extractEvents() — react Function Reference

Source Code

packages/react-dom-bindings/src/events/plugins/SimpleEventPlugin.js lines 57–235

function extractEvents(
  dispatchQueue: DispatchQueue,
  domEventName: DOMEventName,
  targetInst: null | Fiber,
  nativeEvent: AnyNativeEvent,
  nativeEventTarget: null | EventTarget,
  eventSystemFlags: EventSystemFlags,
  targetContainer: EventTarget,
): void {
  const reactName = topLevelEventsToReactNames.get(domEventName);
  if (reactName === undefined) {
    return;
  }
  let SyntheticEventCtor = SyntheticEvent;
  let reactEventType: string = domEventName;
  switch (domEventName) {
    case 'keypress':
      // Firefox creates a keypress event for function keys too. This removes
      // the unwanted keypress events. Enter is however both printable and
      // non-printable. One would expect Tab to be as well (but it isn't).
      // TODO: Fixed in https://bugzilla.mozilla.org/show_bug.cgi?id=968056. Can
      // probably remove.
      if (getEventCharCode(((nativeEvent: any): KeyboardEvent)) === 0) {
        return;
      }
    /* falls through */
    case 'keydown':
    case 'keyup':
      SyntheticEventCtor = SyntheticKeyboardEvent;
      break;
    case 'focusin':
      reactEventType = 'focus';
      SyntheticEventCtor = SyntheticFocusEvent;
      break;
    case 'focusout':
      reactEventType = 'blur';
      SyntheticEventCtor = SyntheticFocusEvent;
      break;
    case 'beforeblur':
    case 'afterblur':
      SyntheticEventCtor = SyntheticFocusEvent;
      break;
    case 'click':
      // Firefox creates a click event on right mouse clicks. This removes the
      // unwanted click events.
      // TODO: Fixed in https://phabricator.services.mozilla.com/D26793. Can
      // probably remove.
      if (nativeEvent.button === 2) {
        return;
      }
    /* falls through */
    case 'auxclick':
    case 'dblclick':
    case 'mousedown':
    case 'mousemove':
    case 'mouseup':
    // TODO: Disabled elements should not respond to mouse events
    /* falls through */
    case 'mouseout':
    case 'mouseover':
    case 'contextmenu':
      SyntheticEventCtor = SyntheticMouseEvent;
      break;
    case 'drag':
    case 'dragend':
    case 'dragenter':
    case 'dragexit':
    case 'dragleave':
    case 'dragover':
    case 'dragstart':
    case 'drop':
      SyntheticEventCtor = SyntheticDragEvent;
      break;
    case 'touchcancel':
    case 'touchend':
    case 'touchmove':
    case 'touchstart':
      SyntheticEventCtor = SyntheticTouchEvent;
      break;
    case ANIMATION_END:
    case ANIMATION_ITERATION: