y.layout
Class NormalizingGraphElementOrderStage

java.lang.Object
  y.layout.AbstractLayoutStage
      y.layout.NormalizingGraphElementOrderStage

All Implemented Interfaces:

Layouter, LayoutStage

public class NormalizingGraphElementOrderStage
extends AbstractLayoutStage

Layout stage that can be used to normalize the order of the elements within a graph. Amongst other factors, the results produced by layout algorithms usually depend on the order of the nodes and edges within a graph. Unfortunately, useful operations such as hiding or unhiding elements from a graph or simply invoking layout algorithms on a graph will have the potential side effect of changing that order. With this layout stage it is possible to establish a predefined order of nodes and edges within a graph to avoid non-deterministic layout behavior. Defining the order of nodes and edges is done by associating each node or edge in the graph with a Comparable value using DataProviders registered with the key COMPARABLE_NODE_DPKEY, or COMPARABLE_EDGE_DPKEY respectively. the DataProvider key

Field Summary

static Object	COMPARABLE_EDGE_DPKEY The DataProvider registered with this key must return a Comparable object for each edge thereby inducing a (global) order for edges.
static Object	COMPARABLE_NODE_DPKEY The DataProvider registered with this key must return a Comparable object for each node thereby inducing a (global) order for nodes.

Fields inherited from interface y.layout.Layouter

EDGE_ID_DPKEY, NODE_ID_DPKEY, SELECTED_EDGES, SELECTED_NODES

Constructor Summary

NormalizingGraphElementOrderStage()

NormalizingGraphElementOrderStage(Layouter coreLayouter)

Method Summary

boolean	canLayout(LayoutGraph graph) Returns true iff the given graph can be laid out by this algorithm.
void	doLayout(LayoutGraph graph) Main layout routine that assigns new layout information to the given graph.
static void	fillComparableMapFromGraph(Graph graph, DataMap comparableNodeMap, DataMap comparableEdgeMap) Convenience method that assigns comparable values for each node and edge.

Methods inherited from class y.layout.AbstractLayoutStage

canLayoutCore, doLayoutCore, getCoreLayouter, setCoreLayouter

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

COMPARABLE_NODE_DPKEY

public static final Object COMPARABLE_NODE_DPKEY

The DataProvider registered with this key must return a Comparable object for each node thereby inducing a (global) order for nodes.

COMPARABLE_EDGE_DPKEY

public static final Object COMPARABLE_EDGE_DPKEY

The DataProvider registered with this key must return a Comparable object for each edge thereby inducing a (global) order for edges.

Constructor Detail

NormalizingGraphElementOrderStage

public NormalizingGraphElementOrderStage()

NormalizingGraphElementOrderStage

public NormalizingGraphElementOrderStage(Layouter coreLayouter)

Method Detail

canLayout

public boolean canLayout(LayoutGraph graph)

Description copied from interface: Layouter

Returns true iff the given graph can be laid out by this algorithm. Calling doLayout with the given graph as its argument will only success if this method returns true.

doLayout

public void doLayout(LayoutGraph graph)

Description copied from interface: Layouter

Main layout routine that assigns new layout information to the given graph.

fillComparableMapFromGraph

public static void fillComparableMapFromGraph(Graph graph,
                                              DataMap comparableNodeMap,
                                              DataMap comparableEdgeMap)

Convenience method that assigns comparable values for each node and edge. The compared values are induced from the current ordering of the nodes and edges within the given graph.