y.layout
Class EdgeReversalStage

java.lang.Object
  y.layout.AbstractLayoutStage
      y.layout.EdgeReversalStage

All Implemented Interfaces:

Layouter, LayoutStage

public class EdgeReversalStage
extends AbstractLayoutStage

EdgeReversalStage selectively reverses edges in a graph, while keeping the layout and label positions of the reversed edges as close to the pre-reversal layout and positions as possible.

Field Summary

static java.lang.Object

REVERSE_EDGES_DPKEY A DataProvider key for selecting edges for reversal

Fields inherited from interface y.layout.Layouter

EDGE_ID_DPKEY, NODE_ID_DPKEY, NODE_TYPE_DPKEY, SELECTED_EDGES, SELECTED_NODES

Constructor Summary

EdgeReversalStage()
Creates a new EdgeReversalStage instance with default settings.

EdgeReversalStage(Layouter coreLayouter)
Creates a new EdgeReversalStage instance using the given algorithm as core layout algorithm.

Method Summary

boolean	canLayout(LayoutGraph graph) Accepts all graphs that can be handled by the core layout algorithm.
void	doLayout(LayoutGraph graph) Reverses all selected edges before calling the core layout algorithm and restores the original edge direction after the core layout algorithm has finished.
static void	findReversedTreeEdges(LayoutGraph graph, Node root, DataAcceptor reversedEdges) Marks edges in a tree-structured graph component that need to be reversed to make the specified node the root of the tree component.
void	reverseEdge(LayoutGraph graph, Edge edge) Reverses the specified edge in the specified graph.
void	reverseEdges(LayoutGraph graph) Reverses selected edges in the specified graph.

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

REVERSE_EDGES_DPKEY

public static final java.lang.Object REVERSE_EDGES_DPKEY

A DataProvider key for selecting edges for reversal

If there is no DataProvider registered with this key, all edges are reversed.

Constructor Detail

EdgeReversalStage

public EdgeReversalStage()

Creates a new EdgeReversalStage instance with default settings.

EdgeReversalStage

public EdgeReversalStage(Layouter coreLayouter)

Creates a new EdgeReversalStage instance using the given algorithm as core layout algorithm.

Parameters:

coreLayouter - the core layout algorithm

See Also:

AbstractLayoutStage.setCoreLayouter(Layouter)

Method Detail

canLayout

public boolean canLayout(LayoutGraph graph)

Accepts all graphs that can be handled by the core layout algorithm.

If there is no core layout algorithm, all graphs are accepted.

Parameters:

graph - the input graph

Returns:

true if there is no core layout algorithm or the core layout algorithm accepts the graph, false otherwise

See Also:

Layouter.doLayout(LayoutGraph)

doLayout

public void doLayout(LayoutGraph graph)

Reverses all selected edges before calling the core layout algorithm and restores the original edge direction after the core layout algorithm has finished.

Parameters:

graph - the input graph

See Also:

Layouter.canLayout(LayoutGraph)

reverseEdges

public void reverseEdges(LayoutGraph graph)

Reverses selected edges in the specified graph. Selected edges are marked in a DataProvider registered with REVERSE_EDGES_DPKEY.

Implementation detail: This method calls reverseEdge(LayoutGraph, Edge) in order to reverse a selected edge.

Parameters:

graph - the graph in which to reverse edges.

See Also:

REVERSE_EDGES_DPKEY, reverseEdge(LayoutGraph, Edge)

reverseEdge

public void reverseEdge(LayoutGraph graph,
                        Edge edge)

Reverses the specified edge in the specified graph. The layout of the specified edge is reversed as specified in LayoutTool.reverseEdgeLayout(EdgeLayout). Moreover, the positions of all labels associated with the specified edge are adjusted to match the pre-reversal position as closely as possible. (Depending on a label's model it might not always be possible to achieve an exact match.)

Parameters:

graph - the graph to which the specified edge belongs

edge - the edge to be reversed

See Also:

LayoutTool.reverseEdgeLayout(EdgeLayout)

findReversedTreeEdges

public static void findReversedTreeEdges(LayoutGraph graph,
                                         Node root,
                                         DataAcceptor reversedEdges)

Marks edges in a tree-structured graph component that need to be reversed to make the specified node the root of the tree component. Only edges in the graph component to which the specified node belongs will be marked.

Parameters:

graph - the graph to which the specified node belongs

root - the node to be considered the root of its tree component

reversedEdges - a DataAcceptor to mark edges for reversal

Throws:

java.lang.IllegalArgumentException - if the specified root node is null or does not belong to the specified graph

See Also:

REVERSE_EDGES_DPKEY