Gtk2::Ex::PodViewer - a Gtk2 widget for displaying Plain old Documentation (POD).

NB: This module used to be called Gtk2::PodViewer. That module is now a stub that points to this module.

        use Gtk2 -init;
        use Gtk2::Ex::PodViewer;

        my $viewer = Gtk2::Ex::PodViewer->new;

        $viewer->load('/path/to/file.pod');     # load a file
        $viewer->load('IO::Scalar');            # load a module
        $viewer->load('perlvar');               # load a perldoc
        $viewer->load('bless');                 # load a function

        $viewer->show;                          # see, it's a widget!

        my $window = Gtk2::Window->new;
        $window->add($viewer);

        $window->show;

        Gtk2->main;

Gtk2::Ex::PodViewer is a widget for rendering Perl POD documents. It is based on the Gtk2::TextView widget and uses Pod::Parser for manipulating POD data.

Gtk2::Ex::PodViewer widgets inherit all the methods and properties of Gtk2::TextView widgets. Full information about text buffers can be found in the Gtk+ documentation at <http://developer.gnome.org/doc/API/2.0/gtk/GtkTextView.html>.

        L<Glib::Object>
        +--- L<Gtk2::Object>
             +--- L<Gtk2::Widget>
                  +--- L<Gtk2::Editable>
                       +--- L<Gtk2::TextView>
                            +--- L<Gtk2::Ex::PodViewer>

        my $view = Gtk2::Ex::PodViewer->new;

creates and returns a new Gtk2::Ex::PodViewer widget.

        $viewer->clear;

This clears the viewer's buffer and resets the iter. You should never need to use this method since the loader methods (see Document Loaders below) will do it for you.

        my $db = $viewer->get_db;

This method returns a hashref that contains the POD document database used internally by Gtk2::Ex::PodViewer. If you want to improve startup performance, you can cache this database using a module like CWStorable. To load a cached database into a viewer object, call

        $viewer->set_db($db);

before making a call to any of the document loader methods below (otherwise, Gtk2::Ex::PodViewer will create a new database for itself). If you want to tell Gtk2::Ex::PodViewer to create a new document database (for example, after a new module has been installed), use

        $viewer->reinitialize_db;

        @marks = $view->get_marks;

This returns an array of section headers. So for example, a POD document of the form

        =pod

        =head1 NAME

        =head1 SYNOPSIS

        =cut

would result in

        @marks = ('NAME', 'SYNOPSIS');

You can then use the contents of this array to create a document index.

        $name = 'SYNOPSIS';

        $mark = $view->get_mark($name);

returns the GtkTextMark object referred to by CW$name.

        $name = 'SYNOPSIS';

        $view->jump_to($name);

this scrolls the PodViewer window to the selected mark.

        $viewer->load($document);

Loads a given document. CW$document can be a perldoc name (eg., CW'perlvar'), a module (eg. CW'IO::Scalar'), a filename or the name of a Perl builtin function from perlfunc. Documents are searched for in that order, that is, the perlvar document will be loaded before a file called CWperlvar in the current directory.

The CWload() method is a wrapper to a number of specialised document loaders. You can call one of these loaders directly to override the order in which Gtk2::Ex::PodViewer searches for documents:

        $viewer->load_doc($perldoc);

loads a perldoc file or Perl module documentation, or undef on failure.

        $viewer->load_file($file);

loads POD from a file, or returns undef on failure.

        $viewer->load_function($function);

This method scans the perlfunc POD document for the documentation for a given function. The algorithm for this is lifted from the Pod::Perldoc module, so it should work identically to CWperldoc -f [function].

        $viewer->load_string($string);

This method renders the POD data in the CW$string variable.

The following document loads are now deprecated, and are now just wrapper of the CWload_doc method:

        $viewer->load_perldoc($perldoc);
        $viewer->load_module($module);

        $parser = $view->parser;

returns the CWGtk2::Ex::PodViewer::Parser object used to render the POD data.

Gtk2::Ex::PodViewer inherits all of Gtk2::TextView's signals, and has the following:

        $viewer->signal_connect('link_clicked', \&clicked);

        sub clicked {
                my ($viewer, $link_text) = @_;
                print "user clicked on '$link_text'\n";
        }

Emitted when the user clicks on a hyperlink within the POD. This may be a section title, a document name, or a URL. The receiving function will be giving two arguments: a reference to the Gtk2::Ex::PodViewer object, and a scalar containing the link text.

        $viewer->signal_connect('link_enter', \&enter);

        sub enter {
                my ($viewer, $link_text) = @_;
                print "user moused over '$link_text'\n";
        }

Emitted when the user moves the mouse pointer over a hyperlink within the POD. This may be a section title, a document name, or a URL. The receiving function will be giving two arguments: a reference to the Gtk2::Ex::PodViewer object, and a scalar containing the link text.

        $viewer->signal_connect('link_leave', \&leave);

        sub clicked {
                my $viewer = shift;
                print "user moused out\n";
        }

Emitted when the user moves the mouse pointer out from a hyperlink within the POD.

You can set the font used to render text in a Gtk2::Ex::PodViewer widget like so:

        $viewer->modify_font(Gtk2::Pango::FontDescription->from_string($FONT_NAME);

To modify the appearance of the various elements of the page, you need to extract the Gtk2::TextTag from the viewer's buffer:

        my $tag = $viewer->get_buffer->get_tag_table->lookup('monospace');
        $tag->set('font' => $FONT_NAME);

The tags used by Gtk2::Ex::PodViewer are: Used to format bold text. Used to format italic text. Used to format headers. Used to format preformatted text. Used to format inline preformatted text. Used to format hyperlinks.

CWpodviewer is installed with Gtk2::Ex::PodViewer. It is a simple Pod viewing program. It is pretty minimal, but does do the job quite well. Those looking for a more feature-complete documentation browser should try PodBrowser, available from <http://jodrell.net/projects/podbrowser>.

Gtk2::Ex::PodViewer is a work in progress. All comments, complaints, offers of help and patches are welcomed.

We currently know about these issues:

•

When rendering long documents the UI freezes for too long.

•

Some strangeness with Unicode.

•

Gtk2 (obviously). The most recent version will be from <http://gtk2-perl.sf.net/>.

•

Pod::Parser

•

IO::Scalar

•

Pod::Simple::Search

Gtk2::Ex::PodViewer::Parser, which is part of the Gtk2::Ex::PodViewer distribution, also requires Locale::gettext.

•

Gtk2 or <http://gtk2-perl.sf.net/>

•

<http://developer.gnome.org/doc/API/2.0/gtk/GtkTextView.html>

•

Gtk2::Ex::PodViewer::Parser

Gavin Brown, Torsten Schoenfeld and Scott Arrington.

(c) 2003-2005 Gavin Brown (gavin.brown@uk.com). All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.