text: /**
   * @license
   * Copyright 2016 Google Inc.
   *
   * 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.
   */
  
  goog.provide('shaka.util.Timer');
  
  
  
  /**
   * A simple cancelable timer.
   * @param {Function} callback
   * @constructor
   * @struct
   */
  shaka.util.Timer = function(callback) {
    /** @private {?number} */
    this.id_ = null;
  
    /** @private {Function} */
    this.callback_ = (function() {
      this.id_ = null;
      callback();
    }.bind(this));
  };
  
  
  /**
   * Cancel the timer, if it's running.
   */
  shaka.util.Timer.prototype.cancel = function() {
    if (this.id_ != null) {
      clearTimeout(this.id_);
      this.id_ = null;
    }
  };
  
  
  /**
   * Schedule the timer, canceling any previous scheduling.
   * @param {number} seconds
   */
  shaka.util.Timer.prototype.schedule = function(seconds) {
    this.cancel();
    this.id_ = setTimeout(this.callback_, seconds * 1000);
  };
  
  
  /**
   * Schedule the timer, canceling any previous scheduling. The timer will
   * automatically reschedule after the callback fires.
   * @param {number} seconds
   */
  shaka.util.Timer.prototype.scheduleRepeated = function(seconds) {
    this.cancel();
    let repeat = (function() {
      this.callback_();
      this.id_ = setTimeout(repeat, seconds * 1000);
    }.bind(this));
    this.id_ = setTimeout(repeat, seconds * 1000);
  };
  