prefuse.action.layout.graph
Class NodeLinkTreeLayout

java.lang.Object
  prefuse.activity.Activity
      prefuse.action.Action
          prefuse.action.GroupAction
              prefuse.action.layout.Layout
                  prefuse.action.layout.graph.TreeLayout
                      prefuse.action.layout.graph.NodeLinkTreeLayout

public class NodeLinkTreeLayout
extends TreeLayout

TreeLayout that computes a tidy layout of a node-link tree diagram. This algorithm lays out a rooted tree such that each depth level of the tree is on a shared line. The orientation of the tree can be set such that the tree goes left-to-right (default), right-to-left, top-to-bottom, or bottom-to-top.

The algorithm used is that of Christoph Buchheim, Michael Jünger, and Sebastian Leipert from their research paper Improving Walker's Algorithm to Run in Linear Time, Graph Drawing 2002. This algorithm corrects performance issues in Walker's algorithm, which generalizes Reingold and Tilford's method for tidy drawings of trees to support trees with an arbitrary number of children at any given node.

Author:

jeffrey heer

Nested Class Summary

static class

NodeLinkTreeLayout.Params Wrapper class holding parameters used for each node in this layout.

Field Summary

static java.lang.String	PARAMS The data field in which the parameters used by this layout are stored.
static Schema	PARAMS_SCHEMA The schema for the parameters used by this layout.

Fields inherited from class prefuse.action.layout.graph.TreeLayout

m_root

Fields inherited from class prefuse.action.layout.Layout

m_anchor, m_bounds, m_bpts, m_insets, m_margin, m_tmpa, m_tmpb

Fields inherited from class prefuse.action.GroupAction

m_group

Fields inherited from class prefuse.action.Action

m_vis

Fields inherited from class prefuse.activity.Activity

DEFAULT_STEP_TIME, INFINITY

Constructor Summary

NodeLinkTreeLayout(java.lang.String group)
Create a new NodeLinkTreeLayout.

NodeLinkTreeLayout(java.lang.String group, int orientation, double dspace, double bspace, double tspace)
Create a new NodeLinkTreeLayout.

Method Summary

double	getBreadthSpacing() Get the spacing between neighbor nodes.
double	getDepthSpacing() Get the spacing between depth levels.
java.awt.geom.Point2D	getLayoutAnchor() Return the layout anchor at which to center or root the layout.
int	getOrientation() Get the orientation of the tree layout.
double	getRootNodeOffset() Get the offset value for placing the root node of the tree.
double	getSubtreeSpacing() Get the spacing between neighboring subtrees.
protected void	initSchema(TupleSet ts)
void	run(double frac) Runs this Action, triggering whatever processing this Action performs.
void	setBreadthSpacing(double b) Set the spacing between neighbor nodes.
void	setDepthSpacing(double d) Set the spacing between depth levels.
void	setOrientation(int orientation) Set the orientation of the tree layout.
void	setRootNodeOffset(double o) Set the offset value for placing the root node of the tree.
void	setSubtreeSpacing(double s) Set the spacing between neighboring subtrees.

Methods inherited from class prefuse.action.layout.graph.TreeLayout

getLayoutRoot, setLayoutRoot

Methods inherited from class prefuse.action.layout.Layout

getLayoutBounds, setLayoutAnchor, setLayoutBounds, setMargin, setX, setY

Methods inherited from class prefuse.action.GroupAction

getGroup, setGroup

Methods inherited from class prefuse.action.Action

getVisualization, run, setVisualization

Methods inherited from class prefuse.activity.Activity

addActivityListener, alwaysRunAfter, cancel, fireActivityCancelled, fireActivityFinished, fireActivityScheduled, fireActivityStarted, fireActivityStepped, getDuration, getNextTime, getPace, getPacingFunction, getStartTime, getStepTime, getStopTime, isEnabled, isRunning, isScheduled, removeActivityListener, run, runAfter, runAt, setDuration, setEnabled, setPacingFunction, setStartTime, setStepTime

Methods inherited from class java.lang.Object

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

Field Detail

PARAMS

public static final java.lang.String PARAMS

The data field in which the parameters used by this layout are stored.

See Also:

Constant Field Values

PARAMS_SCHEMA

public static final Schema PARAMS_SCHEMA

The schema for the parameters used by this layout.

Constructor Detail

NodeLinkTreeLayout

public NodeLinkTreeLayout(java.lang.String group)

Create a new NodeLinkTreeLayout. A left-to-right orientation is assumed.

Parameters:

group - the data group to layout. Must resolve to a Graph instance.

NodeLinkTreeLayout

public NodeLinkTreeLayout(java.lang.String group,
                          int orientation,
                          double dspace,
                          double bspace,
                          double tspace)

Create a new NodeLinkTreeLayout.

Parameters:

group - the data group to layout. Must resolve to a Graph instance.

orientation - the orientation of the tree layout. One of Constants.ORIENT_LEFT_RIGHT, Constants.ORIENT_RIGHT_LEFT, Constants.ORIENT_TOP_BOTTOM, or Constants.ORIENT_BOTTOM_TOP.

dspace - the spacing to maintain between depth levels of the tree

bspace - the spacing to maintain between sibling nodes

tspace - the spacing to maintain between neighboring subtrees

Method Detail

setOrientation

public void setOrientation(int orientation)

Set the orientation of the tree layout.

Parameters:

orientation - the orientation value. One of Constants.ORIENT_LEFT_RIGHT, Constants.ORIENT_RIGHT_LEFT, Constants.ORIENT_TOP_BOTTOM, or Constants.ORIENT_BOTTOM_TOP.

getOrientation

public int getOrientation()

Get the orientation of the tree layout.

Returns:

the orientation value. One of Constants.ORIENT_LEFT_RIGHT, Constants.ORIENT_RIGHT_LEFT, Constants.ORIENT_TOP_BOTTOM, or Constants.ORIENT_BOTTOM_TOP.

setDepthSpacing

public void setDepthSpacing(double d)

Set the spacing between depth levels.

Parameters:

d - the depth spacing to use

getDepthSpacing

public double getDepthSpacing()

Get the spacing between depth levels.

Returns:

the depth spacing

setBreadthSpacing

public void setBreadthSpacing(double b)

Set the spacing between neighbor nodes.

Parameters:

b - the breadth spacing to use

getBreadthSpacing

public double getBreadthSpacing()

Get the spacing between neighbor nodes.

Returns:

the breadth spacing

setSubtreeSpacing

public void setSubtreeSpacing(double s)

Set the spacing between neighboring subtrees.

Parameters:

s - the subtree spacing to use

getSubtreeSpacing

public double getSubtreeSpacing()

Get the spacing between neighboring subtrees.

Returns:

the subtree spacing

setRootNodeOffset

public void setRootNodeOffset(double o)

Set the offset value for placing the root node of the tree. The dimension in which this offset is applied is dependent upon the orientation of the tree. For example, in a left-to-right orientation, the offset will a horizontal offset from the left edge of the layout bounds.

Parameters:

o - the value by which to offset the root node of the tree

getRootNodeOffset

public double getRootNodeOffset()

Get the offset value for placing the root node of the tree.

Returns:

the value by which the root node of the tree is offset

getLayoutAnchor

public java.awt.geom.Point2D getLayoutAnchor()

Description copied from class: Layout

Return the layout anchor at which to center or root the layout. How this point is used (if it is used at all) is dependent on the particular Layout implementation. If no anchor point has been explicitly set, the center coordinate for the first display found in this action's associated Visualization is used, if available.

Overrides:

getLayoutAnchor in class Layout

Returns:

the layout anchor point.

See Also:

Layout.getLayoutAnchor()

run

public void run(double frac)

Description copied from class: Action

Runs this Action, triggering whatever processing this Action performs. Subclass this method to create custom Actions.

Specified by:

run in class GroupAction

Parameters:

frac - the fraction of this Action's duration that has elapsed.

See Also:

Action.run(double)

initSchema

protected void initSchema(TupleSet ts)