Wsrtjtyk

I need to listen to key events in stage but not when the FileChooser is displayed.

Is there a way to stop KeyEvent (e.g. Esc key is pressed.) propagation to (parent) Stage, when FileChooser is displayed?

OR

Detect that the KeyEvent is propagated from FileChooser?

class KeyEventTest extends Application

{

  @Override

  public void start(Stage stage) throws Exception

  {

    Button browseBtn = new Button("Browse File System");

    browseBtn.setOnAction(ae ->

      {

        FileChooser fileChooser = new FileChooser();

        fileChooser.showOpenMultipleDialog(stage);

      });



    stage.setScene(new Scene(new BorderPane(browseBtn), 500, 200));

    stage.setTitle("Test");



    stage.addEventHandler(KeyEvent.KEY_RELEASED, keyEvent ->

      {

        // Do not trigger when Esc key is pressed on FileChooser

        KeyCode keyCode = keyEvent.getCode();

        System.out.println(keyCode);

      });



    stage.centerOnScreen();

    stage.show();

  }



  public static void main(String args)

  {

    launch(args);

  }

}

It is possible to achieve it. You are correct that if you close the FileChooser using either escape or ALT+F4 the event will be propagated, but you need to think which event will? if you have a look only the KeyEvent.KEY_RELEASED will. So if you just add an event filter recording when the key was pressed you can find out when you pressed the escape ( or alt+f4 ) in your main stage or in your FileChooser

So more or less you are trying to find out if the KEY_PRESSED was handled by FileChooser or not. If it was, then the KEY_RELEASED will also be handled from FileChooser otherwise we trigger the KeyEvent in our main app.

Here is an example :

import javafx.application.Application;

import javafx.scene.Scene;

import javafx.scene.control.Button;

import javafx.scene.input.KeyCode;

import javafx.scene.input.KeyEvent;

import javafx.scene.layout.BorderPane;

import javafx.scene.web.WebEngine;

import javafx.scene.web.WebView;

import javafx.stage.FileChooser;

import javafx.stage.Stage;



public class Main extends Application {



    private boolean captureKeys = false;



    public static void main(String args) {

        launch(args);

    }



    @Override

    public void start(Stage stage) {

        Button browseBtn = new Button("Browse File System");

        browseBtn.setOnAction(ae -> {

            captureKeys = false;

            FileChooser fileChooser = new FileChooser();

            fileChooser.showOpenMultipleDialog(stage);

        });



        stage.setScene(new Scene(new BorderPane(browseBtn), 500, 200));



        stage.addEventFilter(KeyEvent.KEY_PRESSED, keyEvent -> {

            captureKeys = true;

            // For debug

            // KeyCode keyCode = keyEvent.getCode();

            // System.out.println("KEY_PRESSED on Stage : " + keyCode);

        });



        stage.addEventHandler(KeyEvent.KEY_RELEASED, keyEvent -> {

            if(captureKeys) {

                KeyCode keyCode = keyEvent.getCode();

                System.out.println(keyCode);

            }

        });



        stage.centerOnScreen();

        stage.show();

    }

}