NAME

XwprimitiveWidgetClass − the X Widget’s primitive widget meta class

SYNOPSIS

#include <X11/StringDefs.h>
#include <X11/Intrinsic.h>
#include <Xw/Xw.h>

CLASSES

The Primitive widget class is built out of the Core class. 

DESCRIPTION

The Primitive class is an X Widget MetaClass.  It is never instantiated as a widget.  Its sole purpose is as a supporting superclass for other widget classes.  It handles border drawing and highlighting, traversal activation and deactivation and various callback lists needed by primitive widgets. 

NEW RESOURCES

Primitive defines a set of resource types used by the programmer to specify the data for widgets which are subclasses of Primitive. 
 

XtNforeground
This resource defines the foreground color for the widget.  Widgets built upon this class can use the foreground for their drawing.

XtNbackgroundTile
This resource defines the tile to be used for the background of the widget.  It defines a particular tile to be combined with the foreground and background pixel colors.  The #defines for setting the tile value through an arg list and the strings to be used in the .Xdefaults files are described in XwCreateTile(3X).

XtNhighlightColor
This resource defines the color to be used in the highlighting drawn by Primitive around the exterior of the widget.

XtNhighlightStyle
Two styles of border highlighting are supported by Primitive.  They include drawing the highlighting with a pattern and widget specific border drawing.  To set the highlight style through an arg list, use the #define XwPATTERN_BORDER. To set the highlight style through the .Xdefaults file, use the string pattern_border.

For Widget Writers:  The highlighting style of XwWIDGET_DEFINED is used exclusively by widgets with special highlighting requirements that need to override the normal highlighting types.  To use, the widget inserts a highlight and unhighlight procedure into its primitive class and forces the highlightStyle field in the primitive instance to the define XwWIDGET_DEFINED.  The primitive class will then make the appropriate calls to the highlight and dehighlight functions. 

XtNhighlightTile
When the highlight style is XwPATTERN_BORDER, one of several tiles can be used for the drawing.  The #defines for setting the values through an arg list and the strings to be used in the .Xdefaults files are described in XwCreateTile(3X).

XtNhighlightThickness
The width of the highlight can be set using this resource.  It is specified as an integer value representing the width, in pixels, of the highlight to be drawn.  This value must be greater than or equal to 0.  Note that highlighting takes place within the window created for a widget and is separate from the window border.

XtNtraversalType
Three modes of border highlighting activation are supported by Primitive. They are, no highlighting, highlight on the cursor entering the widgets window and highlight for keyboard traversal.  The last mode is used by the keyboard traversal mechanism to indicate the widget that is to receive all input occurring within the widget hierarchy.  To set the traversal type through an arg list, one of three defines can be used.  They are XwHIGHLIGHT_OFF, XwHIGHLIGHT_ENTER and XwHIGHLIGHT_TRAVERSAL.  The strings that can be used to set this resource through the .Xdefaults file are highlight_off, highlight_enter, and highlight_traversal.

XtNrecomputeSize
This boolean resource indicates to a primitive widget whether it should recalculate its size when an application makes a XtSetValues call to it.  If set to TRUE, the widget will perform its normal size calculations will may cause its geometry to change.  If set to FALSE, the widget will not recalculate its size.

XtNselect
This is a reserved callback list used by widget subclasses built upon Primitive to implement there callback lists.

XtNrelease
This is a reserved callback list used by widget subclasses built upon Primitive to implement there callback lists.

KEYBOARD TRAVERSAL

If the traversalType resource is set to highlight_traversal (either when the widget is created or during a call to XtSetValues) the Primitive widget’s translation table is augmented with the following translations:  

ACTIONS

focusIn:
If traversal is on for a widget of this class then accept the keyboard focus and visually indicate it by highlighting the widget.

focusOut:
If traversal is on for a widget of this class then indicate that the widget no longer has the focus by unhighlighting the widget.

visibility:
If traversal is on for a widget of this class and the widget that is focused becomes hidden (e.g. another window obscures its visibility), then the focus moves to another visible widget.

unmap:
If traversal is on for a widget of this class and the widget that is focused becomes unmapped, then the focus moves to another mapped widget.

traverseUp:
Inform the parent of a widget of this class that it should transfer keyboard focus to the first widget above this one.

traverseDown:
Inform the parent of a widget of this class that it should transfer keyboard focus to the first widget below this one.

traverseLeft:
Inform the parent of a widget of this class that it should transfer keyboard focus to the first widget to the left of this one.

traverseRight:
Inform the parent of a widget of this class that it should transfer keyboard focus to the first widget to the right of this one.

traverseNext:
Inform the parent of a widget of this class that it should transfer keyboard focus to the next child in the parent’s list of children.

traversePrev:
Inform the parent of a widget of this class that it should transfer keyboard focus to the previous child in the parent’s list of children.

traverseHome:
Inform the parent of a widget of this class that it should transfer keyboard focus to the child which is closest to the upper left hand corner of the parent.  If that child already has the keyboard focus, then ask the grandparent of the widget to give the keyboard focus to whichever of its children which is closest to the upper left hand corner.

traverseNextTop:
Find the topmost parent in a widget of this class hierarch which is a subclass of XwManager and tell it to issues any XtNnextTop callbacks that have been registered with it.  The purpose of this callback is to allow applications to move the keyboard focus between top level widget hierarchies of the same application.

ORIGIN

Hewlett-Packard Company. 

SEE ALSO

CORE(3X), XWCREATETILE(3X)

September 29, 2021