android/src/com/android/tools/idea/editors/navigation/EventDispatcher.java

/*
 * 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.tools.idea.editors.navigation;

import com.android.annotations.NonNull;

import java.util.ArrayList;

public class EventDispatcher<E> extends ArrayList<Listener<E>> implements Listener<E> {
  @Override
  public void notify(@NonNull E event) {
    for (Listener<E> listener : this) {
      listener.notify(event);
    }
  }

  @Override
  public boolean add(Listener<E> listener) {
    //noinspection SimplifiableConditionalExpression
    return !contains(listener) ? super.add(listener) : false;
  }
}