/*
 *    Geotoolkit - An Open Source Java GIS Toolkit
 *    http://www.geotoolkit.org
 *
 *    (C) 2008 - 2009, Geomatys
 *
 *    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.geotoolkit.display2d.style;


import org.geotoolkit.display2d.canvas.RenderingContext2D;
import org.geotoolkit.display2d.style.renderer.SymbolizerRendererService;
import org.opengis.style.Symbolizer;

/**
 * This is a general interface for cached symbolizers.<br>
 * - CachedLineSymbolizer<br>
 * - CachedPointSymbolizer<br>
 * - CachedPolygonSymbolizer<br>
 * - CachedRasterSymbolizer<br>
 * - CachedTextSymbolizer<br>
 * This interface provide commun methods.
 * 
 * @author Johann Sorel (Geomatys)
 * @module
 */
public abstract class CachedSymbolizer<T extends Symbolizer> extends Cache<T>{

    private final SymbolizerRendererService<T,? extends CachedSymbolizer<T>> renderer;

    public CachedSymbolizer(final T styleElement, final SymbolizerRendererService<T,? extends CachedSymbolizer<T>> renderer){
        super(styleElement);
        this.renderer =  renderer;
    }

    /**
     * @return the renderer that created this cache, also the renderer which can render it.
     */
    public SymbolizerRendererService<T,? extends CachedSymbolizer<T>> getRenderer(){
        return renderer;
    }

    /**
     * Get the maximum size of the symbol for the given feature.
     * This is used to calculate the display boundingbox of a feature.
     *
     * @param candidate : feature to evaluate
     * @param ctx : rendering context
     * @return max width of this symbol with the given feature
     *     can be NaN if and only if the given feature is null.
     */
    public final float getMargin(final Object candidate, final RenderingContext2D ctx){
        return getMargin(candidate, ctx.getUnitCoefficient(this.styleElement.getUnitOfMeasure()));
    }

    /**
     * Get the maximum size of the symbol for the given feature.
     * This is used to calculate the display boundingbox of a feature.
     * 
     * @param candidate : feature to evaluate
     * @param coeff : use to adjust symbolizer size, if in display unit value equals 1
     * @return max width of this symbol with the given feature
     *     can be NaN if and only if the given feature is null.
     */
    public abstract float getMargin(Object candidate, float coeff);
    
}