Student Originated Software 1997-1998 Fall Quarter
		A Software Engineering Course at The Evergreen State College

OOP (Smalltalk) - Tuesday, Week 3 •  What we've done so far & what I expect you to know now •  Some key (troubling) concepts •  What you learned ... from class Point •  Start working (in groups) on the assignment  (9:30) •  Present solution ideas (10:00) •  Some (perhaps new) ideas  (if time) •  Lab....  work on the assignment.  (10:45)     If done, do 10.9 to hand in and explain why this would be inefficient.  then start Ch. 11.   So far.... •  Concepts of OOP class, instances, messages, message selector, receiver, methods, class methods, instance methods, information hiding, class hierarchy,  subclass, inheritance, super, self, method lookup, OOP paradigm •  Smalltalk language basics read Smalltalk code, write simple expressions •  Visual Works Programming Environment find your way around •  An example class (Point) •  Thursday - your first programming assignment due Some key (troubling) concepts classes, instances, class methods, instance methods A class is like a factory -- the template for new objects. This is how storage allocation is done! methods protect state (variables); methods encapsulate behavior; What you learned ...from Ch. 7 & 8 -- esply class Point More on class Point (Ch 8) Still More on Class Point What you learned from Class Point •  Objects hide (protect!) their state •  Objects encapsulate behavior (you need know only an object's specification -- what it does;  not how it does it! e.g.,  the interface & implementation sides of a stack) •  A class can have class methods as well as instance methods.  (x:y: and x:y:!) •  newPoint:  An internal representation maybe changed w/o changing behavior. •  Inspectors allow direct access to the instance variables inspected  -- and break encapsulation! The assignment (9:30) Divide into 6 groups  (labaids work together) Appoint a presenter. Everyone warm up on 10.1 and 10.4.... Groups 1,2 do 10.6;  3,4 do 10.7;   5,6 10.10. Do not work in a group with your Smalltalk lab partner! At 10am - present your solution;  10 min per problem. One group present; the other group comment & critique. Additional Concepts.... Class Hierarchy (Ch. 11 - inheritance)