Method constructor

src/scale-manager/ResizeHelper.js:37–69

*Creates an instance of ResizeHelper. * @param {function} resizeCallback * @memberof ResizeHelper

(resizeCallback)

  * @memberof ResizeHelper
  */
  constructor(resizeCallback) {
    this._enabled = true;
    this.resizeCallback = resizeCallback;

    // Setup a listener for the 'resize' event from the window's event system.
    window.addEventListener('resize', this.onWindowResize.bind(this));

    // Defaulted to needing a resize loop on iOS devices due to a potential bug where
    // the window resize event isn't dispatched at the correct time.
    let requiresResizeLoop = this.iOS;

    // Setup environment specific resize event variables
    if (typeof Event === 'function') {
      this.resize();
    }
    else {
      this.resizeEvent = window.document.createEvent('UIEvents');
      this.resizeEvent.initUIEvent('resize', true, false, window, 0);
      requiresResizeLoop = true;
    }

    if (requiresResizeLoop) {
      // The resize loop will observe the aspect ratio of the window and will dispatch events anytime it changes.
      this.aspectRatio = new Property(0);
      this.aspectRatio.subscribe(this.resize.bind(this));

      // Call the first resize tick.
      this.resizeTick();

      // Check for aspect ratio change every 50 milliseconds.
      setInterval(this.resizeTick.bind(this), 50);
    }
  }

  /**
   * For older browsers, specifically for IE11, starts a loop making sure resize events are fired.