Bug 34769 [Navigator] F2/F5 actions not enabled/disabled properly when closing/opening project
bundles/org.eclipse.ui.views/src/org/eclipse/ui/views/navigator/GotoActionGroup.java
upAction = new UpAction(frameList);
		goToResourceAction = new GotoResourceAction(navigator, ResourceNavigatorMessages.getString("GoToResource.label")); 
	}	
	public void updateActionBars() {
		ActionContext context = getContext();
		boolean enable = false;
		
		
		
		
		if (context != null) {
			IStructuredSelection selection =
				(IStructuredSelection) context.getSelection();
	
			if (selection.size() == 1) {
				Object object = selection.getFirstElement();
				if (object instanceof IProject) {
					enable = ((IProject) object).isOpen();
				}
				else
				if (object instanceof IFolder) {
					enable = true;
				}
			}
		}	
		goIntoAction.setEnabled(enable);
		
	}
}