CSC223 2004F, Class 20: Swing (2)

Admin:
* Sam Martin rules!
* No classes for the rest of this week
* Does every group have someone who has used Swing?
* New homework!
  * Reading: (Object-Oriented Heuristics) Read the big hardcover book that's not design patterns (due Monday after break)
  * Programming: Build a series of "draw grid element" methods (due Friday after break)
* Russ says:
  * "Oh shit, what did we do wrong now?"
  * "Good luck, I'm thinking about you."

Overview:
* Discussion of new homework
* Some swing design issues
* Examples
* Exercise (maybe)

/Drawing one portion of the world/

* Decisions: 
  * Represent the world as a collection of "grid points" (x,y)
    * Each grid point is, let's say, 1cm by 1cm
  * Each grid point contains
    * Some pheremone (byte) or pheremones
    * Zero or more bugs
    * Zero or more Other objects
    * "Terrain"
* How do we show the world to the user?  Possibly at different scales
* Goal: Draw one grid point
  * "Small" size (for big overview of the world)
  * "Large" size (for close-up overview of a portion of the world)
* Question: What size should our world be?
  * 100 x 100
* Question: About how many bugs?
  * 50 to 500 per colony
* Question: What happens when a bug goes "north" from a northernmost space?  (Similarly, "west" from westernmost and so on and so forth)
  * Death!
  * Wrap around.
  * Blocked/fenced. [*** DA WINNAH ***]
* Question: Can bugs from one colony detect the pheremones of bugs from another colony?
  * Yes, seems more real world
  * A question we will return to later
* Question: Can bugs from one colony distinguish "our pheremones" vs. "their pheremones"?
  * A question we will return to later.
  * Some ants do realease "propaganda pheremones" to confuse their enemies
* Sam's quickly ad-libbed stupid name
  GUBS: Grinnell Universal Bug Simulator
  * Pronunciation: "Foo"
* Sam's oldest joke: What does ghoti spell?  
* Detour: FISH philosophy

Questions about today's homework ...
* How do we test removeRange, which is protected?
  * Flaw in homework?
  * Solution: Subclass vector and make public removeRange

About swing:
* Reminder:
  * Build containers
  * Build things like buttons to add to the containers
  * Build listeners to add to the individual objects
* Some design issues
  * How do you write listeners?  (Examples ButtonOne, ButtonTwo, ButtonThree)
    * Create an anonymous inner class (ButtonsOne)
    * Make the enclosing class a listener (ButtonsTwo)
    * Create a separate class for listeners (ButtonsThree)
  * What are the advantages and disadvantages of each strategy? 
    * Create an anonymous inner class (ButtonsOne)
      * What they did in 152
      * Can get giant and clunky (Disadvantage)
      * Can write one listener for many objects (advantage).
    * Make the enclosing class a listener (ButtonsTwo)
      * Can write one listener for many objects (advantage).
      * Easy access to fields of the enclosing class.
    * Create a separate class for listeners (ButtonsThree)
      * Compartmentalizes (advantage)
      * Can write one listener for many objects (advantage).
  * How do you create the main frame?
    * Explicitly, with new JFrame()  (NewHello.java)
    * By subclassing JFrame()  (HelloFrame.java)
  * What are the advantages and disadvantages of each strategy?

HAVE A GREAT BREAK!