Package com.luciad.drawing

Interface IIconPainter

public interface IIconPainter
An icon painter can paint an icon as an Image.

This class can be used on any thread, so its implementation must be thread-safe.

Performance considerations: to make sure the rendering backend can avoid as much work as possible

  • IIconPainter#paint must be as performant as possible. This can for example be done by implementing this function lazily, i.e. avoid generating the image in the constructor of the IIconPainter implementation.
  • The same goes for the getWidth/getHeight, getAnchorX/getAnchorY methods. If possible, make these as performant as possible. If there is a more performant way to calculate these without painting the image, that is preferred. The reason is that the rendering backend might need these properties to determine if an icon should effectively be visible or not on the Map.

  • Method Summary

    Modifier and Type
    Method
    Description
    double
    getAnchorX()
    Returns the x coordinate of the anchor point in pixels.
    double
    getAnchorY()
    Returns the y coordinate of the anchor point in pixels.
    double
    getDisplayScale()
    Returns the display scale for which this painter is optimized.
    long
    getHeight()
    Returns the height of this icon.
    long
    getWidth()
    Returns the width of this icon.
    Image
    paint()
    Paints the IIcon as an image.

  • Method Details

    • paint

      @NotNull Image paint()
      Paints the IIcon as an image.

      Remarks
      This method may be invoked from different threads.
      Returns:
      the image of this icon, never null.

    • getWidth

      long getWidth()
      Returns the width of this icon.

      I.e. the width of the Image that is returned by IIconPainter#paint.

      Remarks
      This method may be invoked from different threads.
      Returns:
      the width of this icon.

    • getHeight

      long getHeight()
      Returns the height of this icon.

      I.e. the height of the Image that is returned by IIconPainter#paint

      Remarks
      This method may be invoked from different threads.
      Returns:
      the height of this icon.

    • getAnchorX

      double getAnchorX()
      Returns the x coordinate of the anchor point in pixels.

      The anchor point is the location of the icon that (by default) is attached to another object, e.g. a location on the map. This must be a value in the [0, getWidth()] range. A good default implementation is to return getWidth() / 2.0.

      Remarks
      This method may be invoked from different threads.
      Returns:
      the x coordinate of the anchor point in pixels.

    • getAnchorY

      double getAnchorY()
      Returns the y coordinate of the anchor point in pixels.

      The anchor point is the location of the icon that (by default) is attached to another object, e.g. a location on the map. This must be a value in the [0, getHeight()] range. A good default implementation is to return getHeight() / 2.0.

      Remarks
      This method may be invoked from different threads.
      Returns:
      the y coordinate of the anchor point in pixels.

    • getDisplayScale

      double getDisplayScale()
      Returns the display scale for which this painter is optimized.

      This is not necessarily the same display as the one that was used to create this painter. Some icons may only have a limited number scaled versions of their icon available. This method can then be used by the rendering backend to discover this, and to paint it at the intended size.

      Remarks
      This method may be invoked from different threads.
      Returns:
      the display scale for which this painter is optimized.