OSF

NAME

XmGadget — the Gadget widget class.

SYNOPSIS

#include <Xm/Xm.h>

DESCRIPTION

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. 

Classes

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). 

XmNhelpCallback
Specifies the list of callbacks that is called when the help key sequence is pressed.  The reason sent by the callback is XmCR_HELP. 

XmNhighlightOnEnter
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. 

XmNhighlightThickness
Specifies the thickness of the highlighting rectangle.

XmNnavigationType
Controls whether the Widget is a navigation group.

•XmNONE indicates that the Widget is not a navigation group. 

•XmTAB_GROUP indicates that the Widget is included automatically in keyboard navigation, unless XmAddTabGroup has been called. 

•XmSTICKY_TAB_GROUP indicates that the Widget is included automatically in keyboard navigation, even if XmAddTabGroup has been called. 

•XmEXCLUSIVE_TAB_GROUP indicates that the Widget is included explicitly in keyboard navigation by the application.  With XmEXCLUSIVE_TAB_GROUP, traversal of widgets within the group is based on the order of children. 

If the gadget’s parent is a shell, the default is XmTAB_GROUP; otherwise, the default is XmNONE. 

XmNshadowThickness
Specifies the size of the drawn border shadow.

XmNtraversalOn
Specifies traversal activation for this gadget.

XmNunitType
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:

•XmPIXELS — all values provided to the widget are treated as normal pixel values. 

•Xm100TH_MILLIMETERS — all values provided to the widget are treated as 1/100 millimeter. 

•Xm1000TH_INCHES — all values provided to the widget are treated as 1/1000 inch. 

•Xm100TH_POINTS — all values provided to the widget are treated as 1/100 point.  A point is a unit used in text processing applications and is defined as 1/72 inch. 

•Xm100TH_FONT_UNITS — all values provided to the widget are treated as 1/100 of a font unit.  The value to be used for the font unit is determined in one of three ways:

•The application can use XmSetFontUnits to specify the font unit values. 

•If the application has not called XmSetFontUnits, the font units can be derived from a font.  The user specifies this font by using the font resource in a defaults file or on the command line, or by using the standard command line options −fn and −font. 

•If the application has not called XmSetFontUnits and the user has not specified a font resource, the horizontal and vertical font units default to 10. 

A horizontal font unit is derived from a font as follows:

•If the font has an AVERAGE_WIDTH property, the horizontal font unit is the AVERAGE_WIDTH property divided by 10. 

•If the font has no AVERAGE_WIDTH property but has a QUAD_WIDTH property, the horizontal font unit is the QUAD_WIDTH property. 

•If the font has no AVERAGE_WIDTH or QUAD_WIDTH property, the horizontal font unit is the sum of the font struct’s min_bounds.width and max_bounds.width divided by 2.3. 

A vertical font unit is derived from a font as follows:

•If the font has a PIXEL_SIZE property, the vertical font unit is the PIXEL_SIZE property divided by 1.8. 

•If the font has no PIXEL_SIZE property but has POINT_SIZE and RESOLUTION_Y properties, the vertical font unit is the product of the POINT_SIZE and RESOLUTION_Y properties divided by 1400. 

•If the font has no PIXEL_SIZE, POINT_SIZE, or RESOLUTION_Y properties, the vertical font unit is the sum of the font struct’s max_bounds.ascent and max_bounds.descent divided by 2.2. 

XmNuserData
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. 

Behavior

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. 

RELATED INFORMATION

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