6972078: Can not select single directory with GTKLookAndFeel

src/java.desktop/share/classes/com/sun/java/swing/plaf/gtk/GTKFileChooserUI.java

@@ -488,7 +488,7 @@ public void valueChanged(ListSelectionEvent e) {
                         if (objects.length == 1
                             && ((File)objects[0]).isDirectory()
                             && chooser.isTraversable(((File)objects[0]))
-                            && (chooser.getFileSelectionMode() != JFileChooser.DIRECTORIES_ONLY
+                            && (chooser.getFileSelectionMode() == JFileChooser.FILES_ONLY
                                 || !chooser.getFileSystemView().isFileSystem(((File)objects[0])))) {
                             setDirectorySelected(true);
                             setDirectory(((File)objects[0]));

test/jdk/com/sun/java/swing/plaf/gtk/TestFileChooserSingleDirectorySelection.java

@@ -0,0 +1,218 @@
+/*
+ * Copyright (c) 2022, 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.
+ */
+
+/*
+ * @test
+ * @bug 6972078
+ * @key headful
+ * @requires (os.family == "linux")
+ * @summary Verifies if user is able to select single directory if multi selection
+ * is enabled for JFileChooser.
+ * @run main TestFileChooserSingleDirectorySelection
+ */
+
+import java.io.File;
+import java.awt.BorderLayout;
+import java.awt.event.ActionEvent;
+import java.awt.event.ActionListener;
+import java.awt.event.InputEvent;
+import java.awt.Point;
+import java.awt.Robot;
+import javax.swing.JButton;
+import javax.swing.JFileChooser;
+import javax.swing.JFrame;
+import javax.swing.SwingUtilities;
+import javax.swing.UIManager;
+import javax.swing.UnsupportedLookAndFeelException;
+
+public class TestFileChooserSingleDirectorySelection {
+    private static JFrame frame;
+    private static JFileChooser fileChooser;
+    private static JButton getSelectedFilesButton;
+    private static Robot robot;
+    private static boolean passed;
+    private static File[] testDir;
+    private static File[] tempFile;
+
+    public static void main(String[] args) throws Exception {
+        System.setProperty("sun.java2d.uiScale", "1.0");
+        robot = new Robot();
+        robot.setAutoDelay(100);
+
+        try {
+            // create test directory
+            String tmpDir = System.getProperty("user.home");
+            testDir = new File[1];
+            testDir[0] = new File(tmpDir, "testDir");
+            if (!testDir[0].exists())
+                testDir[0].mkdir();
+            testDir[0].deleteOnExit();
+
+            // create temporary files inside testDir
+            tempFile = new File[5];
+            for (int i = 0; i < 5; ++i) {
+                tempFile[i] = File.createTempFile("temp", ".txt",
+                        new File(testDir[0].getAbsolutePath()));
+                tempFile[i].deleteOnExit();
+            }
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+        for (UIManager.LookAndFeelInfo laf :
+                        UIManager.getInstalledLookAndFeels()) {
+            System.out.println("Testing LAF: " + laf.getClassName());
+            SwingUtilities.invokeAndWait(() -> setLookAndFeel(laf));
+            checkFileOnlyTest(laf);
+            checkDirectoriesOnlyTest(laf);
+            checkFilesAndDirectoriesTest(laf);
+            System.out.println("Passed");
+        }
+    }
+
+    private static void checkFileOnlyTest(UIManager.LookAndFeelInfo laf)
+            throws Exception {
+        System.out.println("Testing File Only mode");
+        try {
+            SwingUtilities.invokeAndWait(() -> {
+                createAndShowUI();
+                fileChooser.setCurrentDirectory(testDir[0]);
+            });
+
+            robot.waitForIdle();
+            robot.delay(1000);
+            fileChooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
+            doTesting(laf, 230);
+        } finally {
+            SwingUtilities.invokeAndWait(() -> {
+                if (frame != null) {
+                    frame.dispose();
+                }
+            });
+        }
+    }
+
+    private static void checkDirectoriesOnlyTest(UIManager.LookAndFeelInfo laf)
+            throws Exception {
+        System.out.println("Testing Directories Only mode");
+        try {
+            SwingUtilities.invokeAndWait(() -> {
+                createAndShowUI();
+            });
+            robot.waitForIdle();
+            robot.delay(1000);
+            fileChooser.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
+            doTesting(laf, 50);
+        } finally {
+            SwingUtilities.invokeAndWait(() -> {
+                if (frame != null) {
+                    frame.dispose();
+                }
+            });
+        }
+    }
+
+    private static void checkFilesAndDirectoriesTest(UIManager.LookAndFeelInfo laf)
+            throws Exception {
+        System.out.println("Testing Files and Directories mode");
+        try {
+            SwingUtilities.invokeAndWait(() -> {
+                createAndShowUI();
+            });
+            robot.waitForIdle();
+            robot.delay(1000);
+            fileChooser.setFileSelectionMode(JFileChooser.FILES_AND_DIRECTORIES);
+            doTesting(laf, 50);
+        } finally {
+            SwingUtilities.invokeAndWait(() -> {
+                if (frame != null) {
+                    frame.dispose();
+                }
+            });
+        }
+    }
+
+    private static void createAndShowUI() {
+        frame = new JFrame("Test File Chooser Single Directory Selection");
+        frame.getContentPane().setLayout(new BorderLayout());
+        fileChooser = new JFileChooser("user.home");
+        fileChooser.setMultiSelectionEnabled(true);
+        fileChooser.setControlButtonsAreShown(false);
+
+        getSelectedFilesButton = new JButton();
+        getSelectedFilesButton.setText("Print selected Files");
+        getSelectedFilesButton.addActionListener(new ActionListener() {
+            public void actionPerformed(ActionEvent evt) {
+                passed = false;
+                File files[] = fileChooser.getSelectedFiles();
+                if (files.length != 0) {
+                    passed = true;
+                }
+            }
+        });
+
+        frame.getContentPane().add(fileChooser, BorderLayout.CENTER);
+        frame.getContentPane().add(getSelectedFilesButton, BorderLayout.SOUTH);
+        frame.pack();
+        frame.setLocationRelativeTo(null);
+        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+        frame.setVisible(true);
+    }
+
+    private static void setLookAndFeel(UIManager.LookAndFeelInfo laf) {
+        try {
+            UIManager.setLookAndFeel(laf.getClassName());
+        } catch (UnsupportedLookAndFeelException ignored) {
+            System.out.println("Unsupported LAF: " + laf.getClassName());
+        } catch (ClassNotFoundException | InstantiationException
+                 | IllegalAccessException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    private static void doTesting(UIManager.LookAndFeelInfo laf, int xOffset) {
+        Point frameLocation = fileChooser.getLocationOnScreen();
+        int frameWidth = frame.getWidth();
+        int frameHeight = frame.getHeight();
+
+        Point btnLocation = getSelectedFilesButton.getLocationOnScreen();
+        int btnWidth = getSelectedFilesButton.getWidth();
+        int btnHeight = getSelectedFilesButton.getHeight();
+        clickMouse(frameLocation, 0, frameHeight, xOffset);
+        clickMouse(btnLocation, btnWidth, btnHeight, 0);
+        checkResult(laf);
+    }
+
+    private static void clickMouse(Point point, int width, int height,
+                                   int xOffset) {
+        robot.mouseMove(point.x + width/2 + xOffset , point.y + height/3);
+        robot.mousePress(InputEvent.BUTTON1_DOWN_MASK);
+        robot.mouseRelease(InputEvent.BUTTON1_DOWN_MASK);
+        robot.delay(100);
+    }
+
+    private static void checkResult(UIManager.LookAndFeelInfo laf) {
+        if (!passed)
+            throw new RuntimeException("getSelectedFiles returned " +
+                    "empty array for LAF: "+laf.getClassName());
+    }
+}