Tk_CreateClientMessageHandler(3tk)

Tk_CreateClientMessageHandler(3Tk Library ProcedureTk_CreateClientMessageHandler(3)

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NAME

     Tk_CreateClientMessageHandler, Tk_DeleteClientMessageHandler
     -  associate  procedure  callback  with ClientMessage type X
     events

SYNOPSIS

     #include <tk.h>

     Tk_CreateClientMessageHandler(proc)

     Tk_DeleteClientMessageHandler(proc)

ARGUMENTS

     Tk_ClientMessageProc *proc (in)           Procedure       to
                                               invoke  whenever a
                                               ClientMessage    X
                                               event   occurs  on
                                               any display.
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DESCRIPTION

     Tk_CreateClientMessageHandler  arranges  for  proc   to   be
     invoked  in  the  future  whenever  a  ClientMessage X event
     occurs    that    is    not    handled    by    WM_PROTOCOL.
     Tk_CreateClientMessageHandler  is intended for use by appli-
     cations which need to watch X ClientMessage events, such  as
     drag and drop applications.

     The callback to proc will be made  by  Tk_HandleEvent;  this
     mechanism  only  works  in  programs  that  dispatch  events
     through Tk_HandleEvent (or through other Tk procedures  that
     call Tk_HandleEvent, such as Tk_DoOneEvent or Tk_MainLoop).

     Proc should have arguments and result that  match  the  type
     Tk_ClientMessageProc:
          typedef int Tk_ClientMessageProc(
              Tk_Window tkwin,
              XEvent *eventPtr);
     The tkwin parameter to proc is the Tk window which is  asso-
     ciated  with  this  event.   EventPtr  is a pointer to the X
     event.

     Whenever  an  X  ClientMessage   event   is   processed   by
     Tk_HandleEvent,  the proc is called if it was not handled as
     a WM_PROTOCOL.  The return value from proc is normally 0.  A
     non-zero  return value indicates that the event is not to be
     handled further; that is, proc has done all processing  that
     is to be allowed for the event.

Tk                      Last change: 8.4                        1

Tk_CreateClientMessageHandler(3Tk Library ProcedureTk_CreateClientMessageHandler(3)

     If there are multiple ClientMessage event handlers, each one
     is  called  for  each event, in the order in which they were
     established.

     Tk_DeleteClientMessageHandler may  be  called  to  delete  a
     previously-created  ClientMessage  event handler: it deletes
     each handler it finds that matches the proc argument.  If no
     such   handler  exists,  then  Tk_DeleteClientMessageHandler
     returns without doing anything.  Although  Tk  supports  it,
     it's probably a bad idea to have more than one callback with
     the same proc argument.

KEYWORDS

     bind, callback, event, handler

Tk                      Last change: 8.4                        2