Question

I am trying to hide/unhide a submenu item (menumanager) from the context (popup menu)
when specific node is selected/not selected in the tree.

Although the setVisible methods triggered as expected it doesn’t effect.

The Code:

TreeViewer tViewer;

tViewer = new TreeViewer(parent, SWT.BORDER | SWT.MULTI | SWT.V_SCROLL);

tViewer.setLabelProvider(new WorkbenchLabelProvider());
tViewer.setContentProvider(new BaseWorkbenchContentProvider());
tViewer.setInput(viewFactory.getInstance().getRoot());      


final MenuManager menuMain = new MenuManager("Main",null);
menuMain.add(mActionClose);


MenuManager menuManager = new MenuManager("#PopupMenu", "contextMenu");
menuManager.add(menuMain);


menuManager.addMenuListener(new IMenuListener() {           
    public void menuAboutToShow(IMenuManager manager) {             

        //Get the selected node in tree
        IStructuredSelection selection = (IStructuredSelection) tViewer.getSelection();

        if (!selection.isEmpty()) { //If something selected
            NNodeBase ob = (NNodeBase) selection.getFirstElement(); //Get the base class of node                                    

            if (!(ob instanceof NTMModel)) {                        
                menuMain.setVisible(false);                     
            }
            else
                menuMain.setVisible(true);                      
        }
    }
});


Menu menu = menuManager.createContextMenu(tViewer.getControl());
tViewer.getControl().setMenu(menu);

Answer 1

You must set the manager to recreate the menu before it is shown:

menuManager.setRemoveAllWhenShown(true);

Then, in menuAboutToShow() you add the items, testing the condition you need:

if ((ob instanceof NTMModel)) {
    menuManager.add(mActionClose);
} else {
    // don't show the menu item
}

You don’t need menuMain anymore.