com.jgraph.layout.hierarchical
Class JGraphMedianHybridCrossingReduction

java.lang.Object
  com.jgraph.layout.hierarchical.JGraphMedianHybridCrossingReduction

All Implemented Interfaces:

JGraphHierarchicalLayoutStep, JGraphLayout.Stoppable

public class JGraphMedianHybridCrossingReduction

extends Object

implements JGraphHierarchicalLayoutStep, JGraphLayout.Stoppable

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

Nested Class Summary

protected class

JGraphMedianHybridCrossingReduction.MedianCellSorter A utility class used to track cells whilst sorting occurs on the median values.

Field Summary

protected int	currentBestCrossings The total number of crossings found in the best configuration so far
protected int	iterationsWithoutImprovement
protected int	maxIterations The maximum number of iterations to perform whilst reducing edge crossings
protected int	maxNoImprovementIterations
protected Object[][]	nestedBestRanks Stores each rank as a collection of cells in the best order found for each layer so far
protected JGraphLayoutProgress	progress The layout progress bar

Constructor Summary

JGraphMedianHybridCrossingReduction()

Method Summary

protected int	calculateRankCrossing(int i, JGraphHierarchyModel model) Calculates the number of edges crossings between the specified rank and the rank below it
JGraphLayoutProgress	getProgress() Returns the progress object that represents the progress of the current layout run.
JGraphHierarchyModel	run(JGraphFacade facade, JGraphHierarchyModel model) 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

maxIterations

protected int maxIterations

The maximum number of iterations to perform whilst reducing edge crossings

nestedBestRanks

protected Object[][] 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

progress

protected JGraphLayoutProgress progress

The layout progress bar

Constructor Detail

JGraphMedianHybridCrossingReduction

public JGraphMedianHybridCrossingReduction()

Method Detail

run

public JGraphHierarchyModel run(JGraphFacade facade,
                                JGraphHierarchyModel model)

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

Specified by:

run in interface JGraphHierarchicalLayoutStep

Parameters:

facade - the facade describing the input graph

model - an internal model of the hierarchical layout

Returns:

the updated hierarchy model

calculateRankCrossing

protected int calculateRankCrossing(int i,
                                    JGraphHierarchyModel 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

getProgress

public JGraphLayoutProgress getProgress()

Description copied from interface: JGraphLayout.Stoppable

Returns the progress object that represents the progress of the current layout run. Once created, this instance should not be replaced during a layout run. For new runs you should use the reset method on the progress. Consequently, the max progress is only valid after the run method has been invoked, which means you should use a listener if you spawn a new thread.

By convention, the layout must check the isStopped method in its inner-most loops and return immediately if the method returns true.

Specified by:

getProgress in interface JGraphLayout.Stoppable

Returns:

Returns the progress.