Servis-Rhino 4211B Betriebsanweisung PDF herunterladen (Seite 263)

Stage stage = (Stage) closeButton.getScene().getWindow();

stage.close();

}

This will find the stage that contains the close button and close that stage.

A potentially far better way of working with dialogs is to use the Dialog capabilities of the Open

Source toolkit known as ControlsFX.

See also:

• Concurrency in JavaFX – Java SE 8

Running work in the background

Imagine that we wish to do some non UI processing that takes some time and, when done, update

the UI. An example of this might be an expensive database query or a Web Service call. We may

want to do this on as the result of a button press or other UI interaction. If we now look at the

diagrams show below. The top half shows the normal flow of operation. The Main thread has

control and when a user clicks a button, the App Callback is invoked on that thread. The App

Callback then makes its slow call to the back-end blocking waiting for the return. When the back-

end completes, the App Callback does some work and finally returns control to the main thread. As

we can see, the main thread gave up control for the whole duration.

If we now look at the second diagram, again the main thread calls the App Callback logic but this

time, the App Callback logic creates a new thread that gets control. The App Callback thread

immediately returns control to the Main thread which can continue to update the UI. We now have

two threads executing in parallel with each other. The worker thread now makes the slow call to

the back end and when it returns, it returns control to the worker thread. Because of contractual

rules, the worker thread may not update any UI. That is the exclusive prerogative of the Java FX

main thread. The worker thread then issues a request to the main thread to run some logic at some

time later and the worker ends. At some later point, the main thread is now able to invoke the

specified logic that the worker thread asked it to call. That logic executes on the main thread in the

App Callback code.

The vitally important thing to note is that the JavaFX thread did NOT have to wait anywhere near

as long as that duration shown in the first diagram.

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Servis-Rhino 4211B Betriebsanweisung Seite 263