# This demonstration script creates a canvas widget showing a 2-D
# plot with data points that can be dragged with the mouse.
# RCS: @(#) $Id: plot.tcl,v 1.3 2001/06/14 10:56:58 dkf Exp $
if {![info exists widgetDemo
]} {
error "This script should be run from the \"widget\" demo."
wm title
$w "Plot Demonstration"
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."
pack $w.buttons
-side bottom
-fill x
-pady 2m
button $w.buttons.dismiss
-text Dismiss
-command "destroy $w"
button $w.buttons.code
-text "See Code" -command "showCode $w"
pack $w.buttons.dismiss
$w.buttons.code
-side left
-expand 1
canvas $c -relief raised
-width 450 -height 300
pack $w.c
-side top
-fill x
set plotFont
{Helvetica
18}
$c create line
100 250 400 250 -width 2
$c create line
100 250 100 50 -width 2
$c create
text 225 20 -text "A Simple Plot" -font $plotFont -fill brown
for {set i
0} {$i <= 10} {incr i
} {
set x
[expr {100 + ($i*30)}]
$c create line
$x 250 $x 245 -width 2
$c create
text $x 254 -text [expr {10*$i}] -anchor n
-font $plotFont
for {set i
0} {$i <= 5} {incr i
} {
set y
[expr {250 - ($i*40)}]
$c create line
100 $y 105 $y -width 2
$c create
text 96 $y -text [expr {$i*50}].0 -anchor e
-font $plotFont
{12 56} {20 94} {33 98} {32 120} {61 180} {75 160} {98 223}
set x
[expr {100 + (3*[lindex $point 0])}]
set y
[expr {250 - (4*[lindex $point 1])/5}]
set item
[$c create oval
[expr {$x-6}] [expr {$y-6}] \
[expr {$x+6}] [expr {$y+6}] -width 1 -outline black
\
$c addtag point withtag
$item
$c bind point
<Any-Enter
> "$c itemconfig current -fill red"
$c bind point
<Any-Leave
> "$c itemconfig current -fill SkyBlue2"
$c bind point
<1> "plotDown $c %x %y"
$c bind point
<ButtonRelease-1
> "$c dtag selected"
bind $c <B1-Motion
> "plotMove $c %x %y"
# This procedure is invoked when the mouse is pressed over one of the
# data points. It sets up state to allow the point to be dragged.
# x, y - The coordinates of the mouse press.
$w addtag selected withtag current
# This procedure is invoked during mouse motion events. It drags the
# x, y - The coordinates of the mouse.
$w move selected
[expr {$x-$plot(lastX
)}] [expr {$y-$plot(lastY
)}]