content: /*
   * Copyright (C) 2013 The Android Open Source Project
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package com.android.server.wm;
  
  import android.view.InputChannel;
  import android.view.InputDevice;
  import android.view.InputEvent;
  import android.view.InputEventReceiver;
  import android.view.MotionEvent;
  import android.view.WindowManagerPolicyConstants.PointerEventListener;
  
  import com.android.server.UiThread;
  
  import java.util.ArrayList;
  
  public class PointerEventDispatcher extends InputEventReceiver {
      private final InputChannel mInputChannel;
      private final ArrayList<PointerEventListener> mListeners = new ArrayList<>();
      private PointerEventListener[] mListenersArray = new PointerEventListener[0];
  
      public PointerEventDispatcher(InputChannel inputChannel) {
          super(inputChannel, UiThread.getHandler().getLooper());
          mInputChannel = inputChannel;
      }
  
      @Override
      public void onInputEvent(InputEvent event) {
          try {
              if (event instanceof MotionEvent
                      && (event.getSource() & InputDevice.SOURCE_CLASS_POINTER) != 0) {
                  final MotionEvent motionEvent = (MotionEvent) event;
                  PointerEventListener[] listeners;
                  synchronized (mListeners) {
                      if (mListenersArray == null) {
                          mListenersArray = new PointerEventListener[mListeners.size()];
                          mListeners.toArray(mListenersArray);
                      }
                      listeners = mListenersArray;
                  }
                  for (int i = 0; i < listeners.length; ++i) {
                      listeners[i].onPointerEvent(motionEvent);
                  }
              }
          } finally {
              finishInputEvent(event, false);
          }
      }
  
      /**
       * Add the specified listener to the list.
       * @param listener The listener to add.
       */
      public void registerInputEventListener(PointerEventListener listener) {
          synchronized (mListeners) {
              if (mListeners.contains(listener)) {
                  throw new IllegalStateException("registerInputEventListener: trying to register" +
                          listener + " twice.");
              }
              mListeners.add(listener);
              mListenersArray = null;
          }
      }
  
      /**
       * Remove the specified listener from the list.
       * @param listener The listener to remove.
       */
      public void unregisterInputEventListener(PointerEventListener listener) {
          synchronized (mListeners) {
              if (!mListeners.contains(listener)) {
                  throw new IllegalStateException("registerInputEventListener: " + listener +
                          " not registered.");
              }
              mListeners.remove(listener);
              mListenersArray = null;
          }
      }
  
      /** Dispose the associated input channel and clean up the listeners. */
      @Override
      public void dispose() {
          super.dispose();
          mInputChannel.dispose();
          synchronized (mListeners) {
              mListeners.clear();
              mListenersArray = null;
          }
      }
  }
  