SerializableGraphSourceBase and undo

[Rajkumar]

I derived out my class based on SerializableGraphSourceBase.

When I add shape to diagram using AddNode, and I try to undo, the shape still exists on the diagram.

How do i specify so as to consider the AddNode action for undo redo ?

[Milena]

Hi Rajkumar,

When using GraphSourceBase and add a shape through AddNode(), before performing the undo method 
you should notify the diagram for that action and update the Undo/RedoStack of the RadDiagram. You can achieve this by using UndoRedoService and UndoableDelegateCommand like so: 

private void AddShape (...)

{

     ....

   graphSource.AddNode(newShape);

 

   UndoableDelegateCommand addShape = new UndoableDelegateCommand(CommandNames.AddShape,

    c =>

    {

        graphSource.AddNode(newShape);

    },

    c =>

    {

        graphSource.RemoveItem(newShape);

    });



   this.diagram.UndoRedoService.AddCommand(addShape);           

}

You can notice that I've used:
- static class CommandNames for the name of the UndoableDelegateCommand and 
- AddNode() and RemoveItem() which comes from SerializableGraphSourceBase. 
This will allow you to take advantage of the built-in Undo/Redo functionality of the diagram and just register the new action.

For your convenience I implemented this approach in the attached project. Please take a look at it and let us know if it works for you.

Regards,
Milena
Telerik