InputDispatcher向InputChannel使用socket写入输入事件，触发InputEventReceiver调用来接收输入事件。

ViewPostImeInputStage处理view控件的事件

@frameworks/base/core/java/android/view/InputEventReceiver.java    
            dispatchInputEvent
@frameworks/base/core/java/android/view/ViewRootImpl.java
                onInputEvent(event);
                    enqueueInputEvent(event, this, 0, true);
                        if (processImmediately) { doProcessInputEvents(); }
                            deliverInputEvent(q);  //在deliverInputEvent函数中做输入事件的实际分发
                                stage = q.shouldSkipIme() ? mFirstPostImeInputStage : mFirstInputStage;  //这里开始选择 责任链的入口，具体请看InputStage的处理流程
                                stage.deliver(q);  //这里主要调用InputStage的deliver方法进行分发，InputStage代表了输入事件的处理阶段，使用责任链模式设计模式。
                                    result = onProcess(q);  // EarlyPostImeInputStage::onProcess
                                            apply(q, result);
                                                if (result == FORWARD) {   forward(q);  } 
                                                    onDeliverToNext(q);
                                                        mNext.deliver(q);
                                                            result = onProcess(q);  //NativePostImeInputStage::onProcess
                                                                mNext.deliver(q);
                                                                    result = onProcess(q); //ViewPostImeInputStage::onProcess
                                                                        if((source & InputDevice.SOURCE_CLASS_POINTER) != 0) { return processPointerEvent(q); }
@frameworks/base/core/java/android/view/View.java
                                                                            boolean handled = mView.dispatchPointerEvent(event);
                                                                                //MotionEvent { action=ACTION_DOWN, actionButton=0, id[0]=0, x[0]=692.0, y[0]=993.0, toolType[0]=TOOL_TYPE_FINGER, displayId=0, buttonState=0, classification=NONE, metaState=0, flags=0x0, edgeFlags=0x0, pointerCount=1, historySize=0, eventTime=455777, downTime=455777, deviceId=-1, source=0x5002, eventId=-701920562 }}
                                                                                dispatchTouchEvent(event); 
                                                                                    if (mInputEventConsistencyVerifier != null) {  mInputEventConsistencyVerifier.onTouchEvent(event, 0);    }                                                                 
@XrView.java
                                                                                    //调用app setOnTouchListener(mTouchListener)注册的Listener
                                                                                    if (li != null && li.mOnTouchListener != null && (mViewFlags & ENABLED_MASK) == ENABLED && li.mOnTouchListener.onTouch(this, event)) {result = true;} 
                                                                                        return true;    //返回true表示已经处理完成，不往下走，fasle则相反
                                                                                    if (!result && onTouchEvent(event)) { result = true;}   //调用app的onTouchEvent或者View.java的onTouchEvent
                                                                                //MotionEvent { action=ACTION_HOVER_MOVE, actionButton=0, id[0]=0, x[0]=664.80475, y[0]=407.85626, toolType[0]=TOOL_TYPE_MOUSE, displayId=0, buttonState=0, classification=NONE, metaState=0, flags=0x0, edgeFlags=0x0, pointerCount=1, historySize=0, eventTime=284960, downTime=284790, deviceId=3, source=0x2002, eventId=1040558423 }
                                                                                dispatchGenericMotionEvent(event);
                                                                                    if (action == MotionEvent.ACTION_HOVER_ENTER || action == MotionEvent.ACTION_HOVER_MOVE || action == MotionEvent.ACTION_HOVER_EXIT) { if (dispatchHoverEvent(event)) }
                                                                                        li.mOnHoverListener.onHover(this, event))
@MyApplication/app/src/main/java/com/example/myapplication/MainActivity.java
                                                                                            public boolean onHover(View view, MotionEvent motionEvent) { return false; }  //回调Button控件的onHover
                                                                                    dispatchGenericMotionEventInternal(event)
                                                                                        onGenericMotionEvent(event)
                                                                            maybeUpdatePointerIcon(event);
                                                                                if (event.getActionMasked() != MotionEvent.ACTION_HOVER_EXIT) { if (!updatePointerIcon(event) && }
                                                                                    InputManager.getInstance().setPointerIconType(pointerType);  // pointerType = 1002, 鼠标样式由箭头变成小手