how to reorder buttons within a vbox

[craig peddie]

Hi,

I working on a gui that has a fixed display size using a border pane layout. The left layout pane is a vbox that holds five buttons, with a button on the bottom that remains fixed in place and provides scroll up/down capability. there are a total of 8 functions available to user in the vbox, and I want to be able to scroll through them using the scroll buttons. This will change the 5 buttons that are displayed in the vbox. I've tried clearing out all the children of the vbox and then adding them back in different order, but I keep getting errors about addiing duplicate children. I'm sure there must be a simple way to do this....anyone have any pointers?

Thanks

[Darryl Burke]

It's hard to know what might be wrong with only that description. To get better help sooner, post a SSCCE (Short, Self Contained, Correct (Compilable), Example) that demonstrates the problem.

Also, when seeking help with errors, it's good practice to copy and paste the exact error message here (or the stack trace, for an Exception thrown at runtime). also identify which line is associated with the error.

[craig peddie]

Here is brief snippet of the code I've got:

  

private void displayNavButtons() {
    	
		buttonArray[0] =  poiButton;              // these entries in the array are references to buttons that loaded from the fxml file
		buttonArray[1] =  musicButton ;
		buttonArray[2] =  phoneButton;
		buttonArray[3] =  msgingButton;
		buttonArray[4] = videoButton ;
		buttonArray[5] =  weatherButton;
		buttonArray[6] =  ownersManualButton;
     	
    	navPanel.getChildren().clear();                // clear out the buttons that are currently being displayed
    	for ( int i=topButtonIndex, j=0; j < 5 ; j++ ) {
     		navPanel.getChildren().add(buttonArray[i]);         //add buttons back to the VBox starting at where the current scroll index is
    		
    		
    		System.out.println("adding button["+i+"]= "+buttonArray[i]);
    		
    	}
    	navPanel.getChildren().add(navPanelScroll);          // add the scroll buttons (a grid pane)back to the bottom of the VBox
    	
    	
    	
     }

Here is the error dump when I try and scroll the buttons:
Glass detected outstanding Java exception at -[GlassViewDelegate sendJavaMouseEvent:]:src/com/sun/mat/ui/GlassViewDelegate.m:543
Exception in thread "JavaFX Application Thread" java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(FXMLLoader.java:1449)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:69)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:217)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:170)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:38)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:37)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:53)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:28)
at javafx.event.Event.fireEvent(Event.java:171)
at javafx.scene.Node.fireEvent(Node.java:6867)
at javafx.scene.control.Button.fire(Button.java:179)
at com.sun.javafx.scene.control.behavior.ButtonBehavior.mouseReleased(ButtonBehavior.java:193)
at com.sun.javafx.scene.control.skin.SkinBase$4.handle(SkinBase.java:336)
at com.sun.javafx.scene.control.skin.SkinBase$4.handle(SkinBase.java:329)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:64)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:217)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:170)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:38)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:37)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:53)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:33)
at javafx.event.Event.fireEvent(Event.java:171)
at javafx.scene.Scene$MouseHandler.process(Scene.java:3311)
at javafx.scene.Scene$MouseHandler.process(Scene.java:3151)
at javafx.scene.Scene$MouseHandler.access$1900(Scene.java:3106)
at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1563)
at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2248)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:250)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:173)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:292)
at com.sun.glass.ui.View.handleMouseEvent(View.java:530)
at com.sun.glass.ui.View.notifyMouse(View.java:924)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:75)
at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:279)
at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(FXMLLoader.java:1446)
... 40 more
Caused by: java.lang.IllegalArgumentException: Children: duplicate children added: parent = VBox[id=navPanel]
at javafx.scene.Parent$1.onProposedChange(Parent.java:307)
at com.sun.javafx.collections.VetoableObservableList.add(VetoableObservableList.java:165)
at com.sun.javafx.collections.ObservableListWrapper.add(ObservableListWrapper.java:144)
at com.promptu.parnassusfx.sample.MainController.displayNavButtons(MainController.java:179)
at com.promptu.parnassusfx.sample.MainController.navScrollDown(MainController.java:161)
... 50 more

Is there a better way to do what I'm attempting?

Thanks.....

[Darryl Burke]

craig peddie wrote:Here is brief snippet of the code I've got:

Doesn't help. did you go through the SSCCE page I linked to?

Here's my SSCCE that doesn't show any errors in clearing and adding back 6 buttons to a VBox. It simply works, which is why we need something we can copy and run to see where your code differs.

import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;

public class RemoveAddVBox extends Application {

  private VBox box = new VBox();
  private Button[] buttons = new Button[6];
  private Button click = new Button("Click");

  public static void main(String[] args) {
    Application.launch(args);
  }

  @Override
  public void start(Stage stage) throws Exception {
    for (int i = 0; i < buttons.length; i++) {
      buttons[i] = new Button("Button " + i);
      box.getChildren().add(buttons[i]);
    }
    VBox outer = new VBox(20);
    outer.getChildren().addAll(box, click);
    click.setOnAction(new EventHandler<ActionEvent>() {
      @Override
      public void handle(ActionEvent t) {
        box.getChildren().clear();
        for (int i = 0; i < buttons.length; i++) {
          buttons[i] = new Button("Button " + i);
          box.getChildren().add(buttons[i]);
        }
      }
    });
    Scene scene = new Scene(outer);
    stage.setScene(scene);
    stage.show();
  }
}