com.yworks.yfiles.layout.router

Class ChannelEdgeRouter

java.lang.Object

com.yworks.yfiles.layout.AbstractLayoutStage

com.yworks.yfiles.layout.router.ChannelEdgeRouter

All Implemented Interfaces:

ILayoutAlgorithm, ILayoutStage

public class ChannelEdgeRouter
extends AbstractLayoutStage

This edge routing algorithm generates orthogonal routes for the edges of the graph.

Compared to the routing algorithm implemented by class EdgeRouter, this implementation is usually faster but supports less constraints and, by default, may produce node-edge overlaps.

Layout Style

Edges are routed in an orthogonal fashion, i.e., edge paths consist only of vertical and horizontal segments.

During the routing process, the positions of the nodes are considered to be fixed and the routing algorithm will not modify their locations or their sizes in any way.

The edge routing algorithm can be applied wherever it is required to route the edges as orthogonal segments, while keeping the positions of the nodes in the diagram fixed. Some potential applications include electric circuit design, floor planning, UML class diagrams/inheritance diagrams and navigation maps.

Sample output of the orthogonal edge routing algorithm with default settings

Concept

This edge routing algorithm combines two strategic steps of edge routing and executes them one after the other. The first strategy is called path finder strategy and will route the edges, potentially with edge overlaps. The second strategy will then split overlapping edge segments inside their channels and distribute them according to the specific distribution strategy.

The default path finding strategy is OrthogonalPatternEdgeRouter. The default edge distribution strategy is OrthogonalSegmentDistributionStage.

Features

This class itself has no special routing options except from specifying the path finding and edge distribution strategy. Most of the features like minimum element distances, grid spacing and path restrictions have to be set on the used instances for the two routing steps.

For incremental edge routing, IDataProvider key AFFECTED_EDGES_DPKEY has to be registered with the graph to mark all edges that should be routed by the algorithm. The routes of the other edges remain unchanged. If there is no such key registered, the algorithm routes all edges.

When exchanging only one of the strategies, make sure, that their algorithms will use the same (sub)set of graph objects. The strategies bound to this routing algorithm, by default, will use key AFFECTED_EDGES_DPKEY to determine the affected edges.

Field Summary

Fields

Modifier and Type	Field and Description
static EdgeDpKey<Boolean>	AFFECTED_EDGES_DPKEY A DataProvider key for marking the edges that should be routed.

Constructor Summary

Constructors

Constructor and Description
ChannelEdgeRouter() Creates a new ChannelEdgeRouter instance with default settings.

Method Summary

Modifier and Type	Method and Description
void	applyLayout(LayoutGraph graph) Performs the orthogonal routing of the edges of the input graph.
protected void	checkNodeSize(LayoutGraph g) Checks the sizes of the nodes to be non-zero.
ILayoutAlgorithm	getEdgeDistributionStrategy() Gets the strategy for the edge distribution step.
ILayoutAlgorithm	getPathFinderStrategy() Gets the strategy for the path finding step.
void	setEdgeDistributionStrategy(ILayoutAlgorithm value) Sets the strategy for the edge distribution step.
void	setPathFinderStrategy(ILayoutAlgorithm value) Sets the strategy for the path finding step.

Methods inherited from class com.yworks.yfiles.layout.AbstractLayoutStage

applyLayoutCore, getCoreLayout, setCoreLayout

Methods inherited from class java.lang.Object

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

Field Detail

AFFECTED_EDGES_DPKEY

public static final EdgeDpKey<Boolean> AFFECTED_EDGES_DPKEY

A DataProvider key for marking the edges that should be routed.

If this key is not registered with the graph, the algorithm will route all edges.

Constructor Detail

ChannelEdgeRouter

public ChannelEdgeRouter()

Creates a new ChannelEdgeRouter instance with default settings.

Method Detail

applyLayout

public void applyLayout(LayoutGraph graph)

Performs the orthogonal routing of the edges of the input graph.

Specified by:

applyLayout in interface ILayoutAlgorithm

Specified by:

applyLayout in class AbstractLayoutStage

The given graph will not be copied during the edge routing process and the result will be immediately applied to the input graph.

Parameters:

graph - the input graph

checkNodeSize

protected void checkNodeSize(LayoutGraph g)

Checks the sizes of the nodes to be non-zero.

Parameters:

g - The graph to check.

getEdgeDistributionStrategy

public ILayoutAlgorithm getEdgeDistributionStrategy()

Gets the strategy for the edge distribution step.

This step distributes overlapping edge segments in their channel. The channel in which the segments can be distributed is defined by the surrounding graph elements.

When exchanging only one of the strategies, make sure, that their algorithms will use the same (sub)set of graph objects. The strategies bound to this routing algorithm, by default, will use key AFFECTED_EDGES_DPKEY to determine the affected edges.

Default Value:

The default value is OrthogonalSegmentDistributionStage

Returns:

the edge distribution strategy

See Also:

setEdgeDistributionStrategy(ILayoutAlgorithm)

getPathFinderStrategy

public ILayoutAlgorithm getPathFinderStrategy()

Gets the strategy for the path finding step.

This step routes the edges and may produce edge overlaps which are later resolved in the edge distribution step.

When exchanging only one of the strategies, make sure, that their algorithms will use the same (sub)set of graph objects. The strategies bound to this routing algorithm, by default, will use key AFFECTED_EDGES_DPKEY to determine the affected edges.

Default Value:

The default value is OrthogonalPatternEdgeRouter

Returns:

the path finder strategy

See Also:

setPathFinderStrategy(ILayoutAlgorithm)

setEdgeDistributionStrategy

public void setEdgeDistributionStrategy(ILayoutAlgorithm value)

Sets the strategy for the edge distribution step.

This step distributes overlapping edge segments in their channel. The channel in which the segments can be distributed is defined by the surrounding graph elements.

When exchanging only one of the strategies, make sure, that their algorithms will use the same (sub)set of graph objects. The strategies bound to this routing algorithm, by default, will use key AFFECTED_EDGES_DPKEY to determine the affected edges.

Default Value:

The default value is OrthogonalSegmentDistributionStage

Parameters:

value - the edge distribution strategy

See Also:

getEdgeDistributionStrategy()

setPathFinderStrategy

public void setPathFinderStrategy(ILayoutAlgorithm value)

Sets the strategy for the path finding step.

This step routes the edges and may produce edge overlaps which are later resolved in the edge distribution step.

When exchanging only one of the strategies, make sure, that their algorithms will use the same (sub)set of graph objects. The strategies bound to this routing algorithm, by default, will use key AFFECTED_EDGES_DPKEY to determine the affected edges.

Default Value:

The default value is OrthogonalPatternEdgeRouter

Parameters:

value - the path finder strategy

See Also:

getPathFinderStrategy()