1# check.tcl --
2#
3# This demonstration script creates a toplevel window containing
4# several checkbuttons.
5#
6# RCS: @(#) $Id$
7
8if {![info exists widgetDemo]} {
9    error "This script should be run from the \"widget\" demo."
10}
11
12package require Tk
13
14set w .check
15catch {destroy $w}
16toplevel $w
17wm title $w "Checkbutton Demonstration"
18wm iconname $w "check"
19positionWindow $w
20
21label $w.msg -font $font -wraplength 4i -justify left -text "Four checkbuttons are displayed below.  If you click on a button, it will toggle the button's selection state and set a Tcl variable to a value indicating the state of the checkbutton.  The first button also follows the state of the other three.  If only some of the three are checked, the first button will display the tri-state mode. Click the \"See Variables\" button to see the current values of the variables."
22pack $w.msg -side top
23
24## See Code / Dismiss buttons
25set btns [addSeeDismiss $w.buttons $w [list safety wipers brakes sober]]
26pack $btns -side bottom -fill x
27
28checkbutton $w.b0 -text "Safety Check" -variable safety -relief flat \
29    -onvalue "all" \
30    -offvalue "none" \
31    -tristatevalue "partial"
32checkbutton $w.b1 -text "Wipers OK" -variable wipers -relief flat
33checkbutton $w.b2 -text "Brakes OK" -variable brakes -relief flat
34checkbutton $w.b3 -text "Driver Sober" -variable sober -relief flat
35pack $w.b0 -side top -pady 2 -anchor w
36pack $w.b1 $w.b2 $w.b3 -side top -pady 2 -anchor w -padx 15
37
38## This code makes $w.b0 function as a tri-state button; it's not
39## needed at all for just straight yes/no buttons.
40
41set in_check 0
42proc tristate_check {n1 n2 op} {
43    global safety wipers brakes sober in_check
44    if {$in_check} {
45	return
46    }
47    set in_check 1
48    if {$n1 eq "safety"} {
49	if {$safety eq "none"} {
50	    set wipers 0
51	    set brakes 0
52	    set sober 0
53	} elseif {$safety eq "all"} {
54	    set wipers 1
55	    set brakes 1
56	    set sober 1
57	}
58    } else {
59	if {$wipers == 1 && $brakes == 1 && $sober == 1} {
60	    set safety all
61	} elseif {$wipers == 1 || $brakes == 1 || $sober == 1} {
62	    set safety partial
63	} else {
64	    set safety none
65	}
66    }
67    set in_check 0
68}
69
70trace variable wipers w tristate_check
71trace variable brakes w tristate_check
72trace variable sober  w tristate_check
73trace variable safety w tristate_check
74