y.layout.hierarchic.incremental
Class ConstraintIncrementalLayerer

java.lang.Object
  y.layout.hierarchic.incremental.ConstraintIncrementalLayerer

All Implemented Interfaces:

Layerer

public class ConstraintIncrementalLayerer
extends java.lang.Object
implements Layerer

This class is a Layerer implementation that observes relative and absolute layering constraints defined by the layer constraint factory. Furthermore, it can handle the edge directedness as specified by DataProvider key IncrementalHierarchicLayouter.EDGE_DIRECTEDNESS_DPKEY.

For a given graph instance, the layer constraint factory can be created using method IncrementalHierarchicLayouter.createLayerConstraintFactory(y.base.Graph). The Layerer can be used for both common layering and layering of incremental nodes.

Sample output of applying ConstraintIncrementalLayerer. The red colored node should reside in the topmost layer, blue nodes in the medium layer while green nodes in the bottommost layer.

Sample output of applying ConstraintIncrementalLayerer on a graph with a PartitionGrid. Same colors represent nodes that belong to the same partition grid cell and should be layered with respect to the partition grid cell to which they belong.

This Layerer is always applied automatically if the graph instance has constraints created with the layering constraint factory.

See Also:

LayerConstraintFactory, IncrementalHierarchicLayouter

Field Summary

static java.lang.String

EDGE_WEIGHTS_DPKEY A DataProvider key for assigning additional edge weights The Layerer tries to maintain edges with higher weights short.

Constructor Summary

ConstraintIncrementalLayerer(Layerer coreLayerer)
Creates a new ConstraintIncrementalLayerer with the given Layerer instance as its core layerer.

Method Summary

void	assignLayers(LayoutGraph graph, Layers layers, LayoutDataProvider ldp) Assigns all nodes of the graph to layers and adds them to the Layers instance based on relative and absolute layering constraints defined by the given layering constraints.
protected void	checkConstraints() Checks if the current setting of constraints is consistent, that is, the induced constraint graph has no cycles.
long	getMaximalDuration() Returns the time limit in milliseconds set for the algorithm.
boolean	isAllowSameLayerEdges() Returns whether or not same-layer edges can be created by this Layerer instance.
void	setAllowSameLayerEdges(boolean allowSameLayerEdges) Specifies whether or not same-layer edges can be created by this Layerer instance.
void	setMaximalDuration(long maximalDuration) Specifies the time limit in milliseconds set for the algorithm.

Methods inherited from class java.lang.Object

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

Field Detail

EDGE_WEIGHTS_DPKEY

public static final java.lang.String EDGE_WEIGHTS_DPKEY

A DataProvider key for assigning additional edge weights

The Layerer tries to maintain edges with higher weights short.

See Also:

Constant Field Values

Constructor Detail

ConstraintIncrementalLayerer

public ConstraintIncrementalLayerer(Layerer coreLayerer)

Creates a new ConstraintIncrementalLayerer with the given Layerer instance as its core layerer.

Parameters:

coreLayerer - the core Layerer instance

Throws:

java.lang.IllegalArgumentException - if the given core layerer is null

Method Detail

isAllowSameLayerEdges

public boolean isAllowSameLayerEdges()

Returns whether or not same-layer edges can be created by this Layerer instance.

This only concerns edges between nodes that have no hard constraints that will force a same-layer edge (i.e. a same-layer constraint).

Returns:

true if same-layer edges can be created, false otherwise

setAllowSameLayerEdges

public void setAllowSameLayerEdges(boolean allowSameLayerEdges)

Specifies whether or not same-layer edges can be created by this Layerer instance.

This only concerns edges between nodes that have no hard constraints that will force a same-layer edge (i.e. a same-layer constraint).

Default Value:

The default value is false. Same-layer edges cannot be created by this Layerer instance.

Parameters:

allowSameLayerEdges - true if same-layer edges can be created, false otherwise

getMaximalDuration

public long getMaximalDuration()

Returns the time limit in milliseconds set for the algorithm.

Values have to be greater than or equal to 0.

Restricting the maximum duration may result in a lower layout quality. Furthermore, the real runtime may exceed the maximum duration since the layout algorithm still has to find a valid solution.

Returns:

a non-negative value that specifies the time limit

See Also:

setMaximalDuration(long)

setMaximalDuration

public void setMaximalDuration(long maximalDuration)

Specifies the time limit in milliseconds set for the algorithm.

Values have to be greater than or equal to 0.

Restricting the maximum duration may result in a lower layout quality. Furthermore, the real runtime may exceed the maximum duration since the layout algorithm still has to find a valid solution.

Default Value:

The default value is Long.MAX_VALUE. The layout algorithm runs unrestricted.

Parameters:

maximalDuration - a non-negative value that specifies the time limit

Throws:

java.lang.IllegalArgumentException - if the maximum duration is negative

assignLayers

public void assignLayers(LayoutGraph graph,
                         Layers layers,
                         LayoutDataProvider ldp)

Assigns all nodes of the graph to layers and adds them to the Layers instance based on relative and absolute layering constraints defined by the given layering constraints.

Specified by:

assignLayers in interface Layerer

A Layers structure will be filled by the Layerer. If the Layerer instance is used for layering incremental nodes, the Layers structure already has to contain all non-incremental nodes.

Parameters:

graph - the input graph

layers - the Layers instance that will be filled with the results of the calculation

ldp - the LayoutDataProvider used for query information about the nodes and edges

See Also:

Layers.insert(byte, int), Layer.add(y.base.Node)

checkConstraints

protected void checkConstraints()

Checks if the current setting of constraints is consistent, that is, the induced constraint graph has no cycles.

Throws:

java.lang.IllegalArgumentException - if the constraint graph is inconsistent