com.yworks.yfiles.layout

Class LayoutMultiplexer

java.lang.Object

com.yworks.yfiles.layout.AbstractLayoutStage

com.yworks.yfiles.layout.LayoutMultiplexer

All Implemented Interfaces:

ILayoutAlgorithm, ILayoutStage

public class LayoutMultiplexer
extends AbstractLayoutStage

A LayoutMultiplexer delegates its layout calls to a core layout algorithm that is dynamically chosen at runtime by inspecting the nodes of the input graph.

If a IDataProvider is registered with the given graph using the look-up key LAYOUT_DPKEY, it is used for retrieving the ILayoutAlgorithm objects that are stored for the graph's nodes. If no such IDataProvider is registered, this layout stage's core layout algorithm (if any) is used for the layout calculation of all nodes.

Note that the first non-null ILayoutAlgorithm instance retrieved from the IDataProvider is used for all nodes.

The main purpose of this class is to enable the use of individual layout algorithms for different components (when used as the core layout algorithm of ComponentLayout) or for the contents of group nodes (when used as the core layout algorithm of RecursiveGroupLayout).

Field Summary

Fields

Modifier and Type	Field and Description
static NodeDpKey<ILayoutAlgorithm>	LAYOUT_DPKEY A DataProvider key for assigning layout algorithms to the nodes At runtime, the layout algorithms are determined and applied to the current graph.

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method and Description
void	applyLayout(LayoutGraph graph) Retrieves and invokes the layout algorithm that is assigned to the graph.
protected ILayoutAlgorithm	getCoreLayout(LayoutGraph graph) Returns the core layout algorithm associated with the nodes contained in the given graph.

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

applyLayoutCore, getCoreLayout, setCoreLayout

Methods inherited from class java.lang.Object

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

Field Detail

LAYOUT_DPKEY

public static final NodeDpKey<ILayoutAlgorithm> LAYOUT_DPKEY

A DataProvider key for assigning layout algorithms to the nodes

At runtime, the layout algorithms are determined and applied to the current graph. The first non-null ILayoutAlgorithm instance is used for the whole graph.

Constructor Detail

LayoutMultiplexer

public LayoutMultiplexer()

Creates a new instance of LayoutMultiplexer.

Method Detail

applyLayout

public void applyLayout(LayoutGraph graph)

Retrieves and invokes the layout algorithm that is assigned to the graph.

Specified by:

applyLayout in interface ILayoutAlgorithm

Specified by:

applyLayout in class AbstractLayoutStage

Parameters:

graph - the input graph

getCoreLayout

protected ILayoutAlgorithm getCoreLayout(LayoutGraph graph)

Returns the core layout algorithm associated with the nodes contained in the given graph.

This implementation looks up the layout algorithm in the IDataProvider registered with the key LAYOUT_DPKEY. The first non-null layout algorithm instance found for a node of the given graph will be returned by this method. If no algorithm is registered at all, it will fall back to the default core layout algorithm.

This method is called in applyLayout(LayoutGraph) and may be overridden to implement a different way of selecting the layout algorithms.

Parameters:

graph - the input graph

Returns:

the according layout algorithm