1 /*
2  * Copyright (c) 2001, 2019, 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.
8  *
9  * This code is distributed in the hope that it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12  * version 2 for more details (a copy is included in the LICENSE file that
13  * accompanied this code).
14  *
15  * You should have received a copy of the GNU General Public License version
16  * 2 along with this work; if not, write to the Free Software Foundation,
17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20  * or visit www.oracle.com if you need additional information or have any
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22  */
23 
24 import java.awt.BasicStroke;
25 import java.awt.Color;
26 import java.awt.Graphics;
27 import java.awt.Graphics2D;
28 import java.awt.GraphicsConfiguration;
29 import java.awt.GraphicsEnvironment;
30 import java.awt.Image;
31 import java.awt.image.BufferedImage;
32 import java.awt.image.VolatileImage;
33 import java.io.File;
34 import java.io.IOException;
35 import java.util.Arrays;
36 import java.util.stream.Collectors;
37 import javax.imageio.ImageIO;
38 
39 import static java.awt.image.BufferedImage.TYPE_INT_RGB;
40 
41 /*
42  * @test
43  * @bug 4469881 8217263
44  * @summary Verifies that dashed rectangles drawn to the screen line
45  *          up with their undashed counterparts
46  * @author flar
47  * @run main/othervm -Dsun.java2d.uiScale=1 DashOffset
48  */
49 public class DashOffset {
50 
51     private static final BasicStroke dash =
52             new BasicStroke(1.0f, BasicStroke.CAP_BUTT,
53                             BasicStroke.JOIN_MITER, 10.0f,
54                             new float[] {2.0f, 2.0f}, 0.0f);
55 
56     private static final Color COLOR1 = Color.BLUE;
57     private static final Color COLOR2 = Color.GREEN;
58 
59     private static final Color BACKGROUND = Color.WHITE;
60 
61     private static final int WIDTH = 20;
62     private static final int HEIGHT = 20;
63 
64     private static final int OFFSET = 2;
65 
66     private static final int MAX_DASH_LENGTH = 3;
67 
main(String[] argv)68     public static void main(String[] argv) throws Exception {
69         final boolean saveImage = argv.length > 0 && "-save".equals(argv[0]);
70 
71         final BufferedImage img = new BufferedImage(WIDTH, HEIGHT,
72                                                     TYPE_INT_RGB);
73         try {
74             draw(img);
75             validate(img);
76         } finally {
77             if (saveImage) {
78                 save(img, "bufferedImage.png");
79             }
80         }
81 
82         if (GraphicsEnvironment.isHeadless()) {
83             return;
84         }
85 
86         BufferedImage snapshot = null;
87         try {
88             final GraphicsConfiguration gc =
89                     GraphicsEnvironment.getLocalGraphicsEnvironment()
90                                        .getDefaultScreenDevice()
91                                        .getDefaultConfiguration();
92 
93             VolatileImage vi = gc.createCompatibleVolatileImage(WIDTH, HEIGHT);
94             int attempt = 0;
95             do {
96                 vi.validate(gc);
97                 draw(vi);
98                 snapshot = vi.getSnapshot();
99             } while (vi.contentsLost() && ++attempt <= 10);
100             if (attempt > 10) {
101                 throw new RuntimeException("Too many attempts: " + attempt);
102             }
103             validate(snapshot);
104         } finally {
105             if (saveImage) {
106                 save(snapshot, "volatileImage.png");
107             }
108         }
109     }
110 
draw(final Image img)111     private static void draw(final Image img) {
112         Graphics g = img.getGraphics();
113         g.setColor(BACKGROUND);
114         g.fillRect(0, 0, WIDTH, HEIGHT);
115         g.setColor(COLOR1);
116         g.drawRect(OFFSET, OFFSET, WIDTH - OFFSET * 2, HEIGHT - OFFSET * 2);
117         g.setColor(COLOR2);
118         g.clipRect(OFFSET, OFFSET, WIDTH - OFFSET * 2 + 1, HEIGHT - OFFSET * 2 + 1);
119         ((Graphics2D) g).setStroke(dash);
120         g.drawRect(OFFSET, OFFSET, WIDTH - OFFSET * 2, HEIGHT - OFFSET * 2);
121         g.dispose();
122     }
123 
validate(final BufferedImage img)124     private static void validate(final BufferedImage img) {
125         checkHorizontalLine(img, OFFSET);
126         checkHorizontalLine(img, HEIGHT - OFFSET);
127         checkVerticalLine(img, OFFSET);
128         checkVerticalLine(img, WIDTH - OFFSET);
129         checkCorners(img);
130     }
131 
checkHorizontalLine(final BufferedImage img, final int y)132     private static void checkHorizontalLine(final BufferedImage img,
133                                             final int y) {
134         int prev = img.getRGB(OFFSET, y);
135         int curr;
136         int count = 1;
137         checkColor(OFFSET, y, prev, COLOR1, COLOR2);
138         for (int x = OFFSET + 1; x <= WIDTH - OFFSET; x++) {
139             curr = img.getRGB(x, y);
140             if (curr != prev) {
141                 checkColor(x, y, curr, COLOR1, COLOR2);
142                 checkCount(x, y, count);
143                 prev = curr;
144                 count = 1;
145             } else {
146                 count++;
147             }
148             if (x < WIDTH - OFFSET) {
149                 checkColor(x, y - 1, img.getRGB(x, y - 1), BACKGROUND);
150                 checkColor(x, y + 1, img.getRGB(x, y + 1), BACKGROUND);
151             }
152         }
153         checkCount(WIDTH - OFFSET, y, count);
154     }
155 
checkVerticalLine(final BufferedImage img, final int x)156     private static void checkVerticalLine(final BufferedImage img,
157                                           final int x) {
158         int prev = img.getRGB(x, OFFSET);
159         checkColor(x, OFFSET, prev, COLOR1, COLOR2);
160         int count = 1;
161         for (int y = OFFSET + 1; y <= HEIGHT - OFFSET; y++) {
162             int curr = img.getRGB(x, y);
163             if (curr != prev) {
164                 checkColor(x, y, curr, COLOR1, COLOR2);
165                 checkCount(x, y, count);
166                 prev = curr;
167                 count = 1;
168             } else {
169                 count++;
170             }
171             if (y < HEIGHT - OFFSET) {
172                 checkColor(x - 1, y, img.getRGB(x - 1, y), BACKGROUND);
173                 checkColor(x + 1, y, img.getRGB(x + 1, y), BACKGROUND);
174             }
175         }
176         checkCount(x, HEIGHT - OFFSET, count);
177     }
178 
checkCorners(final BufferedImage img)179     private static void checkCorners(final BufferedImage img) {
180         int[][] corners = {
181                 {OFFSET - 1, OFFSET - 1},
182                 {OFFSET,     OFFSET - 1},
183                 {OFFSET - 1, OFFSET + 1},
184 
185                 {OFFSET - 1, HEIGHT - OFFSET},
186                 {OFFSET - 1, HEIGHT - OFFSET + 1},
187                 {OFFSET,     HEIGHT - OFFSET + 1},
188 
189                 {WIDTH - OFFSET,     OFFSET - 1},
190                 {WIDTH - OFFSET + 1, OFFSET - 1},
191                 {WIDTH - OFFSET + 1, OFFSET},
192 
193                 {WIDTH - OFFSET + 1, HEIGHT - OFFSET},
194                 {WIDTH - OFFSET + 1, HEIGHT - OFFSET + 1},
195                 {WIDTH - OFFSET,     HEIGHT - OFFSET + 1},
196         };
197 
198         for (int[] corner : corners) {
199             int color = img.getRGB(corner[0], corner[1]);
200             checkColor(corner[0], corner[1], color, BACKGROUND);
201         }
202     }
203 
checkColor(final int x, final int y, final int color, final Color... validColors)204     private static void checkColor(final int x, final int y,
205                                    final int color,
206                                    final Color... validColors) {
207         checkColor(x, y, color, Arrays.stream(validColors)
208                                       .mapToInt(Color::getRGB)
209                                       .toArray());
210     }
211 
checkColor(final int x, final int y, final int color, final int... validColors)212     private static void checkColor(final int x, final int y,
213                                    final int color,
214                                    final int... validColors) {
215         for (int valid : validColors) {
216             if (color == valid) {
217                 return;
218             }
219         }
220         throw new RuntimeException("Unexpected color at " + x + ", " + y
221                 + ": " + Integer.toHexString(color) + "; expected: "
222                 + Arrays.stream(validColors)
223                         .mapToObj(Integer::toHexString)
224                         .collect(Collectors.joining(", ")));
225     }
226 
checkCount(final int x, final int y, final int count)227     private static void checkCount(final int x, final int y, final int count) {
228         if (count > MAX_DASH_LENGTH) {
229             throw new RuntimeException("Dash is longer than " + MAX_DASH_LENGTH
230                     + " at " + x + ", " + y);
231         }
232     }
233 
save(final BufferedImage img, final String fileName)234     private static void save(final BufferedImage img,
235                              final String fileName) throws IOException {
236         ImageIO.write(img, "png", new File(fileName));
237     }
238 
239 }
240