THE SWING UI TOOLKIT

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THE SWING UI TOOLKIT

• Mostly from The Swing Connection

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SWING TOOLKIT

• 100 Java implementation of components
• Pluggable Look Feel
• customizable for different environments, or
• use Java LF in every environment
• Lightweight components
• no separate (child)windows for components
• allows more variation on component structure
• makes LF possible
• Three parts
• component set (subclasses of JComponent)
• support classes
• interfaces

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OTHER APIs
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UI COMPONENTS
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BUTTONS
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MENUS
JMenuBar
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OTHER COMPONENTS

Border Interface
JApplet
JColorChooser
JComboBox
ImageIcon
JInternalFrame
JDialog
JFileChooser
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OTHER COMPONENTS
JList
JLabel
JScrollBar
JScrollPane
JSlider
JOptionPane
JSplitPane
JTabbedPane
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OTHER COMPONENTS
JTable
JTextArea
JTextField
JToolBar
JToolTip
JTree
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ARCHITECTURE

• Goals
• entirely on Java
• pluggable LF
• model-driven programming
• JavaBeans
• compability with AWT
• Use MVC?
• Model represents the data
• View as a visual representation of the data
• Controller takes input and translates it to
  changes in data

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THE UI DELEGATE

• No reason to separate controller and view
• A separate UI object for defining the
  visualrepresentation and controller behaviour
• the UI delegate

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MODELS

• Data-centric applications
• Separate model interface for every component
• GUI-state models
• up-down state in JButton and subclasses
• application data models
• selection state in JToggleButton and subclasses
• Application programmer can implement his/her own
  data models for existing components
• Shared model definitions

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MODEL SEPARATION

• JSlider uses BoundedRangeModel
• public JSlider(int orientation, int min, int max,
  int value) checkOrientation(orientation)
  this.orientation orientation this.model
  new DefaultBoundedRangeModel(value, 0, min,
  max) this.model.addChangeListener(changeListen
  er) updateUI()
• Calling setModel, application can replace the
  default
• JSlider slider new JSlider()BoundedRangeModel
  myModel new DefaultBoundedRangeModel()
  public void setValue(int n)
  System.out.println("SetValue " n)
  super.setValue(n) )slider.setModel
  (myModel)

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CHANGE NOTIFICATION

• Models implement methods for adding andremoving
  listeners
• Lightweight notification
• only notify
• listener queries about the changes
• e.g. scrollabar dragged
• Stateful notification
• event described the change
• for complex data models
• e.g. changes in the column of table

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LIGHTWEIGHT NOTIFICATION

• ChangeListener with one single method
• public void stateChanged(ChangeEvent e)
• Listening to JSlider
• JSlider slider new JSlider()BoundedRangeModel
  model slider.getModel()model.addChangeListener
  (new ChangeListener() public void
  stateChanged(ChangeEvent e) // need to
  query the model to get updated value...
  BoundedRangeModel m (BoundedRangeModel)e.getSour
  ce() System.out.println("model changed "
  m.getValue()) )

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STATEFUL NOTIFICATION

• Tracking JList selection
• String items "One", "Two", "Three")JList
  list new JList(items)ListSelectionModel
  sModel list.getSelectionModel()sModel.addListS
  electionListener (new ListSelectionListener()
  public void valueChanged(ListSelectionEve
  nt e) // get change information directly
  // // from the event instance... if
  (!e.getValueIsAdjusting())
  System.out.println("selection changed "
  e.getFirstIndex())
  )

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IGNORING MODELS

• Most components provide API to the modeldirectly
• E.g. JSliders method
• public int getValue() return
  getModel().getValue()
• Program can simply do the following
• JSlider slider new JSlider()int value
  slider.getValue()
• So, wheres the model, anyway!

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SETTING LOOK FEEL

• To set a particular LF (here CDE/Motif), write
• UIManager.setLookAndFeel( "com.sun.java.swing.p
  laf.motif.MotifLookAndFeel )
• To set the appropriate LF, whatever the current
  environment, write
• UIManager.setLookAndFeel( UIManager.getSystemLo
  okAndFeelClassName() )
• Do the above preferably at the end of the program
  (before instantiating any components)

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THE SWING PACKAGES

• The Accessibility package (javax.accessibility)
• provides support for supporting the screen access
  products for people with disabilities
• Swing has full support for accessibility
• javax.swing
• contains nearly all of the Swing components
• notable exception is JTextComponent (in
  javax.swing.text)
• javax.swing.border
• in need for customized borders, take a look
• javax.swing.event
• includes the additional event classes (not found
  in java.awt.event)

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THE SWING PACKAGES (contd)

• javax.swing.plaf
• classes for providing the LF capabilities
• also javax.swing.plaf.basic including the default
  LF classes
• the current specialized LFs
• javax.swing.plaf.metal
• javax.swing.plaf.motif (or com.sun.java.swing.plaf
  .motif)
• javax.swing.plaf.windows (or com.sun.java.swing.pl
  af.windows)
• also javax.swing.plaf.multi for mixing multiple
  LFs
• javax.swing.table
• including support classes for managing tables
• javax.swing.tree
• support classes for managing trees

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THE SWING PACKAGES (contd)

• javax.swing.text
• support classes for text editing
• Document classes
• JTextComponent (superclass for all text
  components)
• see also separate format packages
• javax.swing.text.html
• javax.swing.text.rtf
• javax.swing.undo
• classes for supporting undo/redo operations

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JComponent

• An abstract root class of almost all of Swing
  components
• Provides
• pluggable LF
• extensibility
• smart trapping of keyboard events (see
  javax.swing.KeyStroke)
• customizable borders
• easy resizing
• tool tips
• autoscrolling
• support for debugging
• support for accessibility
• support for localization

java.lang.Object
java.awt.Component
java.awt.Container
javax.swing.JComponent