Method calcTaskScore_

src/service/resources-impl.js:1399–1412

* Calculates the task's score. A task with the lowest score will be dequeued * from the queue the first. * * There are three components of the score: element's priority, operation or * offset priority and viewport priority. * * Element's priority is constant of the element's name.

(task)

   * @private
   */
  calcTaskScore_(task) {
    // TODO(jridgewell): these should be taking into account the active
    // scroller, which may not be the root scroller. Maybe a weighted average
    // of "scroller scrolls necessary" to see the element.
    // Demo at https://output.jsbin.com/hicigom/quiet
    const viewport = this.viewport_.getRect();
    const box = task.resource.getLayoutBox();
    let posPriority = Math.floor((box.top - viewport.top) / viewport.height);
    if (Math.sign(posPriority) != this.getScrollDirection()) {
      posPriority *= 2;
    }
    posPriority = Math.abs(posPriority);
    return task.priority * PRIORITY_BASE_ + posPriority;
  }

  /**
   * Calculates the timeout of a task. The timeout depends on two main factors: