Package org.geotools.styling.visitor

Class UomRescaleStyleVisitor

Object
DuplicatingStyleVisitor
UomRescaleStyleVisitor
All Implemented Interfaces:
StyleVisitor
public class UomRescaleStyleVisitor extends DuplicatingStyleVisitor
Visitor used for rescaling a Style given a map scale (e.g., meters per pixel) and taking into consideration the Unit of Measure (UOM, e.g., SI.METRE, USCustomary.FOOT) of each symbolizer. The resulting Style's Symbolizer sizes will all be given in PIXELS, so that they can be directly used by a renderer that is unaware of units of measure or the current map scale. For example, points with size == 100 meters could be rescaled to 10 pixels for higher levels of zoom and 2 pixels for a lower level of zoom.

This visitor extends DuplicatingStyleVisitor and as such yields a copy of the original Style. Usage is simply to call the desired visit() method and then call getCopy() to retrieve the result.

Author:
milton, Andrea Aime - GeoSolutions

  • Constructor Details

    • UomRescaleStyleVisitor

      public UomRescaleStyleVisitor(double mapScale)
      Constructor: requires the current mapScale to inform the window to viewport (world to screen) relation in order to correctly rescaleDashArray sizes according to units of measure given in world units (e.g., SI.METRE, USCustomary.FOOT, etc).
      Parameters:
      mapScale - The specified map scale, given in pixels per meter.

  • Method Details

    • rescale

      protected Expression rescale(Expression unscaled, Unit<Length> uom)
      Used to rescaleDashArray the provided unscaled value.
      Parameters:
      unscaled - the unscaled value.
      uom - the unit of measure that will be used to scale.
      Returns:
      the expression multiplied by the provided scale.

    • rescaleDashArray

      protected List<Expression> rescaleDashArray(List<Expression> expressions, Unit<Length> uom)
      Rescale a list of expressions, can handle null.

    • rescale

      protected String rescale(String unscaled, Unit<Length> uom)
      Used to rescaleDashArray the provided unscaled value.
      Parameters:
      unscaled - the unscaled value.
      uom - the unit of measure that will be used to scale.
      Returns:
      the expression multiplied by the provided scale.

    • rescaleStroke

      protected void rescaleStroke(Stroke stroke, Unit<Length> uom)
      Used to rescaleDashArray the provided stroke.
      Parameters:
      stroke - the unscaled stroke, which will be modified in-place.
      uom - the unit of measure that will be used to scale.

    • visit

      public void visit(PointSymbolizer ps)
      Description copied from interface: StyleVisitor
      Called when accept is called on a pointsymbolizer
      Specified by:
      visit in interface StyleVisitor
      Overrides:
      visit in class DuplicatingStyleVisitor
      Parameters:
      ps - the point symbolizer to visit

    • visit

      public void visit(LineSymbolizer line)
      Description copied from interface: StyleVisitor
      Called when accept is called on a linesymbolizer
      Specified by:
      visit in interface StyleVisitor
      Overrides:
      visit in class DuplicatingStyleVisitor
      Parameters:
      line - the line symbolizer to visit

    • visit

      public void visit(PolygonSymbolizer poly)
      Description copied from interface: StyleVisitor
      Called when accept is called on a polygon symbolizer
      Specified by:
      visit in interface StyleVisitor
      Overrides:
      visit in class DuplicatingStyleVisitor
      Parameters:
      poly - the polygon symbolizer to visit

    • visit

      public void visit(TextSymbolizer text)
      Description copied from interface: StyleVisitor
      Called when accept is called on a textsymbolizer
      Specified by:
      visit in interface StyleVisitor
      Overrides:
      visit in class DuplicatingStyleVisitor
      Parameters:
      text - the text symbolizer to visit