Function isTouchEvent

src/cdk/drag-drop/drag-ref.ts:1671–1676

Determines whether an event is a touch event.

(event: MouseEvent | TouchEvent)

/** Determines whether an event is a touch event. */
function isTouchEvent(event: MouseEvent | TouchEvent): event is TouchEvent {
  // This function is called for every pixel that the user has dragged so we need it to be
  // as fast as possible. Since we only bind mouse events and touch events, we can assume
  // that if the event's name starts with `t`, it's a touch event.
  return event.type[0] === 't';
}

/** Callback invoked for `selectstart` events inside the shadow DOM. */
function shadowDomSelectStart(event: Event) {