com.yworks.yfiles.layout.hierarchic

Class HierarchicLayoutCore

java.lang.Object

com.yworks.yfiles.layout.MultiStageLayout

com.yworks.yfiles.layout.hierarchic.HierarchicLayoutCore

All Implemented Interfaces:

ILayoutAlgorithm

public class HierarchicLayoutCore
extends MultiStageLayout

This class arranges graphs in a hierarchic/layered fashion and supports complete re-layout as well as incremental graph layout.

Note that class HierarchicLayout offers a facade to this class which is easier to use. Hence, we strongly recommend to not directly use class HierarchicLayoutCore.

Layout Style

The nodes are distributed into layers such that most of the edges point to the main layout direction. The order of the nodes within the layers ensures that the number of edge crossings is as small as possible. There are different edge routing styles available. Edges can be orthogonal, polyline or octilinear.

Hierarchical diagrams are commonly used for the visualization of hierarchical data, since they facilitate the identification of dependencies and relationships among the nodes of the graph. Possible application domains are the following: workflow visualization, call graph visualization, entity-relationship diagrams, biochemical pathways and network management.

Hierarchic Layout obtained with default settings

Concept

The layout algorithm runs in three main phases:

• Layering – The nodes are distributed into layers by means of Layerer. If the layout orientation is top-to-bottom, the nodes in each layer are arranged horizontally while the layers are ordered vertically top-to-bottom.
• Sequencing – The order of the nodes in each layer is determined such that the number of edge crossings is as small as possible. To specify the sequencing algorithm, use Sequencer.
• Drawing – The layout algorithm assigns the final coordinates to all nodes and routes the edges.

Features

In order to customize this layout algorithm, modify the Layerer, Sequencer, PortAllocator, DrawingDistanceCalculator, and NodePlacer instances.

This layout algorithm is able to incrementally add new elements to an existing drawing of a graph. In order to add elements incrementally, register a IDataProvider with the graph using the INCREMENTAL_HINTS_DPKEY DataProvider key and associate the hints obtained from the IIncrementalHintsFactory with the elements to be added incrementally.

NodeLayoutDescriptor and EdgeLayoutDescriptor instances can be used for specifying individual information (e.g. distances or routing styles) for each node and edge in the graph. The descriptors are bound to the graph using IDataProviders registered with NODE_LAYOUT_DESCRIPTOR_DPKEY or EDGE_LAYOUT_DESCRIPTOR_DPKEY.

HierarchicLayoutCore supports two approaches to connect edges on a specific side or even an exact location to a node. PortConstraints define a single constraint for the ports of an edge. To realize more complex port restrictions, several PortCandidates or PortCandidateSets can be assigned to edges or nodes. If an edge with registered PortCandidates connects to nodes with PortCandidateSets, the layouter will try to match both collections to find an appropriate port. In case there is no matching port candidate, a PortCandidate specified for the edge is preferred. Since their simultaneous existence at the same node may be ambiguous, it is not recommended to use a combination of PortConstraints and PortCandidates in the same layout.

This algorithm specifies a LabelLayoutTranslator instance as the current Labeling and configures it such that the node labels are passed to it by setting NodeLabelTranslationEnabled to true.

In order to enable integrated edge labeling of this algorithm, make sure LabelLayoutTranslator is registered and edge labels are being translated and written back after the layout.

Moreover, this algorithm supports layer and sequence constraints. These constraints can be specified using a ILayerConstraintFactory and ISequenceConstraintFactory, respectively.

See Also:

HierarchicLayout, ILayerer, ISequencer, IPortAllocator, IDrawingDistanceCalculator, INodePlacer

Field Summary

Fields

Modifier and Type	Field and Description
static EdgeDpKey<EdgeLayoutDescriptor>	EDGE_LAYOUT_DESCRIPTOR_DPKEY A DataProvider key for providing layout information for each edge
static GraphObjectDpKey<Object>	INCREMENTAL_HINTS_DPKEY A DataProvider key for specifying incremental hints Incremental hints are created using an incremental hints factory.
static NodeDpKey<Boolean>	INCREMENTAL_NODES_DPKEY A DataProvider key for internal use only.
static NodeDpKey<Integer>	LAYER_INDEX_DPKEY A DataAcceptor key for publishing the layer IDs for all nodes in the graph.
static NodeDpKey<NodeLayoutDescriptor>	NODE_LAYOUT_DESCRIPTOR_DPKEY A DataProvider key for providing layout information for each node
static NodeDpKey<Integer>	SEQUENCE_INDEX_DPKEY A DataAcceptor key for publishing the index inside their layer for all nodes in the graph.
static NodeDpKey<SwimlaneDescriptor>	SWIMLANE_DESCRIPTOR_DPKEY A DataProvider key for providing information about swimlanes If this key is present during the layout, the layout algorithm will arrange nodes in swimlanes.

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method and Description
void	applyLayoutCore(LayoutGraph graph) Calculates a hierarchic layout of the given graph.
protected IDrawingDistanceCalculator	createDrawingDistanceCalculator() Factory method that is called lazily upon first usage by DrawingDistanceCalculator if the given IDrawingDistanceCalculator instance is null.
protected IEdgeReverser	createEdgeReverser() Factory method called during applyLayoutCore(LayoutGraph) and reates an appropriate IEdgeReverser implementation.
protected GroupingSupport	createGrouping(LayoutGraph graph) Factory method that is called during applyLayoutCore(LayoutGraph) and creates a GroupingSupport instance in case of a grouped graph.
IIncrementalHintsFactory	createIncrementalHintsFactory() Creates an IIncrementalHintsFactory implementation used for obtaining hint objects associated with nodes and edges of the graph prior to the invocation of the layout algorithm.
protected ILayerer	createIncrementalLayerer() Factory method called during applyLayoutCore(LayoutGraph) and creates an appropriate ILayerer implementation.
protected void	createItemData(LayoutGraph g, IItemFactory itemFactory) Callback method that is called during applyLayoutCore(LayoutGraph), creates the INodeData and IEdgeData instances and binds them to the elements using the given itemFactory.
ILayerConstraintFactory	createLayerConstraintFactory(Graph graph) Creates a layer constraint factory that allows to create hints that affect the assignment of the nodes to layers.
protected ILayerer	createLayerer() Factory method that is called lazily upon first usage by Layerer if no ILayerer instance is given as input.
protected ILayers	createLayers(ILayoutDataProvider ldp) Factory method called during applyLayoutCore(LayoutGraph) and creates an appropriate ILayers implementation using the given ILayoutDataProvider instance.
protected INodePlacer	createNodePlacer() Factory method that is called lazily upon first usage by NodePlacer if the given INodePlacer instance is null.
protected IPortAllocator	createPortAllocator() Factory method that is called lazily upon first usage by PortAllocator if the given IPortAllocator instance is null.
protected IPortConstraintOptimizer	createPortConstraintOptimizer() Factory method that is called lazily upon first usage by PortConstraintOptimizer if the given IPortConstraintOptimizer instance is null.
ISequenceConstraintFactory	createSequenceConstraintFactory(Graph graph) Creates sequence constraints that affect the sequence of the nodes within each layer.
protected ISequencer	createSequencer() Factory method that is called lazily upon first usage by Sequencer if the given ISequencer instance is null.
protected ISequencer	createSubgraphLayerSequencer() Factory method called during applyLayoutCore(LayoutGraph) and creates a ISequencer implementation that can sequence subgraphs incrementally.
Object	getAlgorithmProperty(Object key) Provides access to implementation specific properties of the algorithms used.
protected ILayoutStage	getCreateLabelLayout() Factory method called during the initialization of this HierarchicLayoutCore instance that creates a label layouter.
IDrawingDistanceCalculator	getDrawingDistanceCalculator() Gets the IDrawingDistanceCalculator instance responsible for determining the minimum distances between elements that belong to the same layer.
protected IDataProvider	getEdgeLayoutDescriptors(LayoutGraph graph) Callback method called during applyLayoutCore(LayoutGraph) and returns a IDataProvider that holds the EdgeLayoutDescriptor information.
double	getGridSpacing() Gets the equidistant spacing between the horizontal and vertical grid lines.
protected IDataProvider	getIncrementalHints(LayoutGraph graph) Callback method called during applyLayoutCore(LayoutGraph) and returns a IDataProvider that holds the com.yworks.yfiles.layout.hierarchic.HierarchicLayoutCore.IncrementalHints information.
ILayerer	getLayerer() Gets the ILayerer instance responsible for generating the layer assignment (first phase of the layout algorithm).
long	getMaximumDuration() Gets the time limit (in milliseconds) set for the layout algorithm.
protected IDataProvider	getNodeLayoutDescriptors(LayoutGraph graph) Callback method called during applyLayoutCore(LayoutGraph) and returns a IDataProvider that holds the NodeLayoutDescriptor information.
INodePlacer	getNodePlacer() Gets the INodePlacer instance responsible for the assignment of the x-(sequence) and preliminary y-coordinates of the nodes.
IPortAllocator	getPortAllocator() Gets the IPortAllocator instance responsible for assigning port coordinates to the adjacent edges of each node.
IPortConstraintOptimizer	getPortConstraintOptimizer() Gets the IPortConstraintOptimizer instance responsible for optimizing the assignment of port constraints to the adjacent edges of each node.
ISequencer	getSequencer() Gets the ISequencer instance responsible for calculating the sequence of nodes within each layer (second phase of the layout algorithm).
protected IDataProvider	getSwimLaneDescriptors(LayoutGraph graph) Callback method called during applyLayoutCore(LayoutGraph) and returns a IDataProvider that holds the SwimlaneDescriptor information.
boolean	isComponentLayoutEnabled() Gets whether or not the ComponentLayout should be enabled.
protected void	publishLayers(LayoutGraph graph, ILayers layers) Callback method that publishes the layering information.
protected void	publishSequences(LayoutGraph graph, ILayers layers, ILayoutDataProvider ldp) Callback method that publishes the sequencing information.
protected void	reduceBendCount(LayoutGraph graph) Removes the bends which are obviously not necessary.
protected void	reduceBendCount(LayoutGraph graph, double bendReductionThreshold) Removes the bends which are obviously not necessary.
void	setAlgorithmProperty(Object key, Object value) Provides access to implementation specific properties of the algorithms used.
void	setComponentLayoutEnabled(boolean value) Sets whether or not the ComponentLayout should be enabled.
void	setDrawingDistanceCalculator(IDrawingDistanceCalculator value) Sets the IDrawingDistanceCalculator instance responsible for determining the minimum distances between elements that belong to the same layer.
void	setGridSpacing(double value) Sets the equidistant spacing between the horizontal and vertical grid lines.
void	setLayerer(ILayerer value) Sets the ILayerer instance responsible for generating the layer assignment (first phase of the layout algorithm).
void	setMaximumDuration(long value) Sets the time limit (in milliseconds) set for the layout algorithm.
void	setNodePlacer(INodePlacer value) Sets the INodePlacer instance responsible for the assignment of the x-(sequence) and preliminary y-coordinates of the nodes.
void	setPortAllocator(IPortAllocator value) Sets the IPortAllocator instance responsible for assigning port coordinates to the adjacent edges of each node.
void	setPortConstraintOptimizer(IPortConstraintOptimizer value) Sets the IPortConstraintOptimizer instance responsible for optimizing the assignment of port constraints to the adjacent edges of each node.
void	setSequencer(ISequencer value) Sets the ISequencer instance responsible for calculating the sequence of nodes within each layer (second phase of the layout algorithm).

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

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

Methods inherited from class java.lang.Object

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

Field Detail

EDGE_LAYOUT_DESCRIPTOR_DPKEY

public static final EdgeDpKey<EdgeLayoutDescriptor> EDGE_LAYOUT_DESCRIPTOR_DPKEY

A DataProvider key for providing layout information for each edge

See Also:

IEdgeData.getEdgeLayoutDescriptor()

INCREMENTAL_HINTS_DPKEY

public static final GraphObjectDpKey<Object> INCREMENTAL_HINTS_DPKEY

A DataProvider key for specifying incremental hints

Incremental hints are created using an incremental hints factory.

See Also:

INCREMENTAL_HINTS_DPKEY, IIncrementalHintsFactory

INCREMENTAL_NODES_DPKEY

public static final NodeDpKey<Boolean> INCREMENTAL_NODES_DPKEY

A DataProvider key for internal use only.

LAYER_INDEX_DPKEY

public static final NodeDpKey<Integer> LAYER_INDEX_DPKEY

A DataAcceptor key for publishing the layer IDs for all nodes in the graph.

If no IDataProvider is registered with this key, the layer information of the nodes is dropped.

See Also:

HierarchicLayout.LAYER_INDEX_DPKEY

NODE_LAYOUT_DESCRIPTOR_DPKEY

public static final NodeDpKey<NodeLayoutDescriptor> NODE_LAYOUT_DESCRIPTOR_DPKEY

A DataProvider key for providing layout information for each node

See Also:

INodeData.getNodeLayoutDescriptor()

SEQUENCE_INDEX_DPKEY

public static final NodeDpKey<Integer> SEQUENCE_INDEX_DPKEY

A DataAcceptor key for publishing the index inside their layer for all nodes in the graph.

If no IDataProvider is registered with this key, the sequence information of the nodes is dropped.

See Also:

HierarchicLayout.SEQUENCE_INDEX_DPKEY

SWIMLANE_DESCRIPTOR_DPKEY

public static final NodeDpKey<SwimlaneDescriptor> SWIMLANE_DESCRIPTOR_DPKEY

A DataProvider key for providing information about swimlanes

If this key is present during the layout, the layout algorithm will arrange nodes in swimlanes. The information about the swimlanes is finally written back to the descriptor instances.

Instances can be shared among multiple nodes in the same lane, but don't have to be shared.

See Also:

SwimlaneDescriptor, INodeData.getSwimLaneDescriptor()

Constructor Detail

HierarchicLayoutCore

public HierarchicLayoutCore()

Creates a new HierarchicLayoutCore instance with the default settings.

See Also:

createLayerer(), createIncrementalLayerer(), createSequencer(), createDrawingDistanceCalculator(), createNodePlacer()

Method Detail

applyLayoutCore

public void applyLayoutCore(LayoutGraph graph)

Calculates a hierarchic layout of the given graph.

Specified by:

applyLayoutCore in class MultiStageLayout

The given graph will not be copied during the layout process and the layout will be immediately applied to the given graph.

Parameters:

graph - the input graph

createDrawingDistanceCalculator

protected IDrawingDistanceCalculator createDrawingDistanceCalculator()

Factory method that is called lazily upon first usage by DrawingDistanceCalculator if the given IDrawingDistanceCalculator instance is null.

The default implementation returns a DefaultDrawingDistanceCalculator instance. It may be overridden to return a custom DefaultDrawingDistanceCalculator instance.

Creating a custom implementation of IDrawingDistanceCalculator will make the properties NodeToNodeDistance, NodeToEdgeDistance and EdgeToEdgeDistance superfluous. Those properties delegate to DefaultDrawingDistanceCalculator and will throw an IllegalStateException if a different class is used. Adjustments of those distances need to be done directly on the custom implementation of IDrawingDistanceCalculator.

Returns:

a IDrawingDistanceCalculator instance

See Also:

getDrawingDistanceCalculator()

createEdgeReverser

protected IEdgeReverser createEdgeReverser()

Factory method called during applyLayoutCore(LayoutGraph) and reates an appropriate IEdgeReverser implementation.

By default, a suitable private implementation of IEdgeReverser is returned. It may be overridden to return a custom IEdgeReverser implementation.

Returns:

an implementation

createGrouping

protected GroupingSupport createGrouping(LayoutGraph graph)

Factory method that is called during applyLayoutCore(LayoutGraph) and creates a GroupingSupport instance in case of a grouped graph.

Parameters:

graph - the input graph

Returns:

a GroupingSupport instance or null if the graph is not grouped

createIncrementalHintsFactory

public IIncrementalHintsFactory createIncrementalHintsFactory()

Creates an IIncrementalHintsFactory implementation used for obtaining hint objects associated with nodes and edges of the graph prior to the invocation of the layout algorithm.

com.yworks.yfiles.layout.hierarchic.HierarchicLayoutCore.IncrementalHints can be obtained from a IDataProvider that is registered with the graph using key INCREMENTAL_HINTS_DPKEY.

Returns:

an IIncrementalHintsFactory instance

See Also:

INCREMENTAL_HINTS_DPKEY

createIncrementalLayerer

protected ILayerer createIncrementalLayerer()

Factory method called during applyLayoutCore(LayoutGraph) and creates an appropriate ILayerer implementation.

By default, a ConstraintIncrementalLayerer instance with a TopologicalLayerer instance as argument is returned. This method may be overridden to return a custom ILayerer implementation.

Returns:

a ILayerer implementation

createItemData

protected void createItemData(LayoutGraph g,
                              IItemFactory itemFactory)

Callback method that is called during applyLayoutCore(LayoutGraph), creates the INodeData and IEdgeData instances and binds them to the elements using the given itemFactory.

Parameters:

g - the input graph

itemFactory - the given IItemFactory instance

createLayerConstraintFactory

public ILayerConstraintFactory createLayerConstraintFactory(Graph graph)

Creates a layer constraint factory that allows to create hints that affect the assignment of the nodes to layers.

By default, a suitable private implementation of ILayerConstraintFactory is returned.

Parameters:

graph - the given graph

Returns:

a ILayerConstraintFactory instance

createLayerer

protected ILayerer createLayerer()

Factory method that is called lazily upon first usage by Layerer if no ILayerer instance is given as input.

The default implementation returns a new MultiComponentLayerer(new WeightedLayerer()) instance. It may be overridden to return a custom ILayerer instance.

Returns:

a ILayerer instance

See Also:

getLayerer(), MultiComponentLayerer, WeightedLayerer

createLayers

protected ILayers createLayers(ILayoutDataProvider ldp)

Factory method called during applyLayoutCore(LayoutGraph) and creates an appropriate ILayers implementation using the given ILayoutDataProvider instance.

By default, a suitable private implementation of ILayers is returned. It may be overridden to return custom implementations of the ILayers interface.

Parameters:

ldp - the given ILayoutDataProvider instance

Returns:

a ILayers implementation

createNodePlacer

protected INodePlacer createNodePlacer()

Factory method that is called lazily upon first usage by NodePlacer if the given INodePlacer instance is null.

The default implementation returns a SimplexNodePlacer instance. It may be overridden to return a custom INodePlacer instance.

Returns:

a INodePlacer instance

See Also:

getNodePlacer(), SimplexNodePlacer

createPortAllocator

protected IPortAllocator createPortAllocator()

Factory method that is called lazily upon first usage by PortAllocator if the given IPortAllocator instance is null.

The default implementation returns a DefaultPortAllocator instance. It may be overridden to return a custom IPortAllocator instance.

Returns:

a IPortAllocator instance

See Also:

getPortAllocator()

createPortConstraintOptimizer

protected IPortConstraintOptimizer createPortConstraintOptimizer()

Factory method that is called lazily upon first usage by PortConstraintOptimizer if the given IPortConstraintOptimizer instance is null.

The default implementation returns null. It may be overridden to return a custom IPortConstraintOptimizer instance.

Returns:

null

See Also:

getPortConstraintOptimizer()

createSequenceConstraintFactory

public ISequenceConstraintFactory createSequenceConstraintFactory(Graph graph)

Creates sequence constraints that affect the sequence of the nodes within each layer.

By default, a suitable private implementation of ISequenceConstraintFactory is returned.

Parameters:

graph - the given graph

Returns:

a ISequenceConstraintFactory instance

createSequencer

protected ISequencer createSequencer()

Factory method that is called lazily upon first usage by Sequencer if the given ISequencer instance is null.

The default implementation returns a DefaultLayerSequencer instance. It may be overridden to return a custom ISequencer instance.

Returns:

a ISequencer instance

See Also:

getSequencer(), DefaultLayerSequencer

createSubgraphLayerSequencer

protected ISequencer createSubgraphLayerSequencer()

Factory method called during applyLayoutCore(LayoutGraph) and creates a ISequencer implementation that can sequence subgraphs incrementally.

By default, a suitable private implementation of ISequencer is returned. It may be overridden to return custom implementations of the ISequencer interface.

Returns:

a ISequencer implementation

getAlgorithmProperty

public Object getAlgorithmProperty(Object key)

Provides access to implementation specific properties of the algorithms used.

Used for internal purposes.

Parameters:

key - the key to a property

Returns:

the associated value or null

See Also:

setAlgorithmProperty(Object, Object)

getCreateLabelLayout

protected ILayoutStage getCreateLabelLayout()

Factory method called during the initialization of this HierarchicLayoutCore instance that creates a label layouter.

In order to use the integrated node label awareness feature one has to use a LabelLayoutTranslator instance and set NodeLabelTranslationEnabled to true. Likewise, in order to make use of the integrated edge labeling EdgeLabelTranslationEnabled must be set to true and also WritingBackEdgeLabelsEnabled must be set to true (which is the default).

Returns:

a new LabelLayoutTranslator instance

getDrawingDistanceCalculator

public IDrawingDistanceCalculator getDrawingDistanceCalculator()

Gets the IDrawingDistanceCalculator instance responsible for determining the minimum distances between elements that belong to the same layer.

To set the default port allocator, see createDrawingDistanceCalculator().

Throws:

IllegalArgumentException - if the specified IDrawingDistanceCalculator is null

Specifying a custom implementation of IDrawingDistanceCalculator will make the properties NodeToNodeDistance, NodeToEdgeDistance and EdgeToEdgeDistance superfluous. Those properties delegate to DefaultDrawingDistanceCalculator and will throw an IllegalStateException if a different class is used. Adjustments of those distances need to be done directly on the custom implementation of IDrawingDistanceCalculator.

Returns:

the given IDrawingDistanceCalculator instance

See Also:

createDrawingDistanceCalculator(), setDrawingDistanceCalculator(IDrawingDistanceCalculator)

getEdgeLayoutDescriptors

protected IDataProvider getEdgeLayoutDescriptors(LayoutGraph graph)

Callback method called during applyLayoutCore(LayoutGraph) and returns a IDataProvider that holds the EdgeLayoutDescriptor information.

The IDataProvider holding the information about the node layout is registered with the graph using key EDGE_LAYOUT_DESCRIPTOR_DPKEY.

Parameters:

graph - the input graph

Returns:

a IDataProvider instance or null

See Also:

EdgeLayoutDescriptor, EDGE_LAYOUT_DESCRIPTOR_DPKEY

getGridSpacing

public double getGridSpacing()

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

When the spacing is negative or zero, no grid is defined, otherwise nodes and edges are placed on multiples of the grid spacing.

The grid feature doesn't work together with exact (layer/sequence) coordinate hints.

Default Value:

The default value is 0. There is no grid specified.

Returns:

the grid spacing

See Also:

IIncrementalHintsFactory, setGridSpacing(double)

getIncrementalHints

protected IDataProvider getIncrementalHints(LayoutGraph graph)

Callback method called during applyLayoutCore(LayoutGraph) and returns a IDataProvider that holds the com.yworks.yfiles.layout.hierarchic.HierarchicLayoutCore.IncrementalHints information.

The IDataProvider holding the information about com.yworks.yfiles.layout.hierarchic.HierarchicLayoutCore.IncrementalHints is registered with the graph using key INCREMENTAL_HINTS_DPKEY.

Parameters:

graph - the input graph

Returns:

a IDataProvider instance or null

See Also:

INCREMENTAL_HINTS_DPKEY

getLayerer

public ILayerer getLayerer()

Gets the ILayerer instance responsible for generating the layer assignment (first phase of the layout algorithm).

To set the default layerer, see createLayerer().

Throws:

IllegalArgumentException - if the specified ILayerer is null

Returns:

the current ILayerer instance

See Also:

createLayerer(), setLayerer(ILayerer)

getMaximumDuration

public long getMaximumDuration()

Gets the time limit (in milliseconds) set for the layout algorithm.

Values have to be greater than or equal to 0.

Throws:

IllegalArgumentException - if the maximum duration is negative

Restricting the maximum duration may result in a lower layout quality. Furthermore, the real runtime may exceed the maximum duration since the layout algorithm still has to find a valid solution.

Default Value:

The default value is Long.MAX_VALUE. The layout algorithm runs unrestricted.

Returns:

a non-negative value that specifies the time limit

See Also:

setMaximumDuration(long)

getNodeLayoutDescriptors

protected IDataProvider getNodeLayoutDescriptors(LayoutGraph graph)

Callback method called during applyLayoutCore(LayoutGraph) and returns a IDataProvider that holds the NodeLayoutDescriptor information.

The IDataProvider holding the information about the node layout is registered with the graph using key NODE_LAYOUT_DESCRIPTOR_DPKEY.

Parameters:

graph - the input graph

Returns:

a IDataProvider instance or null

See Also:

NodeLayoutDescriptor, NODE_LAYOUT_DESCRIPTOR_DPKEY

getNodePlacer

public INodePlacer getNodePlacer()

Gets the INodePlacer instance responsible for the assignment of the x-(sequence) and preliminary y-coordinates of the nodes.

To set the default node placer, see createNodePlacer().

Throws:

IllegalArgumentException - if the specified INodePlacer is null

Returns:

the current INodePlacer instance

See Also:

createNodePlacer(), setNodePlacer(INodePlacer)

getPortAllocator

public IPortAllocator getPortAllocator()

Gets the IPortAllocator instance responsible for assigning port coordinates to the adjacent edges of each node.

To set the default port allocator, see createPortAllocator().

Throws:

IllegalArgumentException - if the specified IPortAllocator is null

Returns:

the current IPortAllocator instance

See Also:

createPortAllocator(), setPortAllocator(IPortAllocator)

getPortConstraintOptimizer

public IPortConstraintOptimizer getPortConstraintOptimizer()

Gets the IPortConstraintOptimizer instance responsible for optimizing the assignment of port constraints to the adjacent edges of each node.

To set the default port allocator, see createPortConstraintOptimizer().

Returns:

the current IPortConstraintOptimizer instance

See Also:

createPortConstraintOptimizer(), setPortConstraintOptimizer(IPortConstraintOptimizer)

getSequencer

public ISequencer getSequencer()

Gets the ISequencer instance responsible for calculating the sequence of nodes within each layer (second phase of the layout algorithm).

To set the default sequencer, see createSequencer().

Throws:

IllegalArgumentException - if the specified ISequencer is null

Returns:

the current ISequencer instance

See Also:

createSequencer(), setSequencer(ISequencer)

getSwimLaneDescriptors

protected IDataProvider getSwimLaneDescriptors(LayoutGraph graph)

Callback method called during applyLayoutCore(LayoutGraph) and returns a IDataProvider that holds the SwimlaneDescriptor information.

The IDataProvider holding the information about swimlanes is registered with the graph using key SWIMLANE_DESCRIPTOR_DPKEY.

Parameters:

graph - the input graph

Returns:

a IDataProvider instance or null

See Also:

SwimlaneDescriptor, SWIMLANE_DESCRIPTOR_DPKEY

isComponentLayoutEnabled

public boolean isComponentLayoutEnabled()

Gets whether or not the ComponentLayout should be enabled.

Overrides:

isComponentLayoutEnabled in class MultiStageLayout

Default Value:

The default value is false. ComponentLayout is disabled.

Returns:

true if ComponentLayout is enabled, false otherwise

See Also:

setComponentLayoutEnabled(boolean)

publishLayers

protected void publishLayers(LayoutGraph graph,
                             ILayers layers)

Callback method that publishes the layering information.

The layering information is stored in a IDataProvider registered with the graph using key LAYER_INDEX_DPKEY.

Parameters:

graph - the input graph

layers - the ILayers implementation that provides the layering information

See Also:

LAYER_INDEX_DPKEY

publishSequences

protected void publishSequences(LayoutGraph graph,
                                ILayers layers,
                                ILayoutDataProvider ldp)

Callback method that publishes the sequencing information.

The sequencing information is stored in a IDataProvider registered with the graph using key SEQUENCE_INDEX_DPKEY.

Parameters:

graph - the input graph

layers - the ILayers implementation that provides the layering information

ldp - the ILayoutDataProvider implementation which provides access to the INodeData and IEdgeData instances

See Also:

LAYER_INDEX_DPKEY

reduceBendCount

protected void reduceBendCount(LayoutGraph graph)

Removes the bends which are obviously not necessary.

By default, this method removes collinear bends from the graph. A bend point is considered to be collinear if it lies on a line with its preceding and succeeding bend point. It may be overridden for a custom implementation of bend removal.

Parameters:

graph - the input graph

reduceBendCount

protected void reduceBendCount(LayoutGraph graph,
                               double bendReductionThreshold)

Removes the bends which are obviously not necessary.

By default, this method removes collinear bends from the graph. A bend point is considered to be collinear if it lies on a line with its preceding and succeeding bend point. It may be overridden for a custom implementation of bend removal.

Parameters:

graph - the input graph

bendReductionThreshold - this method removes a bend, if its horizontal/vertical distance to the closest collinear bend is above this value

setAlgorithmProperty

public void setAlgorithmProperty(Object key,
                                 Object value)

Provides access to implementation specific properties of the algorithms used.

Used for internal purposes.

Parameters:

key - the key to a property

value - the value to associate with the key

See Also:

setAlgorithmProperty(Object, Object)

setComponentLayoutEnabled

public void setComponentLayoutEnabled(boolean value)

Sets whether or not the ComponentLayout should be enabled.

Overrides:

setComponentLayoutEnabled in class MultiStageLayout

Default Value:

The default value is false. ComponentLayout is disabled.

Parameters:

value - true if ComponentLayout is enabled, false otherwise

See Also:

isComponentLayoutEnabled()

setDrawingDistanceCalculator

public void setDrawingDistanceCalculator(IDrawingDistanceCalculator value)

Sets the IDrawingDistanceCalculator instance responsible for determining the minimum distances between elements that belong to the same layer.

To set the default port allocator, see createDrawingDistanceCalculator().

Throws:

IllegalArgumentException - if the specified IDrawingDistanceCalculator is null

Specifying a custom implementation of IDrawingDistanceCalculator will make the properties NodeToNodeDistance, NodeToEdgeDistance and EdgeToEdgeDistance superfluous. Those properties delegate to DefaultDrawingDistanceCalculator and will throw an IllegalStateException if a different class is used. Adjustments of those distances need to be done directly on the custom implementation of IDrawingDistanceCalculator.

Parameters:

value - the given IDrawingDistanceCalculator instance

See Also:

createDrawingDistanceCalculator(), getDrawingDistanceCalculator()

setGridSpacing

public void setGridSpacing(double value)

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

When the spacing is negative or zero, no grid is defined, otherwise nodes and edges are placed on multiples of the grid spacing.

The grid feature doesn't work together with exact (layer/sequence) coordinate hints.

Default Value:

The default value is 0. There is no grid specified.

Parameters:

value - the grid spacing

See Also:

IIncrementalHintsFactory, getGridSpacing()

setLayerer

public void setLayerer(ILayerer value)

Sets the ILayerer instance responsible for generating the layer assignment (first phase of the layout algorithm).

To set the default layerer, see createLayerer().

Throws:

IllegalArgumentException - if the specified ILayerer is null

Parameters:

value - the current ILayerer instance

See Also:

createLayerer(), getLayerer()

setMaximumDuration

public void setMaximumDuration(long value)

Sets the time limit (in milliseconds) set for the layout algorithm.

Values have to be greater than or equal to 0.

Throws:

IllegalArgumentException - if the maximum duration is negative

Restricting the maximum duration may result in a lower layout quality. Furthermore, the real runtime may exceed the maximum duration since the layout algorithm still has to find a valid solution.

Default Value:

The default value is Long.MAX_VALUE. The layout algorithm runs unrestricted.

Parameters:

value - a non-negative value that specifies the time limit

See Also:

getMaximumDuration()

setNodePlacer

public void setNodePlacer(INodePlacer value)

Sets the INodePlacer instance responsible for the assignment of the x-(sequence) and preliminary y-coordinates of the nodes.

To set the default node placer, see createNodePlacer().

Throws:

IllegalArgumentException - if the specified INodePlacer is null

Parameters:

value - the current INodePlacer instance

See Also:

createNodePlacer(), getNodePlacer()

setPortAllocator

public void setPortAllocator(IPortAllocator value)

Sets the IPortAllocator instance responsible for assigning port coordinates to the adjacent edges of each node.

To set the default port allocator, see createPortAllocator().

Throws:

IllegalArgumentException - if the specified IPortAllocator is null

Parameters:

value - the current IPortAllocator instance

See Also:

createPortAllocator(), getPortAllocator()

setPortConstraintOptimizer

public void setPortConstraintOptimizer(IPortConstraintOptimizer value)

Sets the IPortConstraintOptimizer instance responsible for optimizing the assignment of port constraints to the adjacent edges of each node.

To set the default port allocator, see createPortConstraintOptimizer().

Parameters:

value - the current IPortConstraintOptimizer instance

See Also:

createPortConstraintOptimizer(), getPortConstraintOptimizer()

setSequencer

public void setSequencer(ISequencer value)

Sets the ISequencer instance responsible for calculating the sequence of nodes within each layer (second phase of the layout algorithm).

To set the default sequencer, see createSequencer().

Throws:

IllegalArgumentException - if the specified ISequencer is null

Parameters:

value - the current ISequencer instance

See Also:

createSequencer(), getSequencer()