Exercise 4

Consider a simple graphical drawing editor:

With the mouse, the user may select a symbol from the palette, and place it on the drawing. The symbols may be moved around or deleted.

a) Identify the classes needed to represent the symbols and their positions on the drawing area.

Hints:

Solving exercises a, b and c in parallel is a good idea.
You don't have to take into account how properties like size and colour are edited.

b) Design the object relations between the instances of the classes above.

c) Suggest some of the attributes and operations for the identified classes.