/*
 *    GeoTools - The Open Source Java GIS Toolkit
 *    http://geotools.org
 * 
 *    (C) 2002-2008, 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;

import java.util.List;

import org.opengis.filter.expression.Expression;
import org.opengis.filter.expression.VolatileFunction;

/**
 * A simple visitor whose purpose is to extract the set of attributes used by a
 * Style, that is, those that the Style expects to find in order to work
 * properly
 * 
 * This is very similiar to StyleAttributeExtractor, but with these differences:
 * a) it doesnt the count the <PropertyName> tag in the <Geometry> b) it doesnt
 * count anything in the <TextSymbolizer>'s <Priority> tag c) it doesnt count
 * anything in the <TextSymbolizer>'s <Label> tag
 * 
 * The reasons for this are because these fields are ALWAYS taken directly from
 * the feature, not from the style.
 * 
 * So, for making queries (knowing any property that might be possibily be used
 * in the SLD), use StyleAttributeExtractor. If you want to know what a
 * symbolizer actually needs to cache, then use this
 * (StyleAttributeExtractorTruncated).
 * 
 * @author dblasby
 *
 *
 * @source $URL$
 */
public class StyleAttributeExtractorTruncated extends StyleAttributeExtractor
		implements StyleVisitor {

	boolean usingVolatileFunctions = false;
	
	@Override
	public void clear() {
		super.clear();
		usingVolatileFunctions = false;
	}
	
	public boolean isUsingVolatileFunctions() {
		return usingVolatileFunctions;
	}

	public Object visit(org.opengis.filter.expression.Function expression, Object data) {
		usingVolatileFunctions |= (expression instanceof VolatileFunction);
		return super.visit(expression, data);
	};

	public void visit(RasterSymbolizer rs) {
		if (rs != null) {
			if (rs.getImageOutline() != null) {
				rs.getImageOutline().accept(this);
			}

			if (rs.getOpacity() != null) {
				rs.getOpacity().accept(this, null);
			}
		}
	}

	/**
	 * @see org.geotools.styling.StyleVisitor#visit(org.geotools.styling.PointSymbolizer)
	 */
	public void visit(PointSymbolizer ps) {

		if (ps.getGraphic() != null) {
			ps.getGraphic().accept(this);
		}

	}

	/**
	 * @see org.geotools.styling.StyleVisitor#visit(org.geotools.styling.LineSymbolizer)
	 */
	public void visit(LineSymbolizer line) {

		if (line.getStroke() != null) {
			line.getStroke().accept(this);
		}
	}

	/**
	 * @see org.geotools.styling.StyleVisitor#visit(org.geotools.styling.PolygonSymbolizer)
	 */
	public void visit(PolygonSymbolizer poly) {

		if (poly.getStroke() != null) {
			poly.getStroke().accept(this);
		}

		if (poly.getFill() != null) {
			poly.getFill().accept(this);
		}
	}

	/**
	 * @see org.geotools.styling.StyleVisitor#visit(org.geotools.styling.TextSymbolizer)
	 */
	public void visit(TextSymbolizer text) {

		if (text instanceof TextSymbolizer2) {
			if (((TextSymbolizer2) text).getGraphic() != null)
				((TextSymbolizer2) text).getGraphic().accept(this);
		}

		if (text.getFill() != null) {
			text.getFill().accept(this);
		}

		if (text.getHalo() != null) {
			text.getHalo().accept(this);
		}

        if (text.fonts() != null) {
            List<Font> fonts = text.fonts();
            for (Font font : fonts) {
                if (font.getFamily() != null) {
                    for (Expression family : font.getFamily()) {
                        family.accept(this, null);
                    }
                }
                if (font.getSize() != null) {
                    font.getSize().accept(this, null);
                }
                if (font.getStyle() != null) {
                    font.getStyle().accept(this, null);
                }
                if (font.getWeight() != null) {
                    font.getWeight().accept(this, null);
                }
            }
        }

        if (text.getHalo() != null) {
            text.getHalo().accept(this);
        }

        if (text.getLabelPlacement() != null) {
            text.getLabelPlacement().accept(this);
        }

    }

}