touchEventToMouseEvent function

MouseEvent? touchEventToMouseEvent(TouchEvent event)

Converts a TouchEvent event to a MouseEvent.

This helps to use TouchEvent as normal MouseEvent, simplifying UI support for touch events and mouse events.

Implementation

MouseEvent? touchEventToMouseEvent(TouchEvent event) {
  var touches = event.touches;
  if (touches.isEmpty) return null;

  var first = touches.item(0)!;
  var type = '';

  switch (event.type.toLowerCase()) {
    case 'touchstart':
      type = 'mousedown';
      break;
    case 'touchmove':
      type = 'mousemove';
      break;
    case 'touchend':
      type = 'mouseup';
      break;
    default:
      return null;
  }

  EventTarget? target;

  // If `event.target` is null, not dispatched, it will throw an exception.
  try {
    target = event.target;
  }
  // ignore: empty_catches
  catch (ignore) {}

  var simulatedEvent = MouseEvent(
    type,
    MouseEventInit(
      bubbles: event.bubbles,
      cancelable: event.cancelable,
      view: window,
      detail: 1,
      screenX: first.screenX.toInt(),
      screenY: first.screenY.toInt(),
      clientX: first.clientX.toInt(),
      clientY: first.clientY.toInt(),
      ctrlKey: event.ctrlKey,
      altKey: event.altKey,
      shiftKey: event.shiftKey,
      metaKey: event.metaKey,
      button: 0,
      relatedTarget: target,
    ),
  );

  return simulatedEvent;
}