how to remove folder icon in tree grid
How to remove folder icon in tree grid. All the hierarchy should display only names.
That's GXT 2 code, you are in the GXT 3 section, perhaps that's the reason why you hadn't an answer. I jumped directly into GXT 3 code, so I am not competent to answer GXT 2 questions...
Try subclassing TreePanel and override the method calculateIconStyle(M) to return null. According to TreePanelView, it should leave out the icon, though it may still allocate space for it - you'll need to use css to correct that.