Question

In the application above I have a tabpane (the one with “age”, “gender” and “zipcode”) where each tab contains a VBox. The VBox is split in two:

The upper part of the VBox lets you view a list of lists, the lower part of the VBox contains a menu that allows you to change the list of lists.

The button in the lower part of the VBox updates the aforementioned list of lists. I want the upper node in the VBox to be updated anew when the underlying lists are changed.

The relevant code snippet might be

Node createHierarchySplitMenu(HierarchiesFromFile hierarchies, String hierarchyName){

    VBox vBox = new VBox();
    vBox.getChildren().add(createHierarchyScrollPane(hierarchies, hierarchyName));
    vBox.getChildren().add(createHierarchyMenu());

    return vBox;
}

When the button in the node in the lower part of the VBox (created by createHierarchyMenu()) I want createHierarchyScrollPane() to be called again to show the new list of lists. How do I do that?

Is there a regular pattern/way of updating one node from another (when they are at the same level.)?

What have you tried? Nothing worth mentioning- I am stuck.

If you need more info, please ask. Didn’t want to bog you down with code.

Answer 1

From what I understand the solution can be next:

1. Create class to handle createHierarchyScrollPane():

   private class HierarchyScrollPane extends ScrollPane  {
   
       public void update(HierarchiesFromFile hierarchies, String hierarchyName) {
            // code from createHierarchyScrollPane() which works with "this" instead of new Scroll Pane
       }
   }
   

2. Pass instance to createHierarchyMenu():

   Node createHierarchySplitMenu(HierarchiesFromFile hierarchies, String hierarchyName){
   
       VBox vBox = new VBox();
   
       ScrollPaneUpdate hsp = new HierarchyScrollPane();
       hsp.update(hierarchies, hierarchyName);
       vBox.getChildren().add(hsp);
       vBox.getChildren().add(createHierarchyMenu(hsp));
   
       return vBox;
   }
   

3. Somewhere in createHierarchyMenu():

   public void createHierarchyMenu(final HierarchyScrollPane hsp) {
        // ...
        Button btnSetMin = new Button("Set Min");
        btnSetMinsetOnAction(new EventHandler<ActionEvent>() {
           public void handle(ActionEvent t) {
                // your code for data update
                hsp.update(hierarchies, hierarchyName);
           }
        }); 
   }