IMS:InputChannel通過socket發(fā)送Input給App

android11-release
IMS:InputManagerService啟動簡要
IMS:InputReader線程獲取輸入事件
IMS:InputDispatcher線程分發(fā)事件

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InputChannel監(jiān)聽

??IMS與WMS強(qiáng)相關(guān)，這個InputChannel就是在addView時是聲明。APP就是在Activity.java中setContentView()，經(jīng)過AMS與WMS之間交互，這里不過多介紹，最終 WindowManagerImpl.addView() 內(nèi)部再調(diào)用 WindowManagerGlobal.addView()。

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添加App的View

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

public void setView(View view, WindowManager.LayoutParams attrs, View panelParentView,int userId) {synchronized (this) {if (mView == null) {// ... ... ... ...InputChannel inputChannel = null;if ((mWindowAttributes.inputFeatures& WindowManager.LayoutParams.INPUT_FEATURE_NO_INPUT_CHANNEL) == 0) {inputChannel = new InputChannel();}// ... ... ... ...try {mOrigWindowType = mWindowAttributes.type;mAttachInfo.mRecomputeGlobalAttributes = true;collectViewAttributes();adjustLayoutParamsForCompatibility(mWindowAttributes);res = mWindowSession.addToDisplayAsUser(mWindow, mSeq, mWindowAttributes,getHostVisibility(), mDisplay.getDisplayId(), userId, mTmpFrame,mAttachInfo.mContentInsets, mAttachInfo.mStableInsets,mAttachInfo.mDisplayCutout, inputChannel,mTempInsets, mTempControls);setFrame(mTmpFrame);} catch (RemoteException e) {// ... ... ... ...if (DEBUG_LAYOUT) Log.v(mTag, "Added window " + mWindow);// ... ... ... ...if (inputChannel != null) {if (mInputQueueCallback != null) {mInputQueue = new InputQueue();mInputQueueCallback.onInputQueueCreated(mInputQueue);}mInputEventReceiver = new WindowInputEventReceiver(inputChannel,Looper.myLooper());}// ... ... ... ...// 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;// ... ... ... ...}}}

• 1、InputChannel 初始化工作
• 2、mWindowSession.addToDisplayAsUser 通過Binder調(diào)用，進(jìn)入system進(jìn)程的Session。這里最終構(gòu)建(server)、(client)的InputChannel。
• 3、WindowInputEventReceiver 接收器初始化
• 4、InputStage 責(zé)任鏈調(diào)用

構(gòu)建(server)、(client)的InputChannel

frameworks/base/services/core/java/com/android/server/wm/Session.java frameworks/services/core/java/com/android/server/wm/WindowManagerService.java frameworks/services/core/java/com/android/server/wm/WindowState.java frameworks/base/core/java/android/view/InputChannel.java frameworks/base/core/jni/android_view_InputChannel.cpp frameworks/native/libs/input/InputTransport.cpp public int addWindow(Session session, IWindow client, int seq,LayoutParams attrs, int viewVisibility, int displayId, Rect outFrame,Rect outContentInsets, Rect outStableInsets,DisplayCutout.ParcelableWrapper outDisplayCutout, InputChannel outInputChannel,InsetsState outInsetsState, InsetsSourceControl[] outActiveControls,int requestUserId) {// ... ... ... ...final WindowState win = new WindowState(this, session, client, token, parentWindow,appOp[0], seq, attrs, viewVisibility, session.mUid, userId,session.mCanAddInternalSystemWindow);// ... ... ... ...final boolean openInputChannels = (outInputChannel != null&& (attrs.inputFeatures & INPUT_FEATURE_NO_INPUT_CHANNEL) == 0);if (openInputChannels) {win.openInputChannel(outInputChannel);}// ... ... ... ...}

• inputChannels[0] 所對應(yīng) (server) 的 InputChannel ，保存到 mInputChannel；并添加 Connection ，“InputDispatcher” 線程的 Looper 添加對 socket 服務(wù)端的監(jiān)聽
  
• inputChannels[1] 所對應(yīng) (client) 的 InputChannel ，傳遞給 outInputChannel，最終傳遞給 ViewRootImpl 的 mInputChannel

WindowInputEventReceiver接收器初始化

frameworks/base/core/java/android/view/ViewRootImpl.java frameworks/base/core/java/android/view/InputEventReceiver.java frameworks/base/core/jni/android_view_InputEventReceiver.cpp

receiver->initialize()初始化設(shè)置setFdEvents，這里 handler/Looper 輪詢回調(diào) LooperCallback，POLL_CALLBACK某個被監(jiān)聽 fd 被觸發(fā)回調(diào)response.request.callback->handleEvent(fd, events, data);

class NativeInputEventReceiver : public LooperCallback { // ... ... ... ... status_t NativeInputEventReceiver::initialize() {setFdEvents(ALOOPER_EVENT_INPUT);return OK; } // ... ... ... ... void NativeInputEventReceiver::setFdEvents(int events) {if (mFdEvents != events) {mFdEvents = events;int fd = mInputConsumer.getChannel()->getFd();if (events) {mMessageQueue->getLooper()->addFd(fd, 0, events, this, nullptr);} else {mMessageQueue->getLooper()->removeFd(fd);}} }int NativeInputEventReceiver::handleEvent(int receiveFd, int events, void* data) {// ... ... ... ... }

InputStage 責(zé)任鏈調(diào)用

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

InputStage初始化，Input 事件傳遞過來會調(diào)用 InputStage.deliver，通過責(zé)任鏈模式執(zhí)行

InputChannel通過socket發(fā)送Input給App

?? 通過上邊了解相關(guān)的前期工作，接著 IMS:InputDispatcher線程分發(fā)事件 經(jīng)過 InputChannel 通過 socket 向遠(yuǎn)端的socket發(fā)送消息給Window。

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監(jiān)聽 fd 回調(diào) LooperCallback

::send(mFd.get(), &cleanMsg, msgLength, MSG_DONTWAIT | MSG_NOSIGNAL); LooperCallback 回調(diào)到 handleEvent

frameworks/base/core/jni/android_view_InputEventReceiver.cpp frameworks/base/core/java/android/view/InputChannel.java frameworks/base/core/java/android/view/ViewRootImpl.java

最終走到WindowInputEventReceiver的onInputEvent，通過enqueueInputEvent -> doProcessInputEvents -> deliverInputEvent -> stage.deliver(q)調(diào)用執(zhí)行InputStage 責(zé)任鏈

InputStage的各子類Input事件onProcess處理

查看父類InputStage主要result = onProcess(q)處理Input事件，apply->forward->onDeliverToNext->mNext.deliver處理責(zé)任鏈傳遞或finish。

abstract class InputStage {private final InputStage mNext;// ... ... ... ...public InputStage(InputStage next) {mNext = next;}// ... ... ... ...public final void deliver(QueuedInputEvent q) {if ((q.mFlags & QueuedInputEvent.FLAG_FINISHED) != 0) {forward(q);} else if (shouldDropInputEvent(q)) {finish(q, false);} else {traceEvent(q, Trace.TRACE_TAG_VIEW);final int result;try {result = onProcess(q);} finally {Trace.traceEnd(Trace.TRACE_TAG_VIEW);}apply(q, result);}}// ... ... ... ...protected void forward(QueuedInputEvent q) {onDeliverToNext(q);}// ... ... ... ...protected void apply(QueuedInputEvent q, int result) {if (result == FORWARD) {forward(q);} else if (result == FINISH_HANDLED) {finish(q, true);} else if (result == FINISH_NOT_HANDLED) {finish(q, false);} else {throw new IllegalArgumentException("Invalid result: " + result);}}// ... ... ... ...protected void onDeliverToNext(QueuedInputEvent q) {if (DEBUG_INPUT_STAGES) {Log.v(mTag, "Done with " + getClass().getSimpleName() + ". " + q);}if (mNext != null) {mNext.deliver(q);} else {finishInputEvent(q);}}// ... ... ... ...}

例如ViewPostImeInputStage中processKeyEvent

mView.dispatchKeyEvent(event)事件發(fā)送到App界面，這里mView就是DecorView，涉及PhoneWindow.java、DecorView.java

frameworks/base/core/java/com/android/internal/policy/PhoneWindow.java frameworks/base/core/java/com/android/internal/policy/DecorView.java

這里handled可以判斷應(yīng)用是否攔截KeyEvent事件，但是需要明白的是不管應(yīng)用攔不攔截，Input事件都已經(jīng)發(fā)送給應(yīng)用了。

Activity回調(diào)Callback

frameworks/base/core/java/android/app/Activity.java frameworks/base/core/java/com/android/internal/policy/PhoneWindow.java frameworks/base/core/java/com/android/internal/policy/DecorView.java

cb.dispatchKeyEvent(event) 這個Window.Callback是Activity回調(diào)注冊

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