In this example it is shown how to use a tool already built in another pluggin (extCAD) to inherit from its behaviour and to modify or expand it. In short, it has been implemented a polygon autocompletion feature. The user can draw a polygon and if he/she does it over another existing polygon, the tool takes it into account to follow the boundary between the two plolygons.

The files involved are:

• config.xml.- The extension is defined with the corresponding button and toolbar.
• MyInfoExtension.java.- The class that creates and assigns the tool listener.
• tools/AutoCompletePolygon.java