1/*
2 * Copyright (c) 2016, 2017, 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.
18 *
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
21 * questions.
22 */
23
24import java.awt.Image;
25import java.awt.Robot;
26import java.awt.Rectangle;
27import java.awt.Color;
28import java.awt.Point;
29import java.awt.Dimension;
30import java.awt.GradientPaint;
31import java.awt.Graphics2D;
32import java.awt.BorderLayout;
33import java.awt.image.BufferedImage;
34import java.awt.image.MultiResolutionImage;
35import java.util.List;
36import javax.swing.JButton;
37import javax.swing.JFrame;
38import javax.swing.JPanel;
39import javax.swing.SwingUtilities;
40import javax.swing.UIManager;
41import javax.swing.plaf.metal.MetalLookAndFeel;
42
43/*
44 * @test
45 * @bug 8163193 8165213
46 * @key headful
47 * @summary Metal L&F gradient is lighter on HiDPI display
48 * @run main/othervm -Dsun.java2d.uiScale=2 ButtonGradientTest
49 */
50public class ButtonGradientTest {
51    private static JFrame frame;
52    private static JButton button;
53    private static List<Image> images;
54    private static Robot robot;
55
56    public static void main(String[] args) throws Exception {
57        try {
58            robot = new Robot();
59            testGradient();
60        } finally {
61            SwingUtilities.invokeAndWait(() -> {
62                if (frame != null) {
63                    frame.dispose();
64                }
65            });
66        }
67    }
68
69    private static void testGradient() throws Exception {
70        // Create and show the GUI
71        SwingUtilities.invokeAndWait(ButtonGradientTest::createAndShowGUI);
72        robot.waitForIdle();
73        robot.delay(500);
74
75        Rectangle rect = getButtonBounds();
76        List<?> gradient = (List) UIManager.get("Button.gradient");
77        float ratio = ((Number) gradient.get(0)).floatValue();
78        Color c1 = (Color) gradient.get(2);
79        Color c2 = (Color) gradient.get(3);
80        int mid = (int) (ratio * rect.height);
81        // Get the expected gradient color
82        Color gradientColor = getGradientColor(rect.width, mid, c1, c2);
83
84        // Get color from robot captured hidpi image of the button
85        getImageFromRobot();
86        int x = rect.x + rect.width / 2;
87        int y = rect.y + mid / 2;
88        Color buttonColor = new Color(((BufferedImage)(images.get(1))).getRGB(
89                (int)(x), (int)(y)));
90
91        if (!similarColors(buttonColor, gradientColor)) {
92            throw new RuntimeException("Button gradient is changed!");
93        }
94    }
95
96    private static void createAndShowGUI() {
97
98        try {
99            UIManager.setLookAndFeel(new MetalLookAndFeel());
100        } catch (Exception e) {
101            throw new RuntimeException(e);
102        }
103
104        frame = new JFrame();
105        frame.setSize(300, 300);
106        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
107
108        JPanel panel = new JPanel(new BorderLayout());
109        button = new JButton("");
110        panel.add(button);
111        frame.getContentPane().add(panel);
112        frame.setVisible(true);
113    }
114
115    private static void getImageFromRobot() {
116        try {
117            Point butLoc = button.getLocationOnScreen();
118            Dimension butSize = button.getSize();
119            MultiResolutionImage multiResolutionImage =
120                    robot.createMultiResolutionScreenCapture(
121                            new Rectangle((int)butLoc.getX(),
122                                    (int)butLoc.getY(), (int)butSize.getWidth(),
123                                    (int)butSize.getHeight()));
124            images = multiResolutionImage.getResolutionVariants();
125        } catch (Exception e) {
126            throw new RuntimeException(e);
127        }
128
129        if(images.size() < 2) {
130            throw new RuntimeException("HiDpi Image not captured - " +
131                    "Check is this HiDpi display system?");
132        }
133    }
134
135    private static Rectangle getButtonBounds() throws Exception {
136        Rectangle[] rectangles = new Rectangle[1];
137        SwingUtilities.invokeAndWait(() -> {
138            rectangles[0] = button.getBounds();
139            rectangles[0].setLocation(button.getLocationOnScreen());
140        });
141        return rectangles[0];
142    }
143
144    private static Color getGradientColor(int w, int h, Color c1, Color c2) {
145        GradientPaint gradient = new GradientPaint(0, 0, c1, 0, h, c2,
146                true);
147        BufferedImage img = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
148        Graphics2D g = img.createGraphics();
149        g.setPaint(gradient);
150        g.fillRect(0, 0, w, h);
151        g.dispose();
152        return new Color(img.getRGB(w / 2, h / 2));
153    }
154
155    private static boolean similarColors(Color c1, Color c2) {
156        return similar(c1.getRed(), c2.getRed())
157                && similar(c1.getGreen(), c2.getGreen())
158                && similar(c1.getBlue(), c2.getBlue());
159    }
160
161    private static boolean similar(int i1, int i2) {
162        return Math.abs(i2 - i1) < 6;
163    }
164}