webshot

#!/usr/bin/env perl
use common::sense;
use Gtk3 -init;
use Gtk3::WebKit;
use List::Util 'max';
use Getopt::Long;

sub usage {
    print <<END;

Usage: webshot [options] URI [out.png]

Options: 
    -h|--height     Height of the browser windown. If not specified
                    the window will be resized in order for HTML
                    document to fit inside

    -w|--width      Width of the window

    -s|--scale      If specified the resulting image will be scaled
                    to have this width, aspect ratio will be preserved
                    (Image::Magick is required)

    -t|--thumb      Filename to save scaled image. If not specified the 
                    output will be replaced

    -v|--verbose    Print error messages from the browser while 
                    processing the page

    --help          This help

END
    exit(0);
}

my ($height,$width,$scale,$thumb,$verbose);
GetOptions(
    'height=i'=> \$height,
    'width=i' => \$width,
    'scale=i' => \$scale,
    'thumb=s' => \$thumb,
    'verbose!'=> \$verbose,
    'help'    => \&usage
);

my $url = shift @ARGV || usage();
my $out = shift @ARGV || 'out.png';

unless ($verbose){
    open STDERR, '>', '/dev/null';
}

my $window = Gtk3::OffscreenWindow->new('toplevel');

$window->set_default_size($width||1024, $height||768);
$window->signal_connect(destroy => sub { Gtk3->main_quit() });

# Create a WebKit widget
my $view = Gtk3::WebKit::WebView->new();

# Load a page
$view->load_uri($url);

# Pack the widgets together
my $scrolls = Gtk3::ScrolledWindow->new();
$scrolls->add($view);
$window->add($scrolls);
$window->show_all();

# load and draw
Gtk3->main_iteration while Gtk3->events_pending or $view->get_load_status ne 'finished';

unless ($height) {
    # find content height
    my $html = $view->get_dom_document->get_document_element; 
    $height = max( $html->get_client_height, $html->get_scroll_height, $html->get_offset_height );

    # resize window
    $window->set_default_size($width||1024, $height);
    Gtk3->main_iteration while Gtk3->events_pending;
}

$window->get_surface()->write_to_png($out);
if ($scale) {
    require Image::Magick;
    my $img = new Image::Magick;
    $width ||= 1024;
    $height *= $scale/$width;
    $width = $scale;
    
    $img->Read($out);

    $img->Resize(
        width   => $width,
        height  => $height,
        filter  => 'Lagrange'
    );
    $img->Set( density => $width.'x'.$height );
    $img->Set( quality => '85' );
    $img->Write( filename => ($thumb||$out));
}