com.yworks.yfiles.layout.circular

Class SingleCycleLayout

java.lang.Object

com.yworks.yfiles.layout.MultiStageLayout

com.yworks.yfiles.layout.circular.SingleCycleLayout

All Implemented Interfaces:

ILayoutAlgorithm

public class SingleCycleLayout
extends MultiStageLayout

This layout algorithm places all nodes of a graph on a single cycle.

Layout Style

All nodes of a graph are placed on one common circle, generating circular layouts. The edges are drawn as simple, straight lines. The resulting layouts look like a ring. Edges connecting nodes which are not next to each other on the ring are routed inside of the circle. If a graph contains many edges, the number of edge crossings inside the circle may be quite high.

Single-cycle circular layouts are suitable for the visualization of networks such as ring networks or smaller social networks. They are also useful to layout cyclic subgraphs of a larger graph.

An example of a single cycle layout

Concept

First, the nodes are sorted by applying either a custom or some default INodeSequencer. Then, all nodes are placed on a circle with an appropriate radius according to the calculated order.

Features

The order in which the nodes are placed on the circle is a crucial aspect of this algorithm. By specifying a INodeSequencer instance via NodeSequencer, the order can be customized.

There are two options to determine the radius of the circle on which nodes are placed:

1. The radius can be determined automatically. A specified minimum radius will be obeyed when choosing the radius.
2. The radius can be chosen manually. To do so, disable the automatic radius selection and specify the custom radius via FixedRadius.

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method and Description
void	applyLayoutCore(LayoutGraph graph) Arranges the nodes of the given graph such that they all lie on a common circle.
double	getFixedRadius() Gets a fixed radius for the circle on which the nodes will be placed.
double	getInitialAngle() Gets the angle that describes the location on the circle of the first node.
double	getLastAppliedRadius() Gets the radius that was applied to the last layout calculated by this algorithm.
int	getMinimumNodeDistance() Gets the minimum distance between nodes that are next to each other on the circle.
double	getMinimumRadius() Gets the minimum radius for the circle on which the nodes are placed.
INodeSequencer	getNodeSequencer() Gets the INodeSequencer that will be used for determining the order of the nodes for the circle placement.
boolean	isAutomaticRadiusEnabled() Gets whether or not the radius of the circle should be determined automatically.
boolean	isFromSketchModeEnabled() Gets whether or not to consider the coordinates of the input diagram when arranging the graph.
void	setAutomaticRadiusEnabled(boolean value) Sets whether or not the radius of the circle should be determined automatically.
void	setFixedRadius(double value) Sets a fixed radius for the circle on which the nodes will be placed.
void	setFromSketchModeEnabled(boolean value) Sets whether or not to consider the coordinates of the input diagram when arranging the graph.
void	setInitialAngle(double value) Sets the angle that describes the location on the circle of the first node.
void	setMinimumNodeDistance(int value) Sets the minimum distance between nodes that are next to each other on the circle.
void	setMinimumRadius(double value) Sets the minimum radius for the circle on which the nodes are placed.
void	setNodeSequencer(INodeSequencer value) Sets the INodeSequencer that will be used for determining the order of the nodes for the circle placement.
void	setOrientationLayoutEnabled(boolean value) Sets whether or not the ILayoutStage that modifies the orientation of the layout is activated.
void	setSelfLoopRouterEnabled(boolean value) Sets whether or not the ILayoutStage used for routing self-loops is activated.

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

appendStage, applyLayout, checkNodeSize, disableAllStages, getComponentLayout, getHideGroupsStage, getLabeling, getLayoutOrientation, getOrientationLayout, getParallelEdgeRouter, getSelfLoopRouter, getSubgraphLayout, isComponentLayoutEnabled, isHideGroupsStageEnabled, isLabelingEnabled, isOrientationLayoutEnabled, isParallelEdgeRouterEnabled, isSelfLoopRouterEnabled, isSubgraphLayoutEnabled, prependStage, removeStage, setComponentLayout, setComponentLayoutEnabled, setHideGroupsStage, setHideGroupsStageEnabled, setLabeling, setLabelingEnabled, setLayoutOrientation, setOrientationLayout, setParallelEdgeRouter, setParallelEdgeRouterEnabled, setSelfLoopRouter, setSubgraphLayout, setSubgraphLayoutEnabled

Methods inherited from class java.lang.Object

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

Constructor Detail

SingleCycleLayout

public SingleCycleLayout()

Creates a new SingleCycleLayout instance with default settings.

Method Detail

applyLayoutCore

public void applyLayoutCore(LayoutGraph graph)

Arranges the nodes of the given graph such that they all lie on a common circle.

Specified by:

applyLayoutCore in class MultiStageLayout

Parameters:

graph - the input graph

getFixedRadius

public double getFixedRadius()

Gets a fixed radius for the circle on which the nodes will be placed.

Throws:

IllegalArgumentException - if the given radius is negative

If the radius is too small, the nodes on the circle may overlap with each other.

This fixed radius is only considered if the radius is not automatically selected by the layout algorithm.

Default Value:

The default value is 200.

Returns:

the fixed radius for the circle

See Also:

setMinimumRadius(double), setAutomaticRadiusEnabled(boolean), setFixedRadius(double)

getInitialAngle

public double getInitialAngle()

Gets the angle that describes the location on the circle of the first node.

The angle is measured in radians and world coordinates, e.g., 0 means east, Pi/2 means south.

This setting is ignored if the SingleCycleLayout is used by CircularLayout to arrange single-cycle partitions. The CircularLayout will automatically choose the initial angle.

Default Value:

The default value is 0.0. The first node is placed east.

Returns:

the angle for the placement of the first node in radians

See Also:

setInitialAngle(double)

getLastAppliedRadius

public double getLastAppliedRadius()

Gets the radius that was applied to the last layout calculated by this algorithm.

This method is useful if one wants to know the actual radius of a layout calculated by this algorithm.

Returns:

the radius applied to the result of the last layout calculation

getMinimumNodeDistance

public int getMinimumNodeDistance()

Gets the minimum distance between nodes that are next to each other on the circle.

Throws:

IllegalArgumentException - if the given distance is negative

The minimum node distance will be ignored if the automatic radius selection is disabled. In that case, the distance between nodes will follow from the specified fixed radius.

Default Value:

The default value is 30.

Returns:

the non-negative minimum distance between nodes

See Also:

setMinimumNodeDistance(int)

getMinimumRadius

public double getMinimumRadius()

Gets the minimum radius for the circle on which the nodes are placed.

Throws:

IllegalArgumentException - if the given minimum radius is negative

This setting is only considered if the automatic radius selection is enabled. Otherwise, the chosen fixed radius will be used.

Default Value:

The default value is 5.0.

Returns:

the minimum circle radius

See Also:

setFixedRadius(double), setAutomaticRadiusEnabled(boolean), setMinimumRadius(double)

getNodeSequencer

public INodeSequencer getNodeSequencer()

Gets the INodeSequencer that will be used for determining the order of the nodes for the circle placement.

Throws:

IllegalArgumentException - if the specified INodeSequencer is null

Returns:

the sequencer for determining a node order for the circle placement

See Also:

setNodeSequencer(INodeSequencer)

isAutomaticRadiusEnabled

public boolean isAutomaticRadiusEnabled()

Gets whether or not the radius of the circle should be determined automatically.

If enabled, the radius will be chosen such that the distance between nodes which are next to each other on the circle is approximately the same as the minimum node distance.

If this feature is disabled, the radius specified via FixedRadius will be applied.

Default Value:

The default value is true. The radius will be chosen automatically.

Returns:

true, if the radius of the circle is determined automatically, false, otherwise

See Also:

setMinimumRadius(double), setFixedRadius(double), setAutomaticRadiusEnabled(boolean)

isFromSketchModeEnabled

public boolean isFromSketchModeEnabled()

Gets whether or not to consider the coordinates of the input diagram when arranging the graph.

If this feature is enabled, the original circular order of peripheral nodes around an estimated circle center will be preserved.

Default Value:

The default value is false. The coordinates of the input diagram are not considered.

Returns:

true if the initial coordinates of the nodes are considered, false otherwise

See Also:

setFromSketchModeEnabled(boolean)

setAutomaticRadiusEnabled

public void setAutomaticRadiusEnabled(boolean value)

Sets whether or not the radius of the circle should be determined automatically.

If enabled, the radius will be chosen such that the distance between nodes which are next to each other on the circle is approximately the same as the minimum node distance.

If this feature is disabled, the radius specified via FixedRadius will be applied.

Default Value:

The default value is true. The radius will be chosen automatically.

Parameters:

value - true, if the radius of the circle is determined automatically, false, otherwise

See Also:

setMinimumRadius(double), setFixedRadius(double), isAutomaticRadiusEnabled()

setFixedRadius

public void setFixedRadius(double value)

Sets a fixed radius for the circle on which the nodes will be placed.

Throws:

IllegalArgumentException - if the given radius is negative

If the radius is too small, the nodes on the circle may overlap with each other.

This fixed radius is only considered if the radius is not automatically selected by the layout algorithm.

Default Value:

The default value is 200.

Parameters:

value - the fixed radius for the circle

See Also:

setMinimumRadius(double), setAutomaticRadiusEnabled(boolean), getFixedRadius()

setFromSketchModeEnabled

public void setFromSketchModeEnabled(boolean value)

Sets whether or not to consider the coordinates of the input diagram when arranging the graph.

If this feature is enabled, the original circular order of peripheral nodes around an estimated circle center will be preserved.

Default Value:

The default value is false. The coordinates of the input diagram are not considered.

Parameters:

value - true if the initial coordinates of the nodes are considered, false otherwise

See Also:

isFromSketchModeEnabled()

setInitialAngle

public void setInitialAngle(double value)

Sets the angle that describes the location on the circle of the first node.

The angle is measured in radians and world coordinates, e.g., 0 means east, Pi/2 means south.

This setting is ignored if the SingleCycleLayout is used by CircularLayout to arrange single-cycle partitions. The CircularLayout will automatically choose the initial angle.

Default Value:

The default value is 0.0. The first node is placed east.

Parameters:

value - the angle for the placement of the first node in radians

See Also:

getInitialAngle()

setMinimumNodeDistance

public void setMinimumNodeDistance(int value)

Sets the minimum distance between nodes that are next to each other on the circle.

Throws:

IllegalArgumentException - if the given distance is negative

The minimum node distance will be ignored if the automatic radius selection is disabled. In that case, the distance between nodes will follow from the specified fixed radius.

Default Value:

The default value is 30.

Parameters:

value - the non-negative minimum distance between nodes

See Also:

getMinimumNodeDistance()

setMinimumRadius

public void setMinimumRadius(double value)

Sets the minimum radius for the circle on which the nodes are placed.

Throws:

IllegalArgumentException - if the given minimum radius is negative

This setting is only considered if the automatic radius selection is enabled. Otherwise, the chosen fixed radius will be used.

Default Value:

The default value is 5.0.

Parameters:

value - the minimum circle radius

See Also:

setFixedRadius(double), setAutomaticRadiusEnabled(boolean), getMinimumRadius()

setNodeSequencer

public void setNodeSequencer(INodeSequencer value)

Sets the INodeSequencer that will be used for determining the order of the nodes for the circle placement.

Throws:

IllegalArgumentException - if the specified INodeSequencer is null

Parameters:

value - the sequencer for determining a node order for the circle placement

See Also:

getNodeSequencer()

setOrientationLayoutEnabled

public void setOrientationLayoutEnabled(boolean value)

Sets whether or not the ILayoutStage that modifies the orientation of the layout is activated.

Overrides:

setOrientationLayoutEnabled in class MultiStageLayout

If the current layout orientation is LayoutOrientation.TOP_TO_BOTTOM, the orientation of the layout will not be modified.

Based on the undirected layout style, disabling OrientationLayout has no significant effect.

Default Value:

The default value is true. The orientation ILayoutStage is activated.

Parameters:

value - true if the stage that modifies the orientation is activated, false otherwise

See Also:

MultiStageLayout.isOrientationLayoutEnabled(), MultiStageLayout.setOrientationLayout(com.yworks.yfiles.layout.ILayoutStage), MultiStageLayout.setLayoutOrientation(com.yworks.yfiles.layout.LayoutOrientation), OrientationLayout

setSelfLoopRouterEnabled

public void setSelfLoopRouterEnabled(boolean value)

Sets whether or not the ILayoutStage used for routing self-loops is activated.

Overrides:

setSelfLoopRouterEnabled in class MultiStageLayout

CircularLayout cannot handle self-loops. Disabling SelfLoopRouter will lead to errors during execution.

Default Value:

The default value is true. The stage that routes self-loops is activated.

Parameters:

value - true if the stage responsible for routing self-loops is activated, false otherwise

See Also:

MultiStageLayout.isSelfLoopRouterEnabled(), MultiStageLayout.setSelfLoopRouter(com.yworks.yfiles.layout.ILayoutStage), SelfLoopRouter