Correctly compute the right diagram dimensions to fit all shapes
Gracefully deal with errors that occur during image loading
Make diagrams resizeable by Shift-rightclicking while in edit mode.
Make diagram shapes draggable with the mouse in editing mode.
Use Del key to remove shapes from the scene
Set appropriate cursors for the different diagram actions
Add commands for creating diagram shapes
Delete shapes only while in editing mode
Propagate diagram connector events up to parent
Import comments from model
Make the diagram's image's text error padding a class variable
Remove referencing connectors when removing a diagram shape
Add debugging facilities
Update connectors' point coordinates before computing their positions
Rename function to avoid name clash