Package com.luciad.view.lightspeed.label.algorithm.discrete

Class TLspCompositeDiscreteLabelingAlgorithm

java.lang.Object

com.luciad.view.lightspeed.label.algorithm.discrete.ALspDiscreteLabelingAlgorithm

com.luciad.view.lightspeed.label.algorithm.discrete.TLspCompositeDiscreteLabelingAlgorithm

All Implemented Interfaces:

ILcdCloneable, ILspLabelingAlgorithm, Cloneable

public class TLspCompositeDiscreteLabelingAlgorithm
extends ALspDiscreteLabelingAlgorithm

This composite algorithm combines multiple ALspDiscreteLabelingAlgorithms into one labeling algorithm.

The difference with TLspCompositeLabelingAlgorithm is that, although multiple algorithms are combined, this composite algorithm respects the original label order. Labels will be placed in this order, provided that the delegate algorithms respect the order in which they receive the labels.

This composite algorithm uses an ILspLabelingAlgorithmProvider to assign labeling algorithms to labels. It works by creating a composite label iterator using createLabelIterator for each algorithm. It also does this using createLabelPlacementIterator and createLabelPlacementEvaluator.

Since:

2012.0

Nested Class Summary

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

ILspLabelingAlgorithm.LabelContext

Field Summary

Fields inherited from class com.luciad.view.lightspeed.label.algorithm.discrete.ALspDiscreteLabelingAlgorithm

CONSECUTIVE_LABEL_CONFLICT_FAIL_COUNT_KEY, CONSECUTIVE_LABEL_FAIL_COUNT_KEY, LABEL_ATTEMPT_COUNT_KEY, LABEL_CONFLICT_FAIL_COUNT_KEY, LABEL_FAIL_COUNT_KEY, LABEL_PLACED_COUNT_KEY, TOTAL_LABEL_COUNT_KEY

Constructor Summary

Constructors

Constructor	Description
TLspCompositeDiscreteLabelingAlgorithm(ILspLabelingAlgorithmProvider<? extends ALspDiscreteLabelingAlgorithm> aAlgorithmProvider)	Creates a new TLspCompositeDiscreteLabelingAlgorithm using the given algorithm provider.

Method Summary

Modifier and Type	Method	Description
TLspCompositeDiscreteLabelingAlgorithm	clone()	Makes Object.clone() public.
protected Iterator<TLspLabelID>	createLabelIterator(List<TLspLabelID> aLabels, ILspLabelingAlgorithm.LabelContext aLabelContext, ILspLabelConflictChecker aConflictChecker, ILspView aView)	Creates a new Iterator that iterates over the TLspLabelIDs.
protected ILspLabelPlacementEvaluator	createLabelPlacementEvaluator(List<TLspLabelID> aLabels, ILspLabelingAlgorithm.LabelContext aLabelContext, ILspLabelConflictChecker aConflictChecker, ILspView aView)	Creates a new ILspLabelPlacementEvaluator using the given parameters.
protected Iterator<TLspLabelPlacement>	createLabelPlacementIterator(TLspLabelID aLabel, ALspLabelLocations aCurrentLabelLocations, ILspLabelingAlgorithm.LabelContext aLabelContext, ILspLabelConflictChecker aConflictChecker, ILspView aView)	Creates a new Iterator that iterates over the TLspLabelPlacements for the given label.
ILspLabelingAlgorithmProvider<? extends ALspDiscreteLabelingAlgorithm>	getAlgorithmProvider()	Returns the used labeling algorithm provider.
double	getQuality()	Returns the quality setting.
void	setQuality(double aQuality)	Sets the quality.

Methods inherited from class com.luciad.view.lightspeed.label.algorithm.discrete.ALspDiscreteLabelingAlgorithm

placeLabels

Methods inherited from class java.lang.Object

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

Constructor Details

TLspCompositeDiscreteLabelingAlgorithm

public TLspCompositeDiscreteLabelingAlgorithm(ILspLabelingAlgorithmProvider<? extends ALspDiscreteLabelingAlgorithm> aAlgorithmProvider)

Creates a new TLspCompositeDiscreteLabelingAlgorithm using the given algorithm provider.

Parameters:

aAlgorithmProvider - a given algorithm provider.

Method Details

getAlgorithmProvider

public ILspLabelingAlgorithmProvider<? extends ALspDiscreteLabelingAlgorithm> getAlgorithmProvider()

Returns the used labeling algorithm provider.

Returns:

the used labeling algorithm provider.

setQuality

public void setQuality(double aQuality)

Sets the quality. If the quality setting is high, the algorithm will try to place more labels. If it is low, the algorithm will only try to place a small portion of the labels, making label placement faster. Setting the quality to e.g. 0.5 can dramatically improve the label placement performance in some cases.

E.g. it is possible that due to the quality setting, this algorithm will only try to place 10% of the labels. This may still result in high quality results, but this depends on the used data. In general, using a lower quality setting will still work well when the data (and its labels) are distributed uniformly over the screen.

By default, the quality is set to 1.0.

Note: calling this method overrides the quality settings of the delegate algorithms.

Specified by:

setQuality in class ALspDiscreteLabelingAlgorithm

Parameters:

aQuality - the new quality. This is a number in [0, 1].

See Also:

• ALspDiscreteLabelingAlgorithm.getQuality()

getQuality

public double getQuality()

Returns the quality setting.

Note: this does not return an aggregate quality of the delegate algorithms.

Specified by:

getQuality in class ALspDiscreteLabelingAlgorithm

Returns:

the quality setting.

See Also:

• ALspDiscreteLabelingAlgorithm.setQuality(double)

clone

public TLspCompositeDiscreteLabelingAlgorithm 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 ALspDiscreteLabelingAlgorithm

See Also:

• Object.clone()

createLabelIterator

protected Iterator<TLspLabelID> createLabelIterator(List<TLspLabelID> aLabels,
 ILspLabelingAlgorithm.LabelContext aLabelContext,
 ILspLabelConflictChecker aConflictChecker,
 ILspView aView)

Description copied from class: ALspDiscreteLabelingAlgorithm

Creates a new Iterator that iterates over the TLspLabelIDs. The abstract algorithm will continue iterating over TLspLabelIDs as long as Iterator.hasNext() returns true. When it returns false, no more label placements will be tried, and placeLabels returns. Iterator.hasNext() should always be called before calling Iterator.next(), and if it returns true, Iterator.next() should never return null.

The implementation of this method should be as independent as possible. It should not rely on createLabelPlacementIterator or createLabelPlacementEvaluator. Not respecting this might result in unexpected behaviour when wrapping or extending this class.

Override this method to provide a custom implementation.

Specified by:

createLabelIterator in class ALspDiscreteLabelingAlgorithm

Parameters:

aLabels - a list of labels that need to be placed.

aLabelContext - the label info object.

aConflictChecker - the conflict checker to be used when evaluating placements.

aView - the view.

Returns:

a new Iterator that iterates over TLspLabelIDs.

createLabelPlacementIterator

protected Iterator<TLspLabelPlacement> createLabelPlacementIterator(TLspLabelID aLabel,
 ALspLabelLocations aCurrentLabelLocations,
 ILspLabelingAlgorithm.LabelContext aLabelContext,
 ILspLabelConflictChecker aConflictChecker,
 ILspView aView)

Description copied from class: ALspDiscreteLabelingAlgorithm

Creates a new Iterator that iterates over the TLspLabelPlacements for the given label. The abstract algorithm will continue iterating over TLspLabelPlacements as long as Iterator.hasNext() returns true. When it returns false, a new label will be tried. Iterator.hasNext() should always be called before calling Iterator.next(), and if it returns true, Iterator.next() should never return null.

The implementation of this method should be as independent as possible. It should not rely on createLabelIterator or createLabelPlacementEvaluator. Not respecting this might result in unexpected behaviour when wrapping or extending this class.

The returned TLspLabelPlacement should be correctly initialized, that is it should at least be able to return a valid label location, bounds rectangle and bounds rotation. It should also reference its corresponding TLspLabelID.

Override this method to provide a custom implementation.

Specified by:

createLabelPlacementIterator in class ALspDiscreteLabelingAlgorithm

Parameters:

aLabel - the identifier for which an iterator should be created.

aCurrentLabelLocations - an ALspLabelLocations object containing locations for the currently placed labels.

aLabelContext - the label info object.

aConflictChecker - the conflict checker to be used when evaluating placements.

aView - the view.

Returns:

a new Iterator that iterates over TLspLabelPlacements.

createLabelPlacementEvaluator

protected ILspLabelPlacementEvaluator createLabelPlacementEvaluator(List<TLspLabelID> aLabels,
 ILspLabelingAlgorithm.LabelContext aLabelContext,
 ILspLabelConflictChecker aConflictChecker,
 ILspView aView)

Description copied from class: ALspDiscreteLabelingAlgorithm

Creates a new ILspLabelPlacementEvaluator using the given parameters. It evaluates the placements returned by createLabelPlacementIterator, and returns a PlacementResult to denote if the placement should be used for its label or not.

The following actions are undertaken for the following placement results :

• PlacementResult.SUCCESS : the given placement will be used for its label, it will be added to the list of placed representations, and it will be added to the given ILspLabelConflictChecker. After that, ILspLabelPlacementEvaluator.placementApplied will be called and no more placements are tried for the label.
• PlacementResult.FALLBACK : the abstract algorithm will try to find an other placements which returns PlacementResult.SUCCESS. When no such placement is found, this placement will be added to the list of placed labels, and it will be added to the given ILspLabelConflictChecker. After that, ILspLabelPlacementEvaluator.placementApplied will be called.
• PlacementResult.TRY_NEW_PLACEMENT : the abstract algorithm will try to find an other placement which returns PlacementResult.SUCCESS or PlacementResult.FALLBACK. When no such placement is found, ILspLabelPlacementEvaluator.noPlacementApplied is called.
• PlacementResult.FAILED : the abstract algorithm will immediately call ILspLabelPlacementEvaluator.noPlacementApplied and will not try to find other placements for the label.

Override this method to provide a custom implementation.

Specified by:

createLabelPlacementEvaluator in class ALspDiscreteLabelingAlgorithm

Parameters:

aLabels - a list of labels.

aLabelContext - the label info object.

aConflictChecker - the conflict checker to be used when evaluating placements.

aView - the view

Returns:

a new ILspLabelPlacementEvaluator.

See Also:

• ILspLabelPlacementEvaluator