3 # This demonstration script creates a canvas widget showing a 2-D
4 # plot with data points that can be dragged with the mouse.
6 # RCS: @(#) $Id: plot.tcl,v 1.2 1998/09/14 18:23:29 stanton Exp $
8 if {![info exists widgetDemo]} {
9 error "This script should be run from the \"widget\" demo."
15 wm title $w "Plot Demonstration"
20 label $w.msg -font $font -wraplength 4i -justify left -text "This window displays a canvas widget containing a simple 2-dimensional plot. You can doctor the data by dragging any of the points with mouse button 1."
24 pack $w.buttons -side bottom -fill x -pady 2m
25 button $w.buttons.dismiss -text Dismiss -command "destroy $w"
26 button $w.buttons.code -text "See Code" -command "showCode $w"
27 pack $w.buttons.dismiss $w.buttons.code -side left -expand 1
29 canvas $c -relief raised -width 450 -height 300
30 pack $w.c -side top -fill x
32 set plotFont {Helvetica 18}
34 $c create line 100 250 400 250 -width 2
35 $c create line 100 250 100 50 -width 2
36 $c create text 225 20 -text "A Simple Plot" -font $plotFont -fill brown
38 for {set i 0} {$i <= 10} {incr i} {
39 set x [expr {100 + ($i*30)}]
40 $c create line $x 250 $x 245 -width 2
41 $c create text $x 254 -text [expr 10*$i] -anchor n -font $plotFont
43 for {set i 0} {$i <= 5} {incr i} {
44 set y [expr {250 - ($i*40)}]
45 $c create line 100 $y 105 $y -width 2
46 $c create text 96 $y -text [expr $i*50].0 -anchor e -font $plotFont
49 foreach point {{12 56} {20 94} {33 98} {32 120} {61 180}
51 set x [expr {100 + (3*[lindex $point 0])}]
52 set y [expr {250 - (4*[lindex $point 1])/5}]
53 set item [$c create oval [expr $x-6] [expr $y-6] \
54 [expr $x+6] [expr $y+6] -width 1 -outline black \
56 $c addtag point withtag $item
59 $c bind point <Any-Enter> "$c itemconfig current -fill red"
60 $c bind point <Any-Leave> "$c itemconfig current -fill SkyBlue2"
61 $c bind point <1> "plotDown $c %x %y"
62 $c bind point <ButtonRelease-1> "$c dtag selected"
63 bind $c <B1-Motion> "plotMove $c %x %y"
69 # This procedure is invoked when the mouse is pressed over one of the
70 # data points. It sets up state to allow the point to be dragged.
73 # w - The canvas window.
74 # x, y - The coordinates of the mouse press.
76 proc plotDown {w x y} {
79 $w addtag selected withtag current
86 # This procedure is invoked during mouse motion events. It drags the
90 # w - The canvas window.
91 # x, y - The coordinates of the mouse.
93 proc plotMove {w x y} {
95 $w move selected [expr $x-$plot(lastX)] [expr $y-$plot(lastY)]