com.yworks.yfiles.layout.tree

Class AbstractNodePlacer

java.lang.Object

com.yworks.yfiles.layout.tree.AbstractNodePlacer

All Implemented Interfaces:

INodePlacer, ICloneable, Cloneable

Direct Known Subclasses:

AspectRatioNodePlacer, DefaultNodePlacer

public abstract class AbstractNodePlacer
extends Object
implements INodePlacer, ICloneable, Cloneable

Abstract base class for implementations of the INodePlacer interface.

This class provides convenience methods for sub-tasks that are often used during the arrangement of a local root and its children. It also offers prepared implementations for the methods of the INodePlacer interface.

Subclasses just need to override the following two abstract methods: placeSubtree(Node, ParentConnectorDirection) and determineChildConnectors(Node, IDataMap).

Field Summary

Fields

Modifier and Type	Field and Description
protected LayoutGraph	graph The graph instance this class is working on.

Constructor Summary

Constructors

Constructor and Description
AbstractNodePlacer() Creates a new instance of AbstractNodePlacer.

Method Summary

Modifier and Type	Method and Description
AbstractNodePlacer	clone() Returns a clone of this INodePlacer instance.
IProcessor	createProcessor(TreeLayout layouter, LayoutGraph graph, Node currentRoot) Creates an optional IProcessor for pre- and post-processing.
protected abstract ParentConnectorDirection	determineChildConnector(Node child) Determines a connector direction for the given child node.
void	determineChildConnectors(Node localRoot, IDataMap connectorMap) Provides the direction of the connector to the SubtreeShape for each child node.
protected TreeLayout.SubtreeShape	getNodeShape(Node node) Returns the TreeLayout.SubtreeShape for the given node.
protected TreeLayout.SubtreeShape	getSubtreeShape(Node node) Returns the TreeLayout.SubtreeShape for the subtree rooted at the given node.
TreeLayout.SubtreeShape	placeSubtree(IDataProvider nodeShapeProvider, IDataProvider subtreeShapeProvider, LayoutGraph graph, Node localRoot, ParentConnectorDirection parentConnectorDirection) Initializes the local data structures and then delegates the work to the abstract variant of this method (placeSubtree(Node, ParentConnectorDirection)).
protected abstract TreeLayout.SubtreeShape	placeSubtree(Node localRoot, ParentConnectorDirection parentConnectorDirection) Arranges the local root relative to the TreeLayout.SubtreeShape of its children.

Methods inherited from class java.lang.Object

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

Field Detail

graph

protected LayoutGraph graph

The graph instance this class is working on.

Constructor Detail

AbstractNodePlacer

public AbstractNodePlacer()

Creates a new instance of AbstractNodePlacer.

Method Detail

clone

public AbstractNodePlacer clone()

Returns a clone of this INodePlacer instance.

Specified by:

clone in interface ICloneable

Overrides:

clone in class Object

Returns:

an exact copy of this INodePlacer instance

See Also:

Object.clone()

createProcessor

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

Creates an optional IProcessor for pre- and post-processing.

This implementation returns null. Hence, no pre- or post-processing will be done.

Specified by:

createProcessor in interface INodePlacer

Parameters:

layouter - the current TreeLayout instance

graph - the input graph

currentRoot - the root node handled by this INodePlacer

Returns:

null

determineChildConnector

protected abstract ParentConnectorDirection determineChildConnector(Node child)

Determines a connector direction for the given child node.

This method is used in determineChildConnectors(Node, IDataMap) and must be implemented by subclasses.

Parameters:

child - the child node

Returns:

a direction specifier as defined in the INodePlacer interface

determineChildConnectors

public void determineChildConnectors(Node localRoot,
                                     IDataMap connectorMap)

Provides the direction of the connector to the SubtreeShape for each child node.

This implementation uses determineChildConnector(Node) to retrieve the direction for the connectors.

Specified by:

determineChildConnectors in interface INodePlacer

Parameters:

localRoot - the local root node

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

getNodeShape

protected TreeLayout.SubtreeShape getNodeShape(Node node)

Returns the TreeLayout.SubtreeShape for the given node.

This is a convenience method that retrieves a TreeLayout.SubtreeShape for a single node from the corresponding IDataProvider.

This method is used in placeSubtree(Node, ParentConnectorDirection) for retrieving the TreeLayout.SubtreeShapes for the local root nodes. It may be overridden to return a custom implementation of TreeLayout.SubtreeShape.

This method can first be called during the execution of placeSubtree(Node, ParentConnectorDirection). Otherwise, the IDataProvider for querying results will not have been initialized yet.

Parameters:

node - the node

Returns:

the TreeLayout.SubtreeShape for the given node

getSubtreeShape

protected TreeLayout.SubtreeShape getSubtreeShape(Node node)

Returns the TreeLayout.SubtreeShape for the subtree rooted at the given node.

This is a convenience method that retrieves a TreeLayout.SubtreeShape of a complete subtree from the corresponding IDataProvider.

This method is used in placeSubtree(Node, ParentConnectorDirection) for retrieving the TreeLayout.SubtreeShapes for the subtrees that are arranged. It may be overridden to return a custom implementation of TreeLayout.SubtreeShape.

This method can first be called during the execution of placeSubtree(Node, ParentConnectorDirection). Before, the IDataProvider for querying results will not have been initialized yet.

Parameters:

node - the local root node

Returns:

the TreeLayout.SubtreeShape of the subtree rooted at the given local root node

placeSubtree

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

Initializes the local data structures and then delegates the work to the abstract variant of this method (placeSubtree(Node, ParentConnectorDirection)).

Specified by:

placeSubtree in interface INodePlacer

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 for the subtree rooted at the local root node

See Also:

placeSubtree(Node, ParentConnectorDirection)

placeSubtree

protected abstract TreeLayout.SubtreeShape placeSubtree(Node localRoot,
                                                        ParentConnectorDirection parentConnectorDirection)

Arranges the local root relative to the TreeLayout.SubtreeShape of its children.

This is the main method that must be implemented by subclasses. It is called by placeSubtree(IDataProvider, IDataProvider, LayoutGraph, Node, ParentConnectorDirection).

Parameters:

localRoot - the local root node

parentConnectorDirection - the direction of the connector

Returns:

a TreeLayout.SubtreeShape instance that describes the shape of the whole subtree rooted at the given local root