com.yworks.yfiles.layout.tree

Class AssistantNodePlacer

java.lang.Object

com.yworks.yfiles.layout.tree.AbstractRotatableNodePlacer

com.yworks.yfiles.layout.tree.AssistantNodePlacer

All Implemented Interfaces:

IFromSketchNodePlacer, INodePlacer

public class AssistantNodePlacer
extends AbstractRotatableNodePlacer

The AssistantNodePlacer places nodes that are marked as assistants left and right of their parents and all other nodes below the assistant nodes.

Layout Style

Assistants are marked

Concept

This INodePlacer delegates the placement of all assistant nodes to an instance of LeftRightNodePlacer. The non-assistant nodes are handled by another node placer. To be able to do this, AssistantNodePlacer uses a IProcessor which prepares the graph for node placing.

A IDataProvider that is registered using ASSISTANT_NODE_DPKEY returns true for assistant nodes and false for all other nodes.

This node placer produces the best results when using a IPortAssignment that starts all edges at the same port. If the ports are distributed along the border, edge crossings may occur.

Nested Class Summary

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

AbstractRotatableNodePlacer.Matrix, AbstractRotatableNodePlacer.RootAlignment

Field Summary

Fields

Modifier and Type	Field and Description
static NodeDpKey<Boolean>	ASSISTANT_NODE_DPKEY A DataProvider key for marking which nodes are placed as assistants

Fields inherited from class com.yworks.yfiles.layout.tree.AbstractRotatableNodePlacer

createdChildren, graph, nodeShapeProvider, subtreeShapeProvider

Constructor Summary

Constructors

Constructor and Description
AssistantNodePlacer() Creates a new AssistantNodePlacer instance with default settings.
AssistantNodePlacer(AbstractRotatableNodePlacer.Matrix modificationMatrix) Creates a new AssistantNodePlacer instance that uses the transformation defined by the given matrix.

Method Summary

Modifier and Type	Method and Description
Comparator<Object>	createComparator() Delegates the creation of from-sketch comparators to the two INodePlacers handling assistant and non-assistant nodes.
static Comparator<Object>	createCompoundComparator(Comparator<Object> assistantComparator, Comparator<Object> childComparator) Creates a Comparator that compares outgoing edges connecting to assistant nodes and edges connecting to non-assistant nodes separately.
IProcessor	createProcessor(TreeLayout layouter, LayoutGraph graph, Node currentRoot) Creates a IProcessor that prepares the graph for placing assistant node.
protected ParentConnectorDirection	determineChildConnector(Node child) Determines a connector direction for the given child node.
void	determineChildConnectors(Node localRoot, IDataMap connectorMap) Delegates the calculation of the child connectors to the LeftRightNodePlacer which arranges the assistant nodes.
INodePlacer	getChildNodePlacer() Gets the INodePlacer instance that places the non-assistant children.
double	getSpacing() Gets the spacing between subtrees for the delegate INodePlacer.
TreeLayout.SubtreeShape	placeSubtree(IDataProvider nodeShapeProvider, IDataProvider subtreeShapeProvider, LayoutGraph graph, Node localRoot, ParentConnectorDirection parentConnectorDirection) Delegates the arrangement of TreeLayout.SubtreeShapes to an instance of LeftRightNodePlacer.
protected RotatedSubtreeShape	placeSubtree(Node localRoot, ParentConnectorDirection parentConnectorDirection) Arranges the local root relative to the subtree shape of its children.
void	setChildNodePlacer(INodePlacer value) Sets the INodePlacer instance that places the non-assistant children.
void	setSpacing(double value) Sets the spacing between subtrees for the delegate INodePlacer.

Methods inherited from class com.yworks.yfiles.layout.tree.AbstractRotatableNodePlacer

createFromSketchComparator, getModificationMatrix, getNodeShape, getPortConstraint, getSourcePointAbs, getSubtreeShape, translateDirectionToModel, translateDirectionToReal, translatePoint

Methods inherited from class java.lang.Object

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

Field Detail

ASSISTANT_NODE_DPKEY

public static final NodeDpKey<Boolean> ASSISTANT_NODE_DPKEY

A DataProvider key for marking which nodes are placed as assistants

Constructor Detail

AssistantNodePlacer

public AssistantNodePlacer()

Creates a new AssistantNodePlacer instance with default settings.

AssistantNodePlacer

public AssistantNodePlacer(AbstractRotatableNodePlacer.Matrix modificationMatrix)

Creates a new AssistantNodePlacer instance that uses the transformation defined by the given matrix.

Parameters:

modificationMatrix - the transformation matrix

Method Detail

createComparator

public Comparator<Object> createComparator()

Delegates the creation of from-sketch comparators to the two INodePlacers handling assistant and non-assistant nodes.

The from-sketch Comparators are combined into a compound comparator. The one for the edges connecting to assistant nodes is retrieved from a LeftRightNodePlacer while the other one is provided by the child placer.

Overrides:

createComparator in class AbstractRotatableNodePlacer

Returns:

the Comparator to compare edges, considering the initial locations of their target nodes

See Also:

setChildNodePlacer(INodePlacer), createCompoundComparator(Comparator, Comparator), IFromSketchNodePlacer.createFromSketchComparator()

createCompoundComparator

public static final Comparator<Object> createCompoundComparator(Comparator<Object> assistantComparator,
                                                                Comparator<Object> childComparator)

Creates a Comparator that compares outgoing edges connecting to assistant nodes and edges connecting to non-assistant nodes separately.

Parameters:

assistantComparator - the Comparator for edges connecting to assistant nodes

childComparator - the Comparator for edges connecting to non-assistant nodes

Returns:

a Comparator that compares edges to assistant nodes separately from edges to non-assistant nodes

createProcessor

public IProcessor createProcessor(TreeLayout layouter,
                                  LayoutGraph graph,
                                  Node currentRoot)

Creates a IProcessor that prepares the graph for placing assistant node.

The pre-processing step adds a dummy node as a child to the current root and changes all edges of non-assistant children such that they start at this dummy node. That way, AssistantNodePlacer is able to delegate the assistant nodes to a INodePlacer different from the one used for placing non-assistant nodes. The child node placer is assigned to the dummy node. So the non-assistant children are placed by this delegate placer.

All changes will be cleaned up during the post-processing step.

Specified by:

createProcessor in interface INodePlacer

Overrides:

createProcessor in class AbstractRotatableNodePlacer

Parameters:

layouter - the current TreeLayout instance

graph - the input graph

currentRoot - the root node handled by this INodePlacer

Returns:

the IProcessor instance that prepares the graph for AssistantNodePlacer

determineChildConnector

protected ParentConnectorDirection determineChildConnector(Node child)

Determines a connector direction for the given child node.

Specified by:

determineChildConnector in class AbstractRotatableNodePlacer

Throws:

IllegalStateException - if this method is called

This method should not be called! Finding the directions for the connectors is delegated to the INodePlacer for the assistant nodes by determineChildConnectors(Node, IDataMap).

Parameters:

child - the child node

Returns:

a direction specifier as defined in the INodePlacer interface

determineChildConnectors

public void determineChildConnectors(Node localRoot,
                                     IDataMap connectorMap)

Delegates the calculation of the child connectors to the LeftRightNodePlacer which arranges the assistant nodes.

Specified by:

determineChildConnectors in interface INodePlacer

Overrides:

determineChildConnectors in class AbstractRotatableNodePlacer

Parameters:

localRoot - the local root node

connectorMap - the map that must be used for storing the direction specifiers of the child nodes

See Also:

AbstractRotatableNodePlacer.determineChildConnector(Node)

getChildNodePlacer

public INodePlacer getChildNodePlacer()

Gets the INodePlacer instance that places the non-assistant children.

These non-assistant child nodes will be placed below the assistant child nodes and are arranged by the given INodePlacer. Non-assistant child nodes are the ones that are not marked in the IDataProvider registered with ASSISTANT_NODE_DPKEY.

Default Value:

The default value is SimpleNodePlacer. A SimpleNodePlacer with centered local roots is used.

Returns:

the child node placer for the non-assistant children

See Also:

ASSISTANT_NODE_DPKEY, setChildNodePlacer(INodePlacer)

getSpacing

public double getSpacing()

Gets the spacing between subtrees for the delegate INodePlacer.

The spacing needs to be non-negative.

Overrides:

getSpacing in class AbstractRotatableNodePlacer

Throws:

IllegalArgumentException - if the given spacing is negative

Default Value:

The default value is 20.

Returns:

the distance between subtrees

See Also:

setSpacing(double)

placeSubtree

public TreeLayout.SubtreeShape placeSubtree(IDataProvider nodeShapeProvider,
                                            IDataProvider subtreeShapeProvider,
                                            LayoutGraph graph,
                                            Node localRoot,
                                            ParentConnectorDirection parentConnectorDirection)

Delegates the arrangement of TreeLayout.SubtreeShapes to an instance of LeftRightNodePlacer.

The LeftRightNodePlacer places all assistant nodes left and right of the local root node. The TreeLayout.SubtreeShape associated with the dummy node which contains TreeLayout.SubtreeShapes of the non-assistant nodes is placed below the assistant nodes, center-aligned with respect to the local root node.

Specified by:

placeSubtree in interface INodePlacer

Overrides:

placeSubtree in class AbstractRotatableNodePlacer

Parameters:

nodeShapeProvider - the IDataProvider for obtaining an initial shape of the root node

subtreeShapeProvider - the IDataProvider for accessing the pre-calculated shapes of the subtrees

graph - the input graph

localRoot - the root of the subtree that should be arranged by this method

parentConnectorDirection - the direction specifier for the connector of the local root node to its parent node

Returns:

the merged TreeLayout.SubtreeShape containing the local root and all assistant nodes and non-assistant nodes

See Also:

AbstractRotatableNodePlacer.placeSubtree(Node, ParentConnectorDirection)

placeSubtree

protected RotatedSubtreeShape placeSubtree(Node localRoot,
                                           ParentConnectorDirection parentConnectorDirection)

Arranges the local root relative to the subtree shape of its children.

Specified by:

placeSubtree in class AbstractRotatableNodePlacer

Throws:

IllegalStateException - if this method is called

This method should not be called! Placing subtrees is delegated to the INodePlacer for the assistant nodes and the placer for non-assistant nodes by method placeSubtree(IDataProvider, IDataProvider, LayoutGraph, Node, ParentConnectorDirection).

Parameters:

localRoot - the local root node

parentConnectorDirection - the direction specifier for the connector of the local root node to its parent node

Returns:

the merged subtree shape that contains the local root node and all its children

setChildNodePlacer

public void setChildNodePlacer(INodePlacer value)

Sets the INodePlacer instance that places the non-assistant children.

These non-assistant child nodes will be placed below the assistant child nodes and are arranged by the given INodePlacer. Non-assistant child nodes are the ones that are not marked in the IDataProvider registered with ASSISTANT_NODE_DPKEY.

Default Value:

The default value is SimpleNodePlacer. A SimpleNodePlacer with centered local roots is used.

Parameters:

value - the child node placer for the non-assistant children

See Also:

ASSISTANT_NODE_DPKEY, getChildNodePlacer()

setSpacing

public void setSpacing(double value)

Sets the spacing between subtrees for the delegate INodePlacer.

The spacing needs to be non-negative.

Overrides:

setSpacing in class AbstractRotatableNodePlacer

Throws:

IllegalArgumentException - if the given spacing is negative

Default Value:

The default value is 20.

Parameters:

value - the distance between subtrees

See Also:

getSpacing()