Package com.luciad.view.gxy.painter

Class TLcdGXYHaloPainter

java.lang.Object
com.luciad.view.gxy.painter.TLcdGXYHaloPainter
All Implemented Interfaces:
ILcdCloneable, ILcdPropertyChangeSource, ILcdGXYPainter, ILcdGXYPainterProvider, Serializable, Cloneable
public class TLcdGXYHaloPainter extends Object implements ILcdGXYPainter, ILcdGXYPainterProvider
Wrapper for a ILcdGXYPainter that adds halo effects when painting objects. For a more detailed explanation of halos, please refer to TLcdGXYHaloLabelPainter.

Use

This painter uses the Decorator design pattern to add halo support to any existing ILcdGXYPainter or ILcdGXYPainterProvider implementation. If the decorated class implements both, a cast to either ILcdGXYPainter or ILcdGXYPainterProvider is necessary to select the correct constructor. The methods that control the appearance of the halos are equivalent to those in TLcdGXYHaloPainter.

Alternatives

The generic approach of this painter wrapper is not necessarily the best performing way to create a halo around an object. If you have some knowledge of the object you'd like to paint, you might be able to achieve the same effect with less memory and computing needs. For example, for line shapes, you could register two pointlist painters, each with a different line width.
Since:
7.0.17
See Also:

  • Constructor Details

    • TLcdGXYHaloPainter

      public TLcdGXYHaloPainter(ILcdGXYPainter aPainter)
      Creates a new TLcdGXYHaloPainter wrapping the given painter, with default halo parameters (Color = white, thickness = 1)
      Parameters:
      aPainter - the ILcdGXYPainter rendering objects.

    • TLcdGXYHaloPainter

      public TLcdGXYHaloPainter(ILcdGXYPainterProvider aPainterProvider)
      Creates a new TLcdGXYHaloPainter wrapping the given painter provider, with default halo parameters (Color = white, thickness = 1)
      Parameters:
      aPainterProvider - the ILcdGXYPainterProvider rendering objects.

    • TLcdGXYHaloPainter

      public TLcdGXYHaloPainter(ILcdGXYPainter aPainter, Color aHaloColor, int aHaloThickness)
      Creates a new TLcdGXYHaloPainter wrapping the given painter, configured with the given halo color and thickness.
      Parameters:
      aPainter - the ILcdGXYPainter rendering objects.
      aHaloColor - the halo color
      aHaloThickness - the halo thickness

    • TLcdGXYHaloPainter

      public TLcdGXYHaloPainter(ILcdGXYPainterProvider aPainterProvider, Color aHaloColor, int aHaloThickness)
      Creates a new TLcdGXYHaloPainter wrapping the given painter provider, configured with the given halo color and thickness.
      Parameters:
      aPainterProvider - the ILcdGXYPainterProvider rendering objects.
      aHaloColor - the halo color
      aHaloThickness - the halo thickness

  • Method Details

    • isUseImageCache

      public boolean isUseImageCache()
      Returns true when caching is enabled, false otherwise.
      Returns:
      true when caching is enabled, false otherwise.
      See Also:

    • setUseImageCache

      public void setUseImageCache(boolean aUseCache)
      Sets whether to cache the halo renderings as images or not.

      Using the image cache is especially useful when painting is expensive (e.g., when a halo is painted). Enabling the cache has two disadvantages:

      • Caching requires more memory (one BufferedImage for each rendered object).
      • Caching can only be used if the rendered objects do not change, or if they implement ILcdCache. However, the clearImageCache() method can be called to clear the image cache if changes need to be applied.
      Parameters:
      aUseCache - true if halo renderings should be cached
      See Also:

    • clearImageCache

      public void clearImageCache()
      Clears the entire image cache. To remove a single object from the cache, use clearImageCache(Object).

      Note: this method only clears the cached images that are stored in the painter itself. I.e. it doesn't clear the cached images that are stored in the domain objects using ILcdCache.

      See Also:

    • clearImageCache

      public void clearImageCache(Object aObject)
      Clears the image cache for the given object. The next time this object is painted, a new image will be created and cached for it. To remove all cached images in one go, use clearImageCache().

      Note : this method only clears the cached image for the given Object if it is stored in the painter itself, not when it is stored in the domain objects using ILcdCache.

      Parameters:
      aObject - the object for which the cache to be cleared.
      See Also:

    • isHaloEnabled

      public boolean isHaloEnabled()
      Returns true if the halo effect is on, false otherwise.
      Returns:
      true if the halo effect is on, false otherwise
      See Also:

    • setHaloEnabled

      public void setHaloEnabled(boolean aHaloEnabled)
      Switches the halo effect on or off. If halos are not enabled, painting is delegated directly to the wrapped ILcdGXYPainter, without further intervention by this TLcdGXYHaloPainter.
      Parameters:
      aHaloEnabled - true if halos should be added, false otherwise
      See Also:

    • isSelectionHaloEnabled

      public boolean isSelectionHaloEnabled()
      Returns true if the halo effect is on for selected objects, false otherwise.
      Returns:
      true if the halo effect is on for selected objects, false otherwise
      See Also:

    • setSelectionHaloEnabled

      public void setSelectionHaloEnabled(boolean aSelectionHaloEnabled)
      Switches the halo effect on or off for selected objects. If set to true, objects that are drawn in selection mode (and are possibly being edited) will also have a halo. For performance reasons, this property is off by default, so no halos are added when painting in selection mode.
      Parameters:
      aSelectionHaloEnabled - true if halos should be added in selection mode, false otherwise
      See Also:

    • getHaloThickness

      public int getHaloThickness()
      Returns the current halo thickness.
      Returns:
      the current halo thickness
      See Also:

    • setHaloThickness

      public void setHaloThickness(int aThickness)
      Sets the thickness (in pixels) of the halo to be added around objects.
      Parameters:
      aThickness - the new halo thickness
      See Also:

    • setHaloAlgorithm

      public void setHaloAlgorithm(TLcdHaloAlgorithm aHaloAlgorithm)
      Sets the algorithm to be used for rendering halo's. The choice of the halo algorithm may have a major impact on the overall performance of this painter. See TLcdHaloAlgorithm for more information on the available algorithms.
      Parameters:
      aHaloAlgorithm - the algorithm to be used for rendering halo's.
      See Also:

    • getHaloAlgorithm

      public TLcdHaloAlgorithm getHaloAlgorithm()
      Returns the algorithm that is used for rendering halo's.
      Returns:
      the algorithm that is used for rendering halo's.
      See Also:

    • getHaloColor

      public Color getHaloColor()
      Returns the current halo color.
      Returns:
      the current halo color
      See Also:

    • setHaloColor

      public void setHaloColor(Color aColor)
      Sets the color of the halo to be added around objects.
      Parameters:
      aColor - the new halo color
      See Also:

    • getDelegatePainter

      public ILcdGXYPainter getDelegatePainter()
      Returns the ILcdGXYPainter to which the rendering of the objects is delegated.
      Returns:
      the ILcdGXYPainter to which the rendering of the objects is delegated.

    • setDelegatePainter

      public void setDelegatePainter(ILcdGXYPainter aDelegatePainter)
      Sets the ILcdGXYPainter to which the rendering of the objects is to be delegated. Note that, if a delegate painter provider is set, this property is ignored.
      Parameters:
      aDelegatePainter - the ILcdGXYPainter to which the rendering of the objects is delegated.
      See Also:

    • getDelegatePainterProvider

      public ILcdGXYPainterProvider getDelegatePainterProvider()
      Returns the ILcdGXYPainterProvider to which the rendering of the objects is delegated.
      Returns:
      the ILcdGXYPainterProvider to which the rendering of the objects is delegated.
      See Also:

    • setDelegatePainterProvider

      public void setDelegatePainterProvider(ILcdGXYPainterProvider aDelegatePainterProvider)
      Sets the ILcdGXYPainterProvider to which the rendering of the objects is to be delegated. When calling getGXYPainter(Object), the painter to delegate to is automatically retrieved from this painter provider.
      Parameters:
      aDelegatePainterProvider - the ILcdGXYPainterProvider to which the rendering of the objects is delegated.
      See Also:

    • getGXYPainter

      public ILcdGXYPainter getGXYPainter(Object aObject)
      Always returns this painter itself.
      Specified by:
      getGXYPainter in interface ILcdGXYPainterProvider
      Parameters:
      aObject - the object for which a painter is requested
      Returns:
      the painter itself

    • paint

      public void paint(Graphics aGraphics, int aMode, ILcdGXYContext aGXYContext)
      Description copied from interface: ILcdGXYPainter
      Displays the representation of the object in the given mode on the Graphics passed, taking into account the supplied context.

      The visual representation of an object depends on the context. Depending on the context (e.g. is the location covered by the view), an object may or may not have a representation. The context contains:

      • transformations which allow to compute the location in view space of points and bounds given in model, space
      • a pen which can connect points with a line or create arcs around a point,
      • the view for which the object's representation must be painted. This can be useful when the painted object depends on the scale of the view, or the presence of other layers in the view.
      • the current location(s) of the mouse or input device and the last location(s) the mouse or input device was pressed.

      The mode passed in this method indicates what part of the object must be painted, whether it should be painted as selected or not, and whether user interaction (via mouse movements) must be taken into account.

      When the mode passed contains either TRANSLATING, RESHAPING or CREATING, this method is also responsible for interpreting interaction on the representation of an object and modifying the representation of the object accordingly. The painter is not responsible for modifying the object itself, this is done by a corresponding ILcdGXYEditor . Implementations of ILcdGXYPainter and ILcdGXYEditor interfaces must be consistent for an object: the painter must display the result of the user interaction on the object, while the editor is responsible for modifying the object as a result of the user interaction. A good practice to ensure a consistent implementation is to implement both the ILcdGXYPainter and ILcdGXYEditor interfaces in a single class.

      When the mode passed includes SNAPS, the part of the representation which corresponds to the object returned as snap target by the method snapTarget must be painted in order to provide the user with a visual indication of the snap target.

      The Graphics passed in this method can be different from the Graphics returned by a view due to techniques such as double buffering (as applied in Swing). Basic drawing operations must always be performed on the Graphics passed as an argument in this method.

      Specified by:
      paint in interface ILcdGXYPainter
      Parameters:
      aGraphics - the Graphics on which the representation of the object is painted
      aMode - the mode the object is represented in (see class documentation).
      aGXYContext - the ILcdGXYContext the drawing depends on.

    • setObject

      public void setObject(Object aObject)
      Description copied from interface: ILcdGXYPainter
      Sets the Object for which the representation shall be handled by this painter.

      Setting the object on the painter may have an effect on the internal state of the painter, for example, the color to use.

      When the object is set to a painter, the context parameter in subsequent calls to methods in this class must contain a layer that contains this object and for which the painter for this object is this painter.

      Specified by:
      setObject in interface ILcdGXYPainter
      Parameters:
      aObject - the object for which the representation shall be handled by this painter.
      See Also:

    • getObject

      public Object getObject()
      Description copied from interface: ILcdGXYPainter
      Returns the Object for which the representation is currently being handled by this painter.
      Specified by:
      getObject in interface ILcdGXYPainter
      Returns:
      the Object for which the representation is currently being handled by this painter.
      See Also:

    • boundsSFCT

      public void boundsSFCT(Graphics aGraphics, int aMode, ILcdGXYContext aGXYContext, ILcd2DEditableBounds aBoundsSFCT) throws TLcdNoBoundsException
      Description copied from interface: ILcdGXYPainter
      Sets the supplied bounds (in view coordinates, pixels) so that it encompasses the representation of the object in the given mode taking into account the given context.

      If this method returns without exception the bounds argument must encompass the representation of the object. A point outside the bounds will not be contained within the painted object.

      The bounds returned in this method can be seen as the equivalent in the view space of the bounds in the model space for ILcdBounded objects.

      Specified by:
      boundsSFCT in interface ILcdGXYPainter
      Parameters:
      aGraphics - the Graphics on which the representation of the object is painted
      aMode - the mode the object is represented in (see class documentation). For example, an object may be represented differently in SELECTED mode compared to DEFAULT mode. The returned bounds of the representation must take this different representation into account.
      aGXYContext - the context for which the representation of the object is painted. It contains amongst others the transformations from model to world and world to view.
      aBoundsSFCT - the bounds that must be adapted to encompass the representation of the object in the given mode and context. These bounds must not be taken into account when the method has thrown an exception.
      Throws:
      TLcdNoBoundsException - if no bounds can be determined for the representation of the object. This can happen when the object does not have a representation in the given context, for example when it is located in a part of the world which is not visible in the current view.
      See Also:

    • isTouched

      public boolean isTouched(Graphics aGraphics, int aMode, ILcdGXYContext aGXYContext)
      Description copied from interface: ILcdGXYPainter
      Checks if the representation of the object in the given mode is touched at the location as defined in the supplied context.

      The location that must be taken into account to check whether the representation is touched can be retrieved from the context passed with the methods ILcdGXYContext.getX() and ILcdGXYContext.getY(). If the check is part of an ongoing operation of user interaction, for example, when the mouse is being dragged, the location of the start of the operation can also be taken into account using the methods ILcdGXYContext.getDeltaX() and ILcdGXYContext.getDeltaY(). The context contains the transformations required to convert this location into the equivalent location in model space. Implementations of this interface usually follow either of the following patterns:

      • transform the location of the interaction back to model space and compare the coordinates with the object in model space.
      • transform the location to world space and compare with a world representation of the object. This forces the painter into caching a world representation of the object. Caching a view representation of an object is not very practical as it would have to change whenever the view's scale changes or when it is panned. A world representation of an object only changes when the view's XYWorldReference changes, which happens less frequently.

      As the mode influences the way an object is represented, it must also be taken into account when checking whether that representation is being touched. When the mode contains CREATING, RESHAPING or TRANSLATING which indicate that the object must be represented in a state for an ongoing operation, the location of the start of the operation may be taken into account as mentioned above. The painting result can take into account multiple locations, to respond to, for example, multi-touch input. When the mode contains SELECTED, the painter should also check if the non-selected representation is touched, since these are always painted on top of each other.

      The boundsSFCT is often used to speed up the performance of this method as a location outside these bounds can never touch the representation of the object.

      Note that this method does not give an indication of what part of the object is touched. It is up to the painter implementations to provide methods to make this distinction. The method does also not indicate what sensitivity must be applied when checking if an object is touched. It is up to the implementation to decide what should be the maximum distance between the location given in the context and the closest relevant point or area of the representation of the object.

      Specified by:
      isTouched in interface ILcdGXYPainter
      Parameters:
      aGraphics - the Graphics on which the representation of the object is painted
      aMode - the mode the object is represented in
      aGXYContext - contains the location of the interaction and the transformations to convert this location into model coordinates
      Returns:
      true if the representation of the object in the given mode is touched by the location as defined in the context passed, false otherwise
      See Also:

    • anchorPointSFCT

      public void anchorPointSFCT(Graphics aGraphics, int aMode, ILcdGXYContext aGXYContext, Point aPointSFCT) throws TLcdNoBoundsException
      Description copied from interface: ILcdGXYPainter
      Moves the Point passed to the location (in view coordinates, pixels) of the anchor point of the representation of the object in the given mode taking into account the given context.

      The anchor point is an important point of the representation, typically the point which would be used when the object would be represented as a single point. The anchor point is mostly used to attach extra information to the representation of an object, for example, using labels. A typical implementation of this method for painters which can handle ILcdShape objects is the location of the focus point of the shape.

      Specified by:
      anchorPointSFCT in interface ILcdGXYPainter
      Parameters:
      aGraphics - the Graphics on which the representation of the object is painted
      aMode - the mode the object is painted in (see class documentation)
      aGXYContext - the context for which the representation of the object is painted. It contains amongst others the transformations from model to world and world to view.
      aPointSFCT - the point that has to be moved to the location of the anchor point of the representation of the object. This point must not be taken into account when the method has thrown a TLcdNoBoundsException.
      Throws:
      TLcdNoBoundsException - if no anchor point can be determined for the representation of the object. This can be when the object does not have a representation in the given context, for example when it is located in a part of the world which is not visible in the projection as set in the views world reference.
      See Also:

    • supportSnap

      public boolean supportSnap(Graphics aGraphics, ILcdGXYContext aGXYContext)
      Description copied from interface: ILcdGXYPainter
      Returns whether the painter can provide a snap target based on the representation of the object in the given context.
      Specified by:
      supportSnap in interface ILcdGXYPainter
      Parameters:
      aGraphics - the Graphics on which the representation of the object is painted
      aGXYContext - the context in which this object is represented and in which the editing of an object occurs.
      Returns:
      true if an object can be returned that can be used to snap to in the given context, false otherwise.

    • snapTarget

      public Object snapTarget(Graphics aGraphics, ILcdGXYContext aGXYContext)
      Description copied from interface: ILcdGXYPainter
      Returns an object that can be used as snapping target when graphically editing an object. For example, an object which is beneath the current mouse position (as given in the context).

      This method must only be called when supportSnap returns true for the given context.

      Specified by:
      snapTarget in interface ILcdGXYPainter
      Parameters:
      aGraphics - the Graphics on which the representation of the object is painted
      aGXYContext - the context in which this object is represented and in which the editing of an object occurs.
      Returns:
      an object that can be used as snapping target when graphically editing an object. It must be defined in the same model reference as the object set to this painter.
      See Also:

    • getCursor

      public Cursor getCursor(Graphics aGraphics, int aMode, ILcdGXYContext aGXYContext)
      Description copied from interface: ILcdGXYPainter
      Returns a cursor that clarifies the mode and context the painter is operating in. For example, when the mode is TRANSLATING, the cursor could be the MOVE cursor. When no specific cursor is required implementations must return null.
      Specified by:
      getCursor in interface ILcdGXYPainter
      Parameters:
      aGraphics - the Graphics on which the representation of the object is painted
      aMode - the rendering mode to return the cursor for.
      aGXYContext - the context in which the rendering occurs.
      Returns:
      a Cursor to indicate the type of operating aMode and aGXYContext. Returns null if no particular Cursor is required.

    • getDisplayName

      public String getDisplayName()
      Description copied from interface: ILcdGXYPainter
      Returns a textual representation of this painter. This can be useful when different representations of an object are handled by different painter implementations. Having a textual representation can facilitate choosing between different painter implementations.
      Specified by:
      getDisplayName in interface ILcdGXYPainter
      Returns:
      a textual representation of this painter.

    • addPropertyChangeListener

      public void addPropertyChangeListener(PropertyChangeListener aPropertyChangeListener)
      Description copied from interface: ILcdPropertyChangeSource

      Registers the given PropertyChangeListener to be notified when this object's properties change.

      In case you need to register a listener which keeps a reference to an object with a shorter life-time than this change source, you can use a ALcdWeakPropertyChangeListener instance as property change listener.

      Specified by:
      addPropertyChangeListener in interface ILcdPropertyChangeSource
      Parameters:
      aPropertyChangeListener - The listener to be notified
      See Also:

    • removePropertyChangeListener

      public void removePropertyChangeListener(PropertyChangeListener aPropertyChangeListener)
      Description copied from interface: ILcdPropertyChangeSource

      De-registers the given PropertyChangeListener from receiving property change events for this object.

      If the listener was added more than once, it will be notified one less time after being removed. If the listener is null, or was never added, no exception is thrown and no action is taken.

      Specified by:
      removePropertyChangeListener in interface ILcdPropertyChangeSource
      Parameters:
      aPropertyChangeListener - the listener that should no longer be notified of changes of this object's properties
      See Also:

    • clone

      public Object 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
      Specified by:
      clone in interface ILcdGXYPainterProvider
      Overrides:
      clone in class Object
      Returns:
      a clone of this painter provider.
      See Also: