jdk/src/share/classes/java/awt/geom/RectIterator.java

/*
 * Copyright 1997 Sun Microsystems, Inc.  All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Sun designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Sun in the LICENSE file that accompanied this code.
 *
 * This code 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 General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 */

package java.awt.geom;

import java.util.*;

/**
 * A utility class to iterate over the path segments of a rectangle
 * through the PathIterator interface.
 *
 * @author      Jim Graham
 */
class RectIterator implements PathIterator {
    double x, y, w, h;
    AffineTransform affine;
    int index;

    RectIterator(Rectangle2D r, AffineTransform at) {
        this.x = r.getX();
        this.y = r.getY();
        this.w = r.getWidth();
        this.h = r.getHeight();
        this.affine = at;
        if (w < 0 || h < 0) {
            index = 6;
        }
    }

    /**
     * Return the winding rule for determining the insideness of the
     * path.
     * @see #WIND_EVEN_ODD
     * @see #WIND_NON_ZERO
     */
    public int getWindingRule() {
        return WIND_NON_ZERO;
    }

    /**
     * Tests if there are more points to read.
     * @return true if there are more points to read
     */
    public boolean isDone() {
        return index > 5;
    }

    /**
     * Moves the iterator to the next segment of the path forwards
     * along the primary direction of traversal as long as there are
     * more points in that direction.
     */
    public void next() {
        index++;
    }

    /**
     * Returns the coordinates and type of the current path segment in
     * the iteration.
     * The return value is the path segment type:
     * SEG_MOVETO, SEG_LINETO, SEG_QUADTO, SEG_CUBICTO, or SEG_CLOSE.
     * A float array of length 6 must be passed in and may be used to
     * store the coordinates of the point(s).
     * Each point is stored as a pair of float x,y coordinates.
     * SEG_MOVETO and SEG_LINETO types will return one point,
     * SEG_QUADTO will return two points,
     * SEG_CUBICTO will return 3 points
     * and SEG_CLOSE will not return any points.
     * @see #SEG_MOVETO
     * @see #SEG_LINETO
     * @see #SEG_QUADTO
     * @see #SEG_CUBICTO
     * @see #SEG_CLOSE
     */
    public int currentSegment(float[] coords) {
        if (isDone()) {
            throw new NoSuchElementException("rect iterator out of bounds");
        }
        if (index == 5) {
            return SEG_CLOSE;
        }
        coords[0] = (float) x;
        coords[1] = (float) y;
        if (index == 1 || index == 2) {
            coords[0] += (float) w;
        }
        if (index == 2 || index == 3) {
            coords[1] += (float) h;
        }
        if (affine != null) {
            affine.transform(coords, 0, coords, 0, 1);
        }
        return (index == 0 ? SEG_MOVETO : SEG_LINETO);
    }

    /**
     * Returns the coordinates and type of the current path segment in
     * the iteration.
     * The return value is the path segment type:
     * SEG_MOVETO, SEG_LINETO, SEG_QUADTO, SEG_CUBICTO, or SEG_CLOSE.
     * A double array of length 6 must be passed in and may be used to
     * store the coordinates of the point(s).
     * Each point is stored as a pair of double x,y coordinates.
     * SEG_MOVETO and SEG_LINETO types will return one point,
     * SEG_QUADTO will return two points,
     * SEG_CUBICTO will return 3 points
     * and SEG_CLOSE will not return any points.
     * @see #SEG_MOVETO
     * @see #SEG_LINETO
     * @see #SEG_QUADTO
     * @see #SEG_CUBICTO
     * @see #SEG_CLOSE
     */
    public int currentSegment(double[] coords) {
        if (isDone()) {
            throw new NoSuchElementException("rect iterator out of bounds");
        }
        if (index == 5) {
            return SEG_CLOSE;
        }
        coords[0] = x;
        coords[1] = y;
        if (index == 1 || index == 2) {
            coords[0] += w;
        }
        if (index == 2 || index == 3) {
            coords[1] += h;
        }
        if (affine != null) {
            affine.transform(coords, 0, coords, 0, 1);
        }
        return (index == 0 ? SEG_MOVETO : SEG_LINETO);
    }
}