setclass(3Tk)

NAME
     Tk_SetClass, Tk_Class - set or retrieve a window's class

SYNOPSIS
     #include <tk.h>

     Tk_SetClass(tkwin, class)

     Tk_Uid
     Tk_Class(tkwin)

ARGUMENTS
     Tk_Window   tkwin    (in)      Token for window.

     char        *class   (in)      New class name for window.


DESCRIPTION
     Tk_SetClass is called to associate a class with a particular window.  The
     class string identifies the type of the window;  all windows with the
     same general class of behavior (button, menu, etc.) should have the same
     class.  By convention all class names start with a capital letter, and
     there exists a Tcl command with the same name as each class (except all
     in lower-case) which can be used to create and manipulate windows of that
     class.  A window's class string is initialized to NULL when the window is
     created.

     For main windows, Tk automatically propagates the name and class to the
     WM_CLASS property used by window managers.  This happens either when a
     main window is actually created (e.g. in Tk_MakeWindowExist), or when
     Tk_SetClass is called, whichever occurs later.  If a main window has not
     been assigned a class then Tk will not set the WM_CLASS property for the
     window.

     Tk_Class is a macro that returns the current value of tkwin's class.  The
     value is returned as a Tk_Uid, which may be used just like a string
     pointer but also has the properties of a unique identifier (see the
     manual entry for Tk_GetUid for details).  If tkwin has not yet been given
     a class, then Tk_Class will return NULL.


KEYWORDS
     class, unique identifier, window, window manager