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

Field Summary

Fields inherited from class DuplicatingStyleVisitor

copyFilter, ff, pages, sf, STRICT

Constructor Summary

Constructors

Constructor and Description
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).

Method Summary

Modifier and Type	Method and Description
protected Expression	rescale(Expression unscaled, Unit<Length> uom) Used to rescaleDashArray the provided unscaled value.
protected String	rescale(String unscaled, Unit<Length> uom) Used to rescaleDashArray the provided unscaled value.
protected List<Expression>	rescaleDashArray(List<Expression> expressions, Unit<Length> uom) Rescale a list of expressions, can handle null.
protected void	rescaleStroke(Stroke stroke, Unit<Length> uom) Used to rescaleDashArray the provided stroke.
void	visit(LineSymbolizer line) Called when accept is called on a linesymbolizer
void	visit(PointSymbolizer ps) Called when accept is called on a pointsymbolizer
void	visit(PolygonSymbolizer poly) Called when accept is called on a polygon symbolizer
void	visit(TextSymbolizer text) Called when accept is called on a textsymbolizer

Methods inherited from class DuplicatingStyleVisitor

copy, copy, copy, copy, copy, copy, copy, copy, copy, copy, copy, copy, copy, copy, copy, copy, copy, copy, copy, copy, copy, copy, copy, copy, copy, copy, copy, copyExpressions, copyFonts, getCopy, setStrict, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

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 Detail

rescale

protected Expression rescale(Expression unscaled,
                             Unit<Length> uom)

Used to rescaleDashArray the provided unscaled value.

Parameters:

unscaled - the unscaled value.

mapScale - the mapScale in pixels per meter.

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.

mapScale - the mapScale in pixels per meter.

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.

mapScale - the mapScale in pixels per meter.

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