# items.tcl --

#

# This demonstration script creates a canvas that displays the

# canvas item types.

#

# RCS: @(#) $Id: items.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."

}

set w .items

catch {destroy $w}

toplevel $w

wm title $w "Canvas Item Demonstration"

wm iconname $w "Items"

positionWindow $w

set c $w.frame.c

label $w.msg -font $font -wraplength 5i -justify left -text "This window contains a canvas widget with examples of the various kinds of items supported by canvases.  The following operations are supported:\n  Button-1 drag:\tmoves item under pointer.\n  Button-2 drag:\trepositions view.\n  Button-3 drag:\tstrokes out area.\n  Ctrl+f:\t\tprints items under area."

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

frame $w.frame

pack $w.frame -side top -fill both -expand yes

canvas $c -scrollregion {0c 0c 30c 24c} -width 15c -height 10c \

	-relief sunken -borderwidth 2 \

	-xscrollcommand "$w.frame.hscroll set" \

	-yscrollcommand "$w.frame.vscroll set"

scrollbar $w.frame.vscroll -command "$c yview"

scrollbar $w.frame.hscroll -orient horiz -command "$c xview"

grid $c -in $w.frame \

    -row 0 -column 0 -rowspan 1 -columnspan 1 -sticky news

grid $w.frame.vscroll \

    -row 0 -column 1 -rowspan 1 -columnspan 1 -sticky news

grid $w.frame.hscroll \

    -row 1 -column 0 -rowspan 1 -columnspan 1 -sticky news

grid rowconfig    $w.frame 0 -weight 1 -minsize 0

grid columnconfig $w.frame 0 -weight 1 -minsize 0

# Display a 3x3 rectangular grid.

$c create rect 0c 0c 30c 24c -width 2

$c create line 0c 8c 30c 8c -width 2

$c create line 0c 16c 30c 16c -width 2

$c create line 10c 0c 10c 24c -width 2

$c create line 20c 0c 20c 24c -width 2

set font1 {Helvetica 12}

set font2 {Helvetica 24 bold}

if {[winfo depth $c] > 1} {

    set blue DeepSkyBlue3

    set red red

    set bisque bisque3

    set green SeaGreen3

} else {

    set blue black

    set red black

    set bisque black

    set green black

}

# Set up demos within each of the areas of the grid.

$c create text 5c .2c -text Lines -anchor n

$c create line 1c 1c 3c 1c 1c 4c 3c 4c -width 2m -fill $blue \

	-cap butt -join miter -tags item

$c create line 4.67c 1c 4.67c 4c -arrow last -tags item

$c create line 6.33c 1c 6.33c 4c -arrow both -tags item

$c create line 5c 6c 9c 6c 9c 1c 8c 1c 8c 4.8c 8.8c 4.8c 8.8c 1.2c \

	8.2c 1.2c 8.2c 4.6c 8.6c 4.6c 8.6c 1.4c 8.4c 1.4c 8.4c 4.4c \

	-width 3 -fill $red -tags item

$c create line 1c 5c 7c 5c 7c 7c 9c 7c -width .5c \

	-stipple @[file join $tk_library demos images gray25.bmp] \

	-arrow both -arrowshape {15 15 7} -tags item

$c create line 1c 7c 1.75c 5.8c 2.5c 7c 3.25c 5.8c 4c 7c -width .5c \

	-cap round -join round -tags item

$c create text 15c .2c -text "Curves (smoothed lines)" -anchor n

$c create line 11c 4c 11.5c 1c 13.5c 1c 14c 4c -smooth on \

	-fill $blue -tags item

$c create line 15.5c 1c 19.5c 1.5c 15.5c 4.5c 19.5c 4c -smooth on \

	-arrow both -width 3 -tags item

$c create line 12c 6c 13.5c 4.5c 16.5c 7.5c 18c 6c \

	16.5c 4.5c 13.5c 7.5c 12c 6c -smooth on -width 3m -cap round \

	-stipple @[file join $tk_library demos images gray25.bmp] \

	-fill $red -tags item

$c create text 25c .2c -text Polygons -anchor n

$c create polygon 21c 1.0c 22.5c 1.75c 24c 1.0c 23.25c 2.5c \

	24c 4.0c 22.5c 3.25c 21c 4.0c 21.75c 2.5c -fill $green \

	-outline black -width 4 -tags item

$c create polygon 25c 4c 25c 4c 25c 1c 26c 1c 27c 4c 28c 1c \

	29c 1c 29c 4c 29c 4c -fill $red -smooth on -tags item

$c create polygon 22c 4.5c 25c 4.5c 25c 6.75c 28c 6.75c \

	28c 5.25c 24c 5.25c 24c 6.0c 26c 6c 26c 7.5c 22c 7.5c \

	-stipple @[file join $tk_library demos images gray25.bmp] \

	-outline black -tags item

$c create text 5c 8.2c -text Rectangles -anchor n

$c create rectangle 1c 9.5c 4c 12.5c -outline $red -width 3m -tags item

$c create rectangle 0.5c 13.5c 4.5c 15.5c -fill $green -tags item

$c create rectangle 6c 10c 9c 15c -outline {} \

	-stipple @[file join $tk_library demos images gray25.bmp] \

	-fill $blue -tags item

$c create text 15c 8.2c -text Ovals -anchor n

$c create oval 11c 9.5c 14c 12.5c -outline $red -width 3m -tags item

$c create oval 10.5c 13.5c 14.5c 15.5c -fill $green -tags item

$c create oval 16c 10c 19c 15c -outline {} \

	-stipple @[file join $tk_library demos images gray25.bmp] \

	-fill $blue -tags item

$c create text 25c 8.2c -text Text -anchor n

$c create rectangle 22.4c 8.9c 22.6c 9.1c

$c create text 22.5c 9c -anchor n -font $font1 -width 4c \

	-text "A short string of text, word-wrapped, justified left, and anchored north (at the top).  The rectangles show the anchor points for each piece of text." -tags item

$c create rectangle 25.4c 10.9c 25.6c 11.1c

$c create text 25.5c 11c -anchor w -font $font1 -fill $blue \

	-text "Several lines,\n each centered\nindividually,\nand all anchored\nat the left edge." \

	-justify center -tags item

$c create rectangle 24.9c 13.9c 25.1c 14.1c

$c create text 25c 14c -font $font2 -anchor c -fill $red -stipple gray50 \

	-text "Stippled characters" -tags item

$c create text 5c 16.2c -text Arcs -anchor n

$c create arc 0.5c 17c 7c 20c -fill $green -outline black \

	-start 45 -extent 270 -style pieslice -tags item

$c create arc 6.5c 17c 9.5c 20c -width 4m -style arc \

	-outline $blue -start -135 -extent 270 -tags item \

	-outlinestipple @[file join $tk_library demos images gray25.bmp]

$c create arc 0.5c 20c 9.5c 24c -width 4m -style pieslice \

	-fill {} -outline $red -start 225 -extent -90 -tags item

$c create arc 5.5c 20.5c 9.5c 23.5c -width 4m -style chord \

	-fill $blue -outline {} -start 45 -extent 270  -tags item

$c create text 15c 16.2c -text Bitmaps -anchor n

$c create bitmap 13c 20c -tags item \

	-bitmap @[file join $tk_library demos images face.bmp]

$c create bitmap 17c 18.5c -tags item \

	-bitmap @[file join $tk_library demos images noletter.bmp]

$c create bitmap 17c 21.5c -tags item \

	-bitmap @[file join $tk_library demos images letters.bmp]

$c create text 25c 16.2c -text Windows -anchor n

button $c.button -text "Press Me" -command "butPress $c $red"

$c create window 21c 18c -window $c.button -anchor nw -tags item

entry $c.entry -width 20 -relief sunken

$c.entry insert end "Edit this text"

$c create window 21c 21c -window $c.entry -anchor nw -tags item

scale $c.scale -from 0 -to 100 -length 6c -sliderlength .4c \

	-width .5c -tickinterval 0

$c create window 28.5c 17.5c -window $c.scale -anchor n -tags item

$c create text 21c 17.9c -text Button: -anchor sw

$c create text 21c 20.9c -text Entry: -anchor sw

$c create text 28.5c 17.4c -text Scale: -anchor s

# Set up event bindings for canvas:

$c bind item <Any-Enter> "itemEnter $c"

$c bind item <Any-Leave> "itemLeave $c"

bind $c <2> "$c scan mark %x %y"

bind $c <B2-Motion> "$c scan dragto %x %y"

bind $c <3> "itemMark $c %x %y"

bind $c <B3-Motion> "itemStroke $c %x %y"

bind $c <Control-f> "itemsUnderArea $c"

bind $c <1> "itemStartDrag $c %x %y"

bind $c <B1-Motion> "itemDrag $c %x %y"

# Utility procedures for highlighting the item under the pointer:

proc itemEnter {c} {

    global restoreCmd

    if {[winfo depth $c] == 1} {

	set restoreCmd {}

	return

    }

    set type [$c type current]

    if {$type == "window"} {

	set restoreCmd {}

	return

    }

    if {$type == "bitmap"} {

	set bg [lindex [$c itemconf current -background] 4]

	set restoreCmd [list $c itemconfig current -background $bg]

	$c itemconfig current -background SteelBlue2

	return

    }

    set fill [lindex [$c itemconfig current -fill] 4]

    if {(($type == "rectangle") || ($type == "oval") || ($type == "arc"))

	    && ($fill == "")} {

	set outline [lindex [$c itemconfig current -outline] 4]

	set restoreCmd "$c itemconfig current -outline $outline"

	$c itemconfig current -outline SteelBlue2

    } else {

	set restoreCmd "$c itemconfig current -fill $fill"

	$c itemconfig current -fill SteelBlue2

    }

}

proc itemLeave {c} {

    global restoreCmd

    eval $restoreCmd

}

# Utility procedures for stroking out a rectangle and printing what's

# underneath the rectangle's area.

proc itemMark {c x y} {

    global areaX1 areaY1

    set areaX1 [$c canvasx $x]

    set areaY1 [$c canvasy $y]

    $c delete area

}

proc itemStroke {c x y} {

    global areaX1 areaY1 areaX2 areaY2

    set x [$c canvasx $x]

    set y [$c canvasy $y]

    if {($areaX1 != $x) && ($areaY1 != $y)} {

	$c delete area

	$c addtag area withtag [$c create rect $areaX1 $areaY1 $x $y \

		-outline black]

	set areaX2 $x

	set areaY2 $y

    }

}

proc itemsUnderArea {c} {

    global areaX1 areaY1 areaX2 areaY2

    set area [$c find withtag area]

    set items ""

    foreach i [$c find enclosed $areaX1 $areaY1 $areaX2 $areaY2] {

	if {[lsearch [$c gettags $i] item] != -1} {

	    lappend items $i

	}

    }

    puts stdout "Items enclosed by area: $items"

    set items ""

    foreach i [$c find overlapping $areaX1 $areaY1 $areaX2 $areaY2] {

	if {[lsearch [$c gettags $i] item] != -1} {

	    lappend items $i

	}

    }

    puts stdout "Items overlapping area: $items"

}

set areaX1 0

set areaY1 0

set areaX2 0

set areaY2 0

# Utility procedures to support dragging of items.

proc itemStartDrag {c x y} {

    global lastX lastY

    set lastX [$c canvasx $x]

    set lastY [$c canvasy $y]

}

proc itemDrag {c x y} {

    global lastX lastY

    set x [$c canvasx $x]

    set y [$c canvasy $y]

    $c move current [expr {$x-$lastX}] [expr {$y-$lastY}]

    set lastX $x

    set lastY $y

}

# Procedure that's invoked when the button embedded in the canvas

# is invoked.

proc butPress {w color} {

    set i [$w create text 25c 18.1c -text "Ouch!!" -fill $color -anchor n]

    after 500 "$w delete $i"

}