1 /*
2 * Copyright (c) 1997, 1999, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.awt.geom;
27
28 import java.util.*;
29
30 /**
31 * A utility class to iterate over the path segments of a line segment
32 * through the PathIterator interface.
33 *
34 * @author Jim Graham
35 */
36 class LineIterator implements PathIterator {
37 Line2D line;
38 AffineTransform affine;
39 int index;
40
41 LineIterator(Line2D l, AffineTransform at) {
42 this.line = l;
43 this.affine = at;
44 }
45
46 /**
47 * Return the winding rule for determining the insideness of the
48 * path.
49 * @see #WIND_EVEN_ODD
50 * @see #WIND_NON_ZERO
51 */
52 public int getWindingRule() {
53 return WIND_NON_ZERO;
54 }
55
56 /**
57 * Tests if there are more points to read.
58 * @return true if there are more points to read
59 */
60 public boolean isDone() {
61 return (index > 1);
62 }
63
64 /**
65 * Moves the iterator to the next segment of the path forwards
66 * along the primary direction of traversal as long as there are
67 * more points in that direction.
68 */
69 public void next() {
70 index++;
71 }
72
73 /**
74 * Returns the coordinates and type of the current path segment in
75 * the iteration.
76 * The return value is the path segment type:
77 * SEG_MOVETO, SEG_LINETO, SEG_QUADTO, SEG_CUBICTO, or SEG_CLOSE.
78 * A float array of length 6 must be passed in and may be used to
79 * store the coordinates of the point(s).
80 * Each point is stored as a pair of float x,y coordinates.
81 * SEG_MOVETO and SEG_LINETO types will return one point,
82 * SEG_QUADTO will return two points,
83 * SEG_CUBICTO will return 3 points
84 * and SEG_CLOSE will not return any points.
85 * @see #SEG_MOVETO
86 * @see #SEG_LINETO
87 * @see #SEG_QUADTO
88 * @see #SEG_CUBICTO
89 * @see #SEG_CLOSE
90 */
91 public int currentSegment(float[] coords) {
92 if (isDone()) {
93 throw new NoSuchElementException("line iterator out of bounds");
94 }
95 int type;
96 if (index == 0) {
97 coords[0] = (float) line.getX1();
98 coords[1] = (float) line.getY1();
99 type = SEG_MOVETO;
100 } else {
101 coords[0] = (float) line.getX2();
102 coords[1] = (float) line.getY2();
103 type = SEG_LINETO;
104 }
105 if (affine != null) {
106 affine.transform(coords, 0, coords, 0, 1);
107 }
108 return type;
109 }
110
111 /**
112 * Returns the coordinates and type of the current path segment in
113 * the iteration.
114 * The return value is the path segment type:
115 * SEG_MOVETO, SEG_LINETO, SEG_QUADTO, SEG_CUBICTO, or SEG_CLOSE.
116 * A double array of length 6 must be passed in and may be used to
117 * store the coordinates of the point(s).
118 * Each point is stored as a pair of double x,y coordinates.
119 * SEG_MOVETO and SEG_LINETO types will return one point,
120 * SEG_QUADTO will return two points,
121 * SEG_CUBICTO will return 3 points
122 * and SEG_CLOSE will not return any points.
123 * @see #SEG_MOVETO
124 * @see #SEG_LINETO
125 * @see #SEG_QUADTO
126 * @see #SEG_CUBICTO
127 * @see #SEG_CLOSE
128 */
129 public int currentSegment(double[] coords) {
130 if (isDone()) {
131 throw new NoSuchElementException("line iterator out of bounds");
132 }
133 int type;
134 if (index == 0) {
135 coords[0] = line.getX1();
136 coords[1] = line.getY1();
137 type = SEG_MOVETO;
138 } else {
139 coords[0] = line.getX2();
140 coords[1] = line.getY2();
141 type = SEG_LINETO;
142 }
143 if (affine != null) {
144 affine.transform(coords, 0, coords, 0, 1);
145 }
146 return type;
147 }
148 }
149