'\"
'\" Copyright (c) 1997 Maorong Zou
'\" 
.TH EZ_SetClientMessageHandler 3 "" EZWGL "EZWGL Functions"
.BS
.SH NAME
EZ_SetClientMessageHandler \- register a client message handler

.SH SYNOPSIS
.nf
.B #include <EZ.h>
.sp
.BI "void EZ_SetClientMessageHandler( EZ_EventHandler " handler ", void *" data )

.SH ARGUMENTS
\fIhandler\fR  Specifies a client message handler.
.sp
\fIdata\fR  Specifies a client data to be passed to \fIhandler\fR when
invoked.
.SH DESCRIPTION
.PP
\fBEZ_SetClientMessageHandler\fR  registers a client message handler
to an EZWGL application. A client message handler is a procedure that
handles ClientMessage events. Its primary function is to
communicate with the window manager and other applications. 
The default client message handler handles only the message of
type WM_PROTOCOLS/WM_DELETE_WINDOW.
.PP
Here is an example of a client message handler that refrain the window
manager from closing a dialogue widget window.
.PP
.RS
.nf
Atom DeleteWindowAtom = EZ_GetAtom("WM_DELETE_WINDOW");
Atom WMProtocolsAtom = EZ_GetAtom("WM_PROTOCOLS");

void myClientMessageHandler(EZ_Widget *widget, void *data, 
					int etype, XEvent *xev)
{
  XClientMessageEvent *ev = (XClientMessageEvent *)xev;      
      
  if(ev->message_type == WMProtocolsAtom)
    {
      Atom c = (ev->data.l)[0];
      if(c == DeleteWindowAtom)
	{
	  EZ_DisplayWidget(Dialogue);
	  EZ_SetGrab(Dialogue); 
	}
    }
}
.fi
.RE

.SH "SEE ALSO"
EZ_AddEventHandler(3), EZ_AddWidgetCallBack(3)
.br