监听转换变化

Question

有没有办法监听转换变化？例如，当立方体转动时，我想得到通知。特别是我对getLocalToSceneTransform感兴趣。

这是我的尝试：

@Override
public void start(Stage primaryStage) throws Exception {
    final Group root = new Group();
    final Scene scene = new Scene(root);

    final Box cube = new Box(1, 1, 1);
    cube.setRotationAxis(Rotate.Y_AXIS);
    cube.setMaterial(new PhongMaterial(Color.RED));
    root.getChildren().add(cube);
    cube.getLocalToSceneTransform().addEventHandler(TransformChangedEvent.TRANSFORM_CHANGED, (e) -> {
        // never get called
        System.out.println("Transformation has changed");
    });

    final Camera camera = new PerspectiveCamera(true);
    camera.setTranslateZ(-4);
    scene.setCamera(camera);

    final Timeline turnCube = new Timeline();
    turnCube.getKeyFrames().add(new KeyFrame(Duration.seconds(0), new KeyValue(cube.rotateProperty(), 0)));
    turnCube.getKeyFrames().add(new KeyFrame(Duration.seconds(5), new KeyValue(cube.rotateProperty(), 360)));
    turnCube.setCycleCount(Timeline.INDEFINITE);
    turnCube.play();

    primaryStage.setWidth(1024);
    primaryStage.setHeight(768);
    primaryStage.setScene(scene);
    primaryStage.show();
}

当立方体转动时，EventHandler 永远不会被调用。

Answer 1

您可以向多维数据集的localToSceneTransformProperty() 添加一个changeListener，以便在多维数据集旋转时收到通知。

cube.localToSceneTransformProperty().addListener((value, oldValue, newValue) -> {
     System.out.println("Transformation has changed");
});