vle.extension.decision/src/vle/gvle/modeling/decision/DecisionDrawingArea.cpp

Refactoring DecisionDrawingArea

Refactoring the method on_motion_notify_event from DecisionDrawingArea, to respect the MVC architecture.
Refactoring tooltip function\n\n Refactoring tooltip function to respect MVC architecture
Code clarification\nMoved methods from .hpp to .cpp and improved indentation