I saw a reply from michael:"there's a hook method in the tool behavior provider that allows to change the appearance of a shape when it is selected (getSelectionInfoForShape)".
But it can only change color and lineStyle...
Michael Wenz Messages: 1661 Registered: July 2009 Location: Walldorf, Germany
for that I guess you would need to trigger a refresh of the decorators via
refreshRenderingDecorators on the DiagramBehavior instance of your editor.
While providing the decorators for a shape you need to check if the shape is
selected before adding decorators.