Function trapCapturedEvent

code/new-context-api/public/app.js:5267–5276

* Traps a top-level event by using event capturing. * * @param {string} topLevelType Record from `BrowserEventConstants`. * @param {string} handlerBaseName Event name (e.g. "click"). * @param {object} element Element on which to attach listener. * @return {?object} An object with a remove funct

(topLevelType, handlerBaseName, element)

 * @internal
 */
function trapCapturedEvent(topLevelType, handlerBaseName, element) {
  if (!element) {
    return null;
  }
  var dispatch = isInteractiveTopLevelEventType(topLevelType) ? dispatchInteractiveEvent : dispatchEvent;

  addEventCaptureListener(element, handlerBaseName,
  // Check if interactive and wrap in interactiveUpdates
  dispatch.bind(null, topLevelType));
}

function dispatchInteractiveEvent(topLevelType, nativeEvent) {
  interactiveUpdates(dispatchEvent, topLevelType, nativeEvent);