# items.pl
use subs qw/items_button_press items_drag items_enter items_leave items_mark
items_start_drag items_stroke items_under_area/;
use vars qw/$TOP/;
sub items {
# Create a top-level window containing a canvas that displays the various
# item types and allows them to be selected and moved.
my($demo) = @_;
$TOP = $MW->WidgetDemo(
-name => $demo,
-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\tdisplays items under area.", qw/-wraplength 5i/],
-title => 'Canvas Item Demonstration',
-iconname => 'items',
);
my $c = $TOP->Scrolled(qw/Canvas -width 15c -height 10c -relief sunken
-borderwidth 2 -scrollbars se -scrollregion/ =>
[qw/0c 0c 30c 24c/]);
$c->pack(qw/-expand yes -fill both/);
my %iinfo = (); # item information hash
$iinfo{areaX1} = 0;
$iinfo{areaY1} = 0;
$iinfo{areaX2} = 0;
$iinfo{areaY2} = 0;
$iinfo{restore_cmd} = '';
if ($Tk::VERSION cmp '800.015') {
# Display a 3x3 rectangular grid (800.016 or greater).
$c->createGrid(qw/0c 0c 10c 8c -width 2 -lines 1/);
$c->createGrid(qw/0c 0c 5c 4c -lines 1 -dash ./);
$c->createGrid(qw/0c 0c 10m 8m -width 1/);
} else {
# Display a 3x3 rectangular grid.
$c->createRectangle(qw/ 0c 0c 30c 24c -width 2/);
$c->createLine (qw/ 0c 8c 30c 8c -width 2/);
$c->createLine (qw/ 0c 16c 30c 16c -width 2/);
$c->createLine (qw/10c 0c 10c 24c -width 2/);
$c->createLine (qw/20c 0c 20c 24c -width 2/);
}
my $font1 = '-*-Helvetica-Medium-R-Normal--*-120-*-*-*-*-*-*';
my $font2 = '-*-Helvetica-Bold-R-Normal--*-240-*-*-*-*-*-*';
my($blue, $red, $bisque, $green);
if ($TOP->depth > 1) {
$blue = 'DeepSkyBlue3';
$red = 'red';
$bisque = 'bisque3';
$green = 'SeaGreen3';
} else {
$blue = 'black';
$red = 'black';
$bisque = 'black';
$green = 'black';
}
# Set up demos within each of the areas of the grid.
$c->createText(qw/5c .2c -text Lines -anchor n/);
$c->createLine(qw/1c 1c 3c 1c 1c 4c 3c 4c -width 2m/, -fill => $blue,
qw/-cap butt -join miter -tags item/);
$c->createLine(qw/4.67c 1c 4.67c 4c -arrow last -activedash - -tags item/);
$c->createLine(qw/6.33c 1c 6.33c 4c -arrow both -activedash . -tags item/);
$c->createLine(qw/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 -tags item -fill/ => $red);
$c->createLine(qw/1c 5c 7c 5c 7c 7c 9c 7c -width .5c/,
-stipple => '@'.Tk->findINC('demos/images/grey.25'),
qw/-arrow both -tags item -arrowshape/ => [15, 15, 7]);
$c->createLine(qw/1c 7c 1.75c 5.8c 2.5c 7c 3.25c 5.8c 4c 7c -width .5c
-cap round -join round -tags item/);
$c->createText(qw/15c .2c -anchor n -text/ => 'Curves (smoothed lines)');
$c->createLine(qw/11c 4c 11.5c 1c 13.5c 1c 14c 4c -smooth on/,
-fill =>$blue, qw/-tags item/);
$c->createLine(qw/15.5c 1c 19.5c 1.5c 15.5c 4.5c 19.5c 4c -smooth on
-arrow both -width 3 -tags item/);
$c->createLine(qw/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 -tags item/,
-stipple => '@'.Tk->findINC('demos/images/grey.25'),
-fill => $red);
$c->createText(qw/25c .2c -text Polygons -anchor n/);
$c->createPolygon(qw/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 -tags item/,
-fill => $green);
$c->createPolygon(qw/25c 4c 25c 4c 25c 1c 26c 1c 27c 4c 28c 1c 29c 1c
29c 4c 29c 4c -smooth on -tags item/, -fill => $red);
$c->createPolygon(qw/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 -tags item/,
-stipple => '@'.Tk->findINC('demos/images/grey.25'));
$c->createText(qw/5c 8.2c -text Rectangles -anchor n/);
$c->createRectangle(qw/1c 9.5c 4c 12.5c/, -outline => $red,
qw/-width 3m -tags item/);
$c->createRectangle(qw/0.5c 13.5c 4.5c 15.5c/, -fill => $green,
qw/-tags item/);
$c->createRectangle(qw/6c 10c 9c 15c -tags item/, -outline => undef,
-stipple => '@'.Tk->findINC('demos/images/grey.25'),
-fill => $blue);
$c->createText(qw/15c 8.2c -text Ovals -anchor n/);
$c->createOval(qw/11c 9.5c 14c 12.5c/, -outline => $red,
qw/-width 3m -tags item/);
$c->createOval(qw/10.5c 13.5c 14.5c 15.5c/, -fill => $green,
qw/-tags item/);
$c->createOval(qw/16c 10c 19c 15c -tags item/, -outline => undef,
-stipple => '@'.Tk->findINC('demos/images/grey.25'),
-fill => $blue);
$c->createText(qw/25c 8.2c -text Text -anchor n/);
$c->createRectangle(qw/22.4c 8.9c 22.6c 9.1c/);
$c->createText(qw/22.5c 9c -anchor n -width 4c/, -font => $font1,
-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.', qw/-tags item/);
$c->createRectangle(qw/25.4c 10.9c 25.6c 11.1c/);
$c->createText(qw/25.5c 11c -anchor w/, -font => $font1, -fill => $blue,
-text => "Several lines,\n each centered\n" .
"individually,\nand all anchored\nat the left edge.",
qw/-justify center -tags item/);
$c->createRectangle(qw/24.9c 13.9c 25.1c 14.1c/);
$c->createText(qw/25c 14c -anchor c/, -font => $font2, -fill => $red,
-stipple => 'gray50',
-text => 'Stippled characters', qw/-tags item/);
$c->createText(qw/5c 16.2c -text Arcs -anchor n/);
$c->createArc(qw/0.5c 17c 7c 20c/, -fill => $green, qw/-outline black/,
-stipple => '@'.Tk->findINC('demos/images/grey.25'),
qw/-start 45 -extent 270 -style pieslice -tags item/);
$c->createArc(qw/6.5c 17c 9.5c 20c -width 4m -style arc/, -fill => $blue,
qw/-start -135 -extent 270 -tags item/);
$c->createArc(qw/0.5c 20c 9.5c 24c -width 4m -style pieslice/,
-fill => undef, -outline => $red,
qw/-start 225 -extent -90 -tags item/);
$c->createArc(qw/5.5c 20.5c 9.5c 23.5c -width 4m -style chord/,
-fill => $blue, -outline => undef,
qw/-start 45 -extent 270 -tags item/);
$c->createText(qw/15c 16.2c -text Bitmaps -anchor n/);
$c->createBitmap(qw/13c 20c -bitmap/ =>
'@'.Tk->findINC('demos/images/face'), qw/-tags item/);
$c->createBitmap(qw/17c 18.5c/,
-bitmap => '@'.Tk->findINC('demos/images/noletters'),
qw/-tags item/);
$c->createBitmap(qw/17c 21.5c/,
-bitmap => '@'.Tk->findINC('demos/images/letters'),
qw/-tags item/);
$c->createText(qw/25c 16.2c -text Windows -anchor n/);
my $c_button = $c->Button(-text => 'Press Me',
-command => [\&items_button_press, $c, $red],
);
$c->createWindow(qw/21c 18c/, -window => $c_button,
qw/-anchor nw -tags item/);
my $c_entry = $c->Entry(-width => '20', -relief => 'sunken',
-validate => 'all',
-validatecommand => sub {$n++ ? 1 : 0},
-invalidcommand => sub {$TOP->bell});
$c_entry->insert('end' => 'Edit this text');
$c->createWindow(qw/21c 21c/, -window => $c_entry,
qw/-anchor nw -tags item/);
my $c_scale = $c->Scale(qw/-from 0 -to 100 -length 6c -sliderlength .4c
-width .5c -tickinterval 0/);
$c->createWindow(qw/28.5c 17.5c/, -window => $c_scale,
qw/-anchor n -tags item/);
$c->createText(qw/21c 17.9c -text Button: -anchor sw/);
$c->createText(qw/21c 20.9c -text Entry: -anchor sw/);
$c->createText(qw/28.5c 17.4c -text Scale: -anchor s/);
# Set up event bindings for canvas.
$c->bind('item', '<Any-Enter>' => [\&items_enter, \%iinfo]);
$c->bind('item', '<Any-Leave>' => [\&items_leave, \%iinfo]);
# Get real canvas widget reference to apply bind() commands to: the
# Canvas widget is a subwidget of the Scrolled composite widget. To
# reference the X event structure, either use the XEvent() method or
# read the specially localized variable $Tk::event. We'll use XEvent
# first, and the variable from then on.
$c->CanvasBind('<<Copy>>',sub { print "Do Copy\n" });
$c->CanvasBind('<1>' => sub {
my($c) = @_;
my $e = $c->XEvent;
items_start_drag $c, $e->x, $e->y, \%iinfo;
});
$c->CanvasBind('<B1-Motion>' =>
sub {items_drag shift, $Tk::event->x, $Tk::event->y, \%iinfo});
$c->CanvasBind('<2>' =>
sub {shift->scan('mark', $Tk::event->x, $Tk::event->y)});
$c->CanvasBind('<B2-Motion>' =>
sub {shift->scan('dragto', $Tk::event->x, $Tk::event->y)});
$c->CanvasBind('<3>' =>
sub {items_mark shift, $Tk::event->x, $Tk::event->y, \%iinfo});
$c->CanvasBind('<B3-Motion>' =>
sub {items_stroke shift, $Tk::event->x, $Tk::event->y, \%iinfo});
$c->CanvasBind('<Control-f>' => [sub {
my($c, $iinfo) = @_;
my $e = $c->XEvent;
items_under_area $c, $iinfo;
}, \%iinfo]);
$c->CanvasBind('<Any-Enter>' => sub {$_[0]->CanvasFocus});
} # end items
# Utility procedures for highlighting the item under the pointer:
sub items_button_press {
# Procedure that's invoked when the button embedded in the canvas
# is invoked.
my($w, $color) = @_;
my $i = $w->createText(qw/25c 18.1c -anchor n/, -text => 'Ouch!!',
-fill => $color);
$w->after(500, sub { $w->delete($i) });
} # end items_button_press
sub items_drag {
my($c, $x, $y, $iinfo) = @_;
$x = $c->canvasx($x);
$y = $c->canvasy($y);
$c->move('current', $x-$iinfo->{lastX}, $y-$iinfo->{lastY});
$iinfo->{lastX} = $x;
$iinfo->{lastY} = $y;
} # end items_drag
sub items_enter {
my($c, $iinfo) = @_;
$iinfo->{restore_cmd} = '';
if ($TOP->depth == 1) {
$iinfo->{restore_cmd} = '';
return;
}
my $type = $c->type('current');
if ($type eq 'window') {
$iinfo->{restore_cmd} = '';
return;
}
if ($type eq 'bitmap') {
my $bg = ($c->itemconfigure(qw/current -background/))[4];
if (defined $bg) {
$iinfo->{restore_cmd} = "\$c->itemconfigure('current',
-background => '$bg');";
} else {
$iinfo->{restore_cmd} = "\$c->itemconfigure('current',
-background => undef);";
}
$c->itemconfigure(qw/current -background SteelBlue2/);
return;
}
my $fill = ($c->itemconfigure(qw/current -fill/))[4];
my $stipple = ($c->itemconfigure(qw/current -stipple/))[4];
if (defined $stipple) {
$iinfo->{restore_cmd} = "\$c->itemconfigure('current',
-stipple => '$stipple')";
$c->itemconfigure(qw/current -stipple /,'');
} elsif (($type eq 'rectangle' or $type eq 'oval' or $type eq 'arc')
and not defined $fill) {
my $outline = ($c->itemconfigure(qw/current -outline/))[4];
$iinfo->{restore_cmd} = "\$c->itemconfigure('current',
-outline => '$outline')";
$c->itemconfigure(qw/current -outline SteelBlue2/);
} else {
$iinfo->{restore_cmd} = "\$c->itemconfigure('current',
-fill => '$fill')";
$c->itemconfigure(qw/current -fill SteelBlue2/);
}
} # end items_enter
sub items_leave {
my($c, $iinfo) = @_;
eval $iinfo->{restore_cmd};
} # end items_leave
sub items_mark {
my($c, $x, $y, $iinfo) = @_;
$iinfo->{areaX1} = $c->canvasx($x);
$iinfo->{areaY1} = $c->canvasy($y);
$c->delete('area');
} # end items_mark
sub items_start_drag {
my($c, $x, $y, $iinfo) = @_;
$iinfo->{lastX} = $c->canvasx($x);
$iinfo->{lastY} = $c->canvasy($y);
} # end items_start_drag
sub items_stroke {
my($c, $x, $y, $iinfo) = @_;
$x = $c->canvasx($x);
$y = $c->canvasy($y);
if (($iinfo->{areaX1} != $x) and ($iinfo->{areaY1} != $y)) {
$c->delete('area');
$c->addtag('area', 'withtag', $c->create('rectangle',
$iinfo->{areaX1}, $iinfo->{areaY1}, $x, $y, -outline => 'black'));
$iinfo->{areaX2} = $x;
$iinfo->{areaY2} = $y;
}
} # end items_stroke
sub items_under_area {
my($c, $iinfo) = @_;
my $area = $c->find('withtag', 'area');
my @items = ();
my $i;
foreach $i ($c->find('enclosed', $iinfo->{areaX1},
$iinfo->{areaY1}, $iinfo->{areaX2}, $iinfo->{areaY2})) {
my @tags = $c->gettags($i);
if (defined($tags[0]) and grep $_ eq 'item', @tags) {
push @items, $i;
}
}
@items = 'None' unless @items;
print STDOUT 'Items enclosed by area: ', join(' ', @items), ".\n";
@items = ();
foreach $i ($c->find('overlapping', $iinfo->{areaX1}, $iinfo->{areaY1},
$iinfo->{areaX2}, $iinfo->{areaY2})) {
my @tags = $c->gettags($i);
if (defined($tags[0]) and grep $_ eq 'item', @tags) {
push @items, $i;
}
}
@items = 'None' unless @items;
print STDOUT 'Items overlapping area: ', join(' ', @items), ".\n";
} # end items_under_area
1;