Athena Widget Set - C Language Interface - X Consortium ... - X.Org

Creating New Widgets(Subclassing)extern TemplateClassRec templateClassRec;typedef struct {/* resources */char* resource;/* private state */} TemplatePart;typedef struct _TemplateRec {CorePart core;TemplatePart template;} TemplateRec;#endif /* _TemplateP_h */The private header file includes the private header file of its superclass, therebyexposing the entire internal structure of the widget. It may not always be advantageousto do this; your own project development style will dictate the appropriatelevel of detail to expose in each module.The "WindowWidget" needs to declare two fields in its instance structure to holdthe drawing colors, a resource field for the font and a field for the expose and userinput callback lists:typedef struct {/* resources */Pixel color_1;Pixel color_2;XFontStruct* font;XtCallbackList expose_callback;XtCallbackList input_callback;/* private state *//* (none) */} WindowPart;Widget Source FileThe source code file implements the widget class itself. The unique part of this fileis the declaration and initialization of the widget class record structure and thedeclaration of all resources and action routines added by the widget class.The contents of the Template implementation file, < X11/Xaw/Template.c >, are:/* Copyright (c) X Consortium 1987, 1988*/#include #include #include "TemplateP.h"131