[Android FrameWork 6.0源码学习] View的重绘ViewRootImpl的setView方法 _源码学习

亦余心之所善兮，虽九死其犹未悔。这篇文章主要讲述[Android FrameWork 6.0源码学习] View的重绘ViewRootImpl的setView方法相关的知识，希望能为你提供帮助。
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本篇文章来分析一下WindowManager的后续工作，也就是ViewRootImpl的setView函数的工作

/i** * We have one child */ public void setView(View view, WindowManager.LayoutParams attrs, View panelParentView) { synchronized (this) { if (mView == null) { mView = view; //获取当前屏幕最新的状态，并且给当前DecorView注册屏幕监听，用来检测灭屏和亮屏 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; // Keep track of the actual window flags supplied by the client. mClientWindowLayoutFlags = attrs.flags; //清除辅助功能的焦点 setAccessibilityFocus(null, null); if (view instanceof RootViewSurfaceTaker) { mSurfaceHolderCallback = ((RootViewSurfaceTaker)view).willYouTakeTheSurface(); if (mSurfaceHolderCallback != null) { mSurfaceHolder = new TakenSurfaceHolder(); mSurfaceHolder.setFormat(PixelFormat.UNKNOWN); } }// Compute surface insets required to draw at specified Z value. // TODO: Use real shadow insets for a constant max Z. if (!attrs.hasManualSurfaceInsets) { final int surfaceInset = (int) Math.ceil(view.getZ() * 2); attrs.surfaceInsets.set(surfaceInset, surfaceInset, surfaceInset, surfaceInset); } //获取屏幕兼容模式,一般情况下不考虑 mTranslator是空的 CompatibilityInfo compatibilityInfo = mDisplayAdjustments.getCompatibilityInfo(); mTranslator = compatibilityInfo.getTranslator(); //开启硬件加速功能 if (mSurfaceHolder == null) { enableHardwareAcceleration(attrs); }boolean restore = false; //Application不考虑兼容模式 if (mTranslator != null) { mSurface.setCompatibilityTranslator(mTranslator); restore = true; attrs.backup(); mTranslator.translateWindowLayout(attrs); } if (DEBUG_LAYOUT) Log.d(TAG, "WindowLayout in setView:" + attrs); //Application不考虑兼容模式 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; *///在这里开始启用绘制线程，requestLayout会触发整个的绘制过程 requestLayout(); if ((mWindowAttributes.inputFeatures & WindowManager.LayoutParams.INPUT_FEATURE_NO_INPUT_CHANNEL) == 0) { mInputChannel = new InputChannel(); } try { mOrigWindowType = mWindowAttributes.type; mAttachInfo.mRecomputeGlobalAttributes = true; collectViewAttributes(); //mWindow是ViewRootImpl中的一个静态类，这个类可以用来和WindowSession交互，就等于间接在和WindowManagerService交互 //是一个桥梁类 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); if (DEBUG_LAYOUT) Log.v(TAG, "Added window " + mWindow); //在这里处理WindowManagerServices的处理结果，在这里你能看到很多熟悉的异常 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 this type already exists"); case WindowManagerGlobal.ADD_PERMISSION_DENIED: throw new WindowManager.BadTokenException( "Unable to add window " + mWindow + " -- permission denied for this window 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 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()); } //给DecorView绑定mParent参数 view.assignParent(this); mAddedTouchMode = (res & WindowManagerGlobal.ADD_FLAG_IN_TOUCH_MODE) != 0; mAppVisible = (res & WindowManagerGlobal.ADD_FLAG_APP_VISIBLE) != 0; //判断辅助功能是否可用 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; } } }

本篇内容很简单，仅仅是个大绘制流程的初始化工作，接下来会着重分析performTraversals函数，在这个函数中包含了View的onMeasure，onLayout，onDraw的调用
是View重绘过程中很重要的一个函数
【[Android FrameWork 6.0源码学习] View的重绘ViewRootImpl的setView方法】