Java Files

• To add a new widget, say ComboBox, needs Java and C files.
• A GUI independant object ComboBox
• This object must belong to the java.awt package
• This implements all methods that can be done purely in Java such as
  • countItems
  • getRows
• Provides an interface from methods for the object to the GUI dependant methods of the peer
  • addItem(item) calls peer.addItem()
  • clear() calls peer.clear()
• An object ComboBoxPeer that gives virtual methods for all GUI dependant calls.
• This object should belong to the package java.awt.peer
• A GUI dependant object MComboBoxPeer that derives from ComboBoxPeer.
• This object must belong to the package sun.awt.motif
• The object should define GUI dependant characteristics, such as minimumSize()
• the object must define a native call to create the Motif widget - this cannot be done until the parent widget is known. The method is defined as abstract in MComponent.java

  native void create(MComponentPeer parent)
  

  It is invoked by the constructor for the peer.
• The object must define handlers for events of interest from the widget (such as selections). These will be called from C callback functions of the widget.