Java Power Tools: A Foundation for Interactive GUI Exploration Viera K. Proulx, Richard Rasala, Jeff

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Java Power ToolsA Foundation for
InteractiveGUI ExplorationViera K. Proulx,
Richard Rasala, Jeff RaabHCI 2001 Conference
New Orleans, LAAugust 10, 2001www.ccs.neu.edu/t
eaching/EdGroup/JPTNSF DUE CCLI-EMD 995-0829
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GUI Design Requirements

• Easy installation of GUI components
• Recursive behavior (enable, save contents)
• Robust input processing
• Easy creation of action control gadgets
• Simple yet robust graphics support
• Easy extraction of information from views
• Easy setting of the view contents from the
  program

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Benefits of easy-to-build GUIs

• Programming courses
• Focus stays on algorithmics and OO design
• GUI design process
• Focus is on users needs and expectations
• Learning and exploration
• Easy to provide multiple views of data
• Easy to provide persistent display of current
  state
• Easy to install controls for exploration

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Building GUI with JPT Toolkit

• GUI building (single statement each)
• Create GUI object
• Install GUI object in the display
• Extract information
• Display information

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JPT (Java Power Tools)

• String as communication medium
• Model encodes/decodes String
• View extracts/displays String
• Action button linked to action

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The Stringable Interface

• This interface applies to data models
• Data is Stringable if one can encapsulate its
  state in a String
• All data built in layers from the basic types is
  Stringable
• The data in image or sound files is Stringable
  since one need only capture the file name not the
  detailed data
• Stringable is naturally recursive

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The Displayable Interface

• This interface applies to views
• A view is Displayable if its user input can be
  encapsulated into a String
• All views that use widgets whose user data can be
  expressed as Strings can recursively be
  interpreted as Displayable
• Note that Displayable captures only the user
  input state not the full state of the view

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Example 1 Simple Adder

• 5 TextFieldViews
• 2 Actions
• Add
• Clear
• Model
• 4 int inputs x, y, z, w
• 1 int output sum

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Example 1 Simple Adder

• TextFieldView
• Construct xTFV
• Install in GUI with annotation X
• int x xTFV.demandInt()
• xTFV.setViewState(x )

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Example 1 Simple Adder

• action
• Construct add action object
• Define function add()
• Install add action as a button in GUI
  ActionsPanel (with given label)
• Link from button to action is automatic

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Key Issues

• Recursion is the king
• Combine simple Displayable GUI components into
  larger Displayable GUI components
• Combine simpler Stringable models into a larger
  Stringable model
• requestObject() setViewState()

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Example 2 Polygon Painter
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Example 2 Polygon Painter
BufferedPanel
Point2DView
Point2DView
ActionsPanel
ArrayPanel of Point2DViews and more
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Example 2 Polygon Painter

• private void paintPoly()
• // get the graphics context to draw the
  polygon
• Graphics2D G window.getBufferGraphics()
  
• Polygon mypoly (Polygon)polygonView.dem
  andObject()
• // set paint color to user color choice
• G.setPaint(color.getColor())
• mypoly.paintPolygon(G)
• repaint()

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PushDown Automata Explorer

• Language aibjck where i j or i k for i gt
  0

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PushDown Automata Explorer

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Turtle Class Explorer

myTurtle.setPaint(0, 0, 255) myTurtle.step(50.0)
myTurtle.turn(60.0) myTurtle.setPaint(255, 0,
255) myTurtle.step(50.0) myTurtle.turn(60.0) my
Turtle.setPaint(255, 0, 0) myTurtle.step(50.0) m
yTurtle.turn(60.0)
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Race Process Priorities
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Race Process Priorities