dynamic context menu on tree

[nakhli]

I am trying to modify the visible context menu items depending on the selected node in a tree.
I tried using

Tree.addBeforeShowContextMenuHandler(BeforeShowContextMenuEvent.BeforeShowContextMenuHandler)

but it is not getting called before the context menu is shown.

Any ideas on how to achieve this? Thank you.

[PhiLho]

+1 (for Beta3)

I need to customize the context menu depending on the clicked node, but the method isn't called.
I explored a bit the sources, but I don't see where any BeforeShowContextMenuEvent is created.
Is it on the TODO list of Sencha?

[PhiLho]

For the record, there is a workaround, using low-level Dom events:

  private class NodeCell extends SimpleSafeHtmlCell<String>
  {
    // http://stackoverflow.com/questions/5185078/what-is-the-list-of-valid-gwt-dom-consumed-events-for-cells
    private static final String NODE_EVENT_CLICK = "click";
    private static final String NODE_EVENT_CONTEXTMENU = "contextmenu";

    /**
     * Constructor, using a default renderer and defining the events we are interested in.
     */
    public NodeCell()
    {
      super(SimpleSafeHtmlRenderer.getInstance(), NODE_EVENT_CLICK, NODE_EVENT_CONTEXTMENU);
    }

    @Override
    public void onBrowserEvent(
        Context context, Element parent, String value, NativeEvent event,
        ValueUpdater<String> valueUpdater)
    {
      super.onBrowserEvent(context, parent, value, event, valueUpdater);
      if (event.getType().equals(NODE_EVENT_CLICK))
      {
        handleClick(context, value);
      }
      else if (event.getType().equals(NODE_EVENT_CONTEXTMENU))
      {
        handleContextMenu(context, value);
      }
    }
  }

It is not perfect as we get a Context, ie. only a string id, not the data associated to a node, but that's better than nothing and it allows to change the context menu state (disable, hide items) before displaying it.
Note also the management of click on a node, as the select event is fired even if we just open a parent node: if we associate a complex display to such parent, we don't necessarily want to display it on each step of navigating the tree.
Think "file explorer" where you might want to go down a hierarchy without displaying the list of files of each level, for example.
If GXT 3 could distinguish the two events (click to fold / unfold a node, click on the node itself) at a higher level, it would be nice.

[mspronk]

I ran into a similar need to customize the context menu and based on another thread on this forum I was able to accomplish what I needed by selectively showing and hiding (or in my case enabling and disabling) previously created menu items.

final TreePanel<ModelData> tree = new TreePanel<ModelData>(store);

final Menu contextMenu = new Menu();  
MenuItem insert = new MenuItem();  
insert.setText("Insert New List");  
insert.setIcon(Resources.ICONS.addIcon());  
insert.addSelectionListener(new SelectionListener<MenuEvent>() {  
	public void componentSelected(MenuEvent ce) {  
		ModelData folder = tree.getSelectionModel().getSelectedItem();  
		// Do stuff  
	}  
});  
contextMenu.add(insert);  
	  
MenuItem remove = new MenuItem();  
remove.setText("Remove Selected List");  
remove.setIcon(Resources.ICONS.removeIcon());  
remove.addSelectionListener(new SelectionListener<MenuEvent>() {  
	public void componentSelected(MenuEvent ce) {
		List<ModelData> selected = tree.getSelectionModel().getSelectedItems();  
	        for (ModelData sel : selected) {  
			// Do stuff  
		}  
	} 
});  
contextMenu.add(remove);  
tree.setContextMenu(contextMenu);

// Enable/disable applicable context menu items depending on the type
tree.addListener(Events.ContextMenu, new Listener<TreePanelEvent<ModelData>>() {
	public void handleEvent(TreePanelEvent<ModelData> be) {
		if (be.getItem() instanceof SubscriberList) {
			// If it's a list
			contextMenu.getItems().get(0).disable();
 			contextMenu.getItems().get(1).enable();
 		} else {
 			// If it's a client
 			contextMenu.getItems().get(0).enable();
 			contextMenu.getItems().get(1).disable();
		}
	}
});

[PhiLho]

What is this TreePanel? I don't find it in Eclipse.

[sven]

http://www.sencha.com/forum/showthre...er-gets-called