Optimizing cut-and-paste operations in directed-graph editing

This paper describes the implementation strategy for the common editing primitives - select, copy, cut and paste - in a graphical editor for a visual language based on directed graphs. By focusing on minimizing the number of user actions to move parts of a graph structure around the overall structure, this strategy gives the user as much control as possible over which edges will be reconstructed automatically after a cut or paste operation. To minimize the cognitive load on the user, we clearly define the concepts of starting nodes, entry nodes, stopping nodes and exit nodes in the selection. Based on these concepts, we explain how the editing primitives work to try to reconstruct connections between the selection and the rest of the graph.