Tk_CreateClientMessageHandlerTk)Library ProcedTk_CreateClientMessageHandler(3)______________________________________________________________________________NAME
Tk_CreateClientMessageHandler, Tk_DeleteClientMessageHandler - asso‐
ciate 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.
_________________________________________________________________DESCRIPTION
Tk_CreateClientMessageHandler arranges for proc to be invoked in the
future whenever a ClientMessage X event occurs that isn't handled by
WM_PROTOCOL. Tk_CreateClientMessageHandler is intended for use by
applications 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_ClientMes‐
sageProc:
typedef int Tk_ClientMessageProc(
Tk_Window tkwin,
XEvent *eventPtr);
The tkwin parameter to proc is the Tk window which is associated 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 wasn't 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 process‐
ing that is to be allowed for the event.
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-cre‐
ated ClientMessage event handler: it deletes each handler it finds that
matches the proc argument. If no such handler exists, then Tk_Delete‐
ClientMessageHandler returns without doing anything. Although Tk sup‐
ports it, it's probably a bad idea to have more than one callback with
the same proc argument.
KEYWORDS
bind, callback, event, handler
Tk 8.4 Tk_CreateClientMessageHandler(3)
