A consumed event is being delivered to handler, that's a bug right?

John Hendrikx john.hendrikx at gmail.com
Sun May 28 10:05:19 UTC 2023


When I add an onKeyPressed event handler that consumes all keys, and a 
EventType.ROOT handler that monitors events, this 2nd handler still sees 
KEY_PRESSED events which are consumed.  Note the 3rd line in the output 
where a consumed = true event is being delivered.

Output:

KeyPressedHandler KeyEvent [source = javafx.scene.Scene at 36dbf594, target 
= Button at 5dd3d27e[styleClass=button]'111', eventType = KEY_PRESSED, 
consumed = false, character =  , text = f, code = F]
Main KeyEvent [source = javafx.scene.Scene at 36dbf594, target = 
Button at 5dd3d27e[styleClass=button]'111', eventType = KEY_PRESSED, 
consumed = false, character =  , text = f, code = F]
RootHandler KeyEvent [source = javafx.scene.Scene at 36dbf594, target = 
Button at 5dd3d27e[styleClass=button]'111', eventType = KEY_PRESSED, 
consumed = true, character =  , text = f, code = F]
RootHandler KeyEvent [source = javafx.scene.Scene at 36dbf594, target = 
Button at 5dd3d27e[styleClass=button]'111', eventType = KEY_TYPED, consumed 
= false, character = f, text = , code = UNDEFINED]
RootHandler KeyEvent [source = javafx.scene.Scene at 36dbf594, target = 
Button at 5dd3d27e[styleClass=button]'111', eventType = KEY_RELEASED, 
consumed = false, character =  , text = f, code = F]

Code:

     public static class App extends Application {
       @Override
       public void start(Stage primaryStage) {
         Button button1 = new Button("111");

         HBox hBox = new HBox();
         hBox.getChildren().addAll(button1);
         Scene scene = new Scene(hBox, 300, 300);

         scene.addEventHandler(KeyEvent.KEY_PRESSED, e -> {
           System.out.println("KeyPressedHandler " + e);
         });
         scene.addEventHandler(EventType.ROOT, e -> {
           if(e instanceof KeyEvent) {
             System.out.println("RootHandler " + e);
           }
         });
         scene.setOnKeyPressed(e -> {
           System.out.println("Main " + e);
           e.consume();
         });

         primaryStage.setScene(scene);
         primaryStage.show();
       }

       /**
        * @param args the command line arguments
        */
       public static void start(String[] args) {
         App.launch(args);
       }
     }

--John



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