User Interface with Java Tutorial 2

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User Interface with JavaTutorial 2

• CSPP 51041
• Summer 2003
• 530PM,July 31th
• Ryerson 251

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Todays Topics

• A Voting System
• PTA architecture
• Java Swing
• Event multicast and custom events
• Observer and MVC patterns

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Application

• Need to store votes and candidate information
• Vector
• Hashtable
• Need to store the poll open/close information
• Need to store the update rate information
• Use Timer to trigger the update ActionEvent

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Translation

• Listen to multiple events from multi-sources
• System events
• ActionEvent
• ChangeEvent
• Custom events
• CandidateEvent
• VoteEvent
• TrackingEvent
• Aggregate Application as a variable
• Promulgate events to other interested listeners
• Only Translation handles events!

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Presentation

• Contain multiple objects
• Polling booth objects (1..n)
• Tracking station objects (1..n)
• Control Panel (1)
• Each object listens to several events from
  Translation

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Presentation Polling Booth

• Initial state
• State with candidate added (disabled)
• State with candidate added (enabled)

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Presentation Tracking Station

• Initial state
• State with candidate(s) voted

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Presentation Control Panel

• Initial state

• Open state

• Close state

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Composite Event Multicast Model
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ActionEvent Model 1

• ActionEvents from ControlPanel
• Open_Poll
• Close_Poll
• Application function called at Translation
• Do sth to open poll or close poll
• ActionEvent re-fired at Translation

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ActionEvent Model 2

• ActionEvents from ControlPanel
• Remove_Candidate
• Reset_Candidate
• Update
• Application function called at Translation
• Remove candidates
• Reset votes
• TrackingEvent fired at Translation
• ActionEvent fired at Translation for
  Remove_Candidate

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ActionEvent Model 3

• ActionEvent from application
• Update
• Fired by timer
• TrackingEvent fired at Translation

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ChangeEvent Model

• ChangeEvent from ControlPanel
• Change_Updaterate
• Application function called at Translation
• Stop timer if rate60
• Start timer otherwise
• ActionEvent(Update) fired if timer started

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CandidateEvent Model

• CandidateEvents from ControlPanel
• Add_Candidate
• Application function called at Translation
• CandidateEvent re-fired at Translation
• PollBooth adds new button

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VoteEvent Model

• VoteEvent from PollBooth
• Vote
• Application function called at Translation
• TrackingEvent fired at Translation if updaterate
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