package de.intevation.flys.jfree;

import java.awt.Shape;
import java.awt.geom.Rectangle2D;

import java.util.Iterator;

import org.jfree.chart.entity.ChartEntity;
import org.jfree.chart.entity.EntityCollection;

public class JFreeUtil {

    /** Do not instantiate. */
    private JFreeUtil() {
    }


    /**
     * True if \param hotspot collides with a Entity in \param entities.
     * @param hotspot Shape to compare against other shapes (bounds only).
     * @param entities entities against which to compare shape.
     * @param exclusiveEntityClass If not null, consider only entities of
     *        given class.
     * @return true if a collision (non-zero intersection) exists between
     *        shapes.
     */
    public static boolean collides(Shape hotspot, EntityCollection entities,
        Class exclusiveEntityClass) {
        if (entities == null) return false;

        Rectangle2D hotspotBox = hotspot.getBounds2D();

        for (Iterator i = entities.iterator(); i.hasNext(); ) {
            Object next = i.next();
            ChartEntity entity = (ChartEntity) next;
            if (exclusiveEntityClass == null
                || exclusiveEntityClass.isInstance(entity))
                {
                if (entity.getArea().intersects(hotspotBox)) {
                    // Found collision, early stop.
                    return true;
                }
            }
        }

        return false;
    }
}
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