tcldoc Tcl/Tk 9.0.4
/

Home › Tk Library Procedures Tk

Tk_HandleEvent C API

Invoke event handlers for window system events

literal type exactly as shown argument replace with your value ?optional? may be omitted

Synopsis#

#include <tk.h>

Tk_HandleEvent(eventPtr)#

Arguments#

XEvent *eventPtr (in)

Pointer to X event to dispatch to relevant handler(s). It is important that all unused fields of the structure be set to zero.

Description#

Tk_HandleEvent is a lower-level procedure that deals with window events. It is called by Tcl_ServiceEvent (and indirectly by Tcl_DoOneEvent), and in a few other cases within Tk. It makes callbacks to any window event handlers (created by calls to Tk_CreateEventHandler) that match eventPtr and then returns. In some cases it may be useful for an application to bypass the Tk event queue and call Tk_HandleEvent directly instead of calling Tcl_QueueEvent followed by Tcl_ServiceEvent.

This procedure may be invoked recursively. For example, it is possible to invoke Tk_HandleEvent recursively from a handler called by Tk_HandleEvent. This sort of operation is useful in some modal situations, such as when a notifier has been popped up and an application wishes to wait for the user to click a button in the notifier before doing anything else.

Keywords#

callback · event · handler · window

Copyright#