1 files changed, 98 insertions, 0 deletions
diff --git a/library/demos/plot.tcl b/library/demos/plot.tcl
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index 0000000..6067979
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+++ b/library/demos/plot.tcl
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+# plot.tcl --
+#
+# This demonstration script creates a canvas widget showing a 2-D
+# plot with data points that can be dragged with the mouse.
+#
+# SCCS: @(#) plot.tcl 1.5 97/03/02 16:26:19
+
+if {![info exists widgetDemo]} {
+    error "This script should be run from the \"widget\" demo."
+}
+
+set w .plot
+catch {destroy $w}
+toplevel $w
+wm title $w "Plot Demonstration"
+wm iconname $w "Plot"
+positionWindow $w
+set c $w.c
+
+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.msg -side top
+
+frame $w.buttons
+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
+}
+
+foreach point {{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 \
+	    -fill SkyBlue2]
+    $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"
+
+set plot(lastX) 0
+set plot(lastY) 0
+
+# plotDown --
+# 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.
+#
+# Arguments:
+# w -		The canvas window.
+# x, y -	The coordinates of the mouse press.
+
+proc plotDown {w x y} {
+    global plot
+    $w dtag selected
+    $w addtag selected withtag current
+    $w raise current
+    set plot(lastX) $x
+    set plot(lastY) $y
+}
+
+# plotMove --
+# This procedure is invoked during mouse motion events.  It drags the
+# current item.
+#
+# Arguments:
+# w -		The canvas window.
+# x, y -	The coordinates of the mouse.
+
+proc plotMove {w x y} {
+    global plot
+    $w move selected [expr $x-$plot(lastX)] [expr $y-$plot(lastY)]
+    set plot(lastX) $x
+    set plot(lastY) $y
+}