edu.ksu.cis.bnj.gui.components
Class AutoLayouter

java.lang.Object
  edu.ksu.cis.bnj.gui.components.AbstractLayouter
      edu.ksu.cis.bnj.gui.components.AutoLayouter

All Implemented Interfaces:

salvo.jesus.graph.visual.layout.GraphLayoutManager, java.io.Serializable

public class AutoLayouter

extends AbstractLayouter

An implementation of a directed-force layout using logarithmic springs and electrical forces, as discussed in Chapter 10 of the book "Graph Drawing".

However, note that the implementation is a bit different to the equation 10.2 in the book such that:

• Electrical repulsion is subtracted from the force of the spring, since they tend to be opposite forces. The book adds them instead of subtracting.
• The distance between the vertices in the calculation of the electrical repulsion is not squared or multiplied by itself.
• This used logarithimic springs

I am not a mathematician, but the above adjustments to the equation greatly improved the force-directed layout.

Author:

Jesus M. Salvo Jr.

Adapted for BNJ auto-layouter by: Roby Joehanes

List of changes:

• Remove Runnable interface.
• Change all privates to protected.
• Add moveTreshold field with its getter/setter.
• Remove run method.
• Replace layout method with the essence of the previous run method.

See Also:

Serialized Form

Field Summary

protected double	electricalRepulsion
protected java.util.ArrayList	fixedVertexList
protected double	increment
protected boolean	initialized
protected double	springLength
protected double	stiffness

Fields inherited from class edu.ksu.cis.bnj.gui.components.AbstractLayouter

vGraph

Constructor Summary

AutoLayouter(salvo.jesus.graph.visual.VisualGraph vGraph)

Method Summary

void	addEdge(salvo.jesus.graph.visual.VisualEdge vEdge)
void	addFixedVertex(salvo.jesus.graph.visual.VisualVertex vVertex) Adds a VisuaLVertex that will not be moved from its position during the layout operation of ForceDirectedLayout.
void	addVertex(salvo.jesus.graph.visual.VisualVertex vVertex)
void	drawLayout() This method is called to actually paint or draw the layout of the graph.
double	getEletricalRepulsion() Returns the eletrical repulsion between all vertices The default value is 400.
double	getIncrement() Returns the increment by which the vertices gets closer to the equilibrium or closer to the force.
double	getSpringLength() Returns the desired spring length for all edges.
double	getStiffness() Returns the stiffness for all edges.
boolean	isInitialized() Determines if the graph has been initially laid out.
boolean	isVertexFixed(salvo.jesus.graph.visual.VisualVertex vVertex) Returns true if the specified VisualVertex has a fixed position.
void	layout() This method is called to layout the vertices in the graph, running a thread to perform the layout if the thread is not running, or stopping the thread if the thread is running.
protected double	relax(salvo.jesus.graph.visual.VisualVertex vVertex) "Relax" the force on the VisualVertex.
void	removeEdge(salvo.jesus.graph.visual.VisualEdge vEdge)
void	removeFixedVertex(salvo.jesus.graph.visual.VisualVertex vVertex) Removes a VisualVertex from the list of VisualVertices that has a fixed position.
void	removeVertex(salvo.jesus.graph.visual.VisualVertex vVertex)
void	setEletricalRepulsion(double repulsion) Sets the value of the electrical repulsion between all vertices
void	setIncrement(double increment) Sets the increment by which the vertices gets close to the equilibrium or gets closer to the direction of the force.
void	setSpringLength(double length) Sets the desired length of the spring among all edges
void	setStiffness(double stiffness) Sets the value of stiffness among all edges

Methods inherited from class edu.ksu.cis.bnj.gui.components.AbstractLayouter

paintEdge, routeEdge

Methods inherited from class java.lang.Object

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

Field Detail

springLength

protected double springLength

stiffness

protected double stiffness

electricalRepulsion

protected double electricalRepulsion

increment

protected double increment

initialized

protected boolean initialized

fixedVertexList

protected java.util.ArrayList fixedVertexList

Constructor Detail

AutoLayouter

public AutoLayouter(salvo.jesus.graph.visual.VisualGraph vGraph)

Method Detail

getSpringLength

public double getSpringLength()

Returns the desired spring length for all edges. The default value is 50.

getStiffness

public double getStiffness()

Returns the stiffness for all edges. The default value is 50.

getEletricalRepulsion

public double getEletricalRepulsion()

Returns the eletrical repulsion between all vertices The default value is 400.

getIncrement

public double getIncrement()

Returns the increment by which the vertices gets closer to the equilibrium or closer to the force. The default value is 0.50.

setSpringLength

public void setSpringLength(double length)

Sets the desired length of the spring among all edges

setStiffness

public void setStiffness(double stiffness)

Sets the value of stiffness among all edges

setEletricalRepulsion

public void setEletricalRepulsion(double repulsion)

Sets the value of the electrical repulsion between all vertices

setIncrement

public void setIncrement(double increment)

Sets the increment by which the vertices gets close to the equilibrium or gets closer to the direction of the force. This must be a number > 0 and <= 1. The higher the value, the faster the layout reaches equilibrium.

addFixedVertex

public void addFixedVertex(salvo.jesus.graph.visual.VisualVertex vVertex)

Adds a VisuaLVertex that will not be moved from its position during the layout operation of ForceDirectedLayout.

isVertexFixed

public boolean isVertexFixed(salvo.jesus.graph.visual.VisualVertex vVertex)

Returns true if the specified VisualVertex has a fixed position.

removeFixedVertex

public void removeFixedVertex(salvo.jesus.graph.visual.VisualVertex vVertex)

Removes a VisualVertex from the list of VisualVertices that has a fixed position.

isInitialized

public boolean isInitialized()

Determines if the graph has been initially laid out. This method should be called prior to any painting to be done by the graph layout manager, as most internal variables are only initialized during layout.

Specified by:

isInitialized in interface salvo.jesus.graph.visual.layout.GraphLayoutManager

Overrides:

isInitialized in class AbstractLayouter

Returns:

True if the graph has at least been laid out once.

See Also:

GraphLayoutManager.isInitialized()

layout

public void layout()

This method is called to layout the vertices in the graph, running a thread to perform the layout if the thread is not running, or stopping the thread if the thread is running.

Adapted by Roby Joehanes

Specified by:

layout in interface salvo.jesus.graph.visual.layout.GraphLayoutManager

Specified by:

layout in class AbstractLayouter

See Also:

GraphLayoutManager.layout()

relax

protected double relax(salvo.jesus.graph.visual.VisualVertex vVertex)

"Relax" the force on the VisualVertex. "Relax" here means to get closer to the equilibrium position.

This method will:

• Find the spring force between all of its adjacent VisualVertices
• Get the electrical repulsion between all VisualVertices, including those which are not adjacent.

drawLayout

public void drawLayout()

This method is called to actually paint or draw the layout of the graph. This method should only be called after at least one call to layout().

Specified by:

drawLayout in interface salvo.jesus.graph.visual.layout.GraphLayoutManager

Overrides:

drawLayout in class AbstractLayouter

See Also:

GraphLayoutManager.drawLayout()

addVertex

public void addVertex(salvo.jesus.graph.visual.VisualVertex vVertex)

Specified by:

addVertex in interface salvo.jesus.graph.visual.layout.GraphLayoutManager

Overrides:

addVertex in class AbstractLayouter

See Also:

GraphLayoutManager.addVertex(salvo.jesus.graph.visual.VisualVertex)

removeEdge

public void removeEdge(salvo.jesus.graph.visual.VisualEdge vEdge)

Specified by:

removeEdge in interface salvo.jesus.graph.visual.layout.GraphLayoutManager

Overrides:

removeEdge in class AbstractLayouter

See Also:

GraphLayoutManager.removeEdge(salvo.jesus.graph.visual.VisualEdge)

removeVertex

public void removeVertex(salvo.jesus.graph.visual.VisualVertex vVertex)

Specified by:

removeVertex in interface salvo.jesus.graph.visual.layout.GraphLayoutManager

Overrides:

removeVertex in class AbstractLayouter

See Also:

GraphLayoutManager.removeVertex(salvo.jesus.graph.visual.VisualVertex)

addEdge

public void addEdge(salvo.jesus.graph.visual.VisualEdge vEdge)

Specified by:

addEdge in interface salvo.jesus.graph.visual.layout.GraphLayoutManager

Overrides:

addEdge in class AbstractLayouter

See Also:

GraphLayoutManager.addEdge(salvo.jesus.graph.visual.VisualEdge)