content: /*
   * Copyright (C) 2019 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.quickstep.util;
  
  import static com.android.systemui.shared.system.InputChannelCompat.mergeMotionEvent;
  
  import android.view.MotionEvent;
  
  import java.util.ArrayList;
  import java.util.function.Consumer;
  
  /**
   * Utility class to dispatch touch events to a different class. It stores the events locally
   * until a valid dispatcher is available.
   */
  public class CachedEventDispatcher {
  
      private Consumer<MotionEvent> mConsumer;
  
      private ArrayList<MotionEvent> mCache;
      private MotionEvent mLastEvent;
  
      public void dispatchEvent(MotionEvent event) {
          if (mConsumer != null) {
              mConsumer.accept(event);
          } else {
              if (mLastEvent == null || !mergeMotionEvent(event, mLastEvent)) {
                  // Queue event.
                  if (mCache == null) {
                      mCache = new ArrayList<>();
                  }
                  mLastEvent = MotionEvent.obtain(event);
                  mCache.add(mLastEvent);
              }
          }
      }
  
      public void setConsumer(Consumer<MotionEvent> consumer) {
          if (consumer == null) {
              return;
          }
          mConsumer = consumer;
          int cacheCount = mCache == null ? 0 : mCache.size();
          for (int i = 0; i < cacheCount; i++) {
              MotionEvent ev = mCache.get(i);
              mConsumer.accept(ev);
              ev.recycle();
          }
          mCache = null;
          mLastEvent = null;
      }
  
      public boolean hasConsumer() {
          return mConsumer != null;
      }
  }
  