Javafx 2.0 - Get ContextMenu Parent Node in EventHandler

Question

I am writing a javafx UI and would like to get the owner Node of a contextMenu from a eventHandler for the MenuItem that was clicked on.

My Code:

TabPane tabPane = new TabPane();
Tab tab1 = new Tab();
Tab tab2 = new Tab();

tabPane.getTabs().addAll(tab1,tab2);

ContextMenu contextMenu = new ContextMenu();
MenuItem menuItem = new MenuItem("Do Some Action");

menuItem.setOnAction(new EventHandler<ActionEvent>(){
    @override
    public void handle(ActionEvent e){
        // Get the tab which was clicked on and do stuffs with it
    }
});

contextMenu.getItems().add(menuItem);

for(Tab tab: tabPane.getTabs()){
    tab.setContextMenu(contextMenu);
}

What I would like to do is get a reference to the tab that had it's contextMenu selected.

I was able to get a reference to what appears to be the ContextMenu of the MenuItem with the following code inside of the handle(ActionEvent e) method for the menuItem eventHandler:

ContextMenu menu = ((ContextMenu)((MenuItem)e.getSource()).getParentPopup());

My idea from there was to use ContextMenu's .getOwnerNode() method on menu and then have a reference to the tab, but when running that I get a reference to an item that I can't make sense of.

The toString() method for the object returned by .getOwnerNode() returns "TabPaneSkin$TabHeaderSkin$3@14f59cef" which I can't figure out the meaning of.

Is my approach of trying to work my way up the chain until I get to the node correct or is there an entirely different approach that will work better?

All I need to have is the functionality of a ContextMenu, and when the MenuItem is clicked on, I need to have a reference to the tab for which the ContextMenu was selected so I can do cool stuffs with it.

jewelsea jewelsea · Accepted Answer · 2013-05-28T20:36:11

Create a ContextMenu for each tab.
Make each tab final.
Directly reference the final tab in the menu item event handler for the context menu.

Here is a code snippet:

final Tab tab = new Tab("xyzzy");
ContextMenu contextMenu = new ContextMenu();
MenuItem menuItem = new MenuItem("Do Some Action");
menuItem.setOnAction(new EventHandler<ActionEvent>(){
  @Override public void handle(ActionEvent e){
    tab.setText("Activated by User");
  }
});

Every time the user right clicks on a tab header and selects the "Count Click" menu, the content of the related tab is updated with a count of the number of licks counted so far for that tab.

clickcounter

Here is an executable sample:

import javafx.application.*;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.*;
import javafx.stage.Stage;

public class TabContext extends Application {
  @Override public void start(Stage stage) {
    TabPane tabPane = new TabPane();

    tabPane.getTabs().addAll(
      createTab("xyzzy",   "aliceblue"),
      createTab("frobozz", "blanchedalmond")
    );

    stage.setScene(new Scene(tabPane));
    stage.show();
  }

  private Tab createTab(String tabName, String webColor) {
    final Label content = new Label("0");
    content.setAlignment(Pos.CENTER);
    content.setPrefSize(200, 100);
    content.setStyle("-fx-font-size: 30px; -fx-background-color: " + webColor + ";");

    final Tab tab = new Tab(tabName);
    tab.setContent(content);

    ContextMenu contextMenu = new ContextMenu();

    MenuItem menuItem = new MenuItem("Count Click");
    menuItem.setOnAction(new EventHandler<ActionEvent>(){
      @Override public void handle(ActionEvent e){
        content.setText(
          "" + (Integer.parseInt(content.getText()) + 1)
        );
      }
    });

    contextMenu.getItems().add(menuItem);

    tab.setContextMenu(contextMenu);

    return tab;
  }

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

Alternately to using an anonymous inner class this way, you could create an EventHandler subclass with a constructor that includes the Tab for which the EventHandler is attached.

class TabContextMenuHandler implements EventHandler<ActionEvent> {
  private final Tab tab;

  TabContextMenuHandler(Tab tab) {
    this.tab = tab;
  }

  @Override public void handle(ActionEvent event) {
    tab.setText("Activated by User");
  }
}

Javafx 2.0 - Get ContextMenu Parent Node in EventHandler

1 Answers