5021949: JSplitPane setEnabled(false) shouldn't be partially functional

src/java.desktop/share/classes/javax/swing/JSplitPane.java

@@ -41,6 +41,7 @@
 import javax.accessibility.AccessibleStateSet;
 import javax.accessibility.AccessibleValue;
 import javax.swing.plaf.SplitPaneUI;
+import javax.swing.plaf.basic.BasicSplitPaneUI;
 
 /**
  * <code>JSplitPane</code> is used to divide two (and only two)
@@ -362,6 +363,18 @@ public JSplitPane(int newOrientation,
     }
 
 
+    /**
+     * {@inheritDoc}
+     * @param enabled {@inheritDoc}
+     */
+    @Override
+    public void setEnabled(boolean enabled) {
+        super.setEnabled(enabled);
+        if (this.getUI() instanceof BasicSplitPaneUI) {
+            ((BasicSplitPaneUI)(this.getUI())).getDivider().setEnabled(enabled);
+        }
+    }
+
     /**
      * Sets the L&amp;F object that renders this component.
      *

src/java.desktop/share/classes/javax/swing/plaf/basic/BasicSplitPaneDivider.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2024, 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
@@ -360,6 +360,20 @@ else if (e.getPropertyName() == JSplitPane.
         }
     }
 
+    /**
+     * {@inheritDoc}
+     * @param enabled {@inheritDoc}
+     */
+    @Override
+    public void setEnabled(boolean enabled) {
+        if (splitPane.isOneTouchExpandable() &&
+                rightButton != null &&
+                leftButton != null) {
+
+            rightButton.setEnabled(enabled);
+            leftButton.setEnabled(enabled);
+        }
+    }
 
     /**
      * Paints the divider.

test/jdk/javax/swing/JSplitPane/TestSplitPaneEnableTest.java

@@ -0,0 +1,150 @@
+/*
+ * Copyright (c) 2024, 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 5021949
+ * @key headful
+ * @summary  Verifies JSplitPane setEnabled(false) disables one touch expandable clicks
+ * @run main TestSplitPaneEnableTest
+ */
+
+import java.awt.Point;
+import java.awt.Robot;
+import java.awt.event.InputEvent;
+import javax.swing.JButton;
+import javax.swing.JFrame;
+import javax.swing.JSplitPane;
+import javax.swing.plaf.basic.BasicSplitPaneDivider;
+import javax.swing.plaf.basic.BasicSplitPaneUI;
+import javax.swing.SwingUtilities;
+import javax.swing.UIManager;
+import javax.swing.UnsupportedLookAndFeelException;
+
+public class TestSplitPaneEnableTest {
+    private static JButton leftOneTouchButton;
+    private static JButton rightOneTouchButton;
+    private static JFrame frame;
+    private static JSplitPane jsp;
+    private static volatile Point loc;
+    private static volatile int prevDivLoc;
+    private static volatile int curDivLoc;
+
+    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);
+        }
+    }
+
+    public static void main(String[] args) throws Exception {
+        Robot robot = new Robot();
+        for (UIManager.LookAndFeelInfo laf : UIManager.getInstalledLookAndFeels()) {
+            if (laf.getClassName().toLowerCase().contains("gtk")) {
+                continue;
+            }
+            System.out.println("Testing LAF : " + laf.getClassName());
+            SwingUtilities.invokeAndWait(() -> setLookAndFeel(laf));
+
+            try {
+                SwingUtilities.invokeAndWait(() -> {
+                    frame = new JFrame("SplitPaneTest");
+                    jsp = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT,
+                                         new JButton("Left"),
+                                         new JButton("Right"));
+
+                    frame.add(jsp);
+                    jsp.setUI(new TestSplitPaneUI());
+                    jsp.setOneTouchExpandable(true);
+
+                    jsp.setEnabled(false);
+
+                    frame.setSize(400, 200);
+                    frame.setLocationRelativeTo(null);
+                    frame.setVisible(true);
+                });
+
+                robot.waitForIdle();
+                robot.delay(1000);
+
+                SwingUtilities.invokeAndWait(() -> {
+                    loc = leftOneTouchButton.getLocationOnScreen();
+                    prevDivLoc = jsp.getDividerLocation();
+                });
+                robot.mouseMove(loc.x, loc.y);
+                robot.mousePress(InputEvent.BUTTON1_DOWN_MASK);
+                robot.mouseRelease(InputEvent.BUTTON1_DOWN_MASK);
+
+                robot.waitForIdle();
+                robot.delay(1000);
+
+                SwingUtilities.invokeAndWait(() -> {
+                    curDivLoc = jsp.getDividerLocation();
+                });
+                System.out.println("current Divider location " + curDivLoc);
+                if (curDivLoc != prevDivLoc) {
+                    throw new RuntimeException("Divider position changed on disabled oneTouchExpandable arrow click");
+                }
+            } finally {
+                SwingUtilities.invokeAndWait(() -> {
+                    if (frame != null) {
+                        frame.dispose();
+                    }
+                });
+            }
+        }
+    }
+
+    static class TestSplitPaneUI extends BasicSplitPaneUI {
+
+        public TestSplitPaneUI() {
+            super();
+        }
+
+        public BasicSplitPaneDivider createDefaultDivider() {
+            return new TestSplitPaneDivider(this);
+        }
+    }
+
+    static class TestSplitPaneDivider extends BasicSplitPaneDivider {
+
+        public TestSplitPaneDivider(BasicSplitPaneUI ui) {
+            super(ui);
+        }
+
+        protected JButton createLeftOneTouchButton() {
+            leftOneTouchButton = super.createLeftOneTouchButton();
+            return leftOneTouchButton;
+        }
+
+        protected JButton createRightOneTouchButton() {
+            rightOneTouchButton = super.createRightOneTouchButton();
+            return rightOneTouchButton;
+        }
+    }
+}
+