com.yworks.yfiles.layout.orthogonal

Class CompactOrthogonalLayout

java.lang.Object

com.yworks.yfiles.layout.AbstractLayoutStage

com.yworks.yfiles.layout.PartitionLayout

com.yworks.yfiles.layout.orthogonal.CompactOrthogonalLayout

All Implemented Interfaces:

ILayoutAlgorithm, ILayoutStage

public class CompactOrthogonalLayout
extends PartitionLayout

This layout algorithm arranges a graph in a compact, orthogonal fashion.

Layout Style

This layout algorithm is a variant of OrthogonalLayout that tries to arrange nodes in a more compact way. It allows to specify a desired aspect ratio for the bounds of the calculated layout. Nodes of a given graph are arranged such that each edge is drawn as an alternating sequence of horizontal and vertical segments.

CompactOrthogonalLayout is well suited for small and medium-sized sparse graphs and produces compact drawings with no overlapping nodes, few crossings and few bends. It is also especially suitable for printing the diagram on a paper of predefined size. As a disadvantage, this algorithm will usually produce less elegant edge routes than the ones of OrthogonalLayout.

Application domains of orthogonal drawings are software engineering, project management, function call graphs and object-oriented class diagrams.

Sample output of the layout algorithm with aspect ratio 1.0

Concept

This algorithm is implemented as a PartitionLayout and applies the following steps:

• Divides the graph into smaller partitions using PartitionLayout.EdgeBetweennessPartitionFinder.
• Arranges the nodes of each graph partition using OrthogonalLayout.
• Arranges the partitions themselves in a compact manner using PartitionLayout.ComponentPartitionPlacer.
• Routes the edges between partitions (inter-edges) using PartitionLayout.ChannelInterEdgeRouter.

Each of these steps can be individually configured and/or replaced. To do so, use methods PartitionFinder, CoreLayout, PartitionPlacer and InterEdgeRouter, respectively.

Features

The aspect ratio of the resulting layout bounds, i.e., the ratio of width/height of the layout, can be configured using AspectRatio. CompactOrthogonalLayout tries to reach this preferred value. However, depending on the actual graph structure, this may not always be possible.

Octilinear routing of edges can be supported by appending PolylineLayoutStage.

Nested Class Summary

Nested classes/interfaces inherited from class com.yworks.yfiles.layout.PartitionLayout

PartitionLayout.IInterEdgeRouter, PartitionLayout.IPartitionFinder, PartitionLayout.IPartitionPlacer

Constructor Summary

Constructors

Constructor and Description
CompactOrthogonalLayout() Creates a new CompactOrthogonalLayout instance with default settings.

Method Summary

Modifier and Type	Method and Description
double	getAspectRatio() Gets the desired aspect ratio (i.e.
int	getGridSpacing() Gets the equidistant spacing between the horizontal and vertical grid lines.
void	setAspectRatio(double value) Sets the desired aspect ratio (i.e.
void	setGridSpacing(int value) Sets the equidistant spacing between the horizontal and vertical grid lines.

Methods inherited from class com.yworks.yfiles.layout.PartitionLayout

applyLayout, getInterEdgeRouter, getPartitionFinder, getPartitionPlacer, setInterEdgeRouter, setPartitionFinder, setPartitionPlacer

Methods inherited from class com.yworks.yfiles.layout.AbstractLayoutStage

applyLayoutCore, getCoreLayout, setCoreLayout

Methods inherited from class java.lang.Object

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

Constructor Detail

CompactOrthogonalLayout

public CompactOrthogonalLayout()

Creates a new CompactOrthogonalLayout instance with default settings.

Method Detail

getAspectRatio

public double getAspectRatio()

Gets the desired aspect ratio (i.e.

the quotient width/height) of the resulting layout bounds.

The aspect ratio needs to be greater than 0.

Throws:

IllegalArgumentException - if the given aspect ratio is less than or equal to zero

This setting will only have an effect if the partition placer is of type PartitionLayout.ComponentPartitionPlacer.

Default Value:

The default value is 1.

Returns:

the desired aspect ratio

See Also:

PartitionLayout.setPartitionPlacer(PartitionLayout.IPartitionPlacer), PartitionLayout.ComponentPartitionPlacer, setAspectRatio(double)

getGridSpacing

public int getGridSpacing()

Gets the equidistant spacing between the horizontal and vertical grid lines.

Each node will be placed on a grid point. Edges will be routed such that their segments lie on grid lines, if the endpoints of the edges allow to place the ports accordingly.

The grid spacing has to be greater than 0.

Throws:

IllegalArgumentException - if the grid spacing is negative or zero

Setting the grid spacing will only have an effect if the configurable stages have not been replaced by other custom stage implementations.

Default Value:

The default value is 20.

Returns:

the grid spacing

See Also:

setGridSpacing(int)

setAspectRatio

public void setAspectRatio(double value)

Sets the desired aspect ratio (i.e.

the quotient width/height) of the resulting layout bounds.

The aspect ratio needs to be greater than 0.

Throws:

IllegalArgumentException - if the given aspect ratio is less than or equal to zero

This setting will only have an effect if the partition placer is of type PartitionLayout.ComponentPartitionPlacer.

Default Value:

The default value is 1.

Parameters:

value - the desired aspect ratio

See Also:

PartitionLayout.setPartitionPlacer(PartitionLayout.IPartitionPlacer), PartitionLayout.ComponentPartitionPlacer, getAspectRatio()

setGridSpacing

public void setGridSpacing(int value)

Sets the equidistant spacing between the horizontal and vertical grid lines.

Each node will be placed on a grid point. Edges will be routed such that their segments lie on grid lines, if the endpoints of the edges allow to place the ports accordingly.

The grid spacing has to be greater than 0.

Throws:

IllegalArgumentException - if the grid spacing is negative or zero

Setting the grid spacing will only have an effect if the configurable stages have not been replaced by other custom stage implementations.

Default Value:

The default value is 20.

Parameters:

value - the grid spacing

See Also:

getGridSpacing()