Create a couple of RadPanes in one RadPaneGroup so that it shows the tab headers. Create another RadPaneGroup with a RadPane.
Put a RadTreeView in the first RadPane, populate with some items.
OK, select 1 of the TreeView items.
1. If you click on the RadPane header in the separate group to activate it, the selected TreeView item will switch to "SelectedUnfocused" state (turns gray).
2. Click back on the TreeView item to focus it again.
3. This time, click on the other RadPane tab in the same group. Click back on the pane tab header with the TreeView. In this case, the TreeView item is still blue (in a SelectedFocused state). But it actually is not "focused". At least not keyboard focused, so it should be gray.
Code I found :)
If you look in Docking.PaneHeader.OnMouseLeftButtonDown(), when the user selects a RadPaneGroup, Focus() will be called on that group. That is why the RadTreeViewItem turns gray in the first test.
But no such "Focus()" call can be found when only a RadPane is activated. To fix, I put a Focus() call in RadDocking.ActivePaneChanged event, but you may want to do it differently. :)