y.layout.tree
Class AbstractNodePlacer

java.lang.Object
  y.layout.tree.AbstractNodePlacer

All Implemented Interfaces:

Cloneable, NodePlacer

Direct Known Subclasses:

ARNodePlacer, DefaultNodePlacer, TreeDrawer.HierarchicTreePlacer

public abstract class AbstractNodePlacer
extends Object
implements NodePlacer, Cloneable

Utility class that serves as a basis for implementations of the NodePlacer interface. It provides convenience methods for often used sub tasks during a layout. Subclasses need to override the two abstract methods only.

Field Summary

protected LayoutGraph

graph The graph instance this class is working on

Fields inherited from interface y.layout.tree.NodePlacer

DIRECTION_ANY, DIRECTION_EAST, DIRECTION_NONE, DIRECTION_NORTH, DIRECTION_SOUTH, DIRECTION_WEST

Constructor Summary

AbstractNodePlacer()
Creates a new instance of AbstractNodePlacer

Method Summary

Object	clone() Overwritten to support cloning.
Processor	createProcessor(GenericTreeLayouter layouter, LayoutGraph graph, Node currentRoot) Creates an optional Processor for pre- and post-processing.
protected abstract byte	determineChildConnector(Node child) This method must be implemented by subclasses.
void	determineChildConnectors(Node localRoot, DataMap connectorMap) This method initializes internal data structures and then uses the abstract method to determine the child node connector directions.
protected GenericTreeLayouter.SubtreeShape	getNodeShape(Node node) Convenience method that queries the DataProvider for the shape of a single node as a SubtreeShape instance.
protected GenericTreeLayouter.SubtreeShape	getSubtreeShape(Node node) Convenience method that queries the DataProvider for a SubtreeShape.
GenericTreeLayouter.SubtreeShape	placeSubtree(DataProvider nodeShapeProvider, DataProvider subtreeShapeProvider, LayoutGraph graph, Node localRoot, byte parentConnectorDirection) This method initializes the local data structures and then delegates the work to the abstract variant.
protected abstract GenericTreeLayouter.SubtreeShape	placeSubtree(Node localRoot, byte parentConnectorDirection) The main placeSubtree method that must be implemented by subclasses.

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

createProcessor

public Processor createProcessor(GenericTreeLayouter layouter,
                                 LayoutGraph graph,
                                 Node currentRoot)

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

Specified by:

createProcessor in interface NodePlacer

Parameters:

layouter -

graph - the actual graph

currentRoot - the actual root node for this node placer

Returns:

a Processor or null

getSubtreeShape

protected GenericTreeLayouter.SubtreeShape getSubtreeShape(Node node)

Convenience method that queries the DataProvider for a SubtreeShape.
This method can be called during the execution of placeSubtree(Node, byte)

Parameters:

node - the root node whose subtree shape will be returned in the form of a SubtreeShape instance

Returns:

an instance that can be modified

getNodeShape

protected GenericTreeLayouter.SubtreeShape getNodeShape(Node node)

Convenience method that queries the DataProvider for the shape of a single node as a SubtreeShape instance. This instance can be used to modify it and return it in the main placeSubtree method.
This method can be called during the execution of placeSubtree(Node, byte)

Parameters:

node - the node whose shape will be returned in the form of a SubtreeShape instance

Returns:

an instance that can be modified

determineChildConnectors

public void determineChildConnectors(Node localRoot,
                                     DataMap connectorMap)

This method initializes internal data structures and then uses the abstract method to determine the child node connector directions.

Specified by:

determineChildConnectors in interface NodePlacer

Parameters:

localRoot - the local root node

connectorMap - the map that will be used to store the values

See Also:

determineChildConnector(Node)

determineChildConnector

protected abstract byte determineChildConnector(Node child)

This method must be implemented by subclasses. It assigns a connector shape direction to each child.

Parameters:

child - the child node

Returns:

a byte constant as defined in the NodePlacer interface

placeSubtree

protected abstract GenericTreeLayouter.SubtreeShape placeSubtree(Node localRoot,
                                                                 byte parentConnectorDirection)

The main placeSubtree method that must be implemented by subclasses.

Parameters:

localRoot - the local root node

parentConnectorDirection - the direction of the connector shape

Returns:

a SubtreeShape instance that describes the shape of the whole subtree

placeSubtree

public GenericTreeLayouter.SubtreeShape placeSubtree(DataProvider nodeShapeProvider,
                                                     DataProvider subtreeShapeProvider,
                                                     LayoutGraph graph,
                                                     Node localRoot,
                                                     byte parentConnectorDirection)

This method initializes the local data structures and then delegates the work to the abstract variant.

Specified by:

placeSubtree in interface NodePlacer

Parameters:

nodeShapeProvider - this instance can be used to obtain an initial shape of the root node. This shape can then be merged with all the subtrees' shapes and finally be returned by this method.

subtreeShapeProvider - provides access to the pre-calculated shapes of the subtrees. It is guaranteed that at the time of the invocation of this method for every child node the subtree shape has already been calculated

graph - the graph which is to be laid out

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

parentConnectorDirection - the direction byte constant as it is defined in this interface, that must be used for initializing the connector of the localRoot node to the parent node of the localRoot node

Returns:

the shape of the whole subtree

See Also:

placeSubtree(Node, byte)

clone

public Object clone()

Overwritten to support cloning.

Overrides:

clone in class Object

Returns:

an exact copy of this instance