如何发出和处理自定义事件? [英] How to emit and handle custom events?

问题描述

javafx 中有几个预定义的事件类.Event.ANY、KeyEvent.KEY_TYPED、MouseEvent.ANY 等等.还有先进的事件过滤和处理系统.我想重用它来发送一些自定义信号.

There are several predefined event classes in javafx. Event.ANY, KeyEvent.KEY_TYPED, MouseEvent.ANY and so on. There is also advanced filtering and handling system for events. And I'd like to reuse it to send some custom signals.

如何创建自定义事件类型 CustomEvent.Any，以编程方式发出此事件并在节点中处理它?

How can I create my custom event type CustomEvent.Any, emit this event programmatically and handle it in a node?

推荐答案

一般:

1. 创建所需的EventType.
2. 创建相应的事件.
3. 调用 Node.fireEvent().
4. 添加处理程序 和/或 过滤器，用于感兴趣的事件类型.

1. Create a desired EventType.
2. Create the corresponding Event.
3. Call Node.fireEvent().
4. Add Handlers and/or Filters for EventTypes of interest.

一些解释:

如果要创建事件级联，请从All"或Any"类型开始，这将是所有 EventType 的根:

If you want to create an event cascade, start with an "All" or "Any" type, that will be the root of all of the EventTypes:

EventType<MyEvent> OPTIONS_ALL = new EventType<>("OPTIONS_ALL");

这使得创建这种类型的后代成为可能:

This makes possible creating descendants of this type:

EventType<MyEvent> BEFORE_STORE = new EventType<>(OPTIONS_ALL, "BEFORE_STORE");

然后编写MyEvent 类(它扩展了Event).EventTypes 应该输入到这个事件类中(就像我的例子一样).

Then write the MyEvent class (which extends Event). The EventTypes should be typed to this event class (as is my example).

现在使用(或换句话说:触发)事件:

Now use (or in other words: fire) the event:

Event myEvent = new MyEvent();
Node node = ....;
node.fireEvent(myEvent);

如果你想抓住这个事件:

If you want to catch this event:

Node node = ....;
node.addEventHandler(OPTIONS_ALL, event -> handle(...));
node.addEventHandler(BEFORE_STORE, event -> handle(...));

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