001 /*
002 * Copyright 1997-1999 Sun Microsystems, Inc. All Rights Reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation. Sun designates this
008 * particular file as subject to the "Classpath" exception as provided
009 * by Sun in the LICENSE file that accompanied this code.
010 *
011 * This code is distributed in the hope that it will be useful, but WITHOUT
012 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
014 * version 2 for more details (a copy is included in the LICENSE file that
015 * accompanied this code).
016 *
017 * You should have received a copy of the GNU General Public License version
018 * 2 along with this work; if not, write to the Free Software Foundation,
019 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020 *
021 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022 * CA 95054 USA or visit www.sun.com if you need additional information or
023 * have any questions.
024 */
025
026 package java.awt.geom;
027
028 import java.util.*;
029
030 /**
031 * A utility class to iterate over the path segments of a line segment
032 * through the PathIterator interface.
033 *
034 * @version 1.17, 05/05/07
035 * @author Jim Graham
036 */
037 class LineIterator implements PathIterator {
038 Line2D line;
039 AffineTransform affine;
040 int index;
041
042 LineIterator(Line2D l, AffineTransform at) {
043 this .line = l;
044 this .affine = at;
045 }
046
047 /**
048 * Return the winding rule for determining the insideness of the
049 * path.
050 * @see #WIND_EVEN_ODD
051 * @see #WIND_NON_ZERO
052 */
053 public int getWindingRule() {
054 return WIND_NON_ZERO;
055 }
056
057 /**
058 * Tests if there are more points to read.
059 * @return true if there are more points to read
060 */
061 public boolean isDone() {
062 return (index > 1);
063 }
064
065 /**
066 * Moves the iterator to the next segment of the path forwards
067 * along the primary direction of traversal as long as there are
068 * more points in that direction.
069 */
070 public void next() {
071 index++;
072 }
073
074 /**
075 * Returns the coordinates and type of the current path segment in
076 * the iteration.
077 * The return value is the path segment type:
078 * SEG_MOVETO, SEG_LINETO, SEG_QUADTO, SEG_CUBICTO, or SEG_CLOSE.
079 * A float array of length 6 must be passed in and may be used to
080 * store the coordinates of the point(s).
081 * Each point is stored as a pair of float x,y coordinates.
082 * SEG_MOVETO and SEG_LINETO types will return one point,
083 * SEG_QUADTO will return two points,
084 * SEG_CUBICTO will return 3 points
085 * and SEG_CLOSE will not return any points.
086 * @see #SEG_MOVETO
087 * @see #SEG_LINETO
088 * @see #SEG_QUADTO
089 * @see #SEG_CUBICTO
090 * @see #SEG_CLOSE
091 */
092 public int currentSegment(float[] coords) {
093 if (isDone()) {
094 throw new NoSuchElementException(
095 "line iterator out of bounds");
096 }
097 int type;
098 if (index == 0) {
099 coords[0] = (float) line.getX1();
100 coords[1] = (float) line.getY1();
101 type = SEG_MOVETO;
102 } else {
103 coords[0] = (float) line.getX2();
104 coords[1] = (float) line.getY2();
105 type = SEG_LINETO;
106 }
107 if (affine != null) {
108 affine.transform(coords, 0, coords, 0, 1);
109 }
110 return type;
111 }
112
113 /**
114 * Returns the coordinates and type of the current path segment in
115 * the iteration.
116 * The return value is the path segment type:
117 * SEG_MOVETO, SEG_LINETO, SEG_QUADTO, SEG_CUBICTO, or SEG_CLOSE.
118 * A double array of length 6 must be passed in and may be used to
119 * store the coordinates of the point(s).
120 * Each point is stored as a pair of double x,y coordinates.
121 * SEG_MOVETO and SEG_LINETO types will return one point,
122 * SEG_QUADTO will return two points,
123 * SEG_CUBICTO will return 3 points
124 * and SEG_CLOSE will not return any points.
125 * @see #SEG_MOVETO
126 * @see #SEG_LINETO
127 * @see #SEG_QUADTO
128 * @see #SEG_CUBICTO
129 * @see #SEG_CLOSE
130 */
131 public int currentSegment(double[] coords) {
132 if (isDone()) {
133 throw new NoSuchElementException(
134 "line iterator out of bounds");
135 }
136 int type;
137 if (index == 0) {
138 coords[0] = line.getX1();
139 coords[1] = line.getY1();
140 type = SEG_MOVETO;
141 } else {
142 coords[0] = line.getX2();
143 coords[1] = line.getY2();
144 type = SEG_LINETO;
145 }
146 if (affine != null) {
147 affine.transform(coords, 0, coords, 0, 1);
148 }
149 return type;
150 }
151 }
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