lib/tk8.4/demos/cscroll.tcl

   1 # cscroll.tcl --
   2 #
   3 # This demonstration script creates a simple canvas that can be
   4 # scrolled in two dimensions.
   5 #
   6 # RCS: @(#) $Id: cscroll.tcl,v 1.3 2001/06/14 10:56:58 dkf Exp $
   7
   8 if {![info exists widgetDemo]} {
   9     error "This script should be run from the \"widget\" demo."
  10 }
  11
  12 set w .cscroll
  13 catch {destroy $w}
  14 toplevel $w
  15 wm title $w "Scrollable Canvas Demonstration"
  16 wm iconname $w "cscroll"
  17 positionWindow $w
  18 set c $w.c
  19
  20 label $w.msg -font $font -wraplength 4i -justify left -text "This window displays a canvas widget that can be scrolled either using the scrollbars or by dragging with button 2 in the canvas.  If you click button 1 on one of the rectangles, its indices will be printed on stdout."
  21 pack $w.msg -side top
  22
  23 frame $w.buttons
  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
  28
  29 frame $w.grid
  30 scrollbar $w.hscroll -orient horiz -command "$c xview"
  31 scrollbar $w.vscroll -command "$c yview"
  32 canvas $c -relief sunken -borderwidth 2 -scrollregion {-11c -11c 50c 20c} \
  33         -xscrollcommand "$w.hscroll set" \
  34         -yscrollcommand "$w.vscroll set"
  35 pack $w.grid -expand yes -fill both -padx 1 -pady 1
  36 grid rowconfig    $w.grid 0 -weight 1 -minsize 0
  37 grid columnconfig $w.grid 0 -weight 1 -minsize 0
  38
  39 grid $c -padx 1 -in $w.grid -pady 1 \
  40     -row 0 -column 0 -rowspan 1 -columnspan 1 -sticky news
  41 grid $w.vscroll -in $w.grid -padx 1 -pady 1 \
  42     -row 0 -column 1 -rowspan 1 -columnspan 1 -sticky news
  43 grid $w.hscroll -in $w.grid -padx 1 -pady 1 \
  44     -row 1 -column 0 -rowspan 1 -columnspan 1 -sticky news
  45
  46
  47 set bg [lindex [$c config -bg] 4]
  48 for {set i 0} {$i < 20} {incr i} {
  49     set x [expr {-10 + 3*$i}]
  50     for {set j 0; set y -10} {$j < 10} {incr j; incr y 3} {
  51         $c create rect ${x}c ${y}c [expr {$x+2}]c [expr {$y+2}]c \
  52                 -outline black -fill $bg -tags rect
  53         $c create text [expr {$x+1}]c [expr {$y+1}]c -text "$i,$j" \
  54             -anchor center -tags text
  55     }
  56 }
  57
  58 $c bind all <Any-Enter> "scrollEnter $c"
  59 $c bind all <Any-Leave> "scrollLeave $c"
  60 $c bind all <1> "scrollButton $c"
  61 bind $c <2> "$c scan mark %x %y"
  62 bind $c <B2-Motion> "$c scan dragto %x %y"
  63
  64 proc scrollEnter canvas {
  65     global oldFill
  66     set id [$canvas find withtag current]
  67     if {[lsearch [$canvas gettags current] text] >= 0} {
  68         set id [expr {$id-1}]
  69     }
  70     set oldFill [lindex [$canvas itemconfig $id -fill] 4]
  71     if {[winfo depth $canvas] > 1} {
  72         $canvas itemconfigure $id -fill SeaGreen1
  73     } else {
  74         $canvas itemconfigure $id -fill black
  75         $canvas itemconfigure [expr {$id+1}] -fill white
  76     }
  77 }
  78
  79 proc scrollLeave canvas {
  80     global oldFill
  81     set id [$canvas find withtag current]
  82     if {[lsearch [$canvas gettags current] text] >= 0} {
  83         set id [expr {$id-1}]
  84     }
  85     $canvas itemconfigure $id -fill $oldFill
  86     $canvas itemconfigure [expr {$id+1}] -fill black
  87 }
  88
  89 proc scrollButton canvas {
  90     global oldFill
  91     set id [$canvas find withtag current]
  92     if {[lsearch [$canvas gettags current] text] < 0} {
  93         set id [expr {$id+1}]
  94     }
  95     puts stdout "You buttoned at [lindex [$canvas itemconf $id -text] 4]"
  96 }