The Java Display Manager (JDM)

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The Java Display Manager (JDM)
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JDM Widgets

• Many JDM widgets correlate with medm widgets
• Button, MenuButton
• Bar, Slider, Meter, Indicator
• Cartesian Plot, Stripchart (8 pens)
• Label, Text Field
• Bit Field

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JDM Widgets (contd)

• More widgets
• Wheelswitch
• Animated canvas (double-buffered)
• Each widget is a Java bean

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Building JDM Screens

• Screens can be built with any Java IDE that
  supports Java beans
• Java introspection allows IDE to learn about bean
  attributes

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Run-time JDM

• Runs on JVM 1.1.8 and higher
• Bean serialization enables execution of screens
  through a browser
• Screens can be executed directly as applets

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JDM Communication Schematic
JDM Client
CDEV Gateway
IOC
IOC
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JDM summary

• Positives
• Provides great flexibility run-time behavior
• Widgets are easily extensible through inheritance
• Drawbacks
• Screens are fat
• Administration is not straightforward