<canvas
  a:if="{{$pageId >= 0}}"
  id="f2-canvas-{{$pageId}}-{{$id}}"
  class="f2-canvas"
  width="{{width}}"
  height="{{height}}"
  onTap="click"
  onTouchStart="touchStart"
  onTouchMove="touchMove"
  onTouchEnd="touchEnd"
/>
