=pod

=head1 NAME

Gapp::Manual - An introduction to Gapp programming

=head1 POST-MODERN GUI APPLICATIONS

Gapp is a framework for creating GUI applications in Perl 5. Gapp is based on
Moose and Gtk2-Perl. Moose calls itself a I<post-modern> object system, and
relative to Perl 5, it is. Gapp aims to bring that same I<post-modern> feel to
developing Gtk+ applications in perl.

Applications maintain a consistent look and feel without hand-configuring every
widget. Gapp effectively separates GUI design from application logic and data
structures, while keeping your widgets and data up-to-date.

Gapp makes programming complex GUI applications fun and easy.

=head2 PREREQUISITES

Gapp uses both L<Moose> and L<Gtk2> extensively and assumes that the user
understands these modules as well. Any of the Gapp documentation that you find
lacking is probably covered by these modules.

=head2 Moose

The documentation for Moose can be found on the CPAN at
L<http://search.cpan.org/search?query=Moose>.

=head2 Gtk2

The documentation for Gtk2-Perl can be ound at
<http://gtk2-perl.sourceforge.net/doc/pod/index.html>.

The documentation for Gtk+ can be found at
L<http://library.gnome.org/devel/gtk/stable/>.


=head1 A BASIC APPLICATION

  use Gapp;

  $w = Gapp::Window->new(
    properties => {
      title => 'Gapp application',
    },
    signal_connect => [
      [ 'delete-event' => sub { Gapp->quit } ],
    ],
    content => [
      Gapp::Label->new( text => 'Hello World!' ),
    ]
  );

  $w->show_all;

  Gapp->main;
  
=head1 WIDGET PARAMETERS

=over 4

=item properties

Any properties you set here will be applied to the Gtk+ widget upon
construction. You may find valid parameters by referencing that Gtk+
documentation at L<http://library.gnome.org/devel/gtk/stable/>.

In this example we could have said:

  Gapp::Window->new (
    title => 'Gapp applicaiton'
  ...
  
This is because the C<title> parameter delegates to the C<title> property of
the Gtk widget. The documentation for the Gapp widget will provide more
information on properties that have been setup for delegation.

=item signal_connect

You may connect to signals using the C<signal_connect> parameter using the
format in the example.

=item content

You can add widgets to containers using the C<content> parameter. No formatting
options are specified here, just the heirarchy of the widgets. Spacing and
other rendering details are resolved by the layout. That will be discussed more
later.

=back

=head1 WIDGET CONSTRUCTION

As previously mentioned, Gapp is a layer over Gtk2. A L<Gapp::Widget> is used to
manage the construction of a L<Gtk2::Widget>.

The L<Gtk2::Widget> is created on the first call to C<Gapp::gtk_widget>. Make
all configurations to your widget before this happens; any change you make to
the L<Gapp::Widget> will not be reflected in the Gtk widget once it has been
constructed.

In our example program, the call to C<gtk_widget> was made implicitly by calling
C<show_all> all on the window. This is because C<show_all> is set up to delegate
to the Gtk widget's C<show_all> method. The documentation for the Gapp widget
will provide more information on methods that have been setup for delegation.

=head1 WIDGET LAYOUT

The layout determines how widgets are displayed on the screen. It has control
over things like spacing, alignment, borders, etc. By centralizing the code
the determines the appearance of widgets, it is is possible to achieve a
consistent look GUI. By making changes to the layout, you can affect the
appearnce of your whole application. You can subclass layouts too!

=head2 Using a Layout

Layouts are referenced using their class names. You can specify which layout to
use when constructing your widget. All widgets accept the C<layout> parameter.

  Gapp::Window->new( layout => 'My::Custom::Layout', content => ... );

=head2 Creating a Layout

You should see L<Gapp::Layout> for information on creating layouts.

=head1 ACTIONS

Actions can be performed and know how to display themselves in menu's and on
on buttons. You can call them directly or connect them to signals.

  use Gapp::Actions::Basic qw( Quit );

  # call directly
  do_Quit; 

  # connect to signal
  $w = Gapp::Window->new;
  $w->signal_connect( 'delete-event' => Quit );

  # display in menu
  Gapp::MenuItem->new( action => Quit );

You should see L<Gapp::Actions> for information on creatng and using actions.

=head1 TRAITS

Apply traits and roles to your widgets to change their behavior!
 
  Gapp::Entry->new( traits => [qw( MyCustomTrait )] );
  
=head1 FORMS

Advanced form handling allows you to easily get form data from widgets and
vice versa. You don't manually need to update each field in the form.

  $form = Gapp::VBox->new(
    traits => [qw( Form )],
    content => [ Gapp::Entry->new( field => 'user_name' ) ],
  );

=head1 EXTENDING

Gapp extensions provide added functionality. The GappX:: namespace is the
official place to find Gapp extensions. These extensi.ons can be found on the
CPAN.


=head1 AUTHORS

Jeffrey Ray Hallock E<lt>jeffrey.hallock at gmail dot comE<gt>

=head1 COPYRIGHT

    Copyright (c) 2011 Jeffrey Ray Hallock.
    This program is free software; you can redistribute it and/or
    modify it under the same terms as Perl itself.

=cut



