public class TLcdGXYCompositeDiscretePlacementsLabelingAlgorithm extends ALcdGXYDiscretePlacementsLabelingAlgorithm
ALcdGXYDiscretePlacementsLabelingAlgorithm
s
into one labeling algorithm.
The difference with TLcdGXYCompositeLabelingAlgorithm
is that although multiple algorithms are combined, this composite labeling algorithm respects the original
label order as given TLcdCollectedLabelInfoList.getLabels()
.
Labels will be decluttered in this order, provided that the delegate labeling algorithms respect
the order in which they receive the labels.
This composite labeling algorithm uses a ILcdGXYLabelLabelingAlgorithmProvider
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
.
The implementation of this labeling algorithm is thread-safe as long as the set labeling algorithm provider is thread-safe.
Constructor and Description |
---|
TLcdGXYCompositeDiscretePlacementsLabelingAlgorithm(ILcdGXYLabelLabelingAlgorithmProvider<? extends ALcdGXYDiscretePlacementsLabelingAlgorithm> aAlgorithmProvider)
Creates a new
TLcdGXYCompositeDiscretePlacementsLabelingAlgorithm using the
given labeling algorithm provider. |
computeLabelPlacements
public TLcdGXYCompositeDiscretePlacementsLabelingAlgorithm(ILcdGXYLabelLabelingAlgorithmProvider<? extends ALcdGXYDiscretePlacementsLabelingAlgorithm> aAlgorithmProvider)
TLcdGXYCompositeDiscretePlacementsLabelingAlgorithm
using the
given labeling algorithm provider.aAlgorithmProvider
- a given labeling algorithm provider.public ILcdGXYLabelLabelingAlgorithmProvider<? extends ALcdGXYDiscretePlacementsLabelingAlgorithm> getLabelingAlgorithmProvider()
public TLcdGXYCompositeDiscretePlacementsLabelingAlgorithm clone()
ILcdCloneable
Makes Object.clone()
public.
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 );
}
}
clone
in interface ILcdCloneable
clone
in class ALcdGXYDiscretePlacementsLabelingAlgorithm
Object.clone()
public TLcdCollectedLabelInfoList collectLabelInfo(List<TLcdLabelIdentifier> aLabelsToCollect, Graphics aGraphics, ILcdGXYView aGXYView)
ILcdGXYLabelingAlgorithm
TLcdCollectedLabelInfoList
object based
on the given list of TLcdLabelIdentifier
s. The returned
TLcdCollectedLabelInfoList
should contain a TLcdCollectedLabelInfo
object for each label that should be placed.
Each TLcdCollectedLabelInfo
should also contain all information needed by
computeLabelPlacements
to place the labels. In order to enable
correct asynchronous label placing, all calls to the layer and the (label) painters should be
done in this method. The results should then be stored in the info objects.
It is possible that the returned TLcdCollectedLabelInfoList
doesn't contain a
TLcdCollectedLabelInfo
object for every given TLcdLabelIdentifier
.
In that case the missing labels are not placed.
collectLabelInfo
in interface ILcdGXYLabelingAlgorithm
collectLabelInfo
in class ALcdGXYDiscretePlacementsLabelingAlgorithm
aLabelsToCollect
- the labels for which a TLcdCollectedLabelInfoList
should
be created.aGraphics
- the graphics.aGXYView
- the view.TLcdCollectedLabelInfoList
which contains all the information needed to
place the labels.protected Iterator<TLcdCollectedLabelInfo> createLabelIterator(TLcdCollectedLabelInfoList aLabelInfoList, ILcdLabelConflictChecker aBoundsConflictChecker, ILcdGXYView aView)
ALcdGXYDiscretePlacementsLabelingAlgorithm
Iterator
that iterates over the TLcdCollectedLabelInfo
s.
The abstract labeling algorithm will continue iterating over TLcdCollectedLabelInfo
s
as long as Iterator.hasNext()
returns true
. When it returns false
,
no more labels will be tried, and computeLabelPlacements
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.
The returned TLcdCollectedLabelInfo
should be correctly initialized, i.e. it should
contain all information needed to create valid TLcdLabelPlacement
s using
createLabelPlacementIterator
. It should also always point
to its corresponding TLcdCollectedLabeledObjectInfo
.
Override this method to provide a custom implementation.
createLabelIterator
in class ALcdGXYDiscretePlacementsLabelingAlgorithm
aLabelInfoList
- the label infos object that contains all information needed to place the labels.aBoundsConflictChecker
- the bounds conflict checker to be used when evaluating label placements.aView
- the view.Iterator
that iterates over TLcdCollectedLabelInfo
s.protected Iterator<TLcdLabelPlacement> createLabelPlacementIterator(TLcdCollectedLabelInfo aLabel, TLcdCollectedLabelInfoList aLabelInfoList, ILcdLabelConflictChecker aBoundsConflictChecker, ILcdGXYView aView)
ALcdGXYDiscretePlacementsLabelingAlgorithm
Iterator
that iterates over the TLcdLabelPlacement
s
for the given label. The abstract labeling algorithm will continue iterating over
TLcdLabelPlacement
s 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 TLcdLabelPlacement
should be correctly initialized, i.e. it should at
least be able to return a valid label location, bounds rectangle and bounds rotation. It should
also reference its corresponding TLcdCollectedLabelInfo
.
Override this method to provide a custom implementation.
createLabelPlacementIterator
in class ALcdGXYDiscretePlacementsLabelingAlgorithm
aLabel
- the label for which an iterator should be created.aLabelInfoList
- the info object that contains all information needed to place the labels.aBoundsConflictChecker
- the bounds conflict checker to be used when evaluating label placements.aView
- the view.Iterator
that iterates over TLcdLabelPlacement
s.protected ILcdLabelPlacementEvaluator createLabelPlacementEvaluator(TLcdCollectedLabelInfoList aLabelInfoList, ILcdLabelConflictChecker aBoundsConflictChecker, ILcdGXYView aView)
ALcdGXYDiscretePlacementsLabelingAlgorithm
ILcdLabelPlacementEvaluator
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 label placement will be used for its label, it will be added to the list of placed
labels, and it will be added to the given ILcdLabelConflictChecker
. After that,
ILcdLabelPlacementEvaluator.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 ILcdLabelConflictChecker
. After that,
ILcdLabelPlacementEvaluator.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, ILcdLabelPlacementEvaluator.noPlacementApplied
is called.PlacementResult.FAILED
: the
abstract algorithm will immediately call ILcdLabelPlacementEvaluator.noPlacementApplied
and will not try to find other placements for the label.Override this method to provide a custom implementation.
createLabelPlacementEvaluator
in class ALcdGXYDiscretePlacementsLabelingAlgorithm
aLabelInfoList
- the info object that contains all information needed to place the labels.aBoundsConflictChecker
- the bounds conflict checker to be used when evaluating label placements.aView
- the viewILcdLabelPlacementEvaluator