAG_FILTERED;if (!mPolicy->filterInputEvent(&event, policyFlags)) {return; // event was consumed by the filter}mLock.lock();}int32_t repeatCount = 0;KeyEntry* newEntry = new KeyEntry(args->eventTime,args->deviceId, args->source, policyFlags,args->action, flags, keyCode, args->scanCode,metaState, repeatCount, args->downTime);needWake = enqueueInboundEventLocked(newEntry);mLock.unlock();} // release lockif (needWake) {mLooper->wake();}
}

    mPolicy->interceptKeyBeforeQueueing(&event, /*byref*/ policyFlags); 截获按键并处理，也即NativeInputManager::interceptKeyBeforeQueueing

void NativeInputManager::interceptKeyBeforeQueueing(const KeyEvent* keyEvent,uint32_t& policyFlags) {// Policy:// - Ignore untrusted events and pass them along.// - Ask the window manager what to do with normal events and trusted injected events.// - For normal events wake and brighten the screen if currently off or dim.if (mInteractive) {policyFlags |= POLICY_FLAG_INTERACTIVE;}if ((policyFlags & POLICY_FLAG_TRUSTED)) {nsecs_t when = keyEvent->getEventTime();JNIEnv* env = jniEnv();jobject keyEventObj = android_view_KeyEvent_fromNative(env, keyEvent);jint wmActions;if (keyEventObj) {wmActions = env->CallIntMethod(mServiceObj,gServiceClassInfo.interceptKeyBeforeQueueing,keyEventObj, policyFlags);if (checkAndClearExceptionFromCallback(env, "interceptKeyBeforeQueueing")) {wmActions = 0;}android_view_KeyEvent_recycle(env, keyEventObj);env->DeleteLocalRef(keyEventObj);} else {ALOGE("Failed to obtain key event object for interceptKeyBeforeQueueing.");wmActions = 0;}handleInterceptActions(wmActions, when, /*byref*/ policyFlags);} else {if (mInteractive) {policyFlags |= POLICY_FLAG_PASS_TO_USER;}}
}

wmActions = env->CallIntMethod(mServiceObj,gServiceClassInfo.interceptKeyBeforeQueueing,keyEventObj, policyFlags);则会call 到

InputManagerService.java中的interceptKeyBeforeQueueing

    private long interceptKeyBeforeQueueing(InputWindowHandle focus,KeyEvent event, int policyFlags) {return mWindowManagerCallbacks.interceptKeyBeforeQueueing(focus, event, policyFlags);}

mWindowManagerCallbacks实际为InputMonitor

SystemServer.java 文件中startOtherServices调用inputManager.setWindowManagerCallbacks(wm.getInputMonitor())，给mWindowManagerCallbacks

赋值，而wm.getInputMonitor()获取的是InputMonitor， 所以mWindowManagerCallbacks.interceptKeyBeforeQueueing最后调用到InputMonitor:interceptKeyBeforeQueueing

InputMonitor.java文件中：

    public long interceptKeyBeforeQueueing(InputWindowHandle focus, KeyEvent event, int policyFlags) {WindowState windowState = focus != null ? (WindowState) focus.windowState : null;return mService.mPolicy.interceptKeyBeforeDispatching(windowState, event, policyFlags);}

而mService.mPolicy.interceptKeyBeforeQueueing则是WindowManagerService的按键策略机制mPolicy来继续捕获，

mPolicy = PolicyManager.makeNewWindowManager // mPolicy为 PhoneWindowManager

PhoneWindowManager::interceptKeyBeforeDispatching其中就会截获KeyEvent.KEYCODE_POWER

    public int interceptKeyBeforeQueueing(KeyEvent event, int policyFlags) {if (!mSystemBooted) {// If we have not yet booted, don't let key events do anything.return 0;}final boolean interactive = (policyFlags & FLAG_INTERACTIVE) != 0;final boolean down = event.getAction() == KeyEvent.ACTION_DOWN;final boolean canceled = event.isCanceled();......//<span style="color:#ff0000;"> Handle special keys</span>.switch (keyCode) {case KeyEvent.KEYCODE_VOLUME_DOWN:......case <span style="color:#ff0000;">KeyEvent.KEYCODE_POWER</span>: {result &= ~ACTION_PASS_TO_USER;isWakeKey = false; // wake-up will be handled separatelyif (down) {<span style="color:#ff0000;">interceptPowerKeyDown</span>(event, interactive);} else {interceptPowerKeyUp(event, interactive, canceled);}break;}}......return result;}

interceptKeyBeforeQueueing里面就会截获一些特设的按键，下面我们看power键的处理

down 表示一直为ACTION_DOWN状态，就会call  interceptPowerKeyDown使用mHandler发送一个MSG_POWER_LONG_PRESS消息，而mHandler(PolicyHandler)

就会在handleMessage处理消息MSG_POWER_LONG_PRESS

上面处理MSG_POWER_LONG_PRESS消息时，powerLongPress

    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();}<span style="background-color: rgb(255, 0, 0);">showGlobalActionsInternal</span>();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;}}

showGlobalActionsInternal会构造GlobalActions对象并显示

    void showGlobalActionsInternal() {sendCloseSystemWindows(SYSTEM_DIALOG_REASON_GLOBAL_ACTIONS);if (mGlobalActions == null) {mGlobalActions = new <span style="color:#ff0000;">GlobalActions</span>(mContext, mWindowManagerFuncs);}final boolean keyguardShowing = isKeyguardShowingAndNotOccluded();<span style="color:#ff0000;">mGlobalActions.showDialog</span>(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);}}

GlobalActions对话框的显示

GlobalActions主要是针对 “ 静音，重启，关机，飞行模式 ” 等全局按键的特殊快捷功能弹出的一些Dialog对话框。

接着上面mGlobalActions.showDialog，继续分析showDialog

    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 completesmHandler.sendEmptyMessage(<span style="color:#ff0000;">MESSAGE_SHOW</span>);} else {handleShow();}}

mHandler中处理MESSAGE_SHOW消息

    private Handler mHandler = new Handler() {public void handleMessage(Message msg) {switch (msg.what) {case MESSAGE_DISMISS:if (mDialog != null) {mDialog.dismiss();mDialog = null;}break;case MESSAGE_REFRESH:refreshSilentMode();mAdapter.notifyDataSetChanged();break;case MESSAGE_SHOW:<span style="color:#ff0000;">handleShow</span>();break;}}}

handleShow主要是创建Dialog对话框并显示

    private void handleShow() {awakenIfNecessary();mDialog = <span style="color:#ff0000;">createDialog</span>();prepareDialog();// If we only have 1 item and it's a simple press action, just do this action.if (mAdapter.getCount() == 1&& mAdapter.getItem(0) instanceof SinglePressAction&& !(mAdapter.getItem(0) instanceof LongPressAction)) {((SinglePressAction) mAdapter.getItem(0)).onPress();} else {WindowManager.LayoutParams attrs = mDialog.getWindow().getAttributes();attrs.setTitle("GlobalActions");mDialog.getWindow().setAttributes(attrs);<span style="color:#ff0000;"> mDialog.show();</span>mDialog.getWindow().getDecorView().setSystemUiVisibility(View.STATUS_BAR_DISABLE_EXPAND);}}

其中createDialog 创建的GlobalActionsDialog对话框内容比较丰富，创建一些Action ( SilentModeToggleAction/SilentModeTriStateAction, ToggleAction,) 保存在mItems里面, 其实我们也可以发现关机行为处理的PowerAction(ToggleAction 行为)也被添加到mItems ArrayList中。

    private GlobalActionsDialog createDialog() {// Simple toggle style if there's no vibrator, otherwise use a tri-stateif (!mHasVibrator) {mSilentModeAction = new SilentModeToggleAction();} else {mSilentModeAction = new SilentModeTriStateAction(mContext, mAudioManager, mHandler);}mAirplaneModeOn = new ToggleAction(R.drawable.ic_lock_airplane_mode,R.drawable.ic_lock_airplane_mode_off,R.string.global_actions_toggle_airplane_mode,R.string.global_actions_airplane_mode_on_status,R.string.global_actions_airplane_mode_off_status) {void onToggle(boolean on) {if (mHasTelephony && Boolean.parseBoolean(SystemProperties.get(TelephonyProperties.PROPERTY_INECM_MODE))) {mIsWaitingForEcmExit = true;// Launch ECM exit dialogIntent ecmDialogIntent =new Intent(TelephonyIntents.ACTION_SHOW_NOTICE_ECM_BLOCK_OTHERS, null);ecmDialogIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);mContext.startActivity(ecmDialogIntent);} else {changeAirplaneModeSystemSetting(on);}}@Overrideprotected void changeStateFromPress(boolean buttonOn) {if (!mHasTelephony) return;// In ECM mode airplane state cannot be changedif (!(Boolean.parseBoolean(SystemProperties.get(TelephonyProperties.PROPERTY_INECM_MODE)))) {mState = buttonOn ? State.TurningOn : State.TurningOff;mAirplaneState = mState;}}public boolean showDuringKeyguard() {return true;}public boolean showBeforeProvisioning() {return false;}};onAirplaneModeChanged();mItems = new ArrayList<Action>();String[] defaultActions = mContext.getResources().getStringArray(com.android.internal.R.array.config_globalActionsList);ArraySet<String> addedKeys = new ArraySet<String>();for (int i = 0; i < defaultActions.length; i++) {String actionKey = defaultActions[i];if (addedKeys.contains(actionKey)) {// If we already have added this, don't add it again.continue;}if (GLOBAL_ACTION_KEY_POWER.equals(actionKey)) {<span style="background-color: rgb(255, 0, 0);">mItems.add(new PowerAction())</span>;} else if (GLOBAL_ACTION_KEY_AIRPLANE.equals(actionKey)) {mItems.add(mAirplaneModeOn);} else if (GLOBAL_ACTION_KEY_BUGREPORT.equals(actionKey)) {if (Settings.Global.getInt(mContext.getContentResolver(),Settings.Global.BUGREPORT_IN_POWER_MENU, 0) != 0 && isCurrentUserOwner()) {mItems.add(getBugReportAction());}} else if (GLOBAL_ACTION_KEY_SILENT.equals(actionKey)) {if (mShowSilentToggle) {mItems.add(mSilentModeAction);}} else if (GLOBAL_ACTION_KEY_USERS.equals(actionKey)) {if (SystemProperties.getBoolean("fw.power_user_switcher", false)) {addUsersToMenu(mItems);}} else if (GLOBAL_ACTION_KEY_SETTINGS.equals(actionKey)) {mItems.add(getSettingsAction());} else if (GLOBAL_ACTION_KEY_LOCKDOWN.equals(actionKey)) {mItems.add(getLockdownAction());} else {Log.e(TAG, "Invalid global action key " + actionKey);}// Add here so we don't add more than one.addedKeys.add(actionKey);}mAdapter = new MyAdapter();AlertParams params = new AlertParams(mContext);params.mAdapter = mAdapter;params.mOnClickListener = this;params.mForceInverseBackground = true;GlobalActionsDialog dialog = new GlobalActionsDialog(mContext, params);dialog.setCanceledOnTouchOutside(false); // Handled by the custom class.dialog.getListView().<span style="color:#ff0000;">setItemsCanFocus</span>(true);dialog.getListView().<span style="color:#ff0000;">setLongClickable</span>(true);dialog.getListView().<span style="color:#ff0000;">setOnItemLongClickListener</span>(<span style="color:#000099;">new AdapterView.OnItemLongClickListener() {@Overridepublic boolean onItemLongClick(AdapterView<?> parent, View view, int position,long id) {final Action action = mAdapter.getItem(position);if (action instanceof LongPressAction) {return ((LongPressAction) action).onLongPress();}return false;}</span>});dialog.getWindow().setType(WindowManager.LayoutParams.TYPE_KEYGUARD_DIALOG);dialog.setOnDismissListener(this);return dialog;}

在创建GlobalActionsDialog后给各个view设置监听，setItemsCanFocus，setLongClickable，setOnItemLongClickListener，其中setOnItemLongClickListener

就是针对长按键的处理 ((LongPressAction) action).onLongPress()，如果不想处理power长按动作可以dialog.getListView().setOnItemLongClickListener(null)来到达要求。

        public boolean onLongPress() {mWindowManagerFuncs.rebootSafeMode(true);return true;}

而mWindowManagerFuncs有就是WindowManagerService，rebootSafeMode就会调到

    // Called by window manager policy.  Not exposed externally.@Overridepublic void rebootSafeMode(boolean confirm) {ShutdownThread.rebootSafeMode(mContext, confirm);}

ShutdownThread进入安全模式

WindowManagerService 调用rebootSafeMode之后，就转到ShutdownThread 线程来处理

    public static void rebootSafeMode(final Context context, boolean confirm) {mReboot = true;mRebootSafeMode = true;mRebootReason = null;<span style="color:#ff0000;">shutdownInner</span>(context, confirm);}static void shutdownInner(final Context context, boolean confirm) {// ensure that only one thread is trying to power down.// any additional calls are just returnedsynchronized (sIsStartedGuard) {if (sIsStarted) {Log.d(TAG, "Request to shutdown already running, returning.");return;}}final int longPressBehavior = context.getResources().getInteger(com.android.internal.R.integer.config_longPressOnPowerBehavior);final int resourceId = mRebootSafeMode? com.android.internal.R.string.reboot_safemode_confirm: (longPressBehavior == 2? com.android.internal.R.string.shutdown_confirm_question: com.android.internal.R.string.shutdown_confirm);Log.d(TAG, "Notifying thread to start shutdown longPressBehavior=" + longPressBehavior);if (confirm) {final CloseDialogReceiver closer = new CloseDialogReceiver(context);if (sConfirmDialog != null) {sConfirmDialog.dismiss();}sConfirmDialog = new AlertDialog.Builder(context).setTitle(mRebootSafeMode? com.android.internal.R.string.reboot_safemode_title: com.android.internal.R.string.power_off).setMessage(resourceId).setPositiveButton(com.android.internal.R.string.yes, new DialogInterface.OnClickListener() {public void onClick(DialogInterface dialog, int which) {<span style="color:#ff0000;">beginShutdownSequence</span>(context);}}).setNegativeButton(com.android.internal.R.string.no, null).create();closer.dialog = sConfirmDialog;sConfirmDialog.setOnDismissListener(closer);sConfirmDialog.getWindow().setType(WindowManager.LayoutParams.TYPE_KEYGUARD_DIALOG);sConfirmDialog.show();} else {<span style="color:#ff0000;">beginShutdownSequence</span>(context);}}

rebootSafeMode会接着调shutdownInner，最终beginShutdownSequence call   pms电源管理服务来关机重启

    private static void beginShutdownSequence(Context context) {synchronized (sIsStartedGuard) {if (sIsStarted) {Log.d(TAG, "Shutdown sequence already running, returning.");return;}sIsStarted = true;}// throw up an indeterminate system dialog to indicate radio is// shutting down.ProgressDialog pd = new ProgressDialog(context);pd.setTitle(context.getText(com.android.internal.R.string.power_off));pd.setMessage(context.getText(com.android.internal.R.string.shutdown_progress));pd.setIndeterminate(true);pd.setCancelable(false);pd.getWindow().setType(WindowManager.LayoutParams.TYPE_KEYGUARD_DIALOG);pd.show();sInstance.mContext = context;<span style="color:#ff0000;">sInstance.mPowerManager = (PowerManager)context.getSystemService(Context.POWER_SERVICE)</span>;// make sure we never fall asleep againsInstance.mCpuWakeLock = null;try {sInstance.mCpuWakeLock = sInstance.mPowerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, TAG + "-cpu");<span style="color:#ff0000;">sInstance.mCpuWakeLock.setReferenceCounted(false);sInstance.mCpuWakeLock.acquire()</span>;} catch (SecurityException e) {Log.w(TAG, "No permission to acquire wake lock", e);sInstance.mCpuWakeLock = null;}// also make sure the screen stays on for better user experiencesInstance.mScreenWakeLock = null;if (sInstance.mPowerManager.isScreenOn()) {try {sInstance.mScreenWakeLock = sInstance.mPowerManager.newWakeLock(PowerManager.FULL_WAKE_LOCK, TAG + "-screen");sInstance.mScreenWakeLock.setReferenceCounted(false);sInstance.mScreenWakeLock.acquire();} catch (SecurityException e) {Log.w(TAG, "No permission to acquire wake lock", e);sInstance.mScreenWakeLock = null;}}// start the thread that initiates shutdownsInstance.mHandler = new Handler() {};sInstance.start();}

至此整个长按 power键的处理流程结束。

android系统重启功能定制 ，安全模式相关流程，安全模式流程图。