com.mxgraph.layout.hierarchical.stage

Class mxMedianHybridCrossingReduction

java.lang.Object

com.mxgraph.layout.hierarchical.stage.mxMedianHybridCrossingReduction

All Implemented Interfaces:

mxHierarchicalLayoutStage

public class mxMedianHybridCrossingReduction
extends java.lang.Object
implements mxHierarchicalLayoutStage

Performs a vertex ordering within ranks as described by Gansner et al 1993

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected class	mxMedianHybridCrossingReduction.MedianCellSorter A utility class used to track cells whilst sorting occurs on the median values.

Field Summary

Fields

Modifier and Type	Field and Description
protected int	currentBestCrossings The total number of crossings found in the best configuration so far
protected int	iterationsWithoutImprovement
protected mxHierarchicalLayout	layout Reference to the enclosing layout algorithm
protected int	maxIterations The maximum number of iterations to perform whilst reducing edge crossings
protected int	maxNoImprovementIterations
protected mxGraphAbstractHierarchyCell[][]	nestedBestRanks Stores each rank as a collection of cells in the best order found for each layer so far

Constructor Summary

Constructors

Constructor and Description
mxMedianHybridCrossingReduction(mxHierarchicalLayout layout) Constructor that has the roots specified

Method Summary

Modifier and Type	Method and Description
protected int	calculateRankCrossing(int i, mxGraphHierarchyModel model) Calculates the number of edges crossings between the specified rank and the rank below it
void	execute(java.lang.Object parent) Performs a vertex ordering within ranks as described by Gansner et al 1993

Methods inherited from class java.lang.Object

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

Field Detail

layout

protected mxHierarchicalLayout layout

Reference to the enclosing layout algorithm

maxIterations

protected int maxIterations

The maximum number of iterations to perform whilst reducing edge crossings

nestedBestRanks

protected mxGraphAbstractHierarchyCell[][] nestedBestRanks

Stores each rank as a collection of cells in the best order found for each layer so far

currentBestCrossings

protected int currentBestCrossings

The total number of crossings found in the best configuration so far

iterationsWithoutImprovement

protected int iterationsWithoutImprovement

maxNoImprovementIterations

protected int maxNoImprovementIterations

Constructor Detail

mxMedianHybridCrossingReduction

public mxMedianHybridCrossingReduction(mxHierarchicalLayout layout)

Constructor that has the roots specified

Method Detail

execute

public void execute(java.lang.Object parent)

Performs a vertex ordering within ranks as described by Gansner et al 1993

Specified by:

execute in interface mxHierarchicalLayoutStage

calculateRankCrossing

protected int calculateRankCrossing(int i,
                                    mxGraphHierarchyModel model)

Calculates the number of edges crossings between the specified rank and the rank below it

Parameters:

i - the topmost rank of the pair ( higher rank value )

model - the internal hierarchy model of the graph

Returns:

the number of edges crossings with the rank beneath