I have a very strange issue dealing with GraphLinksModel: link is deleted (by pressing Del) only when it was selected with right mouse button click. Can you give me any ideas why this happens?
Are you saying that the problem is that when the user clicks on a Link with the left mouse button, it does not become selected? Or that it is selected but then the user cannot delete it? Or something else?
Does a left mouse button click select a node?
When user presses the left button the link becomes selected(OnSelectionChanged is invoked and SelectionAdorner works), but then user is not able to delete that node by pressing Del (OnDelete() method of CommandHandler is not invoked until link is selected mouse right button click).
Then that seems very mysterious to me too – are you sure you are not changing Part.CanDelete() or Part.Deletable dynamically when you do a left click but not a right click?
Have you overridden any methods on any classes? What event handlers have you defined?
Is there anything you can do to help me reproduce the problem?
It turned out to be a problem with keyboard focus.
Everything became OK when Focusable=false was set to parent control.