Gluon switch scene on custom event

Question

I try to switch the scene of a Gluon application when a custom event is fired.

When I call

MobileApplication.getInstance().switchView(SECONDARY_VIEW);"

I get the error

Exception in thread "Thread-6" java.lang.IllegalStateException: This operation is permitted on the event thread only; currentThread = Thread-6

This is the listener that handles the custom event

ParallelServerInterface.setLoginResponseListener(new LoginResponseListener() {
        @Override
        public void loginResponseReceived(LoginResponse loginResponse) {
            Map<String, String> source = (Map<String, String>) loginResponse.getSource();
            boolean status = source.get("status").equals("true");

            if (status) {
                MobileApplication.getInstance().switchView(SECONDARY_VIEW);
            }
        }
    });

How can this be resolved?

It looks like you are doing this from a background thread. You can use `Platform.runLater(() -> {... switchView...});` to queue the process to be done in the JavaFX application thread. — José Pereda, Oct 20 '19 at 13:42
@JoséPereda, that was it. Please post your comment as an answer and I will accept it right away. — Giwrgos Gkogkas, Oct 20 '19 at 13:45

score 2 · Accepted Answer · answered Oct 20 '19 at 13:55

Any call to MobileApplication.getInstance()::switchView should happen in the JavaFX Application thread, as it basically involves changes in the scenegraph.

Roughly, you are removing the old View (which is a Node), and adding a new one (another Node):

glassPane.getChildren().remove(oldNode);
glassPane.getChildren().add(newNode);

And as you know, anything related to node manipulation has to be done in the JavaFX Application thread.

It seems the login event is triggered in a background thread, so all you need to do is to queue the view switch to the application thread, using Platform.runLater:

    @Override
    public void loginResponseReceived(LoginResponse loginResponse) {
        Map<String, String> source = (Map<String, String>) loginResponse.getSource();
        boolean status = source.get("status").equals("true");

        if (status) {
            // switch view has to be done in the JavaFX Application thread:
            Platform.runLater(() ->
                MobileApplication.getInstance().switchView(SECONDARY_VIEW));
        }
    }

Gluon switch scene on custom event

1 Answers1