Package com.luciad.model

Class TLcd2DBoundsIndexedModel

java.lang.Object
com.luciad.model.ALcdModel
com.luciad.model.TLcd2DBoundsIndexedModel
All Implemented Interfaces:
ILcd2DBoundsIndexedModel, ILcd2DBoundsInteractable, ILcdIntegerIndexedModel, ILcdModel, ILcdBounded, ILcdDisposable, Serializable, AutoCloseable
Direct Known Subclasses:
TLcd2DBoundsIndexedModelTreeNode, TLcdMagneticNorthModel, TLcdNetCDFFilteredModel
public class TLcd2DBoundsIndexedModel extends ALcdModel implements ILcd2DBoundsIndexedModel, ILcdIntegerIndexedModel, Serializable
An implementation of ILcd2DBoundsIndexedModel that is also an ILcdIntegerIndexedModel.

This model stores its elements in a spatial index, based on the bounds of the elements. All elements contained in this model should therefore implement ILcdBounded or expose it. Users should notify this model whenever the bounds of an element in the model are changed, to allow the model to update its index. This can be done by means of the elementChanged(Object, int) method.

All elements are additionally stored in a linear index, allowing fast integer- based queries.

If it is unclear which model to use, this model is a good first choice that has a good overall performance without using too much resources or adding too much complexity to the application. The package documentation provides a detailed overview of all model implementations that are available in this package, and their usage.

The current implementation creates a spatial index based on an R-tree if no initial bounds are specified, or on a BSP-tree if initial bounds are specified. The R-tree is generally slower to build and to modify, but it is slightly faster to query and more memory-efficient.

Although the BSP-tree requires initial bounds, it automatically grows when an element is added outside these bounds. This is achieved by unfolding the bounding rectangle of the tree until the element is contained in it. This unfolding may lead to bounds that are significantly larger than the minimal bounds. Choosing proper initial bounds therefore helps achieving a good performance for accessing the model.

This class is thread-safe for read-only access of its elements. For read-write access, external locking must be used, typically on the model itself. The utility class TLcdLockUtil provides convenient methods readLock(Object), readUnlock(Object), writeLock(Object), and writeUnlock(Object) to do so.

Before LuciadLightspeed version 7.0, the methods for adding, updating, removing, and accessing elements were synchronized. The current implementation no longer performs this internal synchronization, mainly for allowing concurrent read-only access and therefore better performance in multi-threaded applications. Note that internal synchronization on its own was not sufficient for safe concurrent reading and writing (e.g. due to the elements() method, which returns an enumeration). If internal synchronization is required for backward compatibility, one can set the static compatibility flag with setSynchronized(boolean), or one can define the system property com.luciad.model.TLcd2DBoundsIndexedModel.synchronized when starting up the Java Virtual Machine, typically as follows: 

   java -Dcom.luciad.model.TLcd2DBoundsIndexedModel.synchronized ....
Internal synchronization will then be performed, as in previous versions.
See Also:

  • Constructor Details

    • TLcd2DBoundsIndexedModel

      public TLcd2DBoundsIndexedModel()
      Constructs a new, empty TLcd2DBoundsIndexedModel with a default TLcdModelDescriptor.

    • TLcd2DBoundsIndexedModel

      public TLcd2DBoundsIndexedModel(ILcdModelReference aModelReference, ILcdModelDescriptor aModelDescriptor)
      Constructs a new, empty TLcd2DBoundsIndexedModel, initialized with the specified model reference and model descriptor.
      Parameters:
      aModelReference - the model reference describing the coordinate system used in this model.
      aModelDescriptor - the model descriptor providing meta information about this model.

    • TLcd2DBoundsIndexedModel

      public TLcd2DBoundsIndexedModel(ILcdBounds aBounds)
      Constructs a new empty TLcd2DBoundsIndexedModel with a default TLcdModelDescriptor.
      Parameters:
      aBounds - the initial bounds for the spatial indexing scheme of the model. They should ideally encompass all the elements the user plans to add to the model, although this model will extend its bounds when required, by 'unfolding' the rectangle in the appropriate direction, i.e. by doubling the size of the bounds. The bounds of the entire model space are a safe bet, although they will be less efficient when the model is much smaller.

  • Method Details

    • setSynchronized

      public static void setSynchronized(boolean aSynchronized)
      Specifies whether accessing elements should be synchronized, for backward compatibility. The default is false.

    • isSynchronized

      public static boolean isSynchronized()
      Returns whether accessing elements is synchronized.

    • setAddElementFilter

      public void setAddElementFilter(ILcdFilter aFilter)
      Sets the filter that is used to control which elements are accepted for addition to this model. This filter is used by the canAddElement(Object) method, to decide whether an element can be added to this model or not. The filter should not explicitly check whether a specified element is ILcdBounded, this check will always be performed by the canAddElement method. If no filter is set, only the instanceof ILcdBounded test will be performed. By default, no filter is set.
      Parameters:
      aFilter - the filter to be used to control which elements are accepted for addition to this model.
      See Also:

    • getAddElementFilter

      public ILcdFilter getAddElementFilter()
      Returns the filter that is used to control which elements are accepted for addition to this model.
      Returns:
      the filter that is used to control which elements are accepted for addition to this model.
      See Also:

    • setRemoveElementFilter

      public void setRemoveElementFilter(ILcdFilter aFilter)
      Sets the filter that is used to control which elements are accepted for removal from this model. This filter is used by the canRemoveElement(Object) method, to decide whether an element can be removed from this model or not. The filter should not explicitly check whether a specified element is ILcdBounded, this check will always be performed by the canRemoveElement method. If no filter is set, only the instanceof ILcdBounded test will be performed. By default, no filter is set.
      Parameters:
      aFilter - the filter to be used to control which elements are accepted for removal from this model.
      See Also:

    • getRemoveElementFilter

      public ILcdFilter getRemoveElementFilter()
      Returns the filter that is used to control which elements are accepted for removal from this model.
      Returns:
      the filter that is used to control which elements are accepted for removal from this model.
      See Also:

    • canAddElement

      public boolean canAddElement(Object aElement)

      This implementation returns true if and only if all of the following criteria are met:

      • The specified element implements or exposes ILcdBounded.
      • If an addition filter is set, filter.accept(aElement) returns true.
      Specified by:
      canAddElement in interface ILcdModel
      Overrides:
      canAddElement in class ALcdModel
      Parameters:
      aElement - the Object to be checked.
      Returns:
      true if the specified element can be added to this model, false otherwise.

    • addElement

      public void addElement(Object aElement, int aEventMode)
      Adds the specified element to this model.

      Models that support this operation may place limitations on what elements may be added to this model. For example, implementations that are based on a spatial indexing structure will require that elements implement ILcdBounded.

      When adding an element, the user should make sure that canAddElement(aElement) holds, and that the element's geometry is expressed in the same model reference as this model. It is generally undefined what happens if an invalid element is added.

      Implementations of this interface should clearly specify in their documentation any restrictions on what elements may be added. Although it is unspecified what happens if the preconditions are not met, implementations are encouraged to throw meaningful exceptions (for example, NullPointerException, IllegalArgumentException, ClassCastException, UnsupportedOperationException), whenever possible.

      This implementation always throws an UnsupportedOperationException.

      This implementation calls ALcdModel.elementAdded(Object, int) after the element has been added, to send a model change event to this model's listeners.

      Specified by:
      addElement in interface ILcdModel
      Overrides:
      addElement in class ALcdModel
      Parameters:
      aElement - the element to be added to this model.
      aEventMode - the mode for sending out the model change event. This can be FIRE_LATER or NO_EVENT.
      See Also:

    • canRemoveElement

      public boolean canRemoveElement(Object aElement)

      This implementation returns true if and only if all of the following criteria are met:

      • The specified element implements or exposes ILcdBounded.
      • If a removal filter is set, filter.accept(aElement) returns true.
      Specified by:
      canRemoveElement in interface ILcdModel
      Overrides:
      canRemoveElement in class ALcdModel
      Parameters:
      aElement - the element to be verified.
      Returns:
      true if the specified element can be removed from this model, false otherwise.

    • removeElement

      public void removeElement(Object aElement, int aEventMode)
      Removes the specified element from this model. If the specified element is not contained in this model, this method has no effect.

      Although it is unspecified what happens if the preconditions are not met, implementations are encouraged to throw meaningful exceptions (for example, NullPointerException, IllegalArgumentException, ClassCastException, UnsupportedOperationException), whenever possible.

      This implementation always throws an UnsupportedOperationException.

      This implementation calls ALcdModel.elementRemoved(Object, int) after the element has been removed, to sent a model change event to this model's listeners.

      Specified by:
      removeElement in interface ILcdModel
      Overrides:
      removeElement in class ALcdModel
      Parameters:
      aElement - the element to be removed from this model.
      aEventMode - the mode for sending out the model change event. This can be FIRE_LATER or NO_EVENT.
      See Also:

    • removeAllElements

      public void removeAllElements(int aEventMode)
      Removes all elements from this model.

      If an element cannot be removed, this method will return at the first failure. Succeeding elements won't be removed.

      Although it is unspecified what happens if the preconditions are not met, implementations are encouraged to throw meaningful exceptions (for example, NullPointerException, IllegalArgumentException, ClassCastException, UnsupportedOperationException), whenever possible.

      This implementation iterates over all elements in the model, and calls removeElement(Object, int) for each element to be removed, using event mode NO_EVENT if the specified event mode is NO_EVENT, FIRE_LATER otherwise. If the specified event mode is FIRE_NOW, fireCollectedModelChanges() is called afterwards.

      This implementation calls ALcdModel.allElementsRemoved(int) after the elements have been removed, to sent a model change event to this model's listeners.

      Specified by:
      removeAllElements in interface ILcdModel
      Overrides:
      removeAllElements in class ALcdModel
      Parameters:
      aEventMode - the mode for sending out the model change event. This can be FIRE_LATER or NO_EVENT.

    • elementsChanged

      public void elementsChanged(Vector aElements, int aFireEventMode)
      Description copied from class: ALcdModel
      Notifies this model that the elements in the specified vector have changed.

      This implementation calls TLcdModelChangedEventSupport#elementsChanged(java.util.Vector, int).

      Specified by:
      elementsChanged in interface ILcdModel
      Overrides:
      elementsChanged in class ALcdModel
      Parameters:
      aElements - the vector of elements that have changed.
      aFireEventMode - the mode for sending out the model change event. This can be FIRE_LATER or NO_EVENT.

    • allElementsChanged

      public void allElementsChanged(int aFireEventMode)
      Description copied from class: ALcdModel
      Notifies this model that all elements have changed.

      This implementation calls TLcdModelChangedEventSupport#allElementsChanged(int).

      Overrides:
      allElementsChanged in class ALcdModel
      Parameters:
      aFireEventMode - the mode for sending out the model change event. This can be one of FIRE_NOW, FIRE_LATER or NO_EVENT. In case of FIRE_NOW mode, only one event will be fired, containing all changes.

    • elementChanged

      public void elementChanged(Object aElement, int aFireEventMode)
      Description copied from class: ALcdModel
      Notifies this model that the specified element has changed.

      This implementation calls TLcdModelChangedEventSupport#elementChanged(Object, int).

      Specified by:
      elementChanged in interface ILcdModel
      Overrides:
      elementChanged in class ALcdModel
      Parameters:
      aElement - the element that has changed.
      aFireEventMode - the mode for sending out the model change event. This can be FIRE_LATER or NO_EVENT.

    • contains

      public boolean contains(Object aElement)
      Returns true if the specified element is contained in this model, false otherwise.
      Parameters:
      aElement - the element to be tested.
      Returns:
      true if the specified element is contained in this model, false otherwise.

    • size

      public int size()
      Description copied from interface: ILcdIntegerIndexedModel
      Returns the number of elements in this model.
      Specified by:
      size in interface ILcdIntegerIndexedModel
      Returns:
      the number of elements in this model.

    • elements

      public Enumeration elements()
      Description copied from interface: ILcdModel
      Returns an enumeration over all elements of this model. The order in which the elements are enumerated is unspecified by default.
      Specified by:
      elements in interface ILcdModel
      Returns:
      an enumeration over all elements of this model.

    • elementAt

      public Object elementAt(int aIndex)
      Description copied from interface: ILcdIntegerIndexedModel
      Returns the element at the specified index.
      Specified by:
      elementAt in interface ILcdIntegerIndexedModel
      Parameters:
      aIndex - an index into this ILcdModel.
      Returns:
      the element at the specified index.

    • indexOf

      public int indexOf(Object aElement)
      Description copied from interface: ILcdIntegerIndexedModel
      Returns the index of the first occurrence of the specified element in the model, or -1 if this model does not contain the element. More formally: returns the smallest i for which this.elementAt(i).equals(aElement).
      Specified by:
      indexOf in interface ILcdIntegerIndexedModel
      Parameters:
      aElement - the element to search for.
      Returns:
      the index of the first occurrence of the specified element in model vector, or -1 if this model does not contain the element.

    • 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.

    • applyOnInteract2DBounds

      public int applyOnInteract2DBounds(ILcdBounds aBounds, boolean aStrictOverlap, ILcdFunction aFunctionToApply, double aPrecisionX, double aPrecisionY)
      Applies the specified function to all the model elements of which the 2D bounds overlap with the specified bounds. By default, the order in which the function is applied on the elements is unspecified and depends on the implementation.

      The return value of the specified function is used as a stop criterion: the spatial query is interrupted if the function returns false.

      This implementation delegates to applyOnInteract2DBounds(com.luciad.shape.ILcdBounds, boolean, com.luciad.util.ILcdFunction, double, double, double, double, boolean) using the same parameters, using 0.0 as a value for aMinSizeX and aMinSizeY and false for aIncludePoints.

      Specified by:
      applyOnInteract2DBounds in interface ILcd2DBoundsIndexedModel
      Parameters:
      aBounds - the rectangle to test overlap with.
      aStrictOverlap - if false, the spatial search may return more elements than the ones strictly overlapping; if true, the search only returns the elements that are overlapping. The latter mode is more precise, but it may be slower.
      aFunctionToApply - the function to apply on each element that overlaps with the given bounds. The return value of the specified function is used as a stop criterion: the spatial query is interrupted if the function returns false.
      aPrecisionX - the precision required in the x dimension, expressed in model units. For example, for a cartesian grid system expressed in meters, the values should be expressed in meters as well, for a geodetic coordinate system the accuracy values should be expressed in degrees.

      The precision is useful in combination with multi-leveled data (multiple representations of the same object, but with varying accuracy), so that the most appropriate accuracy level can be used. 0 means best possible accuracy, but it might trigger lazy-loaded implementations to load lots of data.

      aPrecisionY - the precision required in the y dimension, expressed in model units.
      Returns:
      the number of elements to which the ILcdFunction has been applied.

    • applyOnInteract2DBounds

      public int applyOnInteract2DBounds(ILcdBounds aBounds, boolean aStrictOverlap, ILcdFunction aFunctionToApply, double aPrecisionX, double aPrecisionY, double aMinSizeX, double aMinSizeY, boolean aIncludePoints)
      Description copied from interface: ILcd2DBoundsInteractable
      Applies the specified function to all the elements of which the 2D bounds overlap with the specified bounds. The order in which the function is applied on the elements is unspecified and depends on the implementation.

      Only elements that have at least the specified minimal size in the x dimension or in the y dimension are considered. This can be useful for quickly eliminating elements that are too small to be visible in a view, for instance. If required, an exception can be made for point elements, which have a size of 0 by 0. They can be forced to be considered, even though they would always be rejected as being too small for any sizes larger than 0.

      The return value of the specified function is used as a stop criterion: the spatial query will be interrupted as soon as the function returns false for an element it was applied on.

      Specified by:
      applyOnInteract2DBounds in interface ILcd2DBoundsIndexedModel
      Specified by:
      applyOnInteract2DBounds in interface ILcd2DBoundsInteractable
      Parameters:
      aBounds - the rectangle to test overlap with.
      aStrictOverlap - if false, the spatial search may return more elements than the ones strictly overlapping; if true, the search only returns the elements that are overlapping. The latter mode is more precise, but it may be slower.
      aFunctionToApply - the function to apply on each element that overlaps with the given bounds.
      aPrecisionX - the precision required in the x dimension, expressed in model units. For example, for a cartesian grid system expressed in meters, the values should be expressed in meters as well, for a geodetic coordinate system the accuracy values should be expressed in degrees.

      The precision is useful in combination with multi-leveled data (multiple representations of the same object, but with varying accuracy), so that the most appropriate accuracy level can be used. 0 means best possible accuracy, but it might trigger lazy-loaded implementations to load lots of data.

      aPrecisionY - the precision required in the y dimension, expressed in model units.
      aMinSizeX - the minimal element size in the x dimension (as in ILcdBounds.getWidth()), expressed in model units. Elements that are smaller than this size will be skipped. This may, for example, be useful when improving the efficiency of painting elements by skipping elements that are smaller than some threshold (e.g. one pixel, converted to model units).
      aMinSizeY - the minimal element size in the y dimension (as in ILcdBounds.getHeight()), expressed in model units.
      aIncludePoints - if true, zero-sized elements (points) are considered as well, even though they might be smaller than the minimum size.
      Returns:
      the number of elements to which the ILcdFunction has been applied.