/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2013, Open Source Geospatial Foundation (OSGeo)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*/
package org.geotools.styling.visitor;
import javax.measure.quantity.Length;
import javax.measure.unit.NonSI;
import javax.measure.unit.SI;
import javax.measure.unit.Unit;
import org.geotools.factory.CommonFactoryFinder;
import org.geotools.filter.visitor.SimplifyingFilterVisitor;
import org.geotools.util.Converters;
import org.opengis.filter.Filter;
import org.opengis.filter.FilterFactory;
import org.opengis.filter.PropertyIsNull;
import org.opengis.filter.expression.Expression;
import org.opengis.filter.expression.Literal;
import org.opengis.filter.expression.NilExpression;
/**
* Helper class that parses a measure with eventual local unit of measure and helps the
* {@link RescalingMode} enumeration to perfom its scaling job
*
* @author Andrea Aime - GeoSolutions
*
*/
class Measure {
static final FilterFactory ff = CommonFactoryFinder.getFilterFactory();
Expression expression;
Double value;
Unit<Length> uom;
Unit<Length> defaultUnit;
public Measure(String value, Unit<Length> defaultUnit) {
setDefaultUnit(defaultUnit);
processLiteralExpression(value, defaultUnit);
}
public Measure(Expression unscaled, Unit<Length> defaultUnit) {
this.expression = unscaled;
setDefaultUnit(defaultUnit);
this.uom = defaultUnit;
if (unscaled instanceof Literal) {
processLiteralExpression((Literal) unscaled, defaultUnit);
} else {
// see if we can still optimize
PropertyIsNull test = ff.isNull(unscaled);
Filter simplified = (Filter) test.accept(new SimplifyingFilterVisitor(), null);
if (simplified == Filter.INCLUDE) {
// special case, the expression was nil to start with
this.expression = NilExpression.NIL;
this.uom = defaultUnit;
} else if (simplified instanceof PropertyIsNull) {
PropertyIsNull pin = (PropertyIsNull) simplified;
Expression se = pin.getExpression();
if (se instanceof Literal) {
processLiteralExpression((Literal) se, defaultUnit);
} else {
this.expression = se;
this.uom = defaultUnit;
}
}
}
}
private void setDefaultUnit(Unit<Length> defaultUnit) {
if (defaultUnit == null) {
this.defaultUnit = NonSI.PIXEL;
} else {
this.defaultUnit = defaultUnit;
}
}
private void processLiteralExpression(Literal literal, Unit<Length> defaultUnit) {
// check if we have a uom attached at the end of the expression
String value = literal.evaluate(null, String.class);
if (value == null) {
// let it go without doing anything, it may be a ConstantExpression.NULL
return;
}
processLiteralExpression(value, defaultUnit);
}
private void processLiteralExpression(String value, Unit<Length> defaultUnit) {
Unit<Length> uom = defaultUnit;
String unitless = value;
if (value.endsWith("px")) {
unitless = value.substring(0, value.length() - 2);
uom = NonSI.PIXEL;
} else if (value.endsWith("ft")) {
unitless = value.substring(0, value.length() - 2);
uom = NonSI.FOOT;
} else if (value.endsWith("m")) {
unitless = value.substring(0, value.length() - 1);
uom = SI.METER;
}
Double measure = Converters.convert(unitless, Double.class);
if (measure == null) {
throw new IllegalArgumentException("Invalid measure '" + value
+ "', was expecting a number, eventually followed by px, m or ft");
}
this.expression = ff.literal(value);
this.value = measure;
this.uom = uom;
}
/**
* Returns true if the uom is set and is not pixel
*
* @return
*/
boolean isRealWorldUnit() {
return uom != null && uom != NonSI.PIXEL;
}
/**
* Returns true if the uom is pixel within a symbolizer whose default unit is also pixel
*
* @param measure
* @return
*/
boolean isPixelInPixelDefault() {
return (uom == null || uom == defaultUnit)
&& (defaultUnit == null || defaultUnit == NonSI.PIXEL);
}
}