/**
 * @fileoverview Event handler that flushes pending events for the current
 * document.
 *
 * @license
 * Copyright 2020 Google LLC
 *
 * 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
 *
 *   https://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.
 */

import {BatchEventFlushingStrategy} from './batch_event_flushing_strategy';

/**
 * Event handler that flushes pending events for the current
 * document.
 */
export class DocumentEventsFlushingStrategy implements BatchEventFlushingStrategy {
  startBatching(flushEventsDelegate: () => void): void {
    if (document) {
      document.addEventListener('pagehide', flushEventsDelegate);
    }
  }

  stopBatching(flushEventsDelegate: () => void): void {
    if (document) {
      document.removeEventListener('pagehide', flushEventsDelegate);
    }
  }
}