xenocara/lib/libXaw/specs/Template_public_header_file.xml

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<sect1 id="Public_Header_File">
<title>Public Header File</title>
<para>
The public header file contains declarations that will be required by any
application module that needs to refer to the widget; whether to create
an instance of the class, to perform an
<function>XtSetValues</function>
operation, or to call a public routine implemented by the widget class.
</para>
<para>
<!-- .LP -->
The contents of the Template public header file,
<function>&lt; X11/Xaw/Template.h &gt;, </function>
are:
</para>
<literallayout class="monospaced">
..
<!-- .CB -->
<!-- .\".so ../../lib/Xaw/Template.h -->
/* Copyright (c) X Consortium 1987, 1988 */
#ifndef _Template_h
#define _Template_h
/****************************************************************
*
* Template widget
*
****************************************************************/
/* Resources:
Name Class RepType Default Value
---- ----- ------- -------------
background Background Pixel XtDefaultBackground
border BorderColor Pixel XtDefaultForeground
borderWidth BorderWidth Dimension 1
destroyCallback Callback Pointer NULL
height Height Dimension 0
mappedWhenManaged MappedWhenManaged Boolean True
sensitive Sensitive Boolean True
width Width Dimension 0
x Position Position 0
y Position Position 0
*/
/* define any special resource names here that are not in &lt;X11/StringDefs.h&gt; */
#define XtNtemplateResource "templateResource"
#define XtCTemplateResource "TemplateResource"
/* declare specific TemplateWidget class and instance datatypes */
typedef struct _TemplateClassRec* TemplateWidgetClass;
typedef struct _TemplateRec* TemplateWidget;
/* declare the class constant */
extern WidgetClass templateWidgetClass;
#endif /* _Template_h */
<!-- .CE -->
</literallayout>
<para>
<!-- .LP -->
<!-- .sp -->
You will notice that most of this file is documentation. The crucial
parts are the last 8 lines where macros for any private resource names
and classes are defined and where the widget class datatypes and class
record pointer are declared.
</para>
<para>
<!-- .LP -->
For the "WindowWidget", we want 2 drawing colors, a callback list for
user input and an
<function>exposeCallback</function> callback list, and we will declare three
convenience procedures, so we need to add
</para>
<literallayout class="monospaced">
<!-- .LP -->
<!-- .sp -->
<!-- .CB -->
/* Resources:
...
callback Callback Callback NULL
drawingColor1 Color Pixel XtDefaultForeground
drawingColor2 Color Pixel XtDefaultForeground
exposeCallback Callback Callback NULL
font Font XFontStruct* XtDefaultFont
...
*/
#define XtNdrawingColor1 "drawingColor1"
#define XtNdrawingColor2 "drawingColor2"
#define XtNexposeCallback "exposeCallback"
extern Pixel WindowColor1(\|/* Widget */\|);
extern Pixel WindowColor2(\|/* Widget */\|);
extern Font\ \ WindowFont(\|/* Widget */\|);
<!-- .CE -->
</literallayout>
<para>
<!-- .LP -->
Note that we have chosen to call the input callback list by the generic
name, <function>callback</function>, rather than a specific name. If widgets that define
a single user-input action all choose the same resource name then there
is greater possibility for an application to switch between widgets of
different types.
</para>
</sect1>