Avoiding Powerpoint Karaoke Dr Stephen Marshall University Teaching Development Centre [e-mail]

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Avoiding Powerpoint KaraokeDr Stephen
MarshallUniversity Teaching Development
Centrestephen.marshall_at_vuw.ac.nz

• Design Examples

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Object

• Behaviour
• Each object has some behaviour that it supplies
• A point in a graphics system get coordinates,
  add to another point
• A bank account withdraw, deposit, calculate
  interest, print statement
• Every object can also be created and destroyed
• What you get
• An obkects methods can access its private state
• If you need to reprogram an objects behaviour,
  you only need to reprogram that object, not the
  whole system (maybe)
• If other objects need to make use of a behaviour,
  they should use that objects public interface
• Identity
• Each object can be distinguished from every other
  object
• Two bank accounts with the same name and balance
  are not the same account
• Withdrawals and deposits in one dont affect the
  other
• You can certainly have two accounts with teh same
  name
• Different banks can have accounts with the same
  number

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Example Small Public Squares

• Problem
• A town needs public spaces. How big should they
  be?
• Context
• You are designing an Identifiable Neighbourhood
• Forces
• The square should be full of life
• People should enjoy just hanging out
• Solution
• Make squares no more than 15 or 20 metres across

• Known Uses
• Cuba Street
• Manners Mall
• Related Patterns
• Pedestrian Density
• Activity Pockets
• Positive Outdoor Space
• Building Fronts
• Stair Seats
• Something Roughly in the Middle

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Issues in Composite

1. Explicit Parent references
2. Sharing components
3. Maximising the Component interface
4. Declaring the child management operations
5. Should Component implement a list of Components?
6. Child ordering
7. Caching to improve performance
8. Who should delete components?
9. Whats the best data structure for storing
   components?