Motif provides widget writers with about a dozen traits. A widget writer can install any number of these traits on a widget. A trait is named by an XrmQuark that symbolizes a specific widget capability. If a widget holds a particular trait, then that widget is announcing a specific capability to other widgets. Conversely, if a widget does not hold a particular trait, than that widget is implicitly announcing to other widgets that it is incapable of providing a particular service.
For example, consider the XmQTaccessTextual trait. A widget holding this trait is announcing to other widgets that it is capable of displaying one primary text parcel. Many standard Motif widgets, including XmText and XmLabel, hold this trait. If you are writing a widget that can display one primary text parcel, then it too should hold this trait.
Table 5-1 summarizes the standard Motif traits.
Table 4. Standard Motif Traits
Trait Name | A Widget Holding This Trait Can: |
XmQTaccessTextual | Display one primary text parcel |
XmQTactivatable | Become a command button in a DialogBox |
XmQTcareParentVisual | Borrow its parent's visual information |
XmQTcontainer | Manage one or more XmQTcontainerItem children |
XmQTcontainerItem | Become a child of an XmQTcontainer parent |
XmQTdialogShellSavvy | Become a child of XmDialogShell |
XmQTjoinSide | Attach itself to one side of a suitable parent |
XmQTmenuSavvy | Become a menu child |
XmQTmenuSystem | Manage a menu system |
XmQTnavigator | Act as a navigator to a scrollable widget |
XmQTscrollFrame | Handle one or more navigator widgets |
XmQTspecifyRenderTable | Supply default render tables |
XmQTtakesDefault | Change its appearance to show that it is the default button |
XmQTtransfer | Transfer data to other widgets and/or receive data from other widgets |