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

Class TLspCurvedPathLabelingAlgorithm

java.lang.Object

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

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

All Implemented Interfaces:

ILcdCloneable, ILspLabelingAlgorithm, Cloneable

public class TLspCurvedPathLabelingAlgorithm
extends ALspDiscreteLabelingAlgorithm

This labeling algorithm tries to find a valid position for a curved text label on a path. This algorithm depends on the used label painter being an ILspPathLocationLabelPainter.

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
TLspCurvedPathLabelingAlgorithm()	Creates a new labeling algorithm that can place labels on paths using TLspPathLabelLocations.

Method Summary

Modifier and Type	Method	Description
TLspCurvedPathLabelingAlgorithm	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.
double	getQuality()	Returns the quality setting.
boolean	isReusePreviousLocations()	Returns if the algorithm tries to reuse the previous label location.
void	setQuality(double aQuality)	Sets the quality.
void	setReusePreviousLocations(boolean aReusePreviousLocations)	Sets if the algorithm tries to reuse the previous label location.

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

TLspCurvedPathLabelingAlgorithm

public TLspCurvedPathLabelingAlgorithm()

Creates a new labeling algorithm that can place labels on paths using TLspPathLabelLocations. The used paths are created by a default path provider that discretizes the anchor of a label (see ILspLabelPainter.getAnchorObject) or the domain object if no anchor is defined explicitly.

Method Details

setQuality

public void setQuality(double aQuality)

Description copied from class: ALspDiscreteLabelingAlgorithm

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.

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()

Description copied from class: ALspDiscreteLabelingAlgorithm

Returns the quality setting.

Specified by:

getQuality in class ALspDiscreteLabelingAlgorithm

Returns:

the quality setting.

See Also:

• ALspDiscreteLabelingAlgorithm.setQuality(double)

isReusePreviousLocations

public boolean isReusePreviousLocations()

Returns if the algorithm tries to reuse the previous label location.

Returns:

if the algorithm tries to reuse the previous label location.

See Also:

• setReusePreviousLocations(boolean)

setReusePreviousLocations

public void setReusePreviousLocations(boolean aReusePreviousLocations)

Sets if the algorithm tries to reuse the previous label location.

Parameters:

aReusePreviousLocations - true if the algorithm should reuse the previous label location, and false otherwise.

See Also:

• isReusePreviousLocations()

clone

public TLspCurvedPathLabelingAlgorithm 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