Creates a interface that defines a variable container...
Creates a interface that defines a variable container
- A variable container is an entity that can eventually accomodate a variable (for example, from a menu or d'n'd)
- The interfaces declares canDrop() method, that will be used to create a menu for a variable containing only the containers available for it, or to enable/disable d'n'd of this variable on a container
- Each visualization widget is a variable container, so it implements canDrop() method
