content: /*
   * Copyright (C) 2015 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 android.view;
  
  import android.annotation.UnsupportedAppUsage;
  import android.os.Looper;
  
  /**
   * Similar to {@link InputEventReceiver}, but batches events to vsync boundaries when possible.
   * @hide
   */
  public class BatchedInputEventReceiver extends InputEventReceiver {
      Choreographer mChoreographer;
      private boolean mBatchedInputScheduled;
  
      @UnsupportedAppUsage
      public BatchedInputEventReceiver(
              InputChannel inputChannel, Looper looper, Choreographer choreographer) {
          super(inputChannel, looper);
          mChoreographer = choreographer;
      }
  
      @Override
      public void onBatchedInputEventPending() {
          scheduleBatchedInput();
      }
  
      @Override
      public void dispose() {
          unscheduleBatchedInput();
          super.dispose();
      }
  
      void doConsumeBatchedInput(long frameTimeNanos) {
          if (mBatchedInputScheduled) {
              mBatchedInputScheduled = false;
              if (consumeBatchedInputEvents(frameTimeNanos) && frameTimeNanos != -1) {
                  // If we consumed a batch here, we want to go ahead and schedule the
                  // consumption of batched input events on the next frame. Otherwise, we would
                  // wait until we have more input events pending and might get starved by other
                  // things occurring in the process. If the frame time is -1, however, then
                  // we're in a non-batching mode, so there's no need to schedule this.
                  scheduleBatchedInput();
              }
          }
      }
  
      private void scheduleBatchedInput() {
          if (!mBatchedInputScheduled) {
              mBatchedInputScheduled = true;
              mChoreographer.postCallback(Choreographer.CALLBACK_INPUT, mBatchedInputRunnable, null);
          }
      }
  
      private void unscheduleBatchedInput() {
          if (mBatchedInputScheduled) {
              mBatchedInputScheduled = false;
              mChoreographer.removeCallbacks(
                      Choreographer.CALLBACK_INPUT, mBatchedInputRunnable, null);
          }
      }
  
      private final class BatchedInputRunnable implements Runnable {
          @Override
          public void run() {
              doConsumeBatchedInput(mChoreographer.getFrameTimeNanos());
          }
      }
      private final BatchedInputRunnable mBatchedInputRunnable = new BatchedInputRunnable();
  }
  