屏蔽系统鼠标按键

在一些系统开发中(例如机顶盒)有可能遇到需求不响应鼠标按键,在开发中怎么解决呢?下面我来给大家演示:

1.系统中按键的响应都是通过在ViewRootImpl中传递给View的,所以要想屏蔽按键就要在ViewRootImpl.java中寻找;

2.在setView中sWindowSession.add(mWindow, mSeq, mWindowAttributes,getHostVisibility(), mAttachInfo.mContentInsets,mInputChannel);建立View与WMS的联系这样WMS就能把消息传递给View了,但是怎么传递的呢?答案是:mInputChannel.

注册:

if (mInputChannel != null) {
                    if (mInputQueueCallback != null) {
                        mInputQueue = new InputQueue(mInputChannel);
                        mInputQueueCallback.onInputQueueCreated(mInputQueue);
                    } else {
                        InputQueue.registerInputChannel(mInputChannel, mInputHandler,
                                Looper.myQueue());
                    }
                }

响应回掉处理:

private final InputHandler mInputHandler = new InputHandler() {
        public void handleKey(KeyEvent event, InputQueue.FinishedCallback finishedCallback) {
            startInputEvent(finishedCallback);
            dispatchKey(event, true);//处理按键
        }

        public void handleMotion(MotionEvent event, InputQueue.FinishedCallback finishedCallback) {
            startInputEvent(finishedCallback);
            dispatchMotion(event, true);//处理触摸,鼠标,摇杆等消息
        }
    };

3.下面看dispatchMotion函数:

private void dispatchMotion(MotionEvent event, boolean sendDone) {
        int source = event.getSource();
        if ((source & InputDevice.SOURCE_CLASS_POINTER) != 0) {
            Log.d(TAG,"----dispatchPointer----");
            dispatchPointer(event, sendDone);//在有鼠标点击事件时会调用
        } else if ((source & InputDevice.SOURCE_CLASS_TRACKBALL) != 0) {
            dispatchTrackball(event, sendDone);
            Log.d(TAG,"----dispatchTrackball----");
        } else {
            dispatchGenericMotion(event, sendDone);
            Log.d(TAG,"----dispatchGenericMotion----");
        }
    }

看dispatchPointer函数,其实里面就是发送了DISPATCH_POINTER消息真正处理是在deliverPointerEvent函数;所以只需要在deliverPointerEvent函数中处理,具体代码:

finishMotionEvent(event, sendDone, true);
return;