CSC223 2004F, Class 10: UML-4

Admin:
* Charlie dropped. Boo Charlie.
* Homework 2 due.
* Homework 3 assigned in vague form.
* Start reading the XP book.  (No, not Windoze XP.  XP as in "eXtreme Programming".) (No, it's not part of the Xgames.)

Overview:
* Sequence diagram example
* Your questions and our answers
* State diagram example
* About the homework

What do the different diagrams suggest?
* See your notes
Which do you prefer?
* Event driven because "it's more object-oriented"
Why are these diagrams better than just writing code?
* Some folks think visually
* Show relationships of stuff far separated in the code

Should worlds know about positions of bugs?
* No
  * Complicated
* Yes
  * Prevents "cheating"
  * World is already keeping track of a lot of stuff.  What's a few bugs more?
  * Bugs don't necessarily control the relationship of themselves to the world (a bug can't necessarily move onto a space with a rock in it)
  * It will make it easier for a bug to query what's around it

Given these design decisions, which technique should we use for drawing the world?
* Probably v3 (event-driven, world keeps track of bugs)

Some design issues
* Should theWorld and aWorldView be merged into one class?  Why or why not?
  * No, because we might want to have different views of the same world (one at large scale, one at small scale)
* Should aWorldView and aDrawingWindow be merged into one class?  Why or why not?
  * aDrawingWindow might change the worldView associated with it (or vice versa)
  * Different drawing windows might draw differently.

Homework for Friday the 24th of September, 2004 c.e.
* Implement a *rough* (working, but need not be perfect) version of theWorld
* The world, when created, should populate itself randomly.
* There are limited kinds of objects that go in the world.
  * Bugs
  * Food
  * Trees (which produce food)
  * BugEaters
  * Rocks
  * BugColonies
  * Pheremones, NONE OF WHICH ARE IN THE WORLD INITIALLY
* Worlds must support listeners.
  * Interesting programming model.  When an object changes, others may care.
  * addListener(WorldListener iCare)
* You need not implement Bugs, Food, Trees, etc.  Use "Stub" classes.

Questions on the reading?
* Quiz Monday!

Happy Slightly-Belated New Year!