y.layout.organic
Class RemoveOverlapsLayoutStage

java.lang.Object
  y.layout.organic.RemoveOverlapsLayoutStage

All Implemented Interfaces:

Layouter, LayoutStage

public class RemoveOverlapsLayoutStage
extends java.lang.Object
implements LayoutStage

This LayoutStage removes node overlaps and guarantees a certain minimum distance between nodes.

Layout Style

This stage only removes overlaps between nodes of the input graph. To do so, overlapping nodes will be moved apart. Results often look like a stretched version of the original graph. Before removing the node overlaps, an optional core layout algorithm is applied.

A graph containing overlaps (left) and the result after the overlap removal

Features

It is possible to define a minimum distance between nodes. This feature allows to not only remove overlaps but forces nodes to keep a specified distance to other nodes.

Overlaps between nodes and edges are not removed by this stage.

Field Summary

protected LayoutGraph	graph The input graph.
protected double[]	h The height values of nodes, ordered within the array based on node indices.
protected Node[]	nodes The node array of the input graph.
protected YRandom	random The source of randomness used during the layout process.
protected double[]	w The width values of nodes, ordered within the array based on node indices.
protected double[]	x The x-coordinates of nodes, ordered within the array based on node indices.
protected double[]	y The y-coordinates of nodes, ordered within the array based on node indices.

Fields inherited from interface y.layout.Layouter

EDGE_ID_DPKEY, NODE_ID_DPKEY, NODE_TYPE_DPKEY, SELECTED_EDGES, SELECTED_NODES

Constructor Summary

RemoveOverlapsLayoutStage(double minimumNodeDistance)
Creates a new RemoveOverlapsLayoutStage instance with a given minimum node distance.

RemoveOverlapsLayoutStage(YRandom random, double minimumNodeDistance)
Creates a new RemoveOverlapsLayoutStage instance with a given minimum node distance and a YRandom instance representing the source of randomness for this layout stage.

Method Summary

boolean	canLayout(LayoutGraph graph) Accepts all graphs which are accepted by the specified core layout algorithm.
void	doLayout(LayoutGraph graph) Removes node overlaps and displaces nodes of the given graph such that they keep the specified minimum distance to each other.
Layouter	getCoreLayouter() Returns the core layout algorithm that is wrapped by this stage and is applied before removing node overlaps.
double	getMinimumNodeDistance() Returns the minimum distance to be kept between any two nodes of the graph.
void	setCoreLayouter(Layouter l) Specifies the core layout algorithm that is wrapped by this stage and is applied before removing node overlaps.
void	setMinimumNodeDistance(double minimumNodeDistance) Specifies the minimum distance to be kept between any two nodes of the graph.
protected void	updatePos() Updates the data structure holding x-coordinates and y-coordinates of the nodes according to the current center coordinates.

Methods inherited from class java.lang.Object

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

Field Detail

graph

protected LayoutGraph graph

The input graph.

random

protected YRandom random

The source of randomness used during the layout process.

x

protected double[] x

The x-coordinates of nodes, ordered within the array based on node indices.

y

protected double[] y

The y-coordinates of nodes, ordered within the array based on node indices.

w

protected double[] w

The width values of nodes, ordered within the array based on node indices.

h

protected double[] h

The height values of nodes, ordered within the array based on node indices.

nodes

protected Node[] nodes

The node array of the input graph.

Constructor Detail

RemoveOverlapsLayoutStage

public RemoveOverlapsLayoutStage(double minimumNodeDistance)

Creates a new RemoveOverlapsLayoutStage instance with a given minimum node distance.

The minimum node distance needs to be non-negative.

Parameters:

minimumNodeDistance - a non-negative minimum distance value

Throws:

java.lang.IllegalArgumentException - if the given distance is negative

RemoveOverlapsLayoutStage

public RemoveOverlapsLayoutStage(YRandom random,
                                 double minimumNodeDistance)

Creates a new RemoveOverlapsLayoutStage instance with a given minimum node distance and a YRandom instance representing the source of randomness for this layout stage.

The minimum node distance needs to be non-negative.

Parameters:

random - the source of randomness for this layout stage

minimumNodeDistance - a non-negative minimum distance value

Throws:

java.lang.IllegalArgumentException - if the given distance is negative

Method Detail

getMinimumNodeDistance

public double getMinimumNodeDistance()

Returns the minimum distance to be kept between any two nodes of the graph.

Due to this distance not only nodes that overlap will be moved to resolve the overlap, but also nodes which are too close to each other with respect to this distance will be displaced.

The minimum node distance needs to be non-negative.

Returns:

the non-negative minimum node distance

See Also:

setMinimumNodeDistance(double)

setMinimumNodeDistance

public void setMinimumNodeDistance(double minimumNodeDistance)

Specifies the minimum distance to be kept between any two nodes of the graph.

Due to this distance not only nodes that overlap will be moved to resolve the overlap, but also nodes which are too close to each other with respect to this distance will be displaced.

The minimum node distance needs to be non-negative.

Parameters:

minimumNodeDistance - the non-negative minimum node distance

Throws:

java.lang.IllegalArgumentException - if the given minimum distance is negative

Sample Graphs:

Minimum distance 0

Minimum distance 20

canLayout

public boolean canLayout(LayoutGraph graph)

Accepts all graphs which are accepted by the specified core layout algorithm.

Specified by:

canLayout in interface Layouter

Parameters:

graph - the input graph

Returns:

true if the core algorithm is null or can handle the given graph, false otherwise

See Also:

Layouter.doLayout(LayoutGraph)

doLayout

public void doLayout(LayoutGraph graph)

Removes node overlaps and displaces nodes of the given graph such that they keep the specified minimum distance to each other.

If a core layout algorithm is specified, it will be executed first.

Specified by:

doLayout in interface Layouter

The given graph will not be copied during the layout process and the layout will be immediately applied to the given graph.

Parameters:

graph - the input graph

See Also:

Layouter.canLayout(LayoutGraph)

updatePos

protected void updatePos()

Updates the data structure holding x-coordinates and y-coordinates of the nodes according to the current center coordinates.

getCoreLayouter

public Layouter getCoreLayouter()

Returns the core layout algorithm that is wrapped by this stage and is applied before removing node overlaps.

Specified by:

getCoreLayouter in interface LayoutStage

Returns:

the core layout algorithm

See Also:

setCoreLayouter(Layouter)

setCoreLayouter

public void setCoreLayouter(Layouter l)

Specifies the core layout algorithm that is wrapped by this stage and is applied before removing node overlaps.

Specified by:

setCoreLayouter in interface LayoutStage

Default Value:

The default value is null.

Parameters:

l - the core layout algorithm