org.eclipse.gef4.layout.algorithms

Class SugiyamaLayoutAlgorithm

java.lang.Object

org.eclipse.gef4.layout.algorithms.SugiyamaLayoutAlgorithm

All Implemented Interfaces:

ILayoutAlgorithm

public class SugiyamaLayoutAlgorithm
extends java.lang.Object
implements ILayoutAlgorithm

The SugiyamaLayoutAlgorithm class implements an algorithm to arrange a directed graph in a layered tree-like layout. The final presentation follows five design principles for enhanced readability: - Hierarchical layout of vertices - Least crossings of lines (edges) - Straightness of lines when ever possible - Close layout of vertices connected to each other, i.e. short paths - Balanced layout of lines coming into or going from a vertex For further information see http://dx.doi.org/10.1109/TSMC.1981.4308636 This layout algorithm works only with - directed graphs (otherwise an appropriate RuntimeException is thrown)

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SugiyamaLayoutAlgorithm.BarycentricCrossingReducer
static interface	SugiyamaLayoutAlgorithm.CrossingReducer An interface for heuristics that reduces edge crossings.
static class	SugiyamaLayoutAlgorithm.DFSLayerProvider Processing the nodes based on depth first search and creating a list of layers
static class	SugiyamaLayoutAlgorithm.Direction Specifies the direction for the SugiyamaLayoutAlgorithm.
static class	SugiyamaLayoutAlgorithm.GreedyCrossingReducer Implemented the CrossingReducer interface.
static interface	SugiyamaLayoutAlgorithm.LayerProvider An interface for creating layers.
static class	SugiyamaLayoutAlgorithm.NodeWrapper Structure to store nodes and their positions in the layers.
static class	SugiyamaLayoutAlgorithm.SimpleLayerProvider
static class	SugiyamaLayoutAlgorithm.SplitCrossingReducer Implements the CrossingReducer interface.

Constructor Summary

Constructors

Constructor and Description
SugiyamaLayoutAlgorithm() Constructs a new SugiyamaLayoutAlgorithm with SugiyamaLayoutAlgorithm.Direction.VERTICAL direction.
SugiyamaLayoutAlgorithm(SugiyamaLayoutAlgorithm.Direction dir) Constructs a new SugiyamaLayoutAlgorithm with the given SugiyamaLayoutAlgorithm.Direction.
SugiyamaLayoutAlgorithm(SugiyamaLayoutAlgorithm.Direction dir, Dimension dim) Constructs a new SugiyamaLayoutAlgorithm with the given SugiyamaLayoutAlgorithm.Direction, and the given dimension.
SugiyamaLayoutAlgorithm(SugiyamaLayoutAlgorithm.Direction dir, Dimension dim, SugiyamaLayoutAlgorithm.LayerProvider layering, SugiyamaLayoutAlgorithm.CrossingReducer crossing) Constructs a tree-like, layered layout of a directed graph.
SugiyamaLayoutAlgorithm(SugiyamaLayoutAlgorithm.Direction dir, SugiyamaLayoutAlgorithm.CrossingReducer crossing) Constructs a new SugiyamaLayoutAlgorithm with the given SugiyamaLayoutAlgorithm.Direction, and SugiyamaLayoutAlgorithm.CrossingReducer.
SugiyamaLayoutAlgorithm(SugiyamaLayoutAlgorithm.Direction dir, SugiyamaLayoutAlgorithm.LayerProvider layerProvider) Constructs a new SugiyamaLayoutAlgorithm with the given SugiyamaLayoutAlgorithm.Direction, SugiyamaLayoutAlgorithm.LayerProvider, and a SugiyamaLayoutAlgorithm.BarycentricCrossingReducer.
SugiyamaLayoutAlgorithm(SugiyamaLayoutAlgorithm.Direction dir, SugiyamaLayoutAlgorithm.LayerProvider layerProvider, SugiyamaLayoutAlgorithm.CrossingReducer crossing) Constructs a new SugiyamaLayoutAlgorithm with the given SugiyamaLayoutAlgorithm.Direction, SugiyamaLayoutAlgorithm.LayerProvider, and SugiyamaLayoutAlgorithm.CrossingReducer.

Method Summary

Modifier and Type	Method and Description
void	applyLayout(boolean clean) Makes this algorithm perform layout computation and apply it to its context.
ILayoutContext	getLayoutContext() Returns the previously set ILayoutContext.
void	setLayoutContext(ILayoutContext context) Sets the layout context for this algorithm.

Methods inherited from class java.lang.Object

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

Constructor Detail

SugiyamaLayoutAlgorithm

public SugiyamaLayoutAlgorithm(SugiyamaLayoutAlgorithm.Direction dir,
                               Dimension dim,
                               SugiyamaLayoutAlgorithm.LayerProvider layering,
                               SugiyamaLayoutAlgorithm.CrossingReducer crossing)

Constructs a tree-like, layered layout of a directed graph.

Parameters:

dir - SugiyamaLayoutAlgorithm.Direction.HORIZONTAL: left to right - SugiyamaLayoutAlgorithm.Direction.VERTICAL : top to bottom

dim - - desired size of the layout area. Uses the BOUNDS_PROPERTY of the LayoutContext if not set

layering - - implementation of LayerProvider interface

crossing - - implementation of CrossingReducer interface

SugiyamaLayoutAlgorithm

public SugiyamaLayoutAlgorithm(SugiyamaLayoutAlgorithm.Direction dir,
                               SugiyamaLayoutAlgorithm.LayerProvider layerProvider,
                               SugiyamaLayoutAlgorithm.CrossingReducer crossing)

Constructs a new SugiyamaLayoutAlgorithm with the given SugiyamaLayoutAlgorithm.Direction, SugiyamaLayoutAlgorithm.LayerProvider, and SugiyamaLayoutAlgorithm.CrossingReducer.

Parameters:

dir - The SugiyamaLayoutAlgorithm.Direction for this SugiyamaLayoutAlgorithm .

layerProvider - The LayerProvider for this SugiyamaLayoutAlgorithm.

crossing - The CrossingReducer for this SugiyamaLayoutAlgorithm.

SugiyamaLayoutAlgorithm

public SugiyamaLayoutAlgorithm(SugiyamaLayoutAlgorithm.Direction dir,
                               SugiyamaLayoutAlgorithm.LayerProvider layerProvider)

Constructs a new SugiyamaLayoutAlgorithm with the given SugiyamaLayoutAlgorithm.Direction, SugiyamaLayoutAlgorithm.LayerProvider, and a SugiyamaLayoutAlgorithm.BarycentricCrossingReducer.

Parameters:

dir - The SugiyamaLayoutAlgorithm.Direction for this SugiyamaLayoutAlgorithm .

layerProvider - The LayerProvider for this SugiyamaLayoutAlgorithm.

SugiyamaLayoutAlgorithm

public SugiyamaLayoutAlgorithm(SugiyamaLayoutAlgorithm.Direction dir,
                               SugiyamaLayoutAlgorithm.CrossingReducer crossing)

Constructs a new SugiyamaLayoutAlgorithm with the given SugiyamaLayoutAlgorithm.Direction, and SugiyamaLayoutAlgorithm.CrossingReducer.

Parameters:

dir - The SugiyamaLayoutAlgorithm.Direction for this SugiyamaLayoutAlgorithm .

crossing - The CrossingReducer for this SugiyamaLayoutAlgorithm.

SugiyamaLayoutAlgorithm

public SugiyamaLayoutAlgorithm(SugiyamaLayoutAlgorithm.Direction dir,
                               Dimension dim)

Constructs a new SugiyamaLayoutAlgorithm with the given SugiyamaLayoutAlgorithm.Direction, and the given dimension.

Parameters:

dir - The SugiyamaLayoutAlgorithm.Direction for this SugiyamaLayoutAlgorithm .

dim - The desired size of the layout area. Uses the BOUNDS_PROPERTY of the LayoutContext if not set.

SugiyamaLayoutAlgorithm

public SugiyamaLayoutAlgorithm(SugiyamaLayoutAlgorithm.Direction dir)

Constructs a new SugiyamaLayoutAlgorithm with the given SugiyamaLayoutAlgorithm.Direction.

Parameters:

dir - The SugiyamaLayoutAlgorithm.Direction for this SugiyamaLayoutAlgorithm .

SugiyamaLayoutAlgorithm

public SugiyamaLayoutAlgorithm()

Constructs a new SugiyamaLayoutAlgorithm with SugiyamaLayoutAlgorithm.Direction.VERTICAL direction.

Method Detail

setLayoutContext

public void setLayoutContext(ILayoutContext context)

Description copied from interface: ILayoutAlgorithm

Sets the layout context for this algorithm. The receiver will unregister from its previous layout context and register to the new one (registration means for example adding listeners). After a call to this method, the receiving algorithm can compute and cache internal data related to given context and perform an initial layout.

Specified by:

setLayoutContext in interface ILayoutAlgorithm

Parameters:

context - a new layout context or null if this algorithm should not perform any layout

getLayoutContext

public ILayoutContext getLayoutContext()

Description copied from interface: ILayoutAlgorithm

Returns the previously set ILayoutContext.

Specified by:

getLayoutContext in interface ILayoutAlgorithm

Returns:

the previously set ILayoutContext

applyLayout

public void applyLayout(boolean clean)

Description copied from interface: ILayoutAlgorithm

Makes this algorithm perform layout computation and apply it to its context.

Specified by:

applyLayout in interface ILayoutAlgorithm

Parameters:

clean - if true the receiver should assume that the layout context has changed significantly and recompute the whole layout even if it keeps track of changes with listeners. False can be used after dynamic layout in a context is turned back on so that layout algorithm working in background can apply accumulated changes. Static layout algorithm can ignore this call entirely if clean is false.