edu.uci.ics.jung.visualization.contrib

Class DAGLayout

java.lang.Object

edu.uci.ics.jung.visualization.AbstractLayout

edu.uci.ics.jung.visualization.SpringLayout

edu.uci.ics.jung.visualization.contrib.DAGLayout

All Implemented Interfaces:

ChangeEventSupport, Layout, LayoutMutable, VertexLocationFunction

public class DAGLayout
extends SpringLayout

Author:

John Yesberg DAGLayout is a layout algorithm which is suitable for tree-like directed acyclic graphs. Parts of it will probably not terminate if the graph is cyclic! The layout will result in directed edges pointing generally upwards. Any vertices with no successors are considered to be level 0, and tend towards the top of the layout. Any vertex has a level one greater than the maximum level of all its successors. Note: had to make minor access changes to SpringLayout to make this work. FORCE_CONSTANT, LengthFunction, SpringVertexData, and SpringEdgeData were all made "protected".

Nested Class Summary

Nested classes/interfaces inherited from class edu.uci.ics.jung.visualization.SpringLayout

SpringLayout.LengthFunction, SpringLayout.SpringDimensionChecker, SpringLayout.SpringEdgeData, SpringLayout.SpringVertexData, SpringLayout.UnitLengthFunction

Field Summary

Fields

Modifier and Type	Field and Description
protected static java.lang.String	MINIMUMLEVELKEY

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

force_multiplier, lengthFunction, repulsion_range, stretch, UNITLENGTHFUNCTION

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

changeSupport, vertex_locations

Constructor Summary

Constructors

Constructor and Description
DAGLayout(Graph g)

Method Summary

Methods

Modifier and Type	Method and Description
void	forceMove(Vertex picked, int x, int y) Override forceMove so that if someone moves a node, we can re-layout everything.
boolean	incrementsAreDone() Override incrementsAreDone so that we can eventually stop.
protected void	initialize_local() Had to override this one as well, to ensure that setRoot() is called.
protected void	initializeLocation(Vertex v, Coordinates coord, java.awt.Dimension d) Sets random locations for a vertex within the dimensions of the space.
protected void	moveNodes() Override the moveNodes() method from SpringLayout.
static void	propagateMinimumLevel(Vertex v) A recursive method for allocating the level for each vertex.
protected void	relaxEdges() Overridden relaxEdges.
static void	setRoot(Graph g) setRoot calculates the level of each vertex in the graph.
static void	setRoot(Vertex v) Set vertex v to be level 0.

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

advancePositions, calcEdgeLength, calculateRepulsion, getAVertex, getForceMultiplier, getLength, getRepulsionRange, getSpringData, getSpringData, getSpringKey, getStatus, getStretch, initialize_local_vertex, isIncremental, setForceMultiplier, setRepulsionRange, setStretch, 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, 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

MINIMUMLEVELKEY

protected static final java.lang.String MINIMUMLEVELKEY

See Also:

Constant Field Values

Constructor Detail

DAGLayout

public DAGLayout(Graph g)

Method Detail

setRoot

public static void setRoot(Graph g)

setRoot calculates the level of each vertex in the graph. Level 0 is allocated to any vertex with no successors. Level n+1 is allocated to any vertex whose successors' maximum level is n.

setRoot

public static void setRoot(Vertex v)

Set vertex v to be level 0.

propagateMinimumLevel

public static void propagateMinimumLevel(Vertex v)

A recursive method for allocating the level for each vertex. Ensures that all predecessors of v have a level which is at least one greater than the level of v.

Parameters:

v -

initializeLocation

protected void initializeLocation(Vertex v,
                      Coordinates coord,
                      java.awt.Dimension d)

Sets random locations for a vertex within the dimensions of the space. This overrides the method in AbstractLayout

Overrides:

initializeLocation in class AbstractLayout

Parameters:

coord -

d -

initialize_local

protected void initialize_local()

Had to override this one as well, to ensure that setRoot() is called.

Overrides:

initialize_local in class SpringLayout

moveNodes

protected void moveNodes()

Override the moveNodes() method from SpringLayout. The only change we need to make is to make sure that nodes don't float higher than the minY coordinate, as calculated by their minimumLevel.

Overrides:

moveNodes in class SpringLayout

incrementsAreDone

public boolean incrementsAreDone()

Override incrementsAreDone so that we can eventually stop.

Specified by:

incrementsAreDone in interface Layout

Overrides:

incrementsAreDone in class SpringLayout

forceMove

public void forceMove(Vertex picked,
             int x,
             int y)

Override forceMove so that if someone moves a node, we can re-layout everything.

relaxEdges

protected void relaxEdges()

Overridden relaxEdges. This one reduces the effect of edges between greatly different levels.

Overrides:

relaxEdges in class SpringLayout