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XmGadget - The Gadget widget class


#include <Xm/Xm.h>


Gadget is a widget class used as a supporting superclass for other gadget classes. It handles shadow-border drawing and highlighting, traversal activation and deactivation, and various callback lists needed by gadgets.

The color and pixmap resources defined by XmManager are directly used by gadgets. If XtSetValues is used to change one of the resources for a manager widget, all of the gadget children within the manager also change.


Gadget inherits behavior and resources from Object and RectObj classes.

The class pointer is xmGadgetClass.

The class name is XmGadget.

New Resources

The following table defines a set of widget resources used by the programmer to specify data. The programmer can also set the resource values for the inherited classes to set attributes for this widget. To reference a resource by name or by class in a .Xdefaults file, remove the XmN or XmC prefix and use the remaining letters. To specify one of the defined values for a resource in a .Xdefaults file, remove the Xm prefix and use the remaining letters (in either lowercase or uppercase, but include any underscores between words). The codes in the access column indicate if the given resource can be set at creation time (C), set by using XtSetValues (S), retrieved by using XtGetValues (G), or is not applicable (N/A).

XmGadget Resource Set
Name Class Type Default Access
XmNbottomShadowColor XmCBottomShadowColor Pixel dynamic G
XmNhelpCallback XmCCallback XtCallbackList NULL C
XmNhighlightColor XmCHighlightColor Pixel dynamic G
XmNhighlightOnEnter XmCHighlightOnEnter Boolean False CSG
XmNhighlightThickness XmCHighlightThickness Dimension 2 CSG
XmNnavigationType XmCNavigationType XmNavigationType XmNONE CSG
XmNshadowThickness XmCShadowThickness Dimension 2 CSG
XmNtopShadowColor XmCTopShadowColor Pixel dynamic G
XmNtraversalOn XmCTraversalOn Boolean True CSG
XmNunitType XmCUnitType unsigned char dynamic CSG
XmNuserData XmCUserData XtPointer NULL CSG
Contains the color to use to draw the bottom and right sides of the border shadow.
Specifies the list of callbacks that is called when the help key sequence is pressed. The reason sent by the callback is XmCR_HELP.
Contains the color of the highlighting rectangle.
Specifies if the highlighting rectangle is drawn when the cursor moves into the widget. If the shell's focus policy is XmEXPLICIT, this resource is ignored, and the widget is highlighted when it has the focus. If the shell's focus policy is XmPOINTER and if this resource is True, the highlighting rectangle is drawn when the the cursor moves into the widget. If the shell's focus policy is XmPOINTER and if this resource is False, the highlighting rectangle is not drawn when the the cursor moves into the widget. The default is False.
Specifies the thickness of the highlighting rectangle.
Determines whether the widget is a tab group.
Specifies the size of the drawn border shadow.
Contains the color to use to draw the top and left sides of the border shadow.
Specifies traversal activation for this gadget.
Provides the basic support for resolution independence. It defines the type of units a widget uses with sizing and positioning resources. If the widget's parent is a subclass of XmManager and if the XmNunitType resource is not explicitly set, it defaults to the unit type of the parent widget. If the widget's parent is not a subclass of XmManager, the resource has a default unit type of XmPIXELS.

XmNunitType can have the following values:

Allows the application to attach any necessary specific data to the gadget. This is an internally unused resource.

Inherited Resources

Gadget inherits the following resources from the named superclass. For a complete description of each resource, refer to the man page for that superclass.

RectObj Resource Set
Name Class Type Default Access
XmNancestorSensitive XmCSensitive Boolean dynamic G
XmNborderWidth XmCBorderWidth Dimension 0 CSG
XmNheight XmCHeight Dimension dynamic CSG
XmNsensitive XmCSensitive Boolean True CSG
XmNwidth XmCWidth Dimension dynamic CSG
XmNx XmCPosition Position 0 CSG
XmNy XmCPosition Position 0 CSG

Object Resource Set
Name Class Type Default Access
XmNdestroyCallback XmCCallback XtCallbackList NULL C

Callback Information

A pointer to the following structure is passed to each callback:

typedef struct
   int     reason;
   XEvent  * event;
} XmAnyCallbackStruct;
Indicates why the callback was invoked. For this callback, reason is set to XmCR_HELP.
Points to the XEvent that triggered the callback.


Gadgets cannot have translations associated with them. Because of this, a Gadget's behavior is determined by the Manager widget into which the Gadget is placed. If focus is on a Gadget, events are passed to the Gadget by its Manager.


Object(3X), RectObj(3X), XmManager(3X), and XmScreen(3X).