How do I create a scrollable context menu in JavaFX?

Question

I have a situation where a context menu can potentially have hundreds of menu items added to it. By default a context menu will show scroll buttons at the top/bottom of the popup, but it takes the full height of the screen. I tried setting the maxHeight and prefHeight values, but this had no effect.

Ideally I would like to show a scroll bar instead of scroll buttons at the top and bottom (ie put it in a scroll pane).

Here is a snippet of the code that I am currently have:

ContextMenu menu = new ContextMenu();
menu.setMaxHeight(500);
menu.setPrefHeight(500);
for(TabFX<T> tab : overflowTabs) {
  MenuItem item = new MenuItem(tab.getTabName());
  if (tab.getGraphic() != null) item.setGraphic(tab.getGraphic());
  item.setOnAction(e -> {
    select(tab);
    layoutTabs();
  });
  menu.getItems().add(item);
}
Point2D p = overflowBtn.localToScreen(0, overflowBtn.getHeight());
menu.show(overflowBtn, p.getX(), p.getY());

Is there a workaround for this?

Answer 1

I had the same issue and I solved it by using the javafx.stage.Popup class with a ScrollPane whichs contains a VBox and that holds the menu items.

Popup popup = new Popup();
VBox vBox = new VBox();
for (int i = 0; i < 4; i++)
{
    Button item = new Button("item " + i);
    item.setOnAction(...);
    vBox.getChildren().add(item);
}
ScrollPane scrollPane = new ScrollPane(vBox);
scrollPane.setMaxHeight(500);//Adjust max height of the popup here
scrollPane.setMaxWidth(200);//Adjust max width of the popup here
popup.getContent().add(scrollPane);
popup.show(rootWindow);

Note: As you can not put a MenuItem into a VBox, I have used a Button in the example because it has the setOnAction(...) method. But you can use whatever you like :)