Package org.geotools.renderer.lite

Interface LabelCache

All Known Implementing Classes:
LabelCacheImpl, SynchronizedLabelCache
public interface LabelCache
Used to cache labels prior to their being drawn on the screen.

Implementations exisit with different trade offs about what labels can fit where.

Since:
2.2
Author:
jeichar

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    clear()
    Clears the cache completely
    void
    clear(String layerId)
    Clears the cache of all information relating to the layer identified.
    void
    disableLayer(String layerId)
    Leaves the label information in the cache but ignores it when calculating what labels are drawn.
    void
    enableLayer(String layerId)
    Enable a layer after being disabled.
    void
    end(Graphics2D graphics, Rectangle displayArea)
    Called to indicate that the map is done rendering.
    void
    endLayer(String layerId, Graphics2D graphics, Rectangle displayArea)
    Called to indicate that a layer is done rendering.
    List
    orderedLabels()
    Return a list with all the values in priority order.
    void
    put(Rectangle2D geometry)
    Reserve the provided geometry prior to sorting out where labels can go.
    void
    put(String layerId, TextSymbolizer symbolizer, Feature feature, LiteShape2 shape, NumberRange<Double> scaleRange)
    Puts a Label in the cache.
    void
    start()
    Called by renderer to indicate that the rendering process is starting.
    void
    startLayer(String layerId)
    Called by renderer to indication the start of rendering a layer.
    void
    stop()
    Tells the cache to stop labelling.

  • Method Details

    • start

      void start()
      Called by renderer to indicate that the rendering process is starting.

    • startLayer

      void startLayer(String layerId)
      Called by renderer to indication the start of rendering a layer. Will add the layer to the set of active layers.
      Parameters:
      layerId - an id for the layer

    • put

      void put(String layerId, TextSymbolizer symbolizer, Feature feature, LiteShape2 shape, NumberRange<Double> scaleRange)
      Puts a Label in the cache.
      Parameters:
      layerId - id indicating the layer the feature is part of
      symbolizer - The symbolizer containing the style information
      feature - the feature that has the information required for the symbolizer to calculate the required render information.
      shape - the shape to be labeled. This is in screen coordinates.
      scaleRange - the scaleRange that the symbolizer is legal

    • put

      void put(Rectangle2D geometry)
      Reserve the provided geometry prior to sorting out where labels can go.

      This facility is used to reserve an area so that labels do not end up overlapping on screen constructs like scalebars or north arrows etc...

      Parameters:
      geometry - The Area of the screen to reserve (in screen coordinates)

    • endLayer

      void endLayer(String layerId, Graphics2D graphics, Rectangle displayArea)
      Called to indicate that a layer is done rendering. The method may draw labels if appropriate for the labeling algorithm
      Parameters:
      graphics - the graphics to draw on.
      displayArea - The size of the display area
      layerId - an id for the layer

    • end

      void end(Graphics2D graphics, Rectangle displayArea)
      Called to indicate that the map is done rendering. The method may draw labels if appropriate for the labeling algorithm
      Parameters:
      graphics - the graphics to draw on.
      displayArea - The size of the display area.

    • stop

      void stop()
      Tells the cache to stop labelling.

    • clear

      void clear()
      Clears the cache completely

    • clear

      void clear(String layerId)
      Clears the cache of all information relating to the layer identified.
      Parameters:
      layerId - id of the layer

    • disableLayer

      void disableLayer(String layerId)
      Leaves the label information in the cache but ignores it when calculating what labels are drawn.
      Parameters:
      layerId - id of the layer to disable.

    • enableLayer

      void enableLayer(String layerId)
      Enable a layer after being disabled. If startLayer is called this does not need to be called as start layer implicitely activates the layer.
      Parameters:
      layerId - layer to activate.

    • orderedLabels

      List orderedLabels()
      Return a list with all the values in priority order. Both grouped and non-grouped
      Returns:
      list with all values in priority order