rectiterator.java

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/*
 * @(#)RectIterator.java	1.10 03/01/23
 *
 * Copyright 2003 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package java.awt.geom;

import java.util.*;

/**
 * A utility class to iterate over the path segments of a rectangle
 * through the PathIterator interface.
 *
 * @version 10 Feb 1997
 * @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);
    }
}