Drag/drop external object to org diagram

When a node is dragged from goXam palette to the diagram and hovers on top of a node, the node turns to a highlighted color. This is done by setting DropOntoEnabled="True" dragging tool property and make the NodeTemplate background bind to a converter and this works. However, when a node is dragged from a treeview, such as RadTreeView from telerik, and hovers on top of the org node, the converter does not seem to work. What do I need to do to make the node change color when an external object is hovered on it?

In your DragOver event handler you can convert the mouse position to model coordinates by calling myDiagram.Panel.TransformViewToModel. Then you could call myDiagram.DraggingTool.DragOver (note: this is a protected method, so you’ll need to subclass the DraggingTool in order to get access).

DraggingTool.DragOver is the same method that is called during a drag from a Palette to a Diagram. So if DraggingTool.DropOntoEnabled is true and if ConsiderDragOver returns true, it will set Part.IsDropOntoAccepted to true, to which your DataTemplate can bind the appearance of some element.