=head1 NAME

 UI::Dialog::Backend::Whiptail - Backend for the Whiptail dialog variant

=head1 SYNOPSIS

  use UI::Dialog::Backend::Whiptail;
  my $d = new UI::Dialog::Backend::Whiptail ( backtitle => 'Demo',
                                              title => 'Default' );

  $d->msgbox( title => 'Welcome!', text => 'Welcome one and all!' );

=head1 ABSTRACT

UI::Dialog::Backend::Whiptail is the UI::Dialog backend for the Whiptail
dialog variant. While this module is used through UI::Dialog or any other loader
module only the compatible methods are ever accessible. However, when using
this module directly in your application (as in the SYNOPSIS example) you are
given access to all the options and features of the real whiptail(1) application.

=head1 DESCRIPTION

This dialog variant is the staple of the Debian console apt/dpkg interface. There
isn't very much interesting about this particular backend. This is very much a
basic dialog variant in comparison to things like Xdialog and cDialog.

=head1 EXPORT

=over 2

 None

=back

=head1 INHERITS

=over 2

 UI::Dialog::Backend

=back

=head1 CONSTRUCTOR

=head2 new( @options )

=over 4

=item EXAMPLE

=over 6

 my $d = new( title => 'Default Title', backtitle => 'Backtitle',
              width => 65, height => 20, listheight => 5 );

=back

=item DESCRIPTION

=over 6

This is the Class Constructor method. It accepts a list of key => value pairs
and uses them as the defaults when interacting with the various widgets.

=back

=item RETURNS

=over 6

 A blessed object reference of the UI::Dialog::Backend::Whiptail class.

=back

=item OPTIONS

The (...)'s after each option indicate the default for the option. An * denotes
support by all the widget methods on a per-use policy defaulting to the values
decided during object creation.

=over 6

=item B<debug = 0,1,2> (0)

=item B<literal = 0,1> (0)

=item B<backtitle = "backtitle"> ('') *

=item B<title = "title"> ('') *

=item B<height = \d+> (0) *

=item B<listheight = \d+> (5) *

=item B<width = \d+> (0) *

=item B<beepbefore = 0,1> (0) *

=item B<beepafter = 0,1> (0) *

=back

=back

=head1 WIDGET METHODS

=head2 yesno( )

=over 4

=item EXAMPLE

=over 6

 if ($d->yesno( text => 'A binary type question?') ) {
     # user pressed yes
 } else {
     # user pressed no or cancel
 }

=back

=item DESCRIPTION

=over 6

Present the end user with a message box that has two buttons, yes and no.

=back

=item RETURNS

=over 6

 TRUE (1) for a response of YES or FALSE (0) for anything else.

=back

=back

=head2 msgbox( )

=over 4

=item EXAMPLE

=over 6

 $d->msgbox( text => 'A simple message' );

=back

=item DESCRIPTION

=over 6

Pesent the end user with a message box that has an OK button.

=back

=item RETURNS

=over 6

TRUE (1) for a response of OK or FALSE (0) for anything else.

=back

=back

=head2 infobox( )

=over 4

=item EXAMPLE

=over 6

 $d->infobox( text => 'A simple 6 second message.', timeout => 6000 );

=back

=item DESCRIPTION

=over 6

Pesent the end user with a message box for a limited duration of time. The
timeout is specified in thousandths of a second, ie: 1000 = 1 second.

=back

=item RETURNS

=over 6

TRUE (1) for a response of OK or FALSE (0) for anything else.

=back

=back

=head2 password( )

=over 4

=item EXAMPLE

=over 6

 my $string = $d->password( text => 'Enter some (hidden) text.' );

=back

=item DESCRIPTION

=over 6

Present the end user with a text input field that doesn't reveal the input
(except to the script) and a message.

=back

=item RETURNS

=over 6

a SCALAR if the response is OK and FALSE (0) for anything else.

=back

=back

=head2 inputbox( )

=over 4

=item EXAMPLE

=over 6

 my $string = $d->inputbox( text => 'Enter some text.',
                            entry => 'this is the input field' );

=back

=item DESCRIPTION

=over 6

Present the end user with a text input field and a message.

=back

=item RETURNS

=over 6

a SCALAR if the response is OK and FALSE (0) for anything else.

=back

=back

=head2 textbox( )

=over 4

=item EXAMPLE

=over 6

 $d->textbox( path => '/path/to/a/text/file' );

=back

=item DESCRIPTION

=over 6

Present the end user with a simple scrolling box containing the contents
of the given text file.

=back

=item RETURNS

=over 6

TRUE (1) if the response is OK and FALSE (0) for anything else.

=back

=back

=head2 menu( )

=over 4

=item EXAMPLE

=over 6

 my $selection1 = $d->menu( text => 'Select one:',
                            list => [ 'tag1', 'item1',
                                      'tag2', 'item2',
                                      'tag3', 'item3' ]
                          );

=back

=item DESCRIPTION

=over 6

Present the user with a selectable list.

=back

=item RETURNS

=over 6

a SCALAR of the chosen tag if the response is OK and FALSE (0) for
anything else.

=back

=back

=head2 checklist( )

=over 4

=item EXAMPLE

=over 6

 my @selection = $d->checklist( text => 'Select one:',
                                list => [ 'tag1', [ 'item1', 0 ],
                                          'tag2', [ 'item2', 1 ],
                                          'tag3', [ 'item3', 1 ] ]
                              );

=back

=item DESCRIPTION

=over 6

Present the user with a selectable checklist.

=back

=item RETURNS

=over 6

an ARRAY of the chosen tags if the response is OK and FALSE (0) for
anything else.

=back

=back

=head2 radiolist( )

=over 4

=item EXAMPLE

=over 6

 my $selection = $d->radiolist( text => 'Select one:',
                                list => [ 'tag1', [ 'item1', 0 ],
                                          'tag2', [ 'item2', 1 ],
                                          'tag3', [ 'item3', 0 ] ]
                              );

=back

=item DESCRIPTION

=over 6

Present the user with a selectable radiolist.

=back

=item RETURNS

=over 6

a SCALAR of the chosen tag if the response is OK and FALSE (0) for
anything else.

=back

=back

=head2 fselect( )

=over 4

=item EXAMPLE

=over 6

 my $text = $d->fselect( path => '/path/to/a/file/or/directory' );

=back

=item DESCRIPTION

=over 6

Present the user with a file selection widget preset with the given path.

=back

=item RETURNS

=over 6

a SCALAR if the response is OK and FALSE (0) for anything else.

=back

=back

=head2 dselect( )

=over 4

=item EXAMPLE

=over 6

 my $text = $d->dselect( path => '/path/to/a/directory' );

=back

=item DESCRIPTION

=over 6

Present the user with a file selection widget preset with the given path.
Unlike fselect() this widget will only return a directory selection.

=back

=item RETURNS

=over 6

a SCALAR if the response is OK and FALSE (0) for anything else.

=back

=back

=head2 gauge_start( )

=over 4

=item EXAMPLE

=over 6

 $d->gauge_start( text => 'gauge...', percentage => 1 );

=back

=item DESCRIPTION

=over 6

Display a meter bar to the user. This get's the widget realized but requires
the use of the other gauge_*() methods for functionality.

=back

=item RETURNS

=over 6

TRUE (1) if the widget loaded fine and FALSE (0) for anything else.

=back

=back

=head2 gauge_inc( )

=over 4

=item EXAMPLE

=over 6

 $d->gauge_inc( 1 );

=back

=item DESCRIPTION

=over 6

Increment the meter by the given amount.

=back

=item RETURNS

=over 6

TRUE (1) if the widget incremented fine and FALSE (0) for anything else.

=back

=back

=head2 gauge_dec( )

=over 4

=item EXAMPLE

=over 6

 $d->gauge_dec( 1 );

=back

=item DESCRIPTION

=over 6

Decrement the meter by the given amount.

=back

=item RETURNS

=over 6

TRUE (1) if the widget incremented fine and FALSE (0) for anything else.

=back

=back

=head2 gauge_set( )

=over 4

=item EXAMPLE

=over 6

 $d->gauge_set( 99 );

=back

=item DESCRIPTION

=over 6

Set the meter bar to the given amount.

=back

=item RETURNS

=over 6

TRUE (1) if the widget set fine and FALSE (0) for anything else.

=back

=back

=head2 gauge_text( )

=over 4

=item EXAMPLE

=over 6

 $d->gauge_text( 'string' );

=back

=item DESCRIPTION

=over 6

Set the meter bar message to the given string.

=back

=item RETURNS

=over 6

TRUE (1) if the widget set fine and FALSE (0) for anything else.

=back

=back

=head2 gauge_stop( )

=over 4

=item EXAMPLE

=over 6

 $d->gauge_stop();

=back

=item DESCRIPTION

=over 6

End the meter bar widget process.

=back

=item RETURNS

=over 6

TRUE (1) if the widget closed fine and FALSE (0) for anything else.

=back

=back

=head1 SEE ALSO

=over 2

=item PERLDOC

 UI::Dialog
 UI::Dialog::Console
 UI::Dialog::Backend

=back

=over 2

=item MAN FILES

 whiptail(1)

=back

=head1 BUGS

 Please email the author with any bug reports. Include the name of the
 module in the subject line.

=head1 AUTHOR

 Kevin C. Krinke, E<lt>kevin@krinke.caE<gt> 

=head1 COPYRIGHT AND LICENSE

 Copyright (C) 2004-2016  Kevin C. Krinke <kevin@krinke.ca>

 This library is free software; you can redistribute it and/or
 modify it under the terms of the GNU Lesser General Public
 License as published by the Free Software Foundation; either
 version 2.1 of the License, or (at your option) any later version.

 This library is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 Lesser General Public License for more details.

 You should have received a copy of the GNU Lesser General Public
 License along with this library; if not, write to the Free Software
 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA

=cut