Tk Source Code

    int flags)			/* Describes what just happened. */
{
    TkMenuEntry *mePtr = clientData;
    TkMenu *menuPtr;
    const char *value;
    const char *name, *onValue;

    if (Tcl_InterpDeleted(interp) || (mePtr->namePtr == NULL)) {
	/*
	 * Do nothing if the interpreter is going away or we have
	 * no variable name.
	 */

    	return NULL;
    }

    menuPtr = mePtr->menuPtr;

    if (menuPtr->menuFlags & MENU_DELETION_PENDING) {
    	return NULL;
    }

    name = Tcl_GetString(mePtr->namePtr);

    /*
     * If the variable is being unset, then re-establish the trace.
     */

    if (flags & TCL_TRACE_UNSETS) {
        ClientData probe = NULL;
	mePtr->entryFlags &= ~ENTRY_SELECTED;

        do {
                probe = Tcl_VarTraceInfo(interp, name,
                        TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
                        MenuVarProc, probe);
                if (probe == (ClientData)mePtr) {
                    break;
                }
        } while (probe);
        if (probe) {
                /* 
                 * We were able to fetch the unset trace for our
                 * namePtr, which means it is not unset and not
                 * the cause of this unset trace. Instead some outdated
                 * former variable must be, and we should ignore it.
                 */
		return NULL;
        }
	Tcl_TraceVar2(interp, name, NULL,
		TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
		MenuVarProc, clientData);
	TkpConfigureMenuEntry(mePtr);
	TkEventuallyRedrawMenu(menuPtr, NULL);
	return NULL;
    }

    /*
     * Use the value of the variable to update the selected status of the menu

    /*
     * If the variable is unset, then immediately recreate it unless the whole
     * interpreter is going away.
     */

    if (flags & TCL_TRACE_UNSETS) {

        if (!Tcl_InterpDeleted(interp) && scalePtr->varNamePtr) {
            ClientData probe = NULL;

            do {
                probe = Tcl_VarTraceInfo(interp,
                        Tcl_GetString(scalePtr->varNamePtr),
                        TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,

    menu .m1
    set foo "hello"
    list [.m1 add checkbutton -variable foo -onvalue hello -offvalue goodbye] \
		[set foo "goodbye"] [unset foo]
} -cleanup {
	deleteWindows
} -result {{} goodbye {}}
test menu-17.6 {MenuVarProc [5d991b822e]} -setup {
	deleteWindows
} -body {
    # Want this not to crash
    menu .b
    set var INIT
    .b add checkbutton -variable var
    trace add variable var unset {apply {args {
        .b entryconfigure 1 -variable {}
    }}}
    unset var
} -cleanup {
	deleteWindows
} -result {}
test menu-17.7 {MenuVarProc [5d991b822e]} -setup {
	deleteWindows
} -body {
    # Want this not to duplicate traces
    menu .b
    set var INIT
    .b add checkbutton -variable var
    trace add variable var unset {apply {args {
        .b entryconfigure 1 -variable new
    }}}
    unset var
} -cleanup {
	deleteWindows
} -result {}


test menu-18.1 {TkActivateMenuEntry} -setup {
	deleteWindows
} -body {
    menu .m1
    .m1 add command -label "test"