=head1 NAME

Tk::AppWindow::CookBook - Some recipies

=head1 OTHER RECIPIES

=over 4

=item L<Tk::AppWindow::CookBook::Extension>

=item L<Tk::AppWindow::CookBook::Plugin>

=item L<Tk::AppWindow::CookBook::ContentManager>

=back

=head1 A SIMPLE IMAGE VIEWER

  #!/usr/bin/perl
  
  use strict;
  use warnings;
  
  
  ################################################################
  # First define the content manager. a content manager handles  #
  # the basic tasks like loading, saving, displaying and         #
  # modifying files. The content manager does the actual work.   #
  ################################################################
  package ImageManager;
  
  use base qw(Tk::Derived Tk::AppWindow::BaseClasses::ContentManager);
  Construct Tk::Widget 'ImageManager';
  require Tk::Pane;
  require Tk::Photo;
  use Tk::PNG;
  use File::Basename;
  use MIME::Base64;
  use Imager;
  
  #Determining which image types we can use;
  my %photoext = ();
  my @types = keys %Imager::formats;
  for (@types) {
     $photoext{'.jpg'} = 1 if $_ eq 'jpeg';
     $photoext{".$_"} = 1;
  }
  
  sub Populate {
     my ($self, $args) = @_;
     
     $self->SUPER::Populate($args);
     #We create a scrolled pane as main viewer. 
     #In it we pack a label with the image.
     my $pn = $self->Scrolled('Pane',
        -scrollbars => 'osoe',
     )->pack(-expand => 1, -fill => 'both');
     $self->CWidg($pn);
     $self->{FILE} = '';
     $self->{IMAGE} = undef;
     $self->ConfigSpecs(
        -zoomto => ['PASSIVE', undef, undef, 'fit'],
        DEFAULT => [$pn],
     );
  }
  
  #overwritten method
  sub doClear {
     my $self = shift;
     $self->{FILE} = '';
     $self->ViewerClear;
     $self->{IMAGE} = undef;
  }
  
  #overwritten method
  sub doLoad {
     my ($self, $file) = @_;
     $self->{FILE} = $file;
     if (-e $file) {
        my ($name,$path,$suffix) = fileparse(lc($file), keys %photoext);
        if (exists $photoext{lc($suffix)}) {
           my $img = Imager->new;
           $img->read(file=>$file) or warn "Cannot read: ", $img->errstr;
           $self->{IMAGE} = $img if defined $img;
        } else {
           warn "Not an image $file"
        }
     } else {
        warn "$file does not exist";
     }
     $self->after(100, ['ZoomDefault', $self]);
     return 1
  }
  
  sub ZoomDefault {
     my $self = shift;
     my $scale = $self->cget('-zoomto');
     if ($scale eq 'fit') {
        $self->ZoomToFit
     } else {
        $self->Zoom($scale)
     }
  }
  
  sub Zoom {
     my ($self, $perc) = @_;
     return $self->ZoomToFit if $perc eq 'fit';
     my $scale = $perc / 100;
     my $img = $self->{IMAGE};
     if (defined $img) {
        my $width = int($img->getwidth * $scale);
        my $height = int($img->getheight * $scale);
        my $new = $img->scale(xpixels => $width, ypixels => $height);
        $self->ViewerClear;
        my $data;
        $new->write(data => \$data, type => 'png');
        my $l = $self->CWidg->Label(
           -image => $self->Photo(
              -data => encode_base64($data), 
              -format => 'png',
           ),
        )->pack;
        $self->{LABEL} = $l;
     }
  }
  
  sub ZoomToFit {
     my $self = shift;
     my $img = $self->{IMAGE};
     if (defined $img) {
        my $pane = $self->CWidg;
        my $x = $pane->width - 4;
        my $y = $pane->height - 4;
        my $width = $img->getwidth;
        my $height = $img->getheight;
        my $scale;
        my $xs = $x / $width;
        my $ys = $y / $height;
        if ($xs > $ys) {
           $scale = $ys
        } else {
           $scale = $xs
        }
        $self->Zoom($scale * 100);
     }
  }
  
  sub ViewerClear {
     my $self = shift;
     my $i = $self->{LABEL};
     $i->destroy if defined $i;
     $self->{LABEL} = undef;
     $self->update;
  }
  
  ################################################################
  # Now that we have a content manager ...                       #
  # We can define the main package                               #
  ################################################################
  
  package main;
  
  require Tk::AppWindow;
  
  my @scales = (400, 200, 100, 50, 25, 10);
  
  my $iv;
  $iv = Tk::AppWindow->new(
     -appname => 'Siv',
     -contentmanagerclass => 'ImageManager',
     -contentmanageroptions => ['-scaleto'],
     -extensions => [qw[Art MDI ToolBar StatusBar MenuBar Selector Settings]],
     -readonly => 1,
     -mainmenuitems => [
        [   'menu',             'View',         "~Zoom"    ], 
        [   'menu_normal',      'Zoom::',      "~Fit",         'scaletofit',            'transform-scale' ], 
        [   'menu_normal',      'Zoom::',      "400",         'scaleto400',            'transform-scale' ], 
        [   'menu_normal',      'Zoom::',      "200",         'scaleto200',            'transform-scale' ], 
        [   'menu_normal',      'Zoom::',      "100",         'scaleto100',            'transform-scale' ], 
        [   'menu_normal',      'Zoom::',      "50",         'scaleto50',            'transform-scale' ], 
        [   'menu_normal',      'Zoom::',      "25",         'scaleto25',            'transform-scale' ], 
        [   'menu_normal',      'Zoom::',      "10",         'scaleto10',            'transform-scale' ], 
     ],
     -useroptions => [
        '*page' => 'Bars',
         '*section' => 'Menubar',
         -menuiconsize => ['list', 'Icon size', -values => sub { return $iv->cmdExecute('available_icon_sizes') }],
         '*end',
        '*section' => 'Toolbar',
        -toolbarvisible => ['boolean', 'Visible at launch'],
         -tooliconsize => ['list', 'Icon size', -values => sub { return $iv->cmdExecute('available_icon_sizes') }],
        -tooltextposition => ['radio', 'Text position', -values => [qw[none left right top bottom]]],
        '*end',
        '*section' => 'Statusbar',
        -statusbarvisible => ['boolean', 'Visible at launch'],
        '*end',
     ],
  );
  
  $iv->cmdConfig('scaletofit' => [\&Zoom, 'fit']);
  for (@scales) {
     my $scale = $_;
     $iv->cmdConfig("scaleto$scale" => [\&Zoom, $scale])
  }
  
  $iv->MainLoop;
  
  sub Zoom {
     my $perc = shift;
     my $mdi = $iv->extGet('MDI');
     my $sel = $mdi->docSelected;
     if (defined $sel) {
        my $doc = $mdi->docGet($sel);
        $doc->Zoom($perc);
     }
  }

=head1 AUTHOR

Hans Jeuken (hanje at cpan dot org)

=head1 SEE ALSO

=over 4

=item L<Tk::AppWindow>

=item L<Tk::AppWindow::BaseClasses::Extension>

=item L<Tk::AppWindow::BaseClasses::SidePanel>

=item L<Tk::AppWindow::Ext::Panels>

=back

=cut





