Android 8.0系統原始碼分析--Activity的視窗Window物件新增過程原始碼分析
阿新 • • 發佈：2019-01-16
這節我們來看一下Activity的視窗Window物件的建立過程，Activity作為Android提供的四大元件之首，我們之所以能非常簡單的使用它，就是因為它的建立過程中，framework為我們作了大量的初始化工作，包括它的視窗Window、視訊記憶體Surface、事件分發的InputChannel等等非常多的工作，都在framework中為我們準備好了，所以我們這節來看一下Window物件的建立過程。
我們的起點是在ActivityThread類的handleResumeActivity方法中，原始碼如下：
這裡的wm.addView(decor, l)就是來新增我們的Activity的根View的，也就是我們這節要分析的起點。引數decor就是我們Activity的根View，它是一個DecorView型別，下面的r.activity.makeVisible()邏輯也就是將我們的Activity的介面顯示出來，所以大家以後分析問題時候，這是一個比較重要的參考點，就是說在Activity類的onResume方法執行完成且回撥之後，我們的介面才能顯示出來。wm是呼叫a.getWindowManager()獲取到的，它實際就是一個WindowManagerImpl物件，它的賦值過程是在Activity類的attach方法完成的，frameworks\base\core\java\android\app\Activity.java類的attach方法的原始碼如下：final void handleResumeActivity(IBinder token, boolean clearHide, boolean isForward, boolean reallyResume, int seq, String reason) { ActivityClientRecord r = mActivities.get(token); if (!checkAndUpdateLifecycleSeq(seq, r, "resumeActivity")) { return; } // If we are getting ready to gc after going to the background, well // we are back active so skip it. unscheduleGcIdler(); mSomeActivitiesChanged = true; // TODO Push resumeArgs into the activity for consideration r = performResumeActivity(token, clearHide, reason); if (r != null) { final Activity a = r.activity; if (localLOGV) Slog.v( TAG, "Resume " + r + " started activity: " + a.mStartedActivity + ", hideForNow: " + r.hideForNow + ", finished: " + a.mFinished); final int forwardBit = isForward ? WindowManager.LayoutParams.SOFT_INPUT_IS_FORWARD_NAVIGATION : 0; // If the window hasn't yet been added to the window manager, // and this guy didn't finish itself or start another activity, // then go ahead and add the window. boolean willBeVisible = !a.mStartedActivity; if (!willBeVisible) { try { willBeVisible = ActivityManager.getService().willActivityBeVisible( a.getActivityToken()); } catch (RemoteException e) { throw e.rethrowFromSystemServer(); } } if (r.window == null && !a.mFinished && willBeVisible) { r.window = r.activity.getWindow(); View decor = r.window.getDecorView(); decor.setVisibility(View.INVISIBLE); ViewManager wm = a.getWindowManager(); WindowManager.LayoutParams l = r.window.getAttributes(); a.mDecor = decor; l.type = WindowManager.LayoutParams.TYPE_BASE_APPLICATION; l.softInputMode |= forwardBit; if (r.mPreserveWindow) { a.mWindowAdded = true; r.mPreserveWindow = false; // Normally the ViewRoot sets up callbacks with the Activity // in addView->ViewRootImpl#setView. If we are instead reusing // the decor view we have to notify the view root that the // callbacks may have changed. ViewRootImpl impl = decor.getViewRootImpl(); if (impl != null) { impl.notifyChildRebuilt(); } } if (a.mVisibleFromClient) { if (!a.mWindowAdded) { a.mWindowAdded = true; wm.addView(decor, l); } else { // The activity will get a callback for this {@link LayoutParams} change // earlier. However, at that time the decor will not be set (this is set // in this method), so no action will be taken. This call ensures the // callback occurs with the decor set. a.onWindowAttributesChanged(l); } } // If the window has already been added, but during resume // we started another activity, then don't yet make the // window visible. } else if (!willBeVisible) { if (localLOGV) Slog.v( TAG, "Launch " + r + " mStartedActivity set"); r.hideForNow = true; } // Get rid of anything left hanging around. cleanUpPendingRemoveWindows(r, false /* force */); // The window is now visible if it has been added, we are not // simply finishing, and we are not starting another activity. if (!r.activity.mFinished && willBeVisible && r.activity.mDecor != null && !r.hideForNow) { if (r.newConfig != null) { performConfigurationChangedForActivity(r, r.newConfig); if (DEBUG_CONFIGURATION) Slog.v(TAG, "Resuming activity " + r.activityInfo.name + " with newConfig " + r.activity.mCurrentConfig); r.newConfig = null; } if (localLOGV) Slog.v(TAG, "Resuming " + r + " with isForward=" + isForward); WindowManager.LayoutParams l = r.window.getAttributes(); if ((l.softInputMode & WindowManager.LayoutParams.SOFT_INPUT_IS_FORWARD_NAVIGATION) != forwardBit) { l.softInputMode = (l.softInputMode & (~WindowManager.LayoutParams.SOFT_INPUT_IS_FORWARD_NAVIGATION)) | forwardBit; if (r.activity.mVisibleFromClient) { ViewManager wm = a.getWindowManager(); View decor = r.window.getDecorView(); wm.updateViewLayout(decor, l); } } r.activity.mVisibleFromServer = true; mNumVisibleActivities++; if (r.activity.mVisibleFromClient) { r.activity.makeVisible(); } } if (!r.onlyLocalRequest) { r.nextIdle = mNewActivities; mNewActivities = r; if (localLOGV) Slog.v( TAG, "Scheduling idle handler for " + r); Looper.myQueue().addIdleHandler(new Idler()); } r.onlyLocalRequest = false; // Tell the activity manager we have resumed. if (reallyResume) { try { ActivityManager.getService().activityResumed(token); } catch (RemoteException ex) { throw ex.rethrowFromSystemServer(); } } } else { // If an exception was thrown when trying to resume, then // just end this activity. try { ActivityManager.getService() .finishActivity(token, Activity.RESULT_CANCELED, null, Activity.DONT_FINISH_TASK_WITH_ACTIVITY); } catch (RemoteException ex) { throw ex.rethrowFromSystemServer(); } } }
這裡會呼叫mWindow.setWindowManager((WindowManager)context.getSystemService(Context.WINDOW_SERVICE), mToken, mComponent.flattenToString(), (info.flags & ActivityInfo.FLAG_HARDWARE_ACCELERATED) != 0)進行值的設定，mWindow物件實際是一個PhoneWindow型別，setWindowManager方法實際呼叫的是父類Window的方法，frameworks\base\core\java\android\view\Window.java類的setWindowManager方法的原始碼如下：final void attach(Context context, ActivityThread aThread, Instrumentation instr, IBinder token, int ident, Application application, Intent intent, ActivityInfo info, CharSequence title, Activity parent, String id, NonConfigurationInstances lastNonConfigurationInstances, Configuration config, String referrer, IVoiceInteractor voiceInteractor, Window window, ActivityConfigCallback activityConfigCallback) { attachBaseContext(context); mFragments.attachHost(null /*parent*/); mWindow = new PhoneWindow(this, window, activityConfigCallback); mWindow.setWindowControllerCallback(this); mWindow.setCallback(this); mWindow.setOnWindowDismissedCallback(this); mWindow.getLayoutInflater().setPrivateFactory(this); if (info.softInputMode != WindowManager.LayoutParams.SOFT_INPUT_STATE_UNSPECIFIED) { mWindow.setSoftInputMode(info.softInputMode); } if (info.uiOptions != 0) { mWindow.setUiOptions(info.uiOptions); } mUiThread = Thread.currentThread(); mMainThread = aThread; mInstrumentation = instr; mToken = token; mIdent = ident; mApplication = application; mIntent = intent; mReferrer = referrer; mComponent = intent.getComponent(); mActivityInfo = info; mTitle = title; mParent = parent; mEmbeddedID = id; mLastNonConfigurationInstances = lastNonConfigurationInstances; if (voiceInteractor != null) { if (lastNonConfigurationInstances != null) { mVoiceInteractor = lastNonConfigurationInstances.voiceInteractor; } else { mVoiceInteractor = new VoiceInteractor(voiceInteractor, this, this, Looper.myLooper()); } } mWindow.setWindowManager( (WindowManager)context.getSystemService(Context.WINDOW_SERVICE), mToken, mComponent.flattenToString(), (info.flags & ActivityInfo.FLAG_HARDWARE_ACCELERATED) != 0); if (mParent != null) { mWindow.setContainer(mParent.getWindow()); } mWindowManager = mWindow.getWindowManager(); mCurrentConfig = config; mWindow.setColorMode(info.colorMode); }
public void setWindowManager(WindowManager wm, IBinder appToken, String appName) {
setWindowManager(wm, appToken, appName, false);
}
/**
* Set the window manager for use by this Window to, for example,
* display panels. This is <em>not</em> used for displaying the
* Window itself -- that must be done by the client.
*
* @param wm The window manager for adding new windows.
*/
public void setWindowManager(WindowManager wm, IBinder appToken, String appName,
boolean hardwareAccelerated) {
mAppToken = appToken;
mAppName = appName;
mHardwareAccelerated = hardwareAccelerated
|| SystemProperties.getBoolean(PROPERTY_HARDWARE_UI, false);
if (wm == null) {
wm = (WindowManager)mContext.getSystemService(Context.WINDOW_SERVICE);
}
mWindowManager = ((WindowManagerImpl)wm).createLocalWindowManager(this);
} @Override
public void addView(@NonNull View view, @NonNull ViewGroup.LayoutParams params) {
applyDefaultToken(params);
mGlobal.addView(view, params, mContext.getDisplay(), mParentWindow);
} public void addView(View view, ViewGroup.LayoutParams params,
Display display, Window parentWindow) {
if (view == null) {
throw new IllegalArgumentException("view must not be null");
}
if (display == null) {
throw new IllegalArgumentException("display must not be null");
}
if (!(params instanceof WindowManager.LayoutParams)) {
throw new IllegalArgumentException("Params must be WindowManager.LayoutParams");
}
final WindowManager.LayoutParams wparams = (WindowManager.LayoutParams) params;
if (parentWindow != null) {
parentWindow.adjustLayoutParamsForSubWindow(wparams);
} else {
// If there's no parent, then hardware acceleration for this view is
// set from the application's hardware acceleration setting.
final Context context = view.getContext();
if (context != null
&& (context.getApplicationInfo().flags
& ApplicationInfo.FLAG_HARDWARE_ACCELERATED) != 0) {
wparams.flags |= WindowManager.LayoutParams.FLAG_HARDWARE_ACCELERATED;
}
}
ViewRootImpl root;
View panelParentView = null;
synchronized (mLock) {
// Start watching for system property changes.
if (mSystemPropertyUpdater == null) {
mSystemPropertyUpdater = new Runnable() {
@Override public void run() {
synchronized (mLock) {
for (int i = mRoots.size() - 1; i >= 0; --i) {
mRoots.get(i).loadSystemProperties();
}
}
}
};
SystemProperties.addChangeCallback(mSystemPropertyUpdater);
}
int index = findViewLocked(view, false);
if (index >= 0) {
if (mDyingViews.contains(view)) {
// Don't wait for MSG_DIE to make it's way through root's queue.
mRoots.get(index).doDie();
} else {
throw new IllegalStateException("View " + view
+ " has already been added to the window manager.");
}
// The previous removeView() had not completed executing. Now it has.
}
// If this is a panel window, then find the window it is being
// attached to for future reference.
if (wparams.type >= WindowManager.LayoutParams.FIRST_SUB_WINDOW &&
wparams.type <= WindowManager.LayoutParams.LAST_SUB_WINDOW) {
final int count = mViews.size();
for (int i = 0; i < count; i++) {
if (mRoots.get(i).mWindow.asBinder() == wparams.token) {
panelParentView = mViews.get(i);
}
}
}
root = new ViewRootImpl(view.getContext(), display);
view.setLayoutParams(wparams);
mViews.add(view);
mRoots.add(root);
mParams.add(wparams);
// do this last because it fires off messages to start doing things
try {
root.setView(view, wparams, panelParentView);
} catch (RuntimeException e) {
// BadTokenException or InvalidDisplayException, clean up.
if (index >= 0) {
removeViewLocked(index, true);
}
throw e;
}
}
} public ViewRootImpl(Context context, Display display) {
mContext = context;
mWindowSession = WindowManagerGlobal.getWindowSession();
mDisplay = display;
mBasePackageName = context.getBasePackageName();
mThread = Thread.currentThread();
mLocation = new WindowLeaked(null);
mLocation.fillInStackTrace();
mWidth = -1;
mHeight = -1;
mDirty = new Rect();
mTempRect = new Rect();
mVisRect = new Rect();
mWinFrame = new Rect();
mWindow = new W(this);
mTargetSdkVersion = context.getApplicationInfo().targetSdkVersion;
mViewVisibility = View.GONE;
mTransparentRegion = new Region();
mPreviousTransparentRegion = new Region();
mFirst = true; // true for the first time the view is added
mAdded = false;
mAttachInfo = new View.AttachInfo(mWindowSession, mWindow, display, this, mHandler, this,
context);
mAccessibilityManager = AccessibilityManager.getInstance(context);
mAccessibilityManager.addAccessibilityStateChangeListener(
mAccessibilityInteractionConnectionManager, mHandler);
mHighContrastTextManager = new HighContrastTextManager();
mAccessibilityManager.addHighTextContrastStateChangeListener(
mHighContrastTextManager, mHandler);
mViewConfiguration = ViewConfiguration.get(context);
mDensity = context.getResources().getDisplayMetrics().densityDpi;
mNoncompatDensity = context.getResources().getDisplayMetrics().noncompatDensityDpi;
mFallbackEventHandler = new PhoneFallbackEventHandler(context);
mChoreographer = Choreographer.getInstance();
mDisplayManager = (DisplayManager)context.getSystemService(Context.DISPLAY_SERVICE);
if (!sCompatibilityDone) {
sAlwaysAssignFocus = true;
sCompatibilityDone = true;
}
loadSystemProperties();
} void checkThread() {
if (mThread != Thread.currentThread()) {
throw new CalledFromWrongThreadException(
"Only the original thread that created a view hierarchy can touch its views.");
}
}構造方法看完，我們接下來繼續看一下ViewRootImpl類的setView方法的實現，原始碼如下：
public void setView(View view, WindowManager.LayoutParams attrs, View panelParentView) {
synchronized (this) {
if (mView == null) {
mView = view;
mAttachInfo.mDisplayState = mDisplay.getState();
mDisplayManager.registerDisplayListener(mDisplayListener, mHandler);
mViewLayoutDirectionInitial = mView.getRawLayoutDirection();
mFallbackEventHandler.setView(view);
mWindowAttributes.copyFrom(attrs);
if (mWindowAttributes.packageName == null) {
mWindowAttributes.packageName = mBasePackageName;
}
attrs = mWindowAttributes;
setTag();
if (DEBUG_KEEP_SCREEN_ON && (mClientWindowLayoutFlags
& WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON) != 0
&& (attrs.flags&WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON) == 0) {
Slog.d(mTag, "setView: FLAG_KEEP_SCREEN_ON changed from true to false!");
}
// Keep track of the actual window flags supplied by the client.
mClientWindowLayoutFlags = attrs.flags;
setAccessibilityFocus(null, null);
if (view instanceof RootViewSurfaceTaker) {
mSurfaceHolderCallback =
((RootViewSurfaceTaker)view).willYouTakeTheSurface();
if (mSurfaceHolderCallback != null) {
mSurfaceHolder = new TakenSurfaceHolder();
mSurfaceHolder.setFormat(PixelFormat.UNKNOWN);
mSurfaceHolder.addCallback(mSurfaceHolderCallback);
}
}
// Compute surface insets required to draw at specified Z value.
// TODO: Use real shadow insets for a constant max Z.
if (!attrs.hasManualSurfaceInsets) {
attrs.setSurfaceInsets(view, false /*manual*/, true /*preservePrevious*/);
}
CompatibilityInfo compatibilityInfo =
mDisplay.getDisplayAdjustments().getCompatibilityInfo();
mTranslator = compatibilityInfo.getTranslator();
// If the application owns the surface, don't enable hardware acceleration
if (mSurfaceHolder == null) {
enableHardwareAcceleration(attrs);
}
boolean restore = false;
if (mTranslator != null) {
mSurface.setCompatibilityTranslator(mTranslator);
restore = true;
attrs.backup();
mTranslator.translateWindowLayout(attrs);
}
if (DEBUG_LAYOUT) Log.d(mTag, "WindowLayout in setView:" + attrs);
if (!compatibilityInfo.supportsScreen()) {
attrs.privateFlags |= WindowManager.LayoutParams.PRIVATE_FLAG_COMPATIBLE_WINDOW;
mLastInCompatMode = true;
}
mSoftInputMode = attrs.softInputMode;
mWindowAttributesChanged = true;
mWindowAttributesChangesFlag = WindowManager.LayoutParams.EVERYTHING_CHANGED;
mAttachInfo.mRootView = view;
mAttachInfo.mScalingRequired = mTranslator != null;
mAttachInfo.mApplicationScale =
mTranslator == null ? 1.0f : mTranslator.applicationScale;
if (panelParentView != null) {
mAttachInfo.mPanelParentWindowToken
= panelParentView.getApplicationWindowToken();
}
mAdded = true;
int res; /* = WindowManagerImpl.ADD_OKAY; */
// Schedule the first layout -before- adding to the window
// manager, to make sure we do the relayout before receiving
// any other events from the system.
requestLayout();
if ((mWindowAttributes.inputFeatures
& WindowManager.LayoutParams.INPUT_FEATURE_NO_INPUT_CHANNEL) == 0) {
mInputChannel = new InputChannel();
}
mForceDecorViewVisibility = (mWindowAttributes.privateFlags
& PRIVATE_FLAG_FORCE_DECOR_VIEW_VISIBILITY) != 0;
try {
mOrigWindowType = mWindowAttributes.type;
mAttachInfo.mRecomputeGlobalAttributes = true;
collectViewAttributes();
res = mWindowSession.addToDisplay(mWindow, mSeq, mWindowAttributes,
getHostVisibility(), mDisplay.getDisplayId(),
mAttachInfo.mContentInsets, mAttachInfo.mStableInsets,
mAttachInfo.mOutsets, mInputChannel);
} catch (RemoteException e) {
mAdded = false;
mView = null;
mAttachInfo.mRootView = null;
mInputChannel = null;
mFallbackEventHandler.setView(null);
unscheduleTraversals();
setAccessibilityFocus(null, null);
throw new RuntimeException("Adding window failed", e);
} finally {
if (restore) {
attrs.restore();
}
}
if (mTranslator != null) {
mTranslator.translateRectInScreenToAppWindow(mAttachInfo.mContentInsets);
}
mPendingOverscanInsets.set(0, 0, 0, 0);
mPendingContentInsets.set(mAttachInfo.mContentInsets);
mPendingStableInsets.set(mAttachInfo.mStableInsets);
mPendingVisibleInsets.set(0, 0, 0, 0);
mAttachInfo.mAlwaysConsumeNavBar =
(res & WindowManagerGlobal.ADD_FLAG_ALWAYS_CONSUME_NAV_BAR) != 0;
mPendingAlwaysConsumeNavBar = mAttachInfo.mAlwaysConsumeNavBar;
if (DEBUG_LAYOUT) Log.v(mTag, "Added window " + mWindow);
if (res < WindowManagerGlobal.ADD_OKAY) {
mAttachInfo.mRootView = null;
mAdded = false;
mFallbackEventHandler.setView(null);
unscheduleTraversals();
setAccessibilityFocus(null, null);
switch (res) {
case WindowManagerGlobal.ADD_BAD_APP_TOKEN:
case WindowManagerGlobal.ADD_BAD_SUBWINDOW_TOKEN:
throw new WindowManager.BadTokenException(
"Unable to add window -- token " + attrs.token
+ " is not valid; is your activity running?");
case WindowManagerGlobal.ADD_NOT_APP_TOKEN:
throw new WindowManager.BadTokenException(
"Unable to add window -- token " + attrs.token
+ " is not for an application");
case WindowManagerGlobal.ADD_APP_EXITING:
throw new WindowManager.BadTokenException(
"Unable to add window -- app for token " + attrs.token
+ " is exiting");
case WindowManagerGlobal.ADD_DUPLICATE_ADD:
throw new WindowManager.BadTokenException(
"Unable to add window -- window " + mWindow
+ " has already been added");
case WindowManagerGlobal.ADD_STARTING_NOT_NEEDED:
// Silently ignore -- we would have just removed it
// right away, anyway.
return;
case WindowManagerGlobal.ADD_MULTIPLE_SINGLETON:
throw new WindowManager.BadTokenException("Unable to add window "
+ mWindow + " -- another window of type "
+ mWindowAttributes.type + " already exists");
case WindowManagerGlobal.ADD_PERMISSION_DENIED:
throw new WindowManager.BadTokenException("Unable to add window "
+ mWindow + " -- permission denied for window type "
+ mWindowAttributes.type);
case WindowManagerGlobal.ADD_INVALID_DISPLAY:
throw new WindowManager.InvalidDisplayException("Unable to add window "
+ mWindow + " -- the specified display can not be found");
case WindowManagerGlobal.ADD_INVALID_TYPE:
throw new WindowManager.InvalidDisplayException("Unable to add window "
+ mWindow + " -- the specified window type "
+ mWindowAttributes.type + " is not valid");
}
throw new RuntimeException(
"Unable to add window -- unknown error code " + res);
}
if (view instanceof RootViewSurfaceTaker) {
mInputQueueCallback =
((RootViewSurfaceTaker)view).willYouTakeTheInputQueue();
}
if (mInputChannel != null) {
if (mInputQueueCallback != null) {
mInputQueue = new InputQueue();
mInputQueueCallback.onInputQueueCreated(mInputQueue);
}
mInputEventReceiver = new WindowInputEventReceiver(mInputChannel,
Looper.myLooper());
}
view.assignParent(this);
mAddedTouchMode = (res & WindowManagerGlobal.ADD_FLAG_IN_TOUCH_MODE) != 0;
mAppVisible = (res & WindowManagerGlobal.ADD_FLAG_APP_VISIBLE) != 0;
if (mAccessibilityManager.isEnabled()) {
mAccessibilityInteractionConnectionManager.ensureConnection();
}
if (view.getImportantForAccessibility() == View.IMPORTANT_FOR_ACCESSIBILITY_AUTO) {
view.setImportantForAccessibility(View.IMPORTANT_FOR_ACCESSIBILITY_YES);
}
// Set up the input pipeline.
CharSequence counterSuffix = attrs.getTitle();
mSyntheticInputStage = new SyntheticInputStage();
InputStage viewPostImeStage = new ViewPostImeInputStage(mSyntheticInputStage);
InputStage nativePostImeStage = new NativePostImeInputStage(viewPostImeStage,
"aq:native-post-ime:" + counterSuffix);
InputStage earlyPostImeStage = new EarlyPostImeInputStage(nativePostImeStage);
InputStage imeStage = new ImeInputStage(earlyPostImeStage,
"aq:ime:" + counterSuffix);
InputStage viewPreImeStage = new ViewPreImeInputStage(imeStage);
InputStage nativePreImeStage = new NativePreImeInputStage(viewPreImeStage,
"aq:native-pre-ime:" + counterSuffix);
mFirstInputStage = nativePreImeStage;
mFirstPostImeInputStage = earlyPostImeStage;
mPendingInputEventQueueLengthCounterName = "aq:pending:" + counterSuffix;
}
}
}setView下面的邏輯，首先根據mWindowSession.addToDisplay方法的返回值判斷視窗新增過程是否正常，如果出現異常，則根據返回值res進行具體的判斷，到底是哪一種異常，並且給出精確的異常資訊。視窗新增正常，繼續給成員變數mInputEventReceiver賦值，它也是事件分發中的一個環節，接著呼叫view.assignParent(this)給根View的成員變數mParent賦值，表示Activity的根View的父物件就是當前的ViewRootImpl，最後構建了一大堆的InputStage物件，我們從這些變數的命名就能看出來它們的作用，分別都是處理各個階段不同的事件處理的，但是建立後一個物件時，為什麼要以前一個物件為引數呢？我們隨便看一下物件的構造方法就明白了，比如NativePostImeInputStage物件的構造方法的原始碼如下：
final class NativePostImeInputStage extends AsyncInputStage
implements InputQueue.FinishedInputEventCallback {
public NativePostImeInputStage(InputStage next, String traceCounter) {
super(next, traceCounter);
}
@Override
protected int onProcess(QueuedInputEvent q) {
if (mInputQueue != null) {
mInputQueue.sendInputEvent(q.mEvent, q, false, this);
return DEFER;
}
return FORWARD;
}
@Override
public void onFinishedInputEvent(Object token, boolean handled) {
QueuedInputEvent q = (QueuedInputEvent)token;
if (handled) {
finish(q, true);
return;
}
forward(q);
}
}好，事件處理的物件都構造好了，我們再回過頭來看一下mWindowSession.addToDisplay邏輯的實現。它的實現在frameworks\base\services\core\java\com\android\server\wm\Session.java類中，addToDisplay方法的原始碼如下：
@Override
public int addToDisplay(IWindow window, int seq, WindowManager.LayoutParams attrs,
int viewVisibility, int displayId, Rect outContentInsets, Rect outStableInsets,
Rect outOutsets, InputChannel outInputChannel) {
return mService.addWindow(this, window, seq, attrs, viewVisibility, displayId,
outContentInsets, outStableInsets, outOutsets, outInputChannel);
}public int addWindow(Session session, IWindow client, int seq,
WindowManager.LayoutParams attrs, int viewVisibility, int displayId,
Rect outContentInsets, Rect outStableInsets, Rect outOutsets,
InputChannel outInputChannel) {
int[] appOp = new int[1];
int res = mPolicy.checkAddPermission(attrs, appOp);
if (res != WindowManagerGlobal.ADD_OKAY) {
return res;
}
boolean reportNewConfig = false;
WindowState parentWindow = null;
long origId;
final int callingUid = Binder.getCallingUid();
final int type = attrs.type;
synchronized(mWindowMap) {
if (!mDisplayReady) {
throw new IllegalStateException("Display has not been initialialized");
}
final DisplayContent displayContent = mRoot.getDisplayContentOrCreate(displayId);
if (displayContent == null) {
Slog.w(TAG_WM, "Attempted to add window to a display that does not exist: "
+ displayId + ". Aborting.");
return WindowManagerGlobal.ADD_INVALID_DISPLAY;
}
if (!displayContent.hasAccess(session.mUid)
&& !mDisplayManagerInternal.isUidPresentOnDisplay(session.mUid, displayId)) {
Slog.w(TAG_WM, "Attempted to add window to a display for which the application "
+ "does not have access: " + displayId + ". Aborting.");
return WindowManagerGlobal.ADD_INVALID_DISPLAY;
}
if (mWindowMap.containsKey(client.asBinder())) {
Slog.w(TAG_WM, "Window " + client + " is already added");
return WindowManagerGlobal.ADD_DUPLICATE_ADD;
}
if (type >= FIRST_SUB_WINDOW && type <= LAST_SUB_WINDOW) {
parentWindow = windowForClientLocked(null, attrs.token, false);
if (parentWindow == null) {
Slog.w(TAG_WM, "Attempted to add window with token that is not a window: "
+ attrs.token + ". Aborting.");
return WindowManagerGlobal.ADD_BAD_SUBWINDOW_TOKEN;
}
if (parentWindow.mAttrs.type >= FIRST_SUB_WINDOW
&& parentWindow.mAttrs.type <= LAST_SUB_WINDOW) {
Slog.w(TAG_WM, "Attempted to add window with token that is a sub-window: "
+ attrs.token + ". Aborting.");
return WindowManagerGlobal.ADD_BAD_SUBWINDOW_TOKEN;
}
}
if (type == TYPE_PRIVATE_PRESENTATION && !displayContent.isPrivate()) {
Slog.w(TAG_WM, "Attempted to add private presentation window to a non-private display. Aborting.");
return WindowManagerGlobal.ADD_PERMISSION_DENIED;
}
AppWindowToken atoken = null;
final boolean hasParent = parentWindow != null;
// Use existing parent window token for child windows since they go in the same token
// as there parent window so we can apply the same policy on them.
WindowToken token = displayContent.getWindowToken(
hasParent ? parentWindow.mAttrs.token : attrs.token);
// If this is a child window, we want to apply the same type checking rules as the
// parent window type.
final int rootType = hasParent ? parentWindow.mAttrs.type : type;
boolean addToastWindowRequiresToken = false;
if (token == null) {
if (rootType >= FIRST_APPLICATION_WINDOW && rootType <= LAST_APPLICATION_WINDOW) {
Slog.w(TAG_WM, "Attempted to add application window with unknown token "
+ attrs.token + ". Aborting.");
return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
}
if (rootType == TYPE_INPUT_METHOD) {
Slog.w(TAG_WM, "Attempted to add input method window with unknown token "
+ attrs.token + ". Aborting.");
return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
}
if (rootType == TYPE_VOICE_INTERACTION) {
Slog.w(TAG_WM, "Attempted to add voice interaction window with unknown token "
+ attrs.token + ". Aborting.");
return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
}
if (rootType == TYPE_WALLPAPER) {
Slog.w(TAG_WM, "Attempted to add wallpaper window with unknown token "
+ attrs.token + ". Aborting.");
return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
}
if (rootType == TYPE_DREAM) {
Slog.w(TAG_WM, "Attempted to add Dream window with unknown token "
+ attrs.token + ". Aborting.");
return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
}
if (rootType == TYPE_QS_DIALOG) {
Slog.w(TAG_WM, "Attempted to add QS dialog window with unknown token "
+ attrs.token + ". Aborting.");
return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
}
if (rootType == TYPE_ACCESSIBILITY_OVERLAY) {
Slog.w(TAG_WM, "Attempted to add Accessibility overlay window with unknown token "
+ attrs.token + ". Aborting.");
return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
}
if (type == TYPE_TOAST) {
// Apps targeting SDK above N MR1 cannot arbitrary add toast windows.
if (doesAddToastWindowRequireToken(attrs.packageName, callingUid,
parentWindow)) {
Slog.w(TAG_WM, "Attempted to add a toast window with unknown token "
+ attrs.token + ". Aborting.");
return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
}
}
final IBinder binder = attrs.token != null ? attrs.token : client.asBinder();
token = new WindowToken(this, binder, type, false, displayContent,
session.mCanAddInternalSystemWindow);
} else if (rootType >= FIRST_APPLICATION_WINDOW && rootType <= LAST_APPLICATION_WINDOW) {
atoken = token.asAppWindowToken();
if (atoken == null) {
Slog.w(TAG_WM, "Attempted to add window with non-application token "
+ token + ". Aborting.");
return WindowManagerGlobal.ADD_NOT_APP_TOKEN;
} else if (atoken.removed) {
Slog.w(TAG_WM, "Attempted to add window with exiting application token "
+ token + ". Aborting.");
return WindowManagerGlobal.ADD_APP_EXITING;
}
} else if (rootType == TYPE_INPUT_METHOD) {
if (token.windowType != TYPE_INPUT_METHOD) {
Slog.w(TAG_WM, "Attempted to add input method window with bad token "
+ attrs.token + ". Aborting.");
return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
}
} else if (rootType == TYPE_VOICE_INTERACTION) {
if (token.windowType != TYPE_VOICE_INTERACTION) {
Slog.w(TAG_WM, "Attempted to add voice interaction window with bad token "
+ attrs.token + ". Aborting.");
return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
}
} else if (rootType == TYPE_WALLPAPER) {
if (token.windowType != TYPE_WALLPAPER) {
Slog.w(TAG_WM, "Attempted to add wallpaper window with bad token "
+ attrs.token + ". Aborting.");
return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
}
} else if (rootType == TYPE_DREAM) {
if (token.windowType != TYPE_DREAM) {
Slog.w(TAG_WM, "Attempted to add Dream window with bad token "
+ attrs.token + ". Aborting.");
return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
}
} else if (rootType == TYPE_ACCESSIBILITY_OVERLAY) {
if (token.windowType != TYPE_ACCESSIBILITY_OVERLAY) {
Slog.w(TAG_WM, "Attempted to add Accessibility overlay window with bad token "
+ attrs.token + ". Aborting.");
return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
}
} else if (type == TYPE_TOAST) {
// Apps targeting SDK above N MR1 cannot arbitrary add toast windows.
addToastWindowRequiresToken = doesAddToastWindowRequireToken(attrs.packageName,
callingUid, parentWindow);
if (addToastWindowRequiresToken && token.windowType != TYPE_TOAST) {
Slog.w(TAG_WM, "Attempted to add a toast window with bad token "
+ attrs.token + ". Aborting.");
return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
}
} else if (type == TYPE_QS_DIALOG) {
if (token.windowType != TYPE_QS_DIALOG) {
Slog.w(TAG_WM, "Attempted to add QS dialog window with bad token "
+ attrs.token + ". Aborting.");
return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
}
} else if (token.asAppWindowToken() != null) {
Slog.w(TAG_WM, "Non-null appWindowToken for system window of rootType=" + rootType);
// It is not valid to use an app token with other system types; we will
// instead make a new token for it (as if null had been passed in for the token).
attrs.token = null;
token = new WindowToken(this, client.asBinder(), type, false, displayContent,
session.mCanAddInternalSystemWindow);
}
final WindowState win = new WindowState(this, session, client, token, parentWindow,
appOp[0], seq, attrs, viewVisibility, session.mUid,
session.mCanAddInternalSystemWindow);
if (win.mDeathRecipient == null) {
// Client has apparently died, so there is no reason to
// continue.
Slog.w(TAG_WM, "Adding window client " + client.asBinder()
+ " that is dead, aborting.");
return WindowManagerGlobal.ADD_APP_EXITING;
}
if (win.getDisplayContent() == null) {
Slog.w(TAG_WM, "Adding window to Display that has been removed.");
return WindowManagerGlobal.ADD_INVALID_DISPLAY;
}
mPolicy.adjustWindowParamsLw(win.mAttrs);
win.setShowToOwnerOnlyLocked(mPolicy.checkShowToOwnerOnly(attrs));
res = mPolicy.prepareAddWindowLw(win, attrs);
if (res != WindowManagerGlobal.ADD_OKAY) {
return res;
}
final boolean openInputChannels = (outInputChannel != null
&& (attrs.inputFeatures & INPUT_FEATURE_NO_INPUT_CHANNEL) == 0);
if (openInputChannels) {
win.openInputChannel(outInputChannel);
}
// If adding a toast requires a token for this app we always schedule hiding
// toast windows to make sure they don't stick around longer then necessary.
// We hide instead of remove such windows as apps aren't prepared to handle
// windows being removed under them.
//
// If the app is older it can add toasts without a token and hence overlay
// other apps. To be maximally compatible with these apps we will hide the
// window after the toast timeout only if the focused window is from another
// UID, otherwise we allow unlimited duration. When a UID looses focus we
// schedule hiding all of its toast windows.
if (type == TYPE_TOAST) {
if (!getDefaultDisplayContentLocked().canAddToastWindowForUid(callingUid)) {
Slog.w(TAG_WM, "Adding more than one toast window for UID at a time.");
return WindowManagerGlobal.ADD_DUPLICATE_ADD;
}
// Make sure this happens before we moved focus as one can make the
// toast focusable to force it not being hidden after the timeout.
// Focusable toasts are always timed out to prevent a focused app to
// show a focusable toasts while it has focus which will be kept on
// the screen after the activity goes away.
if (addToastWindowRequiresToken
|| (attrs.flags & LayoutParams.FLAG_NOT_FOCUSABLE) == 0
|| mCurrentFocus == null
|| mCurrentFocus.mOwnerUid != callingUid) {
mH.sendMessageDelayed(
mH.obtainMessage(H.WINDOW_HIDE_TIMEOUT, win),
win.mAttrs.hideTimeoutMilliseconds);
}
}
// From now on, no exceptions or errors allowed!
res = WindowManagerGlobal.ADD_OKAY;
if (mCurrentFocus == null) {
mWinAddedSinceNullFocus.add(win);
}
if (excludeWindowTypeFromTapOutTask(type)) {
displayContent.mTapExcludedWindows.add(win);
}
origId = Binder.clearCallingIdentity();
win.attach();
mWindowMap.put(client.asBinder(), win);
if (win.mAppOp != AppOpsManager.OP_NONE) {
int startOpResult = mAppOps.startOpNoThrow(win.mAppOp, win.getOwningUid(),
win.getOwningPackage());
if ((startOpResult != AppOpsManager.MODE_ALLOWED) &&
(startOpResult != AppOpsManager.MODE_DEFAULT)) {
win.setAppOpVisibilityLw(false);
}
}
final AppWindowToken aToken = token.asAppWindowToken();
if (type == TYPE_APPLICATION_STARTING && aToken != null) {
aToken.startingWindow = win;
if (DEBUG_STARTING_WINDOW) Slog.v (TAG_WM, "addWindow: " + aToken
+ " startingWindow=" + win);
}
boolean imMayMove = true;
win.mToken.addWindow(win);
if (type == TYPE_INPUT_METHOD) {
win.mGivenInsetsPending = true;
setInputMethodWindowLocked(win);
imMayMove = false;
} else if (type == TYPE_INPUT_METHOD_DIALOG) {
displayContent.computeImeTarget(true /* updateImeTarget */);
imMayMove = false;
} else {
if (type == TYPE_WALLPAPER) {
displayContent.mWallpaperController.clearLastWallpaperTimeoutTime();
displayContent.pendingLayoutChanges |= FINISH_LAYOUT_REDO_WALLPAPER;
} else if ((attrs.flags&FLAG_SHOW_WALLPAPER) != 0) {
displayContent.pendingLayoutChanges |= FINISH_LAYOUT_REDO_WALLPAPER;
} else if (displayContent.mWallpaperController.isBelowWallpaperTarget(win)) {
// If there is currently a wallpaper being shown, and
// the base layer of the new window is below the current
// layer of the target window, then adjust the wallpaper.
// This is to avoid a new window being placed between the
// wallpaper and its target.
displayContent.pendingLayoutChanges |= FINISH_LAYOUT_REDO_WALLPAPER;
}
}
// If the window is being added to a stack that's currently adjusted for IME,
// make sure to apply the same adjust to this new window.
win.applyAdjustForImeIfNeeded();
if (type == TYPE_DOCK_DIVIDER) {
mRoot.getDisplayContent(displayId).getDockedDividerController().setWindow(win);
}
final WindowStateAnimator winAnimator = win.mWinAnimator;
winAnimator.mEnterAnimationPending = true;
winAnimator.mEnteringAnimation = true;
// Check if we need to prepare a transition for replacing window first.
if (atoken != null && atoken.isVisible()
&& !prepareWindowReplacementTransition(atoken)) {
// If not, check if need to set up a dummy transition during display freeze
// so that the unfreeze wait for the apps to draw. This might be needed if
// the app is relaunching.
prepareNoneTransitionForRelaunching(atoken);
}
if (displayContent.isDefaultDisplay) {
final DisplayInfo displayInfo = displayContent.getDisplayInfo();
final Rect taskBounds;
if (atoken != null && atoken.getTask() != null) {
taskBounds = mTmpRect;
atoken.getTask().getBounds(mTmpRect);
} else {
taskBounds = null;
}
if (mPolicy.getInsetHintLw(win.mAttrs, taskBounds, displayInfo.rotation,
displayInfo.logicalWidth, displayInfo.logicalHeight, outContentInsets,
outStableInsets, outOutsets)) {
res |= WindowManagerGlobal.ADD_FLAG_ALWAYS_CONSUME_NAV_BAR;
}
} else {
outContentInsets.setEmpty();
outStableInsets.setEmpty();
}
if (mInTouchMode) {
res |= WindowManagerGlobal.ADD_FLAG_IN_TOUCH_MODE;
}
if (win.mAppToken == null || !win.mAppToken.isClientHidden()) {
res |= WindowManagerGlobal.ADD_FLAG_APP_VISIBLE;
}
mInputMonitor.setUpdateInputWindowsNeededLw();
boolean focusChanged = false;
if (win.canReceiveKeys()) {
focusChanged = updateFocusedWindowLocked(UPDATE_FOCUS_WILL_ASSIGN_LAYERS,
false /*updateInputWindows*/);
if (focusChanged) {
imMayMove = false;
}
}
if (imMayMove) {
displayContent.computeImeTarget(true /* updateImeTarget */);
}
// Don't do layout here, the window must call
// relayout to be displayed, so we'll do it there.
displayContent.assignWindowLayers(false /* setLayoutNeeded */);
if (focusChanged) {
mInputMonitor.setInputFocusLw(mCurrentFocus, false /*updateInputWindows*/);
}
mInputMonitor.updateInputWindowsLw(false /*force*/);
if (localLOGV || DEBUG_ADD_REMOVE) Slog.v(TAG_WM, "addWindow: New client "
+ client.asBinder() + ": window=" + win + " Callers=" + Debug.getCallers(5));
if (win.isVisibleOrAdding() && updateOrientationFromAppTokensLocked(false, displayId)) {
reportNewConfig = true;
}
}
if (reportNewConfig) {
sendNewConfiguration(displayId);
}
Binder.restoreCallingIdentity(origId);
return res;
}首先呼叫mPolicy.checkAddPermission對許可權進行檢查，如果檢查出錯，那麼就直接返回錯誤碼，在ViewRootImpl類的setView方法中就會根據錯誤碼丟擲具體的異常了。許可權檢查過後，繼續判斷我們的視窗憑證WindowToken，如果它非法，那麼也不能正常新增視窗，這裡還涉及到一些視窗排序的FIRST_APPLICATION_WINDOW、LAST_APPLICATION_WINDOW引數，這些表示當前視窗的層級，之前就處理過一個該引數異常，導致系統視窗被應用視窗蓋住的問題，詳情見部落格：從問題單處理了解Toast系統視窗顯示、Activity視窗建立、WindowManagerService對系統視窗組織排布（一）、從問題單處理了解Toast系統視窗顯示、Activity視窗建立、WindowManagerService對系統視窗組織排布（二）。
接下來就是非常重要的引數WindowState的賦值了，它是我們當前Activity視窗在WMS中的一個記錄，它當中儲存著我們當前視窗Window很多重要的資料，我們來看一下frameworks\base\services\core\java\com\android\server\wm\WindowState.java類的構造方法的實現，原始碼如下：
WindowState(WindowManagerService service, Session s, IWindow c, WindowToken token,
WindowState parentWindow, int appOp, int seq, WindowManager.LayoutParams a,
int viewVisibility, int ownerId, boolean ownerCanAddInternalSystemWindow) {
mService = service;
mSession = s;
mClient = c;
mAppOp = appOp;
mToken = token;
mAppToken = mToken.asAppWindowToken();
mOwnerUid = ownerId;
mOwnerCanAddInternalSystemWindow = ownerCanAddInternalSystemWindow;
mWindowId = new WindowId(this);
mAttrs.copyFrom(a);
mViewVisibility = viewVisibility;
mPolicy = mService.mPolicy;
mContext = mService.mContext;
DeathRecipient deathRecipient = new DeathRecipient();
mSeq = seq;
mEnforceSizeCompat = (mAttrs.privateFlags & PRIVATE_FLAG_COMPATIBLE_WINDOW) != 0;
if (localLOGV) Slog.v(
TAG, "Window " + this + " client=" + c.asBinder()
+ " token=" + token + " (" + mAttrs.token + ")" + " params=" + a);
try {
c.asBinder().linkToDeath(deathRecipient, 0);
} catch (RemoteException e) {
mDeathRecipient = null;
mIsChildWindow = false;
mLayoutAttached = false;
mIsImWindow = false;
mIsWallpaper = false;
mIsFloatingLayer = false;
mBaseLayer = 0;
mSubLayer = 0;
mInputWindowHandle = null;
mWinAnimator = null;
return;
}
mDeathRecipient = deathRecipient;
if (mAttrs.type >= FIRST_SUB_WINDOW && mAttrs.type <= LAST_SUB_WINDOW) {
// The multiplier here is to reserve space for multiple
// windows in the same type layer.
mBaseLayer = mPolicy.getWindowLayerLw(parentWindow)
* TYPE_LAYER_MULTIPLIER + TYPE_LAYER_OFFSET;
mSubLayer = mPolicy.getSubWindowLayerFromTypeLw(a.type);
mIsChildWindow = true;
if (DEBUG_ADD_REMOVE) Slog.v(TAG, "Adding " + this + " to " + parentWindow);
parentWindow.addChild(this, sWindowSubLayerComparator);
mLayoutAttached = mAttrs.type !=
WindowManager.LayoutParams.TYPE_APPLICATION_ATTACHED_DIALOG;
mIsImWindow = parentWindow.mAttrs.type == TYPE_INPUT_METHOD
|| parentWindow.mAttrs.type == TYPE_INPUT_METHOD_DIALOG;
mIsWallpaper = parentWindow.mAttrs.type == TYPE_WALLPAPER;
} else {
// The multiplier here is to reserve space for multiple
// windows in the same type layer.
mBaseLayer = mPolicy.getWindowLayerLw(this)
* TYPE_LAYER_MULTIPLIER + TYPE_LAYER_OFFSET;
mSubLayer = 0;
mIsChildWindow = false;
mLayoutAttached = false;
mIsImWindow = mAttrs.type == TYPE_INPUT_METHOD
|| mAttrs.type == TYPE_INPUT_METHOD_DIALOG;
mIsWallpaper = mAttrs.type == TYPE_WALLPAPER;
}
mIsFloatingLayer = mIsImWindow || mIsWallpaper;
if (mAppToken != null && mAppToken.mShowForAllUsers) {
// Windows for apps that can show for all users should also show when the device is
// locked.
mAttrs.flags |= FLAG_SHOW_WHEN_LOCKED;
}
mWinAnimator = new WindowStateAnimator(this);
mWinAnimator.mAlpha = a.alpha;
mRequestedWidth = 0;
mRequestedHeight = 0;
mLastRequestedWidth = 0;
mLastRequestedHeight = 0;
mXOffset = 0;
mYOffset = 0;
mLayer = 0;
mInputWindowHandle = new InputWindowHandle(
mAppToken != null ? mAppToken.mInputApplicationHandle : null, this, c,
getDisplayId());
} void openInputChannel(InputChannel outInputChannel) {
if (mInputChannel != null) {
throw new IllegalStateException("Window already has an input channel.");
}
String name = getName();
InputChannel[] inputChannels = InputChannel.openInputChannelPair(name);
mInputChannel = inputChannels[0];
mClientChannel = inputChannels[1];
mInputWindowHandle.inputChannel = inputChannels[0];
if (outInputChannel != null) {
mClientChannel.transferTo(outInputChannel);
mClientChannel.dispose();
mClientChannel = null;
} else {
// If the window died visible, we setup a dummy input channel, so that taps
// can still detected by input monitor channel, and we can relaunch the app.
// Create dummy event receiver that simply reports all events as handled.
mDeadWindowEventReceiver = new DeadWindowEventReceiver(mClientChannel);
}
mService.mInputManager.registerInputChannel(mInputChannel, mInputWindowHandle);
}