Tk_SetClassProcs(3) Tk Library Procedures Tk_SetClassProcs(3)
NAME
Tk_SetClassProcs - register widget specific procedures
SYNOPSIS
#include <tk.h>
Tk_SetClassProcs(tkwin, procs, instanceData)
ARGUMENTS
Token for window to modify. Pointer to data structure containing wid-
get specific procedures. The data structure pointed to by procs must
be static: Tk keeps a reference to it as long as the window exists.
Arbitrary one-word value to pass to widget callbacks.
DESCRIPTION
Tk_SetClassProcs is called to register a set of procedures that are
used as callbacks in different places.
The structure pointed to by procs contains the following: typedef
struct Tk_ClassProcs {
unsigned int size;
Tk_ClassWorldChangedProc *worldChangedProc;
Tk_ClassCreateProc *createProc;
Tk_ClassModalProc *modalProc; } Tk_ClassProcs; The size field is
used to simplify future expansion of the structure. It should always be
set to (literally) sizeof(Tk_ClassProcs).
worldChangedProc is invoked when the system has altered in some way
that requires some reaction from the widget. For example, when a font
alias (see the font manual entry) is reconfigured, widgets configured
to use that font alias must update their display accordingly. world-
ChangedProc should have arguments and results that match the type
Tk_ClassWorldChangedProc: typedef void Tk_ClassWorldChangedProc(
ClientData instanceData); The instanceData parameter passed to the
worldChangedProc will be identical to the instanceData parameter passed
to Tk_SetClassProcs.
createProc is used to create platform-dependant windows. It is invoked
by Tk_MakeWindowExist. createProc should have arguments and results
that match the type Tk_ClassCreateProc: typedef Window Tk_ClassCre-
ateProc(
Tk_Window tkwin,
Window parent,
ClientData instanceData); The tkwin and instanceData parameters
will be identical to the tkwin and instanceData parameters passed to
Tk_SetClassProcs. The parent parameter will be the parent of the win-
dow to be created. The createProc should return the created window.
modalProc is invoked after all bindings on a widget have been triggered
in order to handle a modal loop. modalProc should have arguments and
results that match the type Tk_ClassModalProc: typedef void Tk_Class-
ModalProc(
Tk_Window tkwin,
XEvent *eventPtr); The tkwin parameter to modalProc will be identi-
cal to the tkwin parameter passed to Tk_SetClassProcs. The eventPtr
parameter will be a pointer to an XEvent structure describing the event
being processed.
KEYWORDS
callback, class
Tk 8.4 Tk_SetClassProcs(3)
SetClassProcs 8.5.4 - Generated Sun Aug 24 13:17:13 CDT 2008