edu.uci.ics.jung.visualization

Class SpringLayout

java.lang.Object

edu.uci.ics.jung.visualization.AbstractLayout

edu.uci.ics.jung.visualization.SpringLayout

All Implemented Interfaces:

ChangeEventSupport, Layout, LayoutMutable, VertexLocationFunction

Direct Known Subclasses:

DAGLayout

public class SpringLayout
extends AbstractLayout
implements LayoutMutable

The SpringLayout package represents a visualization of a set of nodes. The SpringLayout, which is initialized with a Graph, assigns X/Y locations to each node. When called relax(), the SpringLayout moves the visualization forward one step.

Author:

Danyel Fisher, Joshua O'Madadhain

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	SpringLayout.LengthFunction If the edge is weighted, then override this method to show what the visualized length is.
class	SpringLayout.SpringDimensionChecker
protected static class	SpringLayout.SpringEdgeData
protected static class	SpringLayout.SpringVertexData
static class	SpringLayout.UnitLengthFunction Returns all edges as the same length: the input value

Field Summary

Fields

Modifier and Type	Field and Description
protected double	force_multiplier
protected SpringLayout.LengthFunction	lengthFunction
protected int	repulsion_range
protected double	stretch
static SpringLayout.LengthFunction	UNITLENGTHFUNCTION

Fields inherited from class edu.uci.ics.jung.visualization.AbstractLayout

changeSupport, vertex_locations

Constructor Summary

Constructors

Constructor and Description
SpringLayout(Graph g) Constructor for a SpringLayout for a raw graph with associated dimension--the input knows how big the graph is.
SpringLayout(Graph g, SpringLayout.LengthFunction f) Constructor for a SpringLayout for a raw graph with associated component.

Method Summary

Methods

Modifier and Type	Method and Description
void	advancePositions() Relaxation step.
protected void	calcEdgeLength(SpringLayout.SpringEdgeData sed, SpringLayout.LengthFunction f)
protected void	calculateRepulsion()
protected Vertex	getAVertex(Edge e) Utility method, gets a single vertex from this edge.
double	getForceMultiplier()
double	getLength(Edge e)
int	getRepulsionRange()
SpringLayout.SpringEdgeData	getSpringData(Edge e)
SpringLayout.SpringVertexData	getSpringData(Vertex v)
java.lang.Object	getSpringKey()
java.lang.String	getStatus() Returns the status.
double	getStretch()
boolean	incrementsAreDone() For now, we pretend it never finishes.
protected void	initialize_local_vertex(Vertex v) (non-Javadoc)
protected void	initialize_local() Initializes all local information, and is called immediately within the initialize() process.
boolean	isIncremental() This one is an incremental visualization
protected void	moveNodes()
protected void	relaxEdges()
void	setForceMultiplier(double force) Sets the force multiplier for this instance.
void	setRepulsionRange(int range) Sets the node repulsion range (in drawing area units) for this instance.
void	setStretch(double stretch) Sets the stretch parameter for this instance.
void	update()

Methods inherited from class edu.uci.ics.jung.visualization.AbstractLayout

addChangeListener, applyFilter, dontMove, fireStateChanged, forceMove, getBaseKey, getChangeListeners, getCoordinates, getCurrentSize, getEdge, getEdge, getGraph, getLocation, getVertex, getVertex, getVertexIterator, getVisibleEdges, getVisibleGraph, getVisibleVertices, getX, getY, initialize, initialize, initializeLocation, initializeLocations, isLocked, lockVertex, offsetVertex, postInitialize, removeChangeListener, resize, restart, unlockVertex

Methods inherited from class java.lang.Object

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

Methods inherited from interface edu.uci.ics.jung.visualization.Layout

applyFilter, forceMove, getCurrentSize, getGraph, getLocation, getVertex, getVertex, getVisibleEdges, getVisibleVertices, getX, getY, initialize, isLocked, lockVertex, resize, restart, unlockVertex

Methods inherited from interface edu.uci.ics.jung.visualization.VertexLocationFunction

getVertexIterator

Field Detail

stretch

protected double stretch

lengthFunction

protected SpringLayout.LengthFunction lengthFunction

repulsion_range

protected int repulsion_range

force_multiplier

protected double force_multiplier

UNITLENGTHFUNCTION

public static final SpringLayout.LengthFunction UNITLENGTHFUNCTION

Constructor Detail

SpringLayout

public SpringLayout(Graph g)

Constructor for a SpringLayout for a raw graph with associated dimension--the input knows how big the graph is. Defaults to the unit length function.

SpringLayout

public SpringLayout(Graph g,
            SpringLayout.LengthFunction f)

Constructor for a SpringLayout for a raw graph with associated component.

Parameters:

g - the input Graph

f - the length function

Method Detail

getStatus

public java.lang.String getStatus()

Returns the status.

Specified by:

getStatus in interface Layout

Overrides:

getStatus in class AbstractLayout

Returns:

the status, as a string

getStretch

public double getStretch()

Returns:

the current value for the stretch parameter

See Also:

setStretch(double)

setStretch

public void setStretch(double stretch)

Sets the stretch parameter for this instance. This value specifies how much the degrees of an edge's incident vertices should influence how easily the endpoints of that edge can move (that is, that edge's tendency to change its length).

The default value is 0.70. Positive values less than 1 cause high-degree vertices to move less than low-degree vertices, and values > 1 cause high-degree vertices to move more than low-degree vertices. Negative values will have unpredictable and inconsistent results.

Parameters:

stretch -

getRepulsionRange

public int getRepulsionRange()

Returns:

the current value for the node repulsion range

See Also:

setRepulsionRange(int)

setRepulsionRange

public void setRepulsionRange(int range)

Sets the node repulsion range (in drawing area units) for this instance. Outside this range, nodes do not repel each other. The default value is 100. Negative values are treated as their positive equivalents.

Parameters:

range -

getForceMultiplier

public double getForceMultiplier()

Returns:

the current value for the edge length force multiplier

See Also:

setForceMultiplier(double)

setForceMultiplier

public void setForceMultiplier(double force)

Sets the force multiplier for this instance. This value is used to specify how strongly an edge "wants" to be its default length (higher values indicate a greater attraction for the default length), which affects how much its endpoints move at each timestep. The default value is 1/3. A value of 0 turns off any attempt by the layout to cause edges to conform to the default length. Negative values cause long edges to get longer and short edges to get shorter; use at your own risk.

initialize_local

protected void initialize_local()

Description copied from class: AbstractLayout

Initializes all local information, and is called immediately within the initialize() process. The user is responsible for overriding this method to do any construction that may be necessary: for example, to initialize local per-edge or graph-wide data.

Overrides:

initialize_local in class AbstractLayout

getSpringKey

public java.lang.Object getSpringKey()

initialize_local_vertex

protected void initialize_local_vertex(Vertex v)

(non-Javadoc)

Specified by:

initialize_local_vertex in class AbstractLayout

See Also:

AbstractLayout.initialize_local_vertex(edu.uci.ics.jung.graph.Vertex)

calcEdgeLength

protected void calcEdgeLength(SpringLayout.SpringEdgeData sed,
                  SpringLayout.LengthFunction f)

advancePositions

public void advancePositions()

Relaxation step. Moves all nodes a smidge.

Specified by:

advancePositions in interface Layout

Specified by:

advancePositions in class AbstractLayout

See Also:

Layout.advancePositions()

getAVertex

protected Vertex getAVertex(Edge e)

Description copied from class: AbstractLayout

Utility method, gets a single vertex from this edge. The utility's implementation is to get the iterator from the edge's getIncidentVertices() and then return the first element.

Overrides:

getAVertex in class AbstractLayout

relaxEdges

protected void relaxEdges()

calculateRepulsion

protected void calculateRepulsion()

moveNodes

protected void moveNodes()

getSpringData

public SpringLayout.SpringVertexData getSpringData(Vertex v)

getSpringData

public SpringLayout.SpringEdgeData getSpringData(Edge e)

getLength

public double getLength(Edge e)

isIncremental

public boolean isIncremental()

This one is an incremental visualization

Specified by:

isIncremental in interface Layout

incrementsAreDone

public boolean incrementsAreDone()

For now, we pretend it never finishes.

Specified by:

incrementsAreDone in interface Layout

update

public void update()

Specified by:

update in interface LayoutMutable

See Also:

LayoutMutable.update()