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Diffstat (limited to 'tk8.6/doc/CrtCmHdlr.3')
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diff --git a/tk8.6/doc/CrtCmHdlr.3 b/tk8.6/doc/CrtCmHdlr.3 new file mode 100644 index 0000000..bcc9493 --- /dev/null +++ b/tk8.6/doc/CrtCmHdlr.3 @@ -0,0 +1,64 @@ +'\" +'\" Copyright (c) 2000 Ajuba Solutions. +'\" +'\" See the file "license.terms" for information on usage and redistribution +'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. +'\" +.TH Tk_CreateClientMessageHandler 3 "8.4" Tk "Tk Library Procedures" +.so man.macros +.BS +.SH NAME +Tk_CreateClientMessageHandler, Tk_DeleteClientMessageHandler \- associate procedure callback with ClientMessage type X events +.SH SYNOPSIS +.nf +\fB#include <tk.h>\fR +.sp +\fBTk_CreateClientMessageHandler\fR(\fIproc\fR) +.sp +\fBTk_DeleteClientMessageHandler\fR(\fIproc\fR) +.SH ARGUMENTS +.AP Tk_ClientMessageProc *proc in +Procedure to invoke whenever a ClientMessage X event occurs on any display. +.BE +.SH DESCRIPTION +.PP +\fBTk_CreateClientMessageHandler\fR arranges for \fIproc\fR to be invoked +in the future whenever a ClientMessage X event occurs that is not handled by +\fBWM_PROTOCOL\fR. \fBTk_CreateClientMessageHandler\fR is intended for use +by applications which need to watch X ClientMessage events, such as drag and +drop applications. +.PP +The callback to \fIproc\fR will be made by \fBTk_HandleEvent\fR; +this mechanism only works in programs that dispatch events +through \fBTk_HandleEvent\fR (or through other Tk procedures that +call \fBTk_HandleEvent\fR, such as \fBTcl_DoOneEvent\fR or +\fBTk_MainLoop\fR). +.PP +\fIProc\fR should have arguments and result that match the +type \fBTk_ClientMessageProc\fR: +.CS +typedef int \fBTk_ClientMessageProc\fR( + Tk_Window \fItkwin\fR, + XEvent *\fIeventPtr\fR); +.CE +The \fItkwin\fR parameter to \fIproc\fR is the Tk window which is +associated with this event. \fIEventPtr\fR is a pointer to the X event. +.PP +Whenever an X ClientMessage event is processed by \fBTk_HandleEvent\fR, +the \fIproc\fR is called if it was not handled as a \fBWM_PROTOCOL\fR. +The return value from \fIproc\fR is normally 0. +A non-zero return value indicates that the event is not to be handled +further; that is, \fIproc\fR has done all processing that is to be +allowed for the event. +.PP +If there are multiple ClientMessage event handlers, each one is called +for each event, in the order in which they were established. +.PP +\fBTk_DeleteClientMessageHandler\fR may be called to delete a +previously-created ClientMessage event handler: it deletes each handler it +finds that matches the \fIproc\fR argument. If no such handler exists, +then \fBTk_DeleteClientMessageHandler\fR returns without doing anything. +Although Tk supports it, it's probably a bad idea to have more than one +callback with the same \fIproc\fR argument. +.SH KEYWORDS +bind, callback, event, handler |