温馨提示×

温馨提示×

您好,登录后才能下订单哦!

密码登录×
登录注册×
其他方式登录
点击 登录注册 即表示同意《亿速云用户服务条款》

Android Surface理解

发布时间:2020-06-07 16:56:17 来源:网络 阅读:30700 作者:lindt 栏目:移动开发

结合别人的博客和自己看的代码,梳理下自己对surface的理解

1.代码相关文件

/AOSP/frameworks/native/libs/uiAndroid Surface理解

主要是bufferqueuecore与surfaceflinger中分配

GraphicBufferAllocator 通过hw_get_module()&gralloc_open与硬件提供的设备交互
ex: /hardware/qcom/display/libgralloc/alloc_controller.cpp etc.


/AOSP/frameworks/native/libs/gui

Android.mk                   IGraphicBufferAlloc.cpp
BitTube.cpp                  IGraphicBufferConsumer.cpp
BufferItemConsumer.cpp       IGraphicBufferProducer.cpp
BufferItem.cpp               IProducerListener.cpp
BufferQueueConsumer.cpp      ISensorEventConnection.cpp
BufferQueueCore.cpp          ISensorServer.cpp
BufferQueue.cpp              ISurfaceComposerClient.cpp
BufferQueueProducer.cpp      ISurfaceComposer.cpp
BufferSlot.cpp               LayerState.cpp
CleanSpec.mk                 Sensor.cpp
ConsumerBase.cpp             SensorEventQueue.cpp
CpuConsumer.cpp              SensorManager.cpp
DisplayEventReceiver.cpp     StreamSplitter.cpp
GLConsumer.cpp               SurfaceComposerClient.cpp
GraphicBufferAlloc.cpp       SurfaceControl.cpp
GuiConfig.cpp                Surface.cpp
IConsumerListener.cpp        SyncFeatures.cpp
IDisplayEventConnection.cpp  tests

SurfaceComposerClient 中成员变量 sp<ISurfaceComposerClient>  mClient;与surface.cpp binder通信

/AOSP/frameworks/native/services/surfaceflinger

Android.mk         EventControlThread.cpp   MODULE_LICENSE_APACHE2
Barrier.h          EventControlThread.h     MonitoredProducer.cpp
Client.cpp         EventLog                 MonitoredProducer.h
Client.h           EventThread.cpp          RenderEngine
clz.h              EventThread.h            SurfaceFlingerConsumer.cpp
Colorizer.h        FrameTracker.cpp         SurfaceFlingerConsumer.h
DdmConnection.cpp  FrameTracker.h           SurfaceFlinger.cpp
DdmConnection.h    Layer.cpp                SurfaceFlinger.h
DisplayDevice.cpp  LayerDim.cpp             surfaceflinger.rc
DisplayDevice.h    LayerDim.h               tests
DisplayHardware    Layer.h                  Transform.cpp
DispSync.cpp       main_surfaceflinger.cpp  Transform.h
DispSync.h         MessageQueue.cpp
Effects            MessageQueue.h

surfaceflinger管理surface及layer

AOSP/frameworks/base/core/java/android/view

AbsSavedState.java                       MagnificationSpec.aidl
accessibility                            MagnificationSpec.java
AccessibilityInteractionController.java  MenuInflater.java
AccessibilityIterators.java              MenuItem.java
ActionMode.java                          Menu.java
ActionProvider.java                      MotionEvent.aidl
animation                                MotionEvent.java
AnimationRenderStats.aidl                OrientationEventListener.java
Choreographer.java                       OrientationListener.java
CollapsibleActionView.java               package.html
ContextMenu.java                         PointerIcon.aidl
ContextThemeWrapper.java                 PointerIcon.java
DisplayAdjustments.java                  RemotableViewMethod.java
Display.aidl                             RenderNodeAnimator.java
DisplayEventReceiver.java                RenderNode.java
DisplayInfo.aidl                         ScaleGestureDetector.java
DisplayInfo.java                         SearchEvent.java
Display.java                             SoundEffectConstants.java
DisplayListCanvas.java                   SubMenu.java
DragEvent.aidl                           Surface.aidl
DragEvent.java                           SurfaceControl.java
FallbackEventHandler.java                SurfaceHolder.java
FocusFinderHelper.java                   Surface.java
FocusFinder.java                         SurfaceSession.java
FrameInfo.java                           SurfaceView.java
FrameStats.java                          textservice
GestureDetector.java                     TextureView.java
GhostView.java                           ThreadedRenderer.java
GraphicBuffer.aidl                       TouchDelegate.java
GraphicBuffer.java                       VelocityTracker.java
Gravity.java                             ViewAnimationUtils.java
HapticFeedbackConstants.java             ViewConfiguration.java
HardwareLayer.java                       ViewDebug.java
HardwareRenderer.java                    ViewGroup.java
IApplicationToken.aidl                   ViewGroupOverlay.java
IAssetAtlas.aidl                         ViewHierarchyEncoder.java
IGraphicsStats.aidl                      View.java
IInputFilter.aidl                        ViewManager.java
IInputFilterHost.aidl                    ViewOutlineProvider.java
InflateException.java                    ViewOverlay.java
InputChannel.aidl                        ViewParent.java
InputChannel.java                        ViewPropertyAnimator.java
InputDevice.aidl                         ViewPropertyAnimatorRT.java
InputDevice.java                         ViewRootImpl.java
InputEvent.aidl                          ViewStructure.java
InputEventConsistencyVerifier.java       ViewStub.java
InputEvent.java                          ViewTreeObserver.java
InputEventReceiver.java                  WindowAnimationFrameStats.aidl
InputEventSender.java                    WindowAnimationFrameStats.java
InputFilter.java                         WindowCallbackWrapper.java
inputmethod                              WindowContentFrameStats.aidl
InputQueue.java                          WindowContentFrameStats.java
IOnKeyguardExitResult.aidl               WindowId.java
IRotationWatcher.aidl                    WindowInfo.aidl
IWindow.aidl                             WindowInfo.java
IWindowFocusObserver.aidl                WindowInsets.java
IWindowId.aidl                           Window.java
IWindowManager.aidl                      WindowManager.aidl
IWindowSession.aidl                      WindowManagerGlobal.java
IWindowSessionCallback.aidl              WindowManagerImpl.java
KeyCharacterMap.java                     WindowManagerInternal.java
KeyEvent.aidl                            WindowManager.java
KeyEvent.java                            WindowManagerPolicy.java
LayoutInflater.java


2. Activity显示

2.1 Activity创建

/base/core/java/android/app/ActivityThread.java

handleLaunchActivity(ActivityClientRecord r, Intent customIntent) {
...............
    //根据类名以Java反射的方法创建一个Activity 
    Activity a = performLaunchActivity(r, customIntent);
    
    handleResumeActivity(r.token, false, r.isForward,
                    !r.activity.mFinished && !r.startsNotResumed);
................}

2.2 handleResumeActivity 

final void handleResumeActivity(IBinder token,
            boolean clearHide, boolean isForward, boolean reallyResume) {
.....................
if (r.window == null && !a.mFinished && willBeVisible) {
                r.window = r.activity.getWindow();
                //得到一个view对象
                View decor = r.window.getDecorView();
                decor.setVisibility(View.INVISIBLE);
                //获得viewManager
                ViewManager wm = a.getWindowManager();
                WindowManager.LayoutParams l = r.window.getAttributes();
                a.mDecor = decor;
                l.type = WindowManager.LayoutParams.TYPE_BASE_APPLICATION;
                l.softInputMode |= forwardBit;
                if (a.mVisibleFromClient) {
                    a.mWindowAdded = true;
                    //将view加入viewmanager
                    wm.addView(decor, l);
                }
}
..................................}

2.3 Activity 通过setContentView设置UI

Activity.java

public void setContentView(View view, ViewGroup.LayoutParams params) {
        getWindow().setContentView(view, params);
        initWindowDecorActionBar();
    }
    
 public Window getWindow() {
        return mWindow;
    }

上面出现了两个和UI有关系的类:View和Window

Android Surface理解

2.4 Activity Window 与WindowManager
Activity.java

 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) {
        //创建window对象    
        mWindow = new PhoneWindow(this);
        mWindow.setCallback(this);
        mWindow.setOnWindowDismissedCallback(this);
        mWindow.getLayoutInflater().setPrivateFactory(this);
        //创建windowManager      
        mWindow.setWindowManager(
                (WindowManager)context.getSystemService(Context.WINDOW_SERVICE),
                mToken, mComponent.flattenToString(),
                (info.flags & ActivityInfo.FLAG_HARDWARE_ACCELERATED) != 0);
         //保存WindowManager对象       
         mWindowManager = mWindow.getWindowManager();


 setWindowManager由PhoneWindow父类window.java实现

Window.java

public void setWindowManager(WindowManager wm, IBinder appToken, String appName,){
 mWindowManager = ((WindowManagerImpl)wm).createLocalWindowManager(this);
    }

WindowManagerImpl.java

public WindowManagerImpl createLocalWindowManager(Window parentWindow) {
        return new WindowManagerImpl(mDisplay, parentWindow);
    }
public final class WindowManagerImpl implements WindowManager {}

Android Surface理解

   (2.4)中流程总结

2.5 继续分析setContentView()

Activity.java

public void setContentView(View view, ViewGroup.LayoutParams params) {
        getWindow().setContentView(view, params);
        initWindowDecorActionBar();
    }

PhoneWindow.java

 private ViewGroup mContentParent;
 public void setContentView(View view) {
        setContentView(view, new ViewGroup.LayoutParams(MATCH_PARENT, MATCH_PARENT));
    }
    
  public void setContentView(View view, ViewGroup.LayoutParams params) {
  //mContentParent是一个viewGroup对象
  if (mContentParent == null) {
            installDecor();
        } 
        
  if (hasFeature(FEATURE_CONTENT_TRANSITIONS)) {
            view.setLayoutParams(params);
            final Scene newScene = new Scene(mContentParent, view);
            transitionTo(newScene);
        } else {
            //把view加入到ViewGroup中
            mContentParent.addView(view, params);
        }
  ........}

mContentParent是一个ViewGroup类型,它从View中派生,所以也是一个UI单元。从它名字中“Group”所表达的意思分析,它还可以包含其他的View元素。这又是什么意思呢?也就是说,在绘制一个ViewGroup时,它不仅需要把自己的样子画出来,还需要把它包含的View元素的样子也画出来。读者可将它想象成一个容器,容器中的元素就是View。
installDecor()函数
主要用来给view绘制icon ,window title,logo, menu等等


2.6 重回handleResumeActivity 

我们之所以分析2.5内容,是为了弄清楚View, ViewManager(就是WindowManager)这些对象

final void handleResumeActivity(IBinder token,
            boolean clearHide, boolean isForward, boolean reallyResume) {
.....................
if (r.window == null && !a.mFinished && willBeVisible) {
                r.window = r.activity.getWindow();
                //得到一个view对象
                View decor = r.window.getDecorView();
                decor.setVisibility(View.INVISIBLE);
                //获得viewManager
                ViewManager wm = a.getWindowManager();
                WindowManager.LayoutParams l = r.window.getAttributes();
                a.mDecor = decor;
                l.type = WindowManager.LayoutParams.TYPE_BASE_APPLICATION;
                l.softInputMode |= forwardBit;
                if (a.mVisibleFromClient) {
                    a.mWindowAdded = true;
                    //将view加入viewmanager
                    wm.addView(decor, l);
                }
}
..................................}

分析wm.addView(decor,l)

WindowManagerImpl.java

public final class WindowManagerImpl implements WindowManager {
    private final WindowManagerGlobal mGlobal = WindowManagerGlobal.getInstance();
 public void addView(@NonNull View view, @NonNull ViewGroup.LayoutParams params) {
        applyDefaultToken(params);
        mGlobal.addView(view, params, mDisplay, mParentWindow);
    }

WindowManagerGlobal里面可以通过AIDL与IWindowManager.Stub.asInterface 及IWindowSessionCallback.Stub() IPC通信

WindowManagerGlobal.java

public void addView(View view, ViewGroup.LayoutParams params,
            Display display, Window parentWindow) {
            root = new ViewRootImpl(view.getContext(), display);
            view.setLayoutParams(wparams);
            mViews.add(view);
            mRoots.add(root);
            mParams.add(wparams);
            
            root.setView(view, wparams, panelParentView);// TAG 1


2.6.1 ViewRootImpl又是什么东东?


ViewRootImpl.java

public final class ViewRootImpl implements ViewParent,
        View.AttachInfo.Callbacks, HardwareRenderer.HardwareDrawCallbacks{
        final IWindowSession mWindowSession;
        final Display mDisplay;
        final DisplayManager mDisplayManager;
        final W mWindow;
        final Surface mSurface = new Surface();
        
        static class W extends IWindow.Stub {
        private final WeakReference<ViewRootImpl> mViewAncestor;
        private final IWindowSession mWindowSession;}


ViewRootImpl继承了Handler类,看来它能处理消息。ViewRootImpl果真重写了handleMessage函数

一个成员变量叫mSurface,它是Surface类型

surface.java
public class Surface implements Parcelable {

一个W类型的mWindow和一个View类型的mView变量

ViewRootImpl有一个成员变量mSurface,它是Surface类型,它和一块Raw Buffer有关联。

ViewRootImpl是一个ViewParent,它的子View的绘画操作,是在画布Surface上展开的

ViewRootImpl的构造

public ViewRootImpl(Context context, Display display) {
    mDisplay = display;//Display.java Provides information about the size and density of a logical display.
    mWindowSession = WindowManagerGlobal.getWindowSession(); // IWindowSession AIDLmWindo    w = new W(this); //内部W对象,实际是与window通信的AIDL static class W extends IWindow.Stub
    mDisplayManager = (DisplayManager)context.getSystemService(Context.DISPLAY_SERVICE);

WindowManagerGlobal.getWindowSession()将建立Activity的ViewRoot和WindowManagerService的关系

WindowManagerGlobal.java

 public static IWindowSession getWindowSession() {
 
     IWindowManager windowManager = getWindowManagerService();//得到Iwindowmanager对象,
     //IWindowManager 的AIDL Bn端是WindowManagerService class WindowManagerService extends IWindowManager.Stub
     sWindowSession = windowManager.openSession( //然后通过AIDL得到windowsession aidl 对象 不清楚为啥已经有了windowmanager的aidl 干嘛还需要windowsession aidl
     new IWindowSessionCallback.Stub() { })
 }  
 public static IWindowManager getWindowManagerService() {
     sWindowManagerService = IWindowManager.Stub.asInterface(
               ServiceManager.getService("window")); //得到WindowManager AIDL BP对象
         try {
                  sWindowManagerService = getWindowManagerService();
                  ValueAnimator.setDurationScale(sWindowManagerService.getCurrentAnimatorScale());                
              } catch (RemoteException e) {}

ViewRootImpl和WMS的关系

/frameworks/base/services/core/java/com/android/server/wm/WindowManagerService.java

public class WindowManagerService extends IWindowManager.Stub
        implements Watchdog.Monitor, WindowManagerPolicy.WindowManagerFuncs {}
        
        public IWindowSession openSession(IWindowSessionCallback callback, IInputMethodClient client,
            IInputContext inputContext) {
        Session session = new Session(this, callback, client, inputContext);
        return session;
    }

/frameworks/base/services/core/java/com/android/server/wm/Session.java

    final class Session extends IWindowSession.Stub
        implements IBinder.DeathRecipient {
        final WindowManagerService mService;
        final IWindowSessionCallback mCallback;
        final IInputMethodClient mClient;


分析完ViewRootImpl创建过程后,现在返回TAG 1处继续分析ViewRootImpl.setView()
2.6.2 ViewRootImpl.setView()

/frameworks/base/core/java/android/view/ViewRootImpl.java

public void setView(View view, WindowManager.LayoutParams attrs, View panelParentView) {

    // 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);} //计算Z轴坐标
                
    requestLayout();
    res = mWindowSession.addToDisplay(mWindow, mSeq, mWindowAttributes,
              getHostVisibility(), mDisplay.getDisplayId(),
              mAttachInfo.mContentInsets, mAttachInfo.mStableInsets,
              mAttachInfo.mOutsets, mInputChannel);
//requestLayout()流程  TAG2

public void requestLayout() {        scheduleTraversals();}

void scheduleTraversals() {
        mTraversalBarrier = mHandler.getLooper().getQueue().postSyncBarrier();
        mChoreographer.postCallback(
             Choreographer.CALLBACK_TRAVERSAL, mTraversalRunnable, null);
        notifyRendererOfFramePending();
        pokeDrawLockIfNeeded();}
        
final TraversalRunnable mTraversalRunnable = new TraversalRunnable();
//Runnable实现多线程,避免点继承的局限,一个类可以继承多个接口.适合于资源的共享
final class TraversalRunnable implements Runnable {
        @Override
        public void run() {
            doTraversal();
        }
    }
    
void doTraversal() {
    performTraversals();}

private void performTraversals() {
     //mSurface是 surface.java 对象, final Surface mSurface = new Surface();
    // surface.java 通过jni 可以操作Surface.cpp 中surface对象 Surface::Surface(
    //    const sp<IGraphicBufferProducer>& bufferProducer,
    //    bool controlledByApp)
    if (mSurface.isValid()) { 
        if (mAttachInfo.mHardwareRenderer != null) {
            try {
                hwInitialized = mAttachInfo.mHardwareRenderer.initialize(mSurface);
                if (hwInitialized && (host.mPrivateFlags
                     & View.PFLAG_REQUEST_TRANSPARENT_REGIONS) == 0) {
                    // Don't pre-allocate if transparent regions
                    // are requested as they may not be needed
                       mSurface.allocateBuffers();
                }
        }
     //Interface for rendering a view hierarchy using hardware acceleration.
     final HardwareRenderer hardwareRenderer = mAttachInfo.mHardwareRenderer;
     hardwareRenderer.setup(mWidth, mHeight, mAttachInfo,
                            mWindowAttributes.surfaceInsets); 
}
mWindowSession.addToDisplay流程

//mWindowSession(IWindowSession) 通过AIDL 与Session.java交互 final class Session extends IWindowSession.Stub
public int addToDisplay(IWindow window, int seq, WindowManager.LayoutParams attrs,
            int viewVisibility, int displayId, Rect outContentInsets, Rect outStableInset    s,Rect outOutsets, InputChannel outInputChannel) {
        return mService.addWindow(this, window, seq, attrs, viewVisibility, displayId,
                outContentInsets, outStableInsets, outOutsets, outInputChannel);
    }
final WindowManagerService mService;
WindowManagerService.java
public int addWindow(Session session, IWindow client, int seq,
       WindowManager.LayoutParams attrs, int viewVisibility, int displayId,
       Rect outContentInsets, Rect outStableInsets, Rect outOutsets,
       InputChannel outInputChannel) {
            //windowstate A window in the window manager.class WindowState implements WindowManagerPolicy.WindowState 
            WindowState win = new WindowState(this, session, client, token,
                attachedWindow, appOp[0], seq, attrs, viewVisibility, displayContent);
            win.attach();
}
WindowState.java
void attach() {
        mSession.windowAddedLocked();}
Session.java
void windowAddedLocked() {   
    mSurfaceSession = new SurfaceSession();
    mService.mSessions.add(this);
    mNumWindow++;
}

ViewRootImpl 与WMS关系总结

Android Surface理解ViewRootImpl通过IWindowSession和WMS进程进行跨进程通信。
ViewRootImpl内部有一个W类型的对象,它也是一个基于Binder通信的类,W是IWindow的Bn端,用于响应请求。IWindow定义在另一个aidl文件IWindow.aidl中
IWindowSession

System private per-application interface to the window manager.

IWindow 

API back to a client window that the Window Manager uses to inform it of interesting things happening.


IWindow.aidl
void dispatchAppVisibility(boolean visible);
void dispatchWallpaperCommand(

void dispatchDragEvent(in DragEvent event);
void dispatchWindowShown();

这里的事件指的就是按键、触屏等事件。那么,一个按键事件是如何被分发的呢?下面是它大致的流程:WMS所在的SystemServer进程接收到按键事件。WMS找到UI位于屏幕顶端的进程所对应的IWindow对象,调用这个IWindow对象的dispatchKey。IWindow对象的Bn端位于ViewRoot中,ViewRoot再根据内部View的位置信息找到真正处理这个事件的View,最后调用dispatchKey函数完成按键的处理。(这段过程没有去跟代码)

2.7 Activity的UI绘制

    在TAG2处分析过requestLayout。根据前面的分析可知,最终调用到performTraversals()

ViewRootImpl.java

private void performTraversals() {
    relayoutResult = relayoutWindow(params, viewVisibility, insetsPending);//TAG3
    performDraw();//开始绘制
    }
     
private int relayoutWindow(WindowManager.LayoutParams params, int viewVisibility,
    boolean insetsPending) throws RemoteException {
        int relayoutResult = mWindowSession.relayout(
                mWindow, mSeq, params,
                (int) (mView.getMeasuredWidth() * appScale + 0.5f),
                (int) (mView.getMeasuredHeight() * appScale + 0.5f),
                viewVisibility, insetsPending ? WindowManagerGlobal.RELAYOUT_INSETS_PENDING : 0,
                mWinFrame, mPendingOverscanInsets, mPendingContentInsets, mPendingVisibleInsets,
                mPendingStableInsets, mPendingOutsets, mPendingConfiguration, mSurface);
    }//这个函数通过AIDL调用到WMS relayoutWindow().暂时不继续分析
    
private void performDraw() {
     draw(fullRedrawNeeded);}
     
private void draw(boolean fullRedrawNeeded){
     mAttachInfo.mHardwareRenderer.draw(mView, mAttachInfo, this);//hw render完成draw
     //HardwareRenderer.java abstract void draw() }

2.8 Activity 总结

    Activity的顶层View是DecorView,而我们在onCreate函数中通过setContentView设置的View只不过是这个DecorView中的一部分罢了。DecorView是一个FrameLayout类型的ViewGroup。
     Activity和UI有关,它包含一个Window(真实类型是PhoneWindow)和一个WindowManager(真实类型是LocalWindowManager)对象。这两个对象将控制整个Activity的显示。
    LocalWindowManager使用了WindowManagerImpl做为最终的处理对象(Proxy模式),这个WindowManagerImpl中有一个ViewRootImpl对象。ViewRootImpl实现了ViewParent接口,它有两个重要的成员变量,一个是mView,它指向Activity顶层UI单元的DecorView,另外有一个mSurface,这个Surface包含了一个Canvas(画布)(这个surface java对象可以通过JNI 与 surface.cpp中对象交互)。除此之外,ViewRooImplt还通过Binder系统和WindowManagerService进行了跨进程交互。
     ViewRoot能处理Handler的消息,Activity的显示就是由ViewRoot在它的performTraversals函数中完成的。

3. Surface对象

    终于可以分析java与C++处surface对象了,先回忆下surface是如何创建的

    ViewRootImpl.java
    final Surface mSurface = new Surface();

     ViewRootImpl通过IWindowSession和WMS交互,而WMS中会调用的一个attach函数,会构造一个SurfaceSession,前面遇到过但没有继续分析

WindowState.java
void attach() {
        mSession.windowAddedLocked();}
Session.java
void windowAddedLocked() {   
    mSurfaceSession = new SurfaceSession();
    mService.mSessions.add(this);
    mNumWindow++;
}
SurfaceSession.java
 //* An instance of this class represents a connection to the surface
 //* flinger, from which you can create one or more Surface instances that will
 //* be composited to the screen.
public final class SurfaceSession {
    private static native long nativeCreate();
    private static native void nativeDestroy(long ptr);
    private static native void nativeKill(long ptr);}

 由注释可见,surfacesession负责与SF的连接

  在2.7处Activity UI 绘制时,遇到过relayoutWindow(),现在继续看该函数

   ViewRootImpl.java

private void performTraversals() {
    relayoutResult = relayoutWindow(params, viewVisibility, insetsPending);//TAG3
    performDraw();//开始绘制
    }
     
private int relayoutWindow(WindowManager.LayoutParams params, int viewVisibility,
    boolean insetsPending) throws RemoteException {
        int relayoutResult = mWindowSession.relayout(
                mWindow, mSeq, params,
                (int) (mView.getMeasuredWidth() * appScale + 0.5f),
                (int) (mView.getMeasuredHeight() * appScale + 0.5f),
                viewVisibility, insetsPending ? WindowManagerGlobal.RELAYOUT_INSETS_PENDING : 0,
                mWinFrame, mPendingOverscanInsets, mPendingContentInsets, mPendingVisibleInsets,
                mPendingStableInsets, mPendingOutsets, mPendingConfiguration, mSurface);
    }//这个函数通过AIDL调用到WMS relayoutWindow()
Session.java
public int relayout(IWindow window, int seq, WindowManager.LayoutParams attrs,..){
    int res = mService.relayoutWindow(this,....);}
WindowManagerService.java
public int relayoutWindow(Session session, IWindow client, int seq,
            WindowManager.LayoutParams attrs, int requestedWidth,....){
    SurfaceControl surfaceControl = winAnimator.createSurfaceLocked();//TAG4 创建本地surfacecontrol 通过JNI会调用C++最终创建layer, java层保存的surfacecontrol对象是一个surfaceControl.cpp 中对象
    //JNI处返回的surfacecontrol
    //surface->incStrong((void *)nativeCreate);
    //return reinterpret_cast<jlong>(surface.get()); 
   
    outSurface.copyFrom(surfaceControl);//将本地surface拷贝到outSurface }
WindowStateAnimator.java
SurfaceControl createSurfaceLocked() {
    final WindowState w = mWin;
    mSurfaceControl = new SurfaceControl(
               mSession.mSurfaceSession,
               attrs.getTitle().toString(),
               width, height, format, flags);
   // Start a new transaction and apply position & offset.
   SurfaceControl.openTransaction();
   mSurfaceControl.setLayer(mAnimLayer);
   mSurfaceControl.setAlpha(0);
   SurfaceControl.closeTransaction();
   return mSurfaceControl;
}

SurfaceControl是个什么对象?与Surface有何关系
/frameworks/base/core/java/android/view/SurfaceControl.java
看SurfaceControl构造函数说明,surfacecontrol根据name创建surface

/**
* Create a surface with a name.
* <p>
* The surface creation flags specify what kind of surface to create and
* certain options such as whether the surface can be assumed to be opaque
* and whether it should be initially hidden.  Surfaces should always be
* created with the {@link #HIDDEN} flag set to ensure that they are not
* made visible prematurely before all of the surface's properties have been
* configured.
* <p>
* Good practice is to first create the surface with the {@link #HIDDEN} flag
* specified, open a transaction, set the surface layer, layer stack, alpha,
* and position, call {@link #show} if appropriate, and close the transaction.
*
* @param session The surface session, must not be null.
* @param name The surface name, must not be null.
* @param w The surface initial width.
* @param h The surface initial height.
* @param flags The surface creation flags.  Should always include {@link #HIDDEN}
* in the creation flags.
*
* @throws throws OutOfResourcesException If the SurfaceControl cannot be created.
*/
public SurfaceControl(SurfaceSession session,
            String name, int w, int h, int format, int flags){
       mNativeObject = nativeCreate(session, name, w, h, format, flags);
 }
通过JNI android_view_SurfaceControl.cpp
static jlong nativeCreate(JNIEnv* env, jclass clazz, jobject sessionObj,
        jstring nameStr, jint w, jint h, jint format, jint flags) {
    ScopedUtfChars name(env, nameStr);
    sp<SurfaceComposerClient> client(android_view_SurfaceSession_getClient(env, sessionObj));
    sp<SurfaceControl> surface = client->createSurface(
            String8(name.c_str()), w, h, format, flags); }
调用SurfaceComposiClient.cpp
sp<SurfaceControl> SurfaceComposerClient::createSurface(
        const String8& name,
        uint32_t w,
        uint32_t h,
        PixelFormat format,
        uint32_t flags){
        sp<SurfaceControl> sur;
        sp<IGraphicBufferProducer> gbp;
        status_t err = mClient->createSurface(name, w, h, format, flags,
                &handle, &gbp);//mClient 是一个sp<ISurfaceComposerClient>对象,由class Client : public BnSurfaceComposerClient来接收IPC交互,
        sur = new SurfaceControl(this, handle, gbp);// 最终通过JNI返回到TAG4处
        return sur;
}
Client.cpp
// ISurfaceComposerClient interface
/* Client是用来与surfaceflinger交互的桥梁,在sf中被创建 
sp<ISurfaceComposerClient> SurfaceFlinger::createConnection()
{
    sp<ISurfaceComposerClient> bclient;
    sp<Client> client(new Client(this));
*/
status_t Client::createSurface(
        const String8& name,
        uint32_t w, uint32_t h, PixelFormat format, uint32_t flags,
        sp<IBinder>* handle,
        sp<IGraphicBufferProducer>* gbp){
        result = flinger->createLayer(name, client, w, h, format, flags,
                    handle, gbp);}//这里面的flinger是由Client::Client(const sp<SurfaceFlinger>& flinger)在创建时保存起来的
    : mFlinger(flinger)
}
Surfaceflinger.cpp
status_t SurfaceFlinger::createLayer(
        const String8& name,
        const sp<Client>& client,
        uint32_t w, uint32_t h, PixelFormat format, uint32_t flags,
        sp<IBinder>* handle, sp<IGraphicBufferProducer>* gbp){
        sp<Layer> layer;

        switch (flags & ISurfaceComposerClient::eFXSurfaceMask) {
        case ISurfaceComposerClient::eFXSurfaceNormal:
            result = createNormalLayer(client,//创建普通layer gbp是在layer中进行赋值
                    name, w, h, flags, format,
                    handle, gbp, &layer);
            break;
        case ISurfaceComposerClient::eFXSurfaceDim:
            result = createDimLayer(client,//创建磨砂layer gbp是在layer中进行赋值
                    name, w, h, flags,
                    handle, gbp, &layer);
            break;
        default:
            result = BAD_VALUE;
            break;
            
        result = addClientLayer(client, *handle, *gbp, layer);//attach this layer to the client
    }
 //Client中createSurface函数,调用的是SF中createLayer
 //与前面ViewrootImpl.java中 final Surface mSurface = new Surface();有何区分?Layer与surface是如何区分?  前面遇到java surface用于drawSoftware或hwRender时 ex drawsoftware() canvas = mSurface.lockCanvas(dirty);mView.draw(canvas);

Android Surface理解上述流程的小结

3.1 Surface与画图

  lockCanvas 

 Surface.java
 * Gets a {@link Canvas} for drawing into this surface.
        public Canvas lockCanvas(Rect inOutDirty){
            mLockedObject = nativeLockCanvas(mNativeObject, mCanvas, inOutDirty);
            return mCanvas;
        }

   调用JNI
   android_view_Surface.cpp

static jlong nativeLockCanvas(JNIEnv* env, jclass clazz,
        jlong nativeObject, jobject canvasObj, jobject dirtyRectObj) {
    sp<Surface> surface(reinterpret_cast<Surface *>(nativeObject));
    
    Rect dirtyRect;
    Rect* dirtyRectPtr = NULL;

    if (dirtyRectObj) {
        dirtyRect.left   = env->GetIntField(dirtyRectObj, gRectClassInfo.left);
        dirtyRect.top    = env->GetIntField(dirtyRectObj, gRectClassInfo.top);
        dirtyRect.right  = env->GetIntField(dirtyRectObj, gRectClassInfo.right);
        dirtyRect.bottom = env->GetIntField(dirtyRectObj, gRectClassInfo.bottom);
        dirtyRectPtr = &dirtyRect;
    }
    
    ANativeWindow_Buffer outBuffer;
    status_t err = surface->lock(&outBuffer, dirtyRectPtr);//一块表示脏区域的dirtyRectPtr
    //从surface.cpp 中dequeueBuffer()获得一个GraphicBuffer, 然后将buffer的长宽,format 等赋制给outBuffer,
    
    //
    SkImageInfo info = SkImageInfo::Make(outBuffer.width, outBuffer.height,
                                         convertPixelFormat(outBuffer.format),
                                         kPremul_SkAlphaType);
                                         
    SkBitmap bitmap;
    ssize_t bpr = outBuffer.stride * bytesPerPixel(outBuffer.format);
    bitmap.setInfo(info, bpr);
    
     if (outBuffer.width > 0 && outBuffer.height > 0) {
        bitmap.setPixels(outBuffer.bits); // bitmap 指向一片存储区域
    } else {
        // be safe with an empty bitmap.
        bitmap.setPixels(NULL);
    }
    
    Canvas* nativeCanvas = GraphicsJNI::getNativeCanvas(env, canvasObj);
    nativeCanvas->setBitmap(bitmap);//将Bitmap设置到这个Canvas中,这样进UI绘画时就有画布了
    // Create another reference to the surface and return it.  This reference
    // should be passed to nativeUnlockCanvasAndPost in place of mNativeObject,
    // because the latter could be replaced while the surface is locked.
    sp<Surface> lockedSurface(surface);
    lockedSurface->incStrong(&sRefBaseOwner);
    return (jlong) lockedSurface.get();
 }

   lockCanvas获得一块存储区域,然后将它和Canvas绑定到一起,这样,UI绘画的结果就记录在这块存储区域里了

  再看unlockCanvas
 Surface.java

  private void unlockSwCanvasAndPost(Canvas canvas) { // 只有sw 渲染的才走这边?
      try {
            nativeUnlockCanvasAndPost(mLockedObject, canvas);
          } finally {
            nativeRelease(mLockedObject);
            mLockedObject = 0;
        }
  }

android_view_Surface.cpp

static void nativeUnlockCanvasAndPost(JNIEnv* env, jclass clazz,
        jlong nativeObject, jobject canvasObj) {
            sp<Surface> surface(reinterpret_cast<Surface *>(nativeObject));        
// detach the canvas from the surface
    Canvas* nativeCanvas = GraphicsJNI::getNativeCanvas(env, canvasObj);
    nativeCanvas->setBitmap(SkBitmap());
    // unlock surface
    status_t err = surface->unlockAndPost();
}

Surface.cpp

status_t Surface::unlockAndPost()
{
    status_t err = mLockedBuffer->unlockAsync(&fd);
    //通过mGraphicBufferProducer->queueBuffer
    err = queueBuffer(mLockedBuffer.get(), fd);
}

直接使用别人的图片surface画图过程

Android Surface理解


    

    回忆下上文surface 是如何创建的

sp<SurfaceControl> SurfaceComposerClient::createSurface(
        const String8& name,
        uint32_t w,
        uint32_t h,
        PixelFormat format,
        uint32_t flags){
        sp<IGraphicBufferProducer> gbp;
        status_t err = mClient->createSurface(name, w, h, format, flags,
                &handle, &gbp);
        ALOGE_IF(err, "SurfaceComposerClient::createSurface error %s", strerror(-err));
        if (err == NO_ERROR) {
            sur = new SurfaceControl(this, handle, gbp);
        }
}

 

mClient  sp<ISurfaceComposerClient>  mClient;

  class Client : public BnSurfaceComposerClient

  Client 中mFlinger  sp<SurfaceFlinger> mFlinger;  这样SurfaceComposerClient 就通过IPC 与surfaceflinger 交互起来了

status_t Client::createSurface(
        const String8& name,
        uint32_t w, uint32_t h, PixelFormat format, uint32_t flags,
        sp<IBinder>* handle,
        sp<IGraphicBufferProducer>* gbp)
{    
    sp<MessageBase> msg = new MessageCreateLayer(mFlinger.get(),
            name, this, w, h, format, flags, handle, gbp);
    mFlinger->postMessageSync(msg);
    return static_cast<MessageCreateLayer*>( msg.get() )->getResult();
}



Client::createSurface() 与 android_view_Surface.cpp 中nativeReadFromParcel

surfacecontrol.cpp
status_t SurfaceControl::writeSurfaceToParcel(
        const sp<SurfaceControl>& control, Parcel* parcel)
{
    sp<IGraphicBufferProducer> bp;
    if (control != NULL) {
        bp = control->mGraphicBufferProducer;
    }
    return parcel->writeStrongBinder(IInterface::asBinder(bp));//Surface 核心是不是就是IGraphicBufferProducer 指针
}
android_view_Surface.cpp
static jlong nativeReadFromParcel(JNIEnv* env, jclass clazz,
        jlong nativeObject, jobject parcelObj) {
    Parcel* parcel = parcelForJavaObject(env, parcelObj);
sp<Surface> self(reinterpret_cast<Surface *>(nativeObject));
    sp<IBinder> binder(parcel->readStrongBinder());
    // update the Surface only if the underlying IGraphicBufferProducer
    // has changed.
    if (self != NULL
            && (IInterface::asBinder(self->getIGraphicBufferProducer()) == binder)) {
        // same IGraphicBufferProducer, return ourselves
        return jlong(self.get());// 直接返回surface sp
    }
    //当GraphicBufferProducer改变时,新建一个surface,并将原先surface decStrong 释放,返回新surface指针
    sp<Surface> sur;
    sp<IGraphicBufferProducer> gbp(interface_cast<IGraphicBufferProducer>(binder));
    if (gbp != NULL) {
        // we have a new IGraphicBufferProducer, create a new Surface for it
        sur = new Surface(gbp, true);
        // and keep a reference before passing to java
        sur->incStrong(&sRefBaseOwner);
    }
    if (self != NULL) {
        // and loose the java reference to ourselves
        self->decStrong(&sRefBaseOwner);
    }
    return jlong(sur.get());


向AI问一下细节

免责声明:本站发布的内容(图片、视频和文字)以原创、转载和分享为主,文章观点不代表本网站立场,如果涉及侵权请联系站长邮箱:is@yisu.com进行举报,并提供相关证据,一经查实,将立刻删除涉嫌侵权内容。

AI