com.luciad.view.lightspeed.label.algorithm

LuciadLightspeedClass TLspCompositeLabelingAlgorithm

java.lang.Object

com.luciad.view.lightspeed.label.algorithm.TLspCompositeLabelingAlgorithm

All Implemented Interfaces:

ILcdCloneable, ILspLabelingAlgorithm, Cloneable

public class TLspCompositeLabelingAlgorithm
extends Object
implements ILspLabelingAlgorithm

This composite labeling algorithm combines several ILspLabelingAlgorithms. It works by assigning algorithms to labels using getAlgorithmProvider(). Labels that use the same algorithm are grouped, and then handled by it.

The order in which the algorithms are executed is determined by the sortAlgorithms method. By default it sorts the algorithms based on the priorities of the view representations that are placed by them. The highest priority of all of its labels is assigned to each algorithm. The algorithms are then sorted based on this priority. When two algorithms have the same priority assigned, the original order in which the algorithms are given is respected.

The default order can be customized by overriding the sortAlgorithms method.

Since:

2012.0

Nested Class Summary

Nested classes/interfaces inherited from interface com.luciad.view.lightspeed.label.algorithm.ILspLabelingAlgorithm

ILspLabelingAlgorithm.LabelContext

Constructor Summary

Constructors

Constructor and Description
TLspCompositeLabelingAlgorithm(ILspLabelingAlgorithmProvider<ILspLabelingAlgorithm> aAlgorithmProvider) Creates a composite labeling algorithm that uses the given ILspLabelingAlgorithmProvider to assign algorithms to labels.

Method Summary

Modifier and Type	Method and Description
TLspCompositeLabelingAlgorithm	clone() Makes Object.clone() public.
ILspLabelingAlgorithmProvider<ILspLabelingAlgorithm>	getAlgorithmProvider() Returns the used labeling algorithm provider.
List<TLspLabelPlacement>	placeLabels(List<TLspLabelID> aLabelIDs, ILspLabelingAlgorithm.LabelContext aLabelContext, ILspLabelConflictChecker aConflictChecker, ILspView aView) This method computes a list of label placements for the given List of labels.
protected List<ILspLabelingAlgorithm>	sortAlgorithms(Map<ILspLabelingAlgorithm,List<TLspLabelID>> aLabels, ILspLabelingAlgorithm.LabelContext aLabelContext, ILspView aView) This method sorts the given List of algorithms.

Methods inherited from class java.lang.Object

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

Constructor Detail

TLspCompositeLabelingAlgorithm

public TLspCompositeLabelingAlgorithm(ILspLabelingAlgorithmProvider<ILspLabelingAlgorithm> aAlgorithmProvider)

Creates a composite labeling algorithm that uses the given ILspLabelingAlgorithmProvider to assign algorithms to labels.

Parameters:

aAlgorithmProvider - a labeling algorithm provider that returns algorithms for a given label.

Method Detail

getAlgorithmProvider

public ILspLabelingAlgorithmProvider<ILspLabelingAlgorithm> getAlgorithmProvider()

Returns the used labeling algorithm provider.

Returns:

the used labeling algorithm provider.

sortAlgorithms

protected List<ILspLabelingAlgorithm> sortAlgorithms(Map<ILspLabelingAlgorithm,List<TLspLabelID>> aLabels,
                                                     ILspLabelingAlgorithm.LabelContext aLabelContext,
                                                     ILspView aView)

This method sorts the given List of algorithms. The algorithms will be used in this order to place labels. The original order of the algorithms is determined by the order of the labels in aLabels.

The default implementation sorts the algorithms based on the priorities of the view representations that are placed by them. The highest priority of all of its representations is assigned to each algorithm. The labeling algorithms are then sorted based on this priority. When two algorithms have the same priority assigned, the original order in which the algorithms are given is respected.

Override this method to provide a custom placement order.

Parameters:

aLabels - a mapping of algorithms, and the labels placed by them.

aLabelContext - the label info object.

aView - the view.

Returns:

the sorted List of algorithms.

clone

public TLspCompositeLabelingAlgorithm clone()

Description copied from interface: ILcdCloneable

Makes Object.clone() public.

When for example extending from java.lang.Object, it can be implemented like this:

 public Object clone() {
   try {
     return super.clone();
   } catch ( CloneNotSupportedException e ) {
     // Cannot happen: extends from Object and implements Cloneable (see also Object.clone)
     throw new RuntimeException( e );
   }
 }
 

Specified by:

clone in interface ILcdCloneable

Overrides:

clone in class Object

See Also:

Object.clone()

placeLabels

public List<TLspLabelPlacement> placeLabels(List<TLspLabelID> aLabelIDs,
                                            ILspLabelingAlgorithm.LabelContext aLabelContext,
                                            ILspLabelConflictChecker aConflictChecker,
                                            ILspView aView)

Description copied from interface: ILspLabelingAlgorithm

This method computes a list of label placements for the given List of labels. The returned label placements should contain a valid label location and label bounds. They should also point to their corresponding TLspLabelID

The returned List of TLspLabelPlacements contains label placements that are either visible or invisible. When a placement is present in the list, it means that the location should be stored. When a placement in the list is marked as visible, it means that its location should be marked as visible in the label placer

Specified by:

placeLabels in interface ILspLabelingAlgorithm

Parameters:

aLabelIDs - the labels to be placed.

aLabelContext - provides context information, such as priorities, PaintState, ...

aConflictChecker - the conflict checker that can be used to detect conflicts between labels.

aView - the view.

Returns:

a list of label placements.