SDK Package: TFS Source Control Explorer extension

Hi,

I'm writing an extension for Source Control Explorer in MSVS 2010 through SDK Package which will add an additional context menu item.

I've already figured to add an item to the context menu. What I'm currently interested in is how to get the information about selected folder (or branch or something) in Source Control Explorer, i.e. how to know which object have I selected in Source Control Explorer window and going to perform an action on it?

Thanks in advance for any help,