Package com.luciad.lucy.addons.tea.shapevisibility

Class TLcyShapeObserver

java.lang.Object

com.luciad.lucy.addons.tea.shapevisibility.TLcyShapeObserver

All Implemented Interfaces:

ILcdBounded

public final class TLcyShapeObserver
extends Object
implements ILcdBounded

Domain object representing an observer in a shape visibility calculation. Currently only point shapes are supported as observers. These observers are contained in the observer model of the map.

Each observer has:

• A link to the domain object for which this observer was created.
• A list of domain objects that are currently being observed by this observer.
• Methods to start and stop observing objects.
• During the visibility calculations, certain settings are used for each observer and observee. These settings are derived from the ILcyVisibilityCalculationPropertiesProvider which is created in the add-on.

Creating observer instances is done through the TLcyShapeVisibilityManager:

    //Retrieve the manager from the services
    TLcyShapeVisibilityManager manager = aLucyEnv.getService(TLcyShapeVisibilityManager.class);

    //Ask the manager to create an observer for the specified domain object
    //Interacting with the manager must happen on the AWT thread (Event Dispatch Thread)
    if (manager.canAddObserver(aDomainObjectContext)) {
      TLcyShapeObserver pointObserver = manager.addObserver(aDomainObjectContext);
    }

Since:

2019.1

Method Summary

Modifier and Type	Method	Description
boolean	canObserve(TLcdDomainObjectContext aDomainObjectContext)	Returns true when the specified domain object context can be observed by this observer.
ILcdBounds	getBounds()	Returns the ILcdBounds by which the geometry of this ILcdBounded object is bounded.
List<TLcdDomainObjectContext>	getObservees()	Returns the list of domain object contexts this observer is currently observing.
TLcdDomainObjectContext	getObserver()	Returns the domain object context for which this observer was created.
TLcdCoverageAltitudeMode	getObserverCoverageAltitudeMode()	Returns the altitude mode indicating how to interpret the Z-values of the observer shape.
ILcdPoint	getObserverShape()	Returns the point shape based on the point that was created by the TLcyShapeVisibilityAddOn.createPointObserverShapeProvider() function for this observer, and which is used in the visibility calculations.
TLcyShapeObservationResult	startObserving(TLcdDomainObjectContext aDomainObjectContext)	Start observing the specified domain object using this observer.
void	stopObserving(TLcdDomainObjectContext aDomainObjectContext)	Stop observing the specified domain object with this observer.

Methods inherited from class java.lang.Object

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

Method Details

getObserver

public TLcdDomainObjectContext getObserver()

Returns the domain object context for which this observer was created.

Returns:

the domain object context which this observer was created.

getObserverShape

public ILcdPoint getObserverShape()

Returns the point shape based on the point that was created by the TLcyShapeVisibilityAddOn.createPointObserverShapeProvider() function for this observer, and which is used in the visibility calculations.

The returned point:

• is defined in the model reference of the model containing the observer.
• has a Z-value that should be interpreted using getObserverCoverageAltitudeMode().

The returned point should not be modified.

Returns:

the point shape used in the visibility calculations for this observer

Since:

2020.1

See Also:

• getObserverCoverageAltitudeMode()

getObserverCoverageAltitudeMode

public TLcdCoverageAltitudeMode getObserverCoverageAltitudeMode()

Returns the altitude mode indicating how to interpret the Z-values of the observer shape. This altitude mode is determined by the TLcyShapeVisibilityAddOn.createPointObserverShapeProvider() function.

Returns:

the altitude mode for the observer shape.

Since:

2020.1

See Also:

• getObserverShape()

getObservees

public List<TLcdDomainObjectContext> getObservees()

Returns the list of domain object contexts this observer is currently observing.

This list cannot be modified directly. Use the startObserving(TLcdDomainObjectContext) and stopObserving(TLcdDomainObjectContext) methods to start or stop observing specific domain objects.

Returns:

the list of domain object contexts this observer is currently observing. Possibly empty, never null

canObserve

public boolean canObserve(TLcdDomainObjectContext aDomainObjectContext)

Returns true when the specified domain object context can be observed by this observer.

Currently this method only returns true when:

• The view in the context is the same view as the one for which this observer was created.
• The domain object is not the same as the one for which this observer was created: the observer cannot observe itself.
• The model, layer and view are specified in the context.
• The model in the context is not a model created by the TLcyShapeVisibilityAddOn.
• This observer is not yet observing the domain object.
• The TLcyShapeVisibilityAddOn.createObserveeShapeProvider() function can retrieve a shape for the context.

Parameters:

aDomainObjectContext - The context to check

Returns:

true when the specified domain object context can be observed by this observer.

startObserving

public TLcyShapeObservationResult startObserving(TLcdDomainObjectContext aDomainObjectContext)
                                          throws IllegalArgumentException

Start observing the specified domain object using this observer. This method modifies the observer, so it must be called under a write lock as illustrated below:

      //Find the observer model in the view
      ILcdModel pointObserverModel = view.getLayers()
                                         .stream()
                                         .map(ILcdLayer::getModel)
                                         .filter(model -> Objects.equals(TLcyShapeVisibilityAddOn.OBSERVER_MODEL_TYPE_NAME, model.getModelDescriptor().getTypeName()))
                                         .findFirst()
                                         .orElseThrow(() -> new RuntimeException("Cannot find the model containing the observers"));
      //Let the observer observe another shape
      //As this modifies the point observer, it requires a lock on the point observer model
      try (TLcdLockUtil.Lock autoUnlock = TLcdLockUtil.writeLock(pointObserverModel)) {
        if (pointObserver.canObserve(aDomainObjectContextToObserve)) {
          //Tell the observer to start observing another object
          pointObserver.startObserving(aDomainObjectContextToObserve);
          //Indicate to the model that the observer has been changed
          pointObserverModel.elementChanged(pointObserver, ILcdModel.FIRE_LATER);
        }
      } finally {
        pointObserverModel.fireCollectedModelChanges();
      }

This method returns immediately and doesn't wait for the calculation to finish. This means the matrix in the observation result will not yet contain the result of this observer.

When the calculation finishes, the TLcyShapeObservationResult instance will be updated and a model change event is fired for the observation results model.

Parameters:

aDomainObjectContext - The domain object this observer needs to observe.

Returns:

The observation result for aDomainObjectContext. If the object was not yet under observation by a different observer, this will be a new instance. If the object was already under observation by other observers, the existing result for that observee is updated and returned.

Throws:

IllegalArgumentException - When the specified context cannot be observed (by this observer).

See Also:

• canObserve(TLcdDomainObjectContext)

stopObserving

public void stopObserving(TLcdDomainObjectContext aDomainObjectContext)

Stop observing the specified domain object with this observer. This method modifies the observer, so it must be called under a write lock as illustrated blow:

      //Find the observer model in the view
      ILcdModel pointObserverModel = view.getLayers()
                                         .stream()
                                         .map(ILcdLayer::getModel)
                                         .filter(model -> Objects.equals(TLcyShapeVisibilityAddOn.OBSERVER_MODEL_TYPE_NAME, model.getModelDescriptor().getTypeName()))
                                         .findFirst()
                                         .orElseThrow(() -> new RuntimeException("Cannot find the model containing the observers"));
      //Stop observing a specific shape
      //As this modifies the point observer, it requires a lock on the point observer model
      try (TLcdLockUtil.Lock autoUnlock = TLcdLockUtil.writeLock(pointObserverModel)) {
        //Tell the observer to stop observing a specific object
        pointObserver.stopObserving(aDomainObjectContextToObserve);
        //Indicate to the model that the observer has been changed
        pointObserverModel.elementChanged(pointObserver, ILcdModel.FIRE_LATER);
      } finally {
        pointObserverModel.fireCollectedModelChanges();
      }

Parameters:

aDomainObjectContext - The domain object this observer should stop observing.

getBounds

public ILcdBounds getBounds()

Description copied from interface: ILcdBounded

Returns the ILcdBounds by which the geometry of this ILcdBounded object is bounded.

If the geometry does not allow retrieving valid bounds (for example a polyline with 0 points) the return value is unspecified. It is highly recommended to return an undefined bounds. You can create undefined bounds using the default constructors of TLcdLonLatBounds or TLcdXYBounds.

Specified by:

getBounds in interface ILcdBounded

Returns:

the ILcdBounds by which the geometry of this ILcdBounded object is bounded.