/usr/share/perl5/Layout/Manager.pm is in liblayout-manager-perl 0.34-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 | package Layout::Manager;
use Moose;
our $AUTHORITY = 'cpan:GPHAT';
our $VERSION = '0.34';
sub do_layout {
my ($self, $container) = @_;
die('Need a container') unless defined($container);
return 0 unless $container->component_count;
return 0 if $container->prepared && $self->_check_container($container);
# Layout child containers first, since we can't fit them into this one
# without knowing the sizes.
foreach my $comp (@{ $container->components }) {
next unless defined($comp) && $comp->visible;
if($comp->can('do_layout')) {
$comp->do_layout($comp);
}
}
$container->prepared(1);
return 1;
}
sub _check_container {
my ($self, $cont) = @_;
foreach my $comp (@{ $cont->components }) {
unless($comp->prepared) {
$cont->prepared(0);
return 0;
}
if($comp->can('do_layout')) {
if(!$self->_check_container($comp)) {
$comp->prepared(0);
return 0;
}
}
}
return 1;
}
__PACKAGE__->meta->make_immutable;
no Moose;
1;
__END__
=head1 NAME
Layout::Manager - 2D Layout Management
=head1 SYNOPSIS
Layout::Manager provides a simple interface for creating layout managers, or
classes that size and position components within a container.
A few managers are provided for reference, but this module is primarily meant
to serve as a base for outside implementations.
use Layout::Manager;
my $foo = Layout::Manager->new;
$foo->do_layout($component);
=head1 USING A LAYOUT MANAGER
Layout::Manager relies on L<Graphics::Primitive::Container> as a source for
it's components.
Various implementations of Layout::Manager will require you do add components
with slightly different second arguments, but the general case will be:
$lm->add_component($comp, $constraints);
The contents of B<$constraints> must be discerned by reading the documentation
for the layout manager you are using.
The B<$comp> argument must be a L<Graphics::Primitive::Component>.
Layout manager works hand-in-hand with Graphics::Primitive, so you'll want to
check out the L<lifecyle|Graphics::Primitive::Component#LIFECYCLE> documented
in L<Graphics::Primitive::Component>. It will look something like this:
$cont->add_component($foo, { some => metadata });
$driver->prepare($cont);
my $lm = new Layout::Manager::SomeImplementation;
$lm->do_layout($cont);
$driver->pack($cont);
$driver->draw($cont);
When you are ready to lay out your container, you'll need to call the
L<do_layout> method with a single argument: the component in which you are
laying things out. When I<do_layout> returns all of the components should be
resized and repositioned according to the rules of the Layout::Manager
implementation.
=head2 PREPARATION
Subsequent calls to do_layout will be ignored if the Container is prepared.
The Container's C<prepared> flag and the flags of all it's children are
checked, so any modifications to B<any> child component will cause the entire
container (and any container children) to be laid out again.
=head1 WRITING A LAYOUT MANAGER
Layout::Manager provides all the methods necessary for your implementation,
save the I<do_layout> method. This method will be called when it is time to
layout the components.
The I<add_component> method takes two arguments: the component and a second,
abritrary piece of data. If your layout manager is simple, like
L<Compass|Layout::Manager::Compass>, you may only require a simple variable
like "NORTH". If you create something more complex the second argument may be
a hashref or an object.
The value of the I<components> method is an arrayref of hashrefs. The
hashrefs have two keys:
=over
=item B<component>
The component to be laid out.
=item B<args>
The argument provided to I<add_component>.
=back
=head1 TIPS
Layout manager implementations should honor the I<visible> attribute of a
component, as those components need to be ignored.
=head1 METHODS
=head2 do_layout
Lays out this manager's components in the specified container.
=head1 AUTHOR
Cory Watson, C<< <gphat@cpan.org> >>
=head1 SEE ALSO
perl(1), L<Graphics::Primitive>
=head1 COPYRIGHT & LICENSE
Copyright 2008 - 2010 Cory G Watson
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
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