event listener

一、作用

二、添加事件冒泡监听器

export function addEventBubbleListener(
  target: EventTarget,
  eventType: string,
  listener: Function,
): Function {
  target.addEventListener(eventType, listener, false);
  return listener;
}

三、添加事件捕获监听器

export function addEventCaptureListener(
  target: EventTarget,
  eventType: string,
  listener: Function,
): Function {
  target.addEventListener(eventType, listener, true);
  return listener;
}

四、添加带有被动标志的事件捕获监听器

export function addEventCaptureListenerWithPassiveFlag(
  target: EventTarget,
  eventType: string,
  listener: Function,
  passive: boolean,
): Function {
  target.addEventListener(eventType, listener, {
    capture: true,
    passive,
  });
  return listener;
}

五、添加带被动标志的事件冒泡监听器

export function addEventBubbleListenerWithPassiveFlag(
  target: EventTarget,
  eventType: string,
  listener: Function,
  passive: boolean,
): Function {
  target.addEventListener(eventType, listener, {
    passive,
  });
  return listener;
}

六、移除事件监听器

export function removeEventListener(
  target: EventTarget,
  eventType: string,
  listener: Function,
  capture: boolean,
): void {
  target.removeEventListener(eventType, listener, capture);
}