NAME

       Tk_SetClassProcs - register widget specific procedures

SYNOPSIS

       #include <tk.h>

       Tk_SetClassProcs(tkwin, procs, instanceData)

ARGUMENTS

       Tk_Window tkwin (in)                    Token for window to modify.

       const Tk_ClassProcs *procs (in)         Pointer  to data structure containing widget specific procedures.
                                               The data structure pointed to by procs must be static: Tk keeps a
                                               reference to it as long as the window exists.

       ClientData instanceData (in)            Arbitrary one-word value to pass to widget callbacks.
________________________________________________________________________________________________________________

DESCRIPTION

       Tk_SetClassProcs  is  called  to  register  a  set  of procedures that are used as callbacks in different
       places.

       The structure pointed to by procs contains the following:
              typedef struct Tk_ClassProcs {
                  unsigned int size;
                  Tk_ClassWorldChangedProc *worldChangedProc;
                  Tk_ClassCreateProc *createProc;
                  Tk_ClassModalProc *modalProc;
              } Tk_ClassProcs;
       The size field is used to simplify future expansion  of  the  structure.  It  should  always  be  set  to
       (literally) sizeof(Tk_ClassProcs).

       worldChangedProc  is invoked when the system has altered in some way that requires some reaction from the
       widget.  For example, when a font alias (see the font manual entry) is reconfigured,  widgets  configured
       to use that font alias must update their display accordingly.  worldChangedProc should have arguments and
       results that match the type Tk_ClassWorldChangedProc:
              typedef void Tk_ClassWorldChangedProc(
                      ClientData instanceData);
       The instanceData parameter passed to the worldChangedProc will be identical to the instanceData parameter
       passed to Tk_SetClassProcs.

       createProc  is  used  to  create  platform-dependent  windows.   It  is  invoked  by  Tk_MakeWindowExist.
       createProc should have arguments and results that match the type Tk_ClassCreateProc:
              typedef Window Tk_ClassCreateProc(
                      Tk_Window tkwin,
                      Window parent,
                      ClientData instanceData);
       The tkwin and instanceData parameters will be identical to the tkwin and instanceData  parameters  passed
       to  Tk_SetClassProcs.   The  parent  parameter  will  be  the  parent  of  the window to be created.  The
       createProc should return the created window.

       modalProc is invoked after all bindings on a widget have been triggered in order to handle a modal  loop.
       modalProc should have arguments and results that match the type Tk_ClassModalProc:
              typedef void Tk_ClassModalProc(
                      Tk_Window tkwin,
                      XEvent *eventPtr);
       The  tkwin  parameter  to  modalProc will be identical to the tkwin parameter passed to Tk_SetClassProcs.
       The eventPtr parameter will be a pointer to an XEvent structure describing the event being processed.

KEYWORDS

       callback, class