TouchEvent: targetTouches property

A TouchList listing all the Touch objects for touch points that are still in contact with the touch surface and whose touchstart event occurred inside the same target element as the current target element.

This example illustrates the TouchEvent object's TouchEvent.targetTouches property. The TouchEvent.targetTouches property is a TouchList object that includes those TPs that are currently touching the surface and started on the element that is the target of the current event. As such, the targetTouches list is a strict subset of the touches list.

In following code snippet, the function compares the length of the touches list to the length of the targetTouches list and returns true if the lengths are the same and returns false otherwise.

function touches_in_target(ev) {
  // Return true if all of the touches are within the target element;
  // otherwise return false.
  return ev.touches.length === ev.targetTouches.length;
}