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JavaFX TilePane

JavaFX TitledPane

JavaFX VBox

JavaFX Other classes

JavaFX Popup

JavaFX PopupWindow

JavaFX Event Handling

Event handling is the notion that when a user interacts with JavaFX components, they can fire

events. These events can then be caught be event listeners and acted upon. For example, if we add

a button to our solution, then the click of the button is meant to drive some logic. This means that

we have to register the desired logic as a listener upon button click events.

The core to the story is the notion of the javafx.event.Event class. This class represents a

generic event and can be subclassed to create more specialized versions. Among the core properties

of an event are:

• Event type – What kind of event does this event represent

• Source – Who originated the event

• Target – Who is the target of the event

When we wish to register an event handler (the code that catches the event), we can use the

addEventHandler() method. This takes two properties:

• The type of the event we are watching for.

• An instance of an EventHandler to be given control when the event is detected.

The type of event will be a subclass of EventType

A class which can receive events implements the EventTarget interface. This includes all the

existing atomic components.

Now, let us get practical. Let us assume we want to create a new event called "MyEvent". We

could build this as follows:

public static class MyEvent extends Event {

private static final long serialVersionUID = 1L;

public MyEvent(EventType<? extends MyEvent> eventType) {

super(eventType);

}

public static final EventType<MyEvent> ANY = new EventType<MyEvent>(Event.ANY, "MYEVENT");

public static final EventType<MyEvent> MYEVENT_A = new EventType<MyEvent>(MyEvent.ANY,

"MYEVENT_A");

}

Now if we wish to fire such an event, we can call:

fireEvent(new MyEvent(MyEvent.MYEVENT_A));

To catch this event, we can use:

myClass.addEventHandler(MyEvent.MYEVENT_A, new EventHandler<MyEvent>() {

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Servis-Rhino 4211B Betriebsanweisung Seite 283