How do I scroll to a certain component in Java FX? - javafx

Question

I need to scroll down to a certain label component in Java FX. How do I do that ? I have ids attached to label component.
<ScrollPane>
<VBox fx:id="menuItemsBox">
<Label text="....."/>
<Label text="....."/>
<Label text="....."/>
....
<Label text="....."/>
</VBox>
</ScrollPane>

Answer 1

You can set the scrollPane's vValue to the Node's LayoutY value. Since the setVvlaue() accepts value between 0.0 to 1.0, you need to have computation to range your input according to it.
scrollPane.setVvalue(/*Some Computation*/);
This must be set after the stage's isShowing() is true.
Complete Example
public class Main extends Application {
#Override
public void start(Stage primaryStage) throws Exception {
ScrollPane pane = new ScrollPane();
VBox box = new VBox();
IntStream.range(1, 10).mapToObj(i -> new Label("Label" + i)).forEach(box.getChildren()::add);
pane.setContent(box);
Scene scene = new Scene(pane, 200, 50);
primaryStage.setScene(scene);
primaryStage.show();
// Logic to scroll to the nth child
Bounds bounds = pane.getViewportBounds();
// get(3) is the index to `label4`.
// You can change it to any label you want
pane.setVvalue(box.getChildren().get(3).getLayoutY() *
(1/(box.getHeight()-bounds.getHeight())));
}
}