Android4.2锁屏源码跟踪

PS：源码目录以Frameworks为基准 ， 源码android4.2。

首先我们定位到Android虚拟机启动之后java层的第一个类：./base/services/java/com/android/server/SystemServer.java
在main中通过JNI调用./base/cmds/system_server/System_main.cpp,代码如下：
System.loadLibrary("android_servers");
        init1(args);
./base/cmds/System_main.cpp的main中 system_init();   又跳转至./base/cmds/system_server/library/System_init.cpp中，在system_init中有如下代码：
JNIEnv* env = runtime->getJNIEnv();
    if (env == NULL) {
        return UNKNOWN_ERROR;
    }
    jclass clazz = env->FindClass("com/android/server/SystemServer");
    if (clazz == NULL) {
        return UNKNOWN_ERROR;
    }
    jmethodID methodId = env->GetStaticMethodID(clazz, "init2", "()V");
    if (methodId == NULL) {
        return UNKNOWN_ERROR;
    }
    env->CallStaticVoidMethod(clazz, methodId);
	
	由上可知：我们又回到了./base/services/java/com/android/server/SystemServer.java中。在init2中启动所有相关的东东。代码：
Thread thr = new ServerThread();
        thr.setName("android.server.ServerThread");
        thr.start();

	PS：其中ServerThread类也在SystemServer.java中。
	
	我们继续跟踪ServerThread.run() 方法，在run方法中主要是启动一系列的服务，根据主题的需要我们定位到
	
wm = WindowManagerService.main(context, power, display, inputManager,
                    uiHandler, wmHandler,
                    factoryTest != SystemServer.FACTORY_TEST_LOW_LEVEL,
                    !firstBoot, onlyCore);
            ServiceManager.addService(Context.WINDOW_SERVICE, wm);

	而在./base/services/java/com/android/server/wm/WindowManagerService.java 的main 中调用了WindowManagerService构造方法，构造方法中又在initPolicy中调用了（./base/policy/src/com/android/internal/policy/impl/PhoneWindowManager.java）mPolicy.init（），该方法对PhoneWindowManager里面的重要变量，进行初始化。

    /** {@inheritDoc} */
    public void init(Context context, IWindowManager windowManager,
            WindowManagerFuncs windowManagerFuncs) {
        mContext = context;
        mWindowManager = windowManager;
        mWindowManagerFuncs = windowManagerFuncs;
        mHeadless = "1".equals(SystemProperties.get("ro.config.headless", "0"));
        if (!mHeadless) {
            // don't create KeyguardViewMediator if headless
            mKeyguardMediator = new KeyguardViewMediator(context, null);
        }
        mHandler = new PolicyHandler();
        mOrientationListener = new MyOrientationListener(mContext);
        try {
            mOrientationListener.setCurrentRotation(windowManager.getRotation());
        } catch (RemoteException ex) { }
        mSettingsObserver = new SettingsObserver(mHandler);
        mSettingsObserver.observe();
        mShortcutManager = new ShortcutManager(context, mHandler);
        mShortcutManager.observe();
        mHomeIntent =  new Intent(Intent.ACTION_MAIN, null);
        mHomeIntent.addCategory(Intent.CATEGORY_HOME);
        mHomeIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK
                | Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED);
        mCarDockIntent =  new Intent(Intent.ACTION_MAIN, null);
        mCarDockIntent.addCategory(Intent.CATEGORY_CAR_DOCK);
        mCarDockIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK
                | Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED);
        mDeskDockIntent =  new Intent(Intent.ACTION_MAIN, null);
        mDeskDockIntent.addCategory(Intent.CATEGORY_DESK_DOCK);
        mDeskDockIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK
                | Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED);

        mPowerManager = (PowerManager)context.getSystemService(Context.POWER_SERVICE);
        mBroadcastWakeLock = mPowerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK,
                "PhoneWindowManager.mBroadcastWakeLock");
        mEnableShiftMenuBugReports = "1".equals(SystemProperties.get("ro.debuggable"));
        mLidOpenRotation = readRotation(
                com.android.internal.R.integer.config_lidOpenRotation);
        mCarDockRotation = readRotation(
                com.android.internal.R.integer.config_carDockRotation);
        mDeskDockRotation = readRotation(
                com.android.internal.R.integer.config_deskDockRotation);
        mCarDockEnablesAccelerometer = mContext.getResources().getBoolean(
                com.android.internal.R.bool.config_carDockEnablesAccelerometer);
        mDeskDockEnablesAccelerometer = mContext.getResources().getBoolean(
                com.android.internal.R.bool.config_deskDockEnablesAccelerometer);
        mLidKeyboardAccessibility = mContext.getResources().getInteger(
                com.android.internal.R.integer.config_lidKeyboardAccessibility);
        mLidNavigationAccessibility = mContext.getResources().getInteger(
                com.android.internal.R.integer.config_lidNavigationAccessibility);
        mLidControlsSleep = mContext.getResources().getBoolean(
                com.android.internal.R.bool.config_lidControlsSleep);
        // register for dock events
        IntentFilter filter = new IntentFilter();
        filter.addAction(UiModeManager.ACTION_ENTER_CAR_MODE);
        filter.addAction(UiModeManager.ACTION_EXIT_CAR_MODE);
        filter.addAction(UiModeManager.ACTION_ENTER_DESK_MODE);
        filter.addAction(UiModeManager.ACTION_EXIT_DESK_MODE);
        filter.addAction(Intent.ACTION_DOCK_EVENT);
        Intent intent = context.registerReceiver(mDockReceiver, filter);
        if (intent != null) {
            // Retrieve current sticky dock event broadcast.
            mDockMode = intent.getIntExtra(Intent.EXTRA_DOCK_STATE,
                    Intent.EXTRA_DOCK_STATE_UNDOCKED);
        }

        // register for dream-related broadcasts
        filter = new IntentFilter();
        filter.addAction(Intent.ACTION_DREAMING_STARTED);
        filter.addAction(Intent.ACTION_DREAMING_STOPPED);
        context.registerReceiver(mDreamReceiver, filter);

        // register for multiuser-relevant broadcasts
        filter = new IntentFilter(Intent.ACTION_USER_SWITCHED);
        context.registerReceiver(mMultiuserReceiver, filter);

        mVibrator = (Vibrator)context.getSystemService(Context.VIBRATOR_SERVICE);
        mLongPressVibePattern = getLongIntArray(mContext.getResources(),
                com.android.internal.R.array.config_longPressVibePattern);
        mVirtualKeyVibePattern = getLongIntArray(mContext.getResources(),
                com.android.internal.R.array.config_virtualKeyVibePattern);
        mKeyboardTapVibePattern = getLongIntArray(mContext.getResources(),
                com.android.internal.R.array.config_keyboardTapVibePattern);
        mSafeModeDisabledVibePattern = getLongIntArray(mContext.getResources(),
                com.android.internal.R.array.config_safeModeDisabledVibePattern);
        mSafeModeEnabledVibePattern = getLongIntArray(mContext.getResources(),
                com.android.internal.R.array.config_safeModeEnabledVibePattern);

        mScreenshotChordEnabled = mContext.getResources().getBoolean(
                com.android.internal.R.bool.config_enableScreenshotChord);

        // Controls rotation and the like.
        initializeHdmiState();

        // Match current screen state.
        if (mPowerManager.isScreenOn()) {
            screenTurningOn(null);
        } else {
            screenTurnedOff(WindowManagerPolicy.OFF_BECAUSE_OF_USER);
        }
    }

	我们回到ServerThread.run中，继续查看wm:
		
try {
            wm.displayReady();	
        } catch (Throwable e) {
            reportWtf("making display ready", e);
        }
public void systemReady() {
        mPolicy.systemReady();
    }

	在./base/policy/src/com/android/internal/policy/impl/PhoneWindowManager.java中的systemReady有：
		
 /** {@inheritDoc} */
    public void systemReady() {
        if (mKeyguardMediator != null) {
            // tell the keyguard
            mKeyguardMediator.onSystemReady();
        }
        synchronized (mLock) {
            updateOrientationListenerLp();
            mSystemReady = true;
            mHandler.post(new Runnable() {
                public void run() {
                    updateSettings();
                }
            });
        }
    }

	而在mKeyguardMediator.onSystemReady();--------------------------./base/policy/src/com/android/internal/policy/impl/keyguard/KeyguardUpdateMonitor.java ，有：
		
 public void onSystemReady() {
        mSearchManager = (SearchManager) mContext.getSystemService(Context.SEARCH_SERVICE);
        synchronized (this) {
            if (DEBUG) Log.d(TAG, "onSystemReady");
            mSystemReady = true;
            mUpdateMonitor.registerCallback(mUpdateCallback);

            // Suppress biometric unlock right after boot until things have settled if it is the
            // selected security method, otherwise unsuppress it.  It must be unsuppressed if it is
            // not the selected security method for the following reason:  if the user starts
            // without a screen lock selected, the biometric unlock would be suppressed the first
            // time they try to use it.
            //
            // Note that the biometric unlock will still not show if it is not the selected method.
            // Calling setAlternateUnlockEnabled(true) simply says don't suppress it if it is the
            // selected method.
            if (mLockPatternUtils.usingBiometricWeak()
                    && mLockPatternUtils.isBiometricWeakInstalled()) {
                if (DEBUG) Log.d(TAG, "suppressing biometric unlock during boot");
                mUpdateMonitor.setAlternateUnlockEnabled(false);
            } else {
                mUpdateMonitor.setAlternateUnlockEnabled(true);
            }

            doKeyguardLocked();
        }
        // Most services aren't available until the system reaches the ready state, so we
        // send it here when the device first boots.
        maybeSendUserPresentBroadcast();
    }

		而 doKeyguardLocked(); 中就是调用锁屏相关: 其中有 
		mSuppressNextLockSound = true;
            	doKeyguardLocked();  即进行正式锁屏
		
		KeyguardViewMediator实现这部分调度是通过持有一个KeyguardViewManager来实现的。总之KeyguardUpdateMonitor是所有会影响整个待机解/锁屏业务的事件的监控器。(除了作为监控器，它还发挥着类似上下文的作用，也许我们应该把这个类命名为(KeyguardContext)。它监控诸如时间改变、电池状态改变、时区改变、SIM卡状态变化、电话状态变化、电话信号变化等事件。它是一个观察者模式的被观察对象。观察者通过调用KeyguardUpdateMonitor的以下方法进行注册，观察自己感兴趣的变化。
	KeyguardUpdateMonitor的观察者包括KeyguardViewMediator、LockScreen、PatternUnlockScreen、AccountUnlockScreen、PasswordUnlockScreen、SimUnlockScreen等。观察者通过调用KeyguardUpdateMonitor的removeCallback(Object)取消观察。
	KeyguardViewManager负责管理待机屏UI界面的创建、显示、隐藏、重置以及通过一个回调KeyguardViewCallback通知调度器KeyguardViewMediator进行相关的调度。
	LockPatternKeyguardView（KeyguardViewBase）是所有锁屏和解锁UI界面的宿主。它有2个模式Mode. LockScreen和Mode. UnlockScreen。它负责根据当前上下文环境切换当前应该显示的待机屏。
它提供一个回调给当前显示的待机屏并处理其回调，如果回调动作是自己处理不了的，则继续报告给KeyguardViewMediator进行处理。
	锁屏界面就是LockScreen；解锁界面包括SIM卡解锁SimUnlockScreen、图案解锁PatternUnlockScreen、密码解锁PasswordUnlockScreen、帐号解锁AccountUnlockScreen
解锁成功后，锁屏流程转到KeyguardViewMediator的keyguardDone(boolean, boolean) 进行后续的流程（如转到Launcher桌面）。
	在锁屏宿主LockPatternKeyguardView中有updateScreen(Mode mode, boolean force) ，他根据锁屏模式进行相关的屏幕重建，在此过程一般调用recreateLockScreen()或者是recreateUnlockScreen(UnlockMode unlockMode)方法，在recreateLockScreen()会跳转至LockScreen构造函数；而recreateUnlockScreen(UnlockMode unlockMode)方法会根据unlockMode的具体值：
	
enum UnlockMode {

        /**
         * Unlock by drawing a pattern.
         */
        Pattern,

        /**
         * Unlock by entering a sim pin.
         */
        SimPin,

        /**
         * Unlock by entering a sim puk.
         */
        SimPuk,

        /**
         * Unlock by entering an account's login and password.
         */
        Account,

        /**
         * Unlock by entering a password or PIN
         */
        Password,

        /**
         * Unknown (uninitialized) value
         */
        Unknown
    }

	进入到相关的锁屏类中，包括：PatternUnlockScreen   ， SimPukUnlockScreen   ，SimUnlockScreen  ， AccountUnlockScreen ，  PasswordUnlockScreen 。然后就是在相关的类的构造函数中加载相关的布局文件。
下面以PasswordUnlockScreen为例进行跟踪：

在其构造函数中有：

if (mCreationOrientation != Configuration.ORIENTATION_LANDSCAPE) {
            Log.d(TAG, "portrait mode");
            inflater.inflate(R.layout.keyguard_screen_unlock_portrait, this, true);
        } else {
            Log.d(TAG, "landscape mode");
            inflater.inflate(R.layout.keyguard_screen_unlock_landscape, this, true);
        }

通过查找我们找到相关布局文件，如图：

而我现在所定制的平板为800*480，所以我以  ../base/core/res/res/layout-sw600dp/keyguard_screen_unlock_portrait.xml  为例：布局如下：

基本上锁屏界面出现的先关视图都在里面有所体现。下面查看上图中所引用的 com.android.internal.widget中的LockPatternView类，在它的构造函数中有如下相关设置：

mPathPaint.setAntiAlias(true);
        mPathPaint.setDither(true);
        mPathPaint.setColor(Color.WHITE);   // TODO this should be from the style
        mPathPaint.setAlpha(mStrokeAlpha);
        mPathPaint.setStyle(Paint.Style.STROKE);
        mPathPaint.setStrokeJoin(Paint.Join.ROUND);
        mPathPaint.setStrokeCap(Paint.Cap.ROUND);
        // lot's of bitmaps!
        mBitmapBtnDefault = getBitmapFor(R.drawable.btn_code_lock_default_holo);
        mBitmapBtnTouched = getBitmapFor(R.drawable.btn_code_lock_touched_holo);
        mBitmapCircleDefault = getBitmapFor(R.drawable.indicator_code_lock_point_area_default_holo);
        mBitmapCircleGreen = getBitmapFor(R.drawable.indicator_code_lock_point_area_green_holo);
        mBitmapCircleRed = getBitmapFor(R.drawable.indicator_code_lock_point_area_red_holo);

        mBitmapArrowGreenUp = getBitmapFor(R.drawable.indicator_code_lock_drag_direction_green_up);
        mBitmapArrowRedUp = getBitmapFor(R.drawable.indicator_code_lock_drag_direction_red_up);

        // bitmaps have the size of the largest bitmap in this group
        final Bitmap bitmaps[] = { mBitmapBtnDefault, mBitmapBtnTouched, mBitmapCircleDefault,
                mBitmapCircleGreen, mBitmapCircleRed };

通过查找匹配，我们可以印证是否相关的位图是在锁屏界面中出现的：

....................................................................................................................................待