com.yworks.yfiles.layout.hierarchic

Class GivenLayersLayerer

java.lang.Object

com.yworks.yfiles.layout.hierarchic.GivenLayersLayerer

All Implemented Interfaces:

ILayerer

public class GivenLayersLayerer
extends Object
implements ILayerer

This layering algorithm implementation assigns nodes to layers given a mapping of nodes to layer IDs.

The layer IDs are given by a IDataProvider that returns the integer layer ID of each node of the graph. Nodes with the same ID are in the same layer while the layers are sorted according to their IDs such that the smallest ID represents the top layer.

Field Summary

Fields

Modifier and Type	Field and Description
static NodeDpKey<Integer>	LAYER_ID_DPKEY A DataProvider key for storing the layer IDs.

Constructor Summary

Constructors

Constructor and Description
GivenLayersLayerer() Creates an instance of GivenLayersLayerer.

Method Summary

Modifier and Type	Method and Description
void	assignLayers(LayoutGraph graph, ILayers layers, ILayoutDataProvider ldp) Assigns all nodes of the graph to layers and adds them to the ILayers instance.
int	assignNodeLayer(LayoutGraph graph, INodeMap layerID, EdgeList reversedEdges) Assigns the nodes of the graph to layers given by the IDataProvider registered with the graph using key LAYER_ID_DPKEY.
int	normalize(Graph graph, IDataProvider layerId, IDataAcceptor normalizedLayerId) Convenience method that removes empty layers and ensures that the smallest layer has value 0.

Methods inherited from class java.lang.Object

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

Field Detail

LAYER_ID_DPKEY

public static final NodeDpKey<Integer> LAYER_ID_DPKEY

A DataProvider key for storing the layer IDs.

This IDataProvider stores for each node the layer ID to which it belongs. Nodes with the same ID are in the same layer while the layers are sorted according to their IDs such that the smallest ID represents the top layer.

Constructor Detail

GivenLayersLayerer

public GivenLayersLayerer()

Creates an instance of GivenLayersLayerer.

Method Detail

assignLayers

public void assignLayers(LayoutGraph graph,
                         ILayers layers,
                         ILayoutDataProvider ldp)

Assigns all nodes of the graph to layers and adds them to the ILayers instance.

Specified by:

assignLayers in interface ILayerer

Parameters:

graph - the input graph

layers - the ILayers instance that will be filled with the results of the calculation

ldp - the ILayoutDataProvider used for querying information about the nodes and edges

See Also:

ILayers.insert(com.yworks.yfiles.layout.hierarchic.LayerType, int), ILayer.add(com.yworks.yfiles.algorithms.Node)

assignNodeLayer

public int assignNodeLayer(LayoutGraph graph,
                           INodeMap layerID,
                           EdgeList reversedEdges)

Assigns the nodes of the graph to layers given by the IDataProvider registered with the graph using key LAYER_ID_DPKEY.

Throws:

IllegalArgumentException - if no IDataProvider with key LAYER_ID_DPKEY is registered with the given graph

Parameters:

graph - the graph

layerID - the INodeMap that will be filled during the execution and holds the zero-based index of the layer to which each node belongs; this INodeMap is a normalized variant of the given IDataProvider registered with the graph using key LAYER_ID_DPKEY and the first layer has the number 0

reversedEdges - the EdgeList containing the edges that have been reversed

Returns:

the number of layers after the removal of empty layers

normalize

public int normalize(Graph graph,
                     IDataProvider layerId,
                     IDataAcceptor normalizedLayerId)

Convenience method that removes empty layers and ensures that the smallest layer has value 0.

Parameters:

graph - the graph

layerId - the IDataProvider that returns an integer value (layer) for each node; the first layer has the number 0

normalizedLayerId - the IDataAcceptor that will be filled by the layout algorithm and holds an integer value (layer ID after normalization) for each node

Returns:

the number of layers after the removal of empty layers