NAME

       Graph::Easy::Layout::Chain - Chain of nodes for layouter

SYNOPSIS

               # used internally, do not use directly

               use Graph::Easy;
               use Graph::Easy::Layout::Chain;

               my $graph = Graph::Easy->new( );
               my ($node, $node2) = $graph->add_edge( 'A', 'B' );

               my $chain = Graph::Easy::Layout::Chain->new(
                       start => $node,
                       graph => $graph, );

               $chain->add_node( $node2 );

DESCRIPTION

       A "Graph::Easy::Layout::Chain" object represents a chain of nodes for the layouter.

METHODS

   new()
               my $chain = Graph::Easy::Layout::Chain->new( start => $node );

       Create a new chain and set its starting node to $node.

   length()
               my $len = $chain->length();

       Return the length of the chain, in nodes.

               my $len = $chain->length( $node );

       Given an optional $node as argument, returns the length from that node onwards. For the
       chain with the three nodes A, B and C would return 3, 2, and 1 for A, B and C,
       respectively.

       Returns 0 if the passed node is not part of this chain.

   nodes()
               my @nodes = $chain->nodes();

       Return all the node objects in the chain as list, in order.

   add_node()
               $chain->add_node( $node );

       Add $node to the end of the chain.

   start()
               my $node = $chain->start();

       Return first node in the chain.

   end()
               my $node = $chain->end();

       Return last node in the chain.

   layout()
               my $todo = $chain->layout();

       Return an action stack as array ref, containing the nec. actions to layout the chain
       (nodes, plus interlinks in the chain).

       Will recursively traverse all chains linked to this chain.

   merge()
               my $chain->merge ( $other_chain );
               my $chain->merge ( $other_chain, $where );

       Merge the other chain into ourselves, adding its nodes at our end.  The other chain is
       emptied and must be deleted by the caller.

       If $where is defined and a member of $other_chain, absorb only the nodes from $where
       onwards, instead of all of them.

   error()
               $last_error = $node->error();

               $node->error($error);                   # set new messages
               $node->error('');                       # clear error

       Returns the last error message, or '' for no error.

   dump()
               $chain->dump();

       Dump the chain to STDERR, to aid debugging.

EXPORT

       None by default.

SEE ALSO

       Graph::Easy, Graph::Easy::Layout.

AUTHOR

       Copyright (C) 2004 - 2006 by Tels <http://bloodgate.com>.

       See the LICENSE file for more details.