You can grasp the idea of bridge pattern and see real life examples in code and class diagrams.

1. BRIDGE PATTERN
“ decoupling an abstraction from its implementation ”
Jang,Taeksoon
(NHN NEXT)
Wednesday, March 26, 14

2. MOTIVATION
- Suppose an abstraction should have different implementation
- Simple implementation would just extend the object itself
-Then, inheritance binds an implementation to the abstraction
- When a class changes often, you should change all classes
“ Bridge Pattern helps minimize changes in class ”
Wednesday, March 26, 14

3. BRIDGE PATTERN DEFINED
- Separate abstraction and implementation
Class itself : Abstraction
What class can do : Implementation
Wednesday, March 26, 14

4. PARTICIPANT
Abstraction : defines abstract interface and maintains the implementor
reference
Refined Abstraction : extends the interface defined by abstraction
Implementor : defines the interface for implementation classes
Concrete Implementor : implements the Implementor interface
Wednesday, March 26, 14

5. EXAMPLE & CODE
[ Requirement 1 ]
“ I need a program
that can draw circles and rectangles.“
Wednesday, March 26, 14

6. EXAMPLE & CODE
[ WhatYou Do ]
Wednesday, March 26, 14

7. EXAMPLE & CODE
[ Requirement 2 ]
“ I want shapes to be colorful, blue and red! ”
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8. EXAMPLE & CODE
[ WhatYou Do ]
in progress....
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9. HERE COMES
BRIDGE PATTERN !!!
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10. EXAMPLE & CODE
[ WhatYou Do ]
Wednesday, March 26, 14

11. EXAMPLE & CODE
[ Requirement 3 ]
“ I honestly want Green color andTriangle.“
(oh yes....)
Wednesday, March 26, 14

12. EXAMPLE & CODE
[ WhatYou Do ]
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13. EXAMPLE & CODE
Abstraction
Implementation Client
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14. REAL WORLD EXAMPLE
- GUI Framework
Separate Window abstraction from
Window implementation
for Linux,Windows, or Mac OS.
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15. REAL WORLD EXAMPLE
ex) Java AWT (Abstract WindowToolkit)
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16. BENEFIT OF BRIDGE PATTERN
- Avoid binding between abstraction and implementation
=> Able to select implementation at run time
- Reduction in the number of sub classes
- Abstraction and Implementation can be varied independently
- Cleaner code without ‘if’ or ‘switch’ statement
Wednesday, March 26, 14

17. ADAPTER VS BRIDGE
Adapter
- meant to change the interface of an existing object
- intended to make unrelated classes work together
- My Code + Someone else’s Code
Bridge
- intended to decouple abstraction from its implementation
- Entirely My Code and My Structure
Wednesday, March 26, 14