/*
 * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

import java.awt.Color;
import java.awt.FlowLayout;
import java.awt.Font;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.HeadlessException;
import java.awt.Image;
import java.awt.Insets;
import java.awt.Panel;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.geom.AffineTransform;
import java.awt.image.AbstractMultiResolutionImage;
import java.awt.image.BufferedImage;
import java.awt.image.ImageObserver;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextArea;
import javax.swing.SwingUtilities;

/* @test
 * @bug 8147440 8147016
 * @summary HiDPI (Windows): Swing components have incorrect sizes after
 *          changing display resolution
 * @author Alexander Scherbatiy
 * @run main/manual/othervm WindowResizingOnDPIChangingTest
 */
public class WindowResizingOnDPIChangingTest {

    private static volatile boolean testResult = false;
    private static volatile CountDownLatch countDownLatch;
    private static TestFrame undecoratedFrame;
    private static TestFrame decoratedFrame;
    private static JFrame mainFrame;

    private static final String INSTRUCTIONS = "INSTRUCTIONS:\n"
            + "Verify that window is properly resized after the display DPI updating.\n"
            + "\n"
            + "The test is applicable for OSes that allows to change the display DPI\n"
            + "without the system rebooting (like Windows 8.1 and higher). Press PASS for other\n"
            + "systems. \n"
            + "\n"
            + "1. Set the display DPI size to 192 (DPI scale factor 200%)\n"
            + "2. Press Show Frames button\n"
            + "Two frames decorated and undecorated appear.\n"
            + "3. Check that the string \"scale 2x\" is painted on the windows.\n"
            + "4. Set the display DPI size to 96 (DPI scale factor 100%)\n"
            + "5. Check that the string \"scale: 1x\" is painted on the windows.\n"
            + "6. Check that the windows are properly resized in the same way as native applications\n"
            + "7. Check that the windows are properly repainted and do not contain drawing artifacts\n"
            + "If so, press PASS, else press FAIL.\n";

    public static void main(String args[]) throws Exception {

        countDownLatch = new CountDownLatch(1);
        SwingUtilities.invokeLater(WindowResizingOnDPIChangingTest::createUI);
        countDownLatch.await(15, TimeUnit.MINUTES);
        if (!testResult) {
            throw new RuntimeException("Test fails!");
        }
    }

    private static void createUI() {

        mainFrame = new JFrame("DPI change test");
        GridBagLayout layout = new GridBagLayout();
        JPanel mainControlPanel = new JPanel(layout);
        JPanel resultButtonPanel = new JPanel(layout);

        GridBagConstraints gbc = new GridBagConstraints();

        JPanel testPanel = new JPanel(new FlowLayout());
        JButton frameButton = new JButton("Show Frames");
        frameButton.addActionListener((e) -> {
            int x = 20;
            int y = 10;
            int w = 400;
            int h = 300;

            undecoratedFrame = new TestFrame(w, h, true);
            undecoratedFrame.setLocation(x, y);
            undecoratedFrame.setVisible(true);

            decoratedFrame = new TestFrame(w, h, false);
            decoratedFrame.setLocation(x + w + 10, y);
            decoratedFrame.setVisible(true);

        });
        testPanel.add(frameButton);

        gbc.gridx = 0;
        gbc.gridy = 0;
        gbc.fill = GridBagConstraints.HORIZONTAL;
        mainControlPanel.add(testPanel, gbc);

        JTextArea instructionTextArea = new JTextArea();
        instructionTextArea.setText(INSTRUCTIONS);
        instructionTextArea.setEditable(false);
        instructionTextArea.setBackground(Color.white);

        gbc.gridx = 0;
        gbc.gridy = 1;
        gbc.fill = GridBagConstraints.HORIZONTAL;
        mainControlPanel.add(instructionTextArea, gbc);

        JButton passButton = new JButton("Pass");
        passButton.setActionCommand("Pass");
        passButton.addActionListener((ActionEvent e) -> {
            testResult = true;
            disposeFrames();
            countDownLatch.countDown();

        });

        JButton failButton = new JButton("Fail");
        failButton.setActionCommand("Fail");
        failButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                disposeFrames();
                countDownLatch.countDown();
            }
        });

        gbc.gridx = 0;
        gbc.gridy = 0;
        resultButtonPanel.add(passButton, gbc);

        gbc.gridx = 1;
        gbc.gridy = 0;
        resultButtonPanel.add(failButton, gbc);

        gbc.gridx = 0;
        gbc.gridy = 2;
        mainControlPanel.add(resultButtonPanel, gbc);

        mainFrame.add(mainControlPanel);
        mainFrame.pack();

        mainFrame.addWindowListener(new WindowAdapter() {

            @Override
            public void windowClosing(WindowEvent e) {
                disposeFrames();
                countDownLatch.countDown();
            }
        });
        mainFrame.setVisible(true);
    }

    private static void disposeFrames() {
        if (decoratedFrame != null && decoratedFrame.isVisible()) {
            decoratedFrame.dispose();
        }
        if (undecoratedFrame != null && undecoratedFrame.isVisible()) {
            undecoratedFrame.dispose();
        }
        if (mainFrame != null && mainFrame.isVisible()) {
            mainFrame.dispose();
        }
    }

    static class TestFrame extends Frame {

        private final TestMultiResolutionImage mrImage;

        public TestFrame(int width, int height, boolean undecorated) throws HeadlessException {
            super("Test Frame. Undecorated: " + undecorated);
            setSize(width, height);
            mrImage = new TestMultiResolutionImage(width, height);

            setUndecorated(undecorated);
            Panel panel = new Panel(new FlowLayout()) {
                @Override
                public void paint(Graphics g) {
                    super.paint(g);
                    AffineTransform tx = ((Graphics2D) g).getTransform();
                    mrImage.scaleX = tx.getScaleX();
                    mrImage.scaleY = tx.getScaleY();
                    Insets insets = getInsets();
                    g.drawImage(mrImage, insets.left, insets.bottom, null);
                }
            };
            add(panel);
        }
    }

    static class TestMultiResolutionImage extends AbstractMultiResolutionImage {

        final int width;
        final int height;
        double scaleX;
        double scaleY;

        public TestMultiResolutionImage(int width, int height) {
            this.width = width;
            this.height = height;
        }

        @Override
        public int getWidth(ImageObserver observer) {
            return width;
        }

        @Override
        public int getHeight(ImageObserver observer) {
            return height;
        }

        @Override
        protected Image getBaseImage() {
            return getResolutionVariant(width, height);
        }

        @Override
        public Image getResolutionVariant(double destImageWidth, double destImageHeight) {

            int w = (int) destImageWidth;
            int h = (int) destImageHeight;

            BufferedImage img = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
            Graphics2D g = img.createGraphics();
            g.scale(scaleX, scaleY);
            int red = (int) (255 / scaleX);
            int green = (int) (250 / scaleX);
            int blue = (int) (20 / scaleX);
            g.setColor(new Color(red, green, blue));
            g.fillRect(0, 0, width, height);

            g.setColor(Color.decode("#87CEFA"));
            Font f = g.getFont();
            g.setFont(new Font(f.getName(), Font.BOLD, 24));
            g.drawString(String.format("scales: [%1.2fx, %1.2fx]", scaleX, scaleY),
                    width / 6, height / 2);

            g.dispose();
            return img;
        }

        @Override
        public List<Image> getResolutionVariants() {
            return Collections.unmodifiableList(Arrays.asList(getBaseImage()));
        }
    }
}