8283387: [macos] a11y : Screen magnifier does not show selected Tab

Reviewed-by: prr, aivanov

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

@@ -55,6 +55,7 @@ import javax.accessibility.AccessibleRole;
 import javax.accessibility.AccessibleSelection;
 import javax.accessibility.AccessibleState;
 import javax.accessibility.AccessibleStateSet;
+import javax.accessibility.AccessibleValue;
 import javax.swing.event.ChangeEvent;
 import javax.swing.event.ChangeListener;
 import javax.swing.plaf.TabbedPaneUI;
@@ -2074,7 +2075,7 @@ public class JTabbedPane extends JComponent
     }
 
     private class Page extends AccessibleContext
-        implements Serializable, Accessible, AccessibleComponent {
+        implements Serializable, Accessible, AccessibleComponent, AccessibleValue {
         String title;
         Color background;
         Color foreground;
@@ -2168,7 +2169,6 @@ public class JTabbedPane extends JComponent
             return this;
         }
 
-
         // AccessibleContext methods
 
         public String getAccessibleName() {
@@ -2202,6 +2202,43 @@ public class JTabbedPane extends JComponent
             return states;
         }
 
+        @Override
+        public AccessibleValue getAccessibleValue() {
+            return this;
+        }
+
+        @Override
+        public Number getCurrentAccessibleValue() {
+            return (getPageIndex() == parent.getSelectedIndex() ?
+                    Integer.valueOf(1) : Integer.valueOf(0));
+        }
+
+        @Override
+        public boolean setCurrentAccessibleValue(Number n) {
+            if (getPageIndex() != parent.getSelectedIndex()) {
+                if (n.intValue() != 0) {
+                    // Set current page selected
+                    parent.setSelectedIndex(getPageIndex());
+                }
+            } else {
+                if (n.intValue() == 0) {
+                    // Can not "deselect" because what page should i select instead?
+                    return false;
+                }
+            }
+            return true;
+        }
+
+        @Override
+        public Number getMinimumAccessibleValue() {
+            return Integer.valueOf(0);
+        }
+
+        @Override
+        public Number getMaximumAccessibleValue() {
+            return Integer.valueOf(1);
+        }
+
         public int getAccessibleIndexInParent() {
             return getPageIndex();
         }
@@ -2360,7 +2397,7 @@ public class JTabbedPane extends JComponent
          * one exists and the page is disabled.  Otherwise, null
          * is returned.
          */
-        public AccessibleIcon [] getAccessibleIcon() {
+        public AccessibleIcon[] getAccessibleIcon() {
             AccessibleIcon accessibleIcon = null;
             if (enabled && icon instanceof ImageIcon) {
                 AccessibleContext ac =

test/jdk/javax/accessibility/JTabbedPane/AccessibleTabbedPaneTest.java

@@ -0,0 +1,72 @@
+/*
+ * 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.
+ */
+
+import javax.accessibility.AccessibleValue;
+import javax.swing.JPanel;
+import javax.swing.JTabbedPane;
+
+/**
+ * @test
+ * @bug 8283387
+ * @summary [macos] a11y : Screen magnifier does not show selected Tab
+ *          JTabbedPane accessible children had no AccessibleValue manipulation API
+ *          Testing this API since it was added in the fix for 8283387
+ * @run main AccessibleTabbedPaneTest
+ */
+
+public class AccessibleTabbedPaneTest {
+    public static void main(String[] args) {
+        JTabbedPane pane = new JTabbedPane();
+        JPanel p1, p2, p3;
+        p1 = new JPanel();
+        p2 = new JPanel();
+        p3 = new JPanel();
+        pane.add("One", p1);
+        pane.add("Two", p2);
+        pane.add("Three", p3);
+        for (int i = 0; i < pane.getAccessibleContext().getAccessibleChildrenCount(); i++) {
+            if (pane.getAccessibleContext()
+                    .getAccessibleChild(i)
+                    .getAccessibleContext()
+                    .getAccessibleValue() == null) {
+                throw new RuntimeException("Test failed, accessible value for tab "+ i + " is null");
+            }
+        }
+        AccessibleValue p2a = pane.getAccessibleContext()
+                                  .getAccessibleChild(1)
+                                  .getAccessibleContext()
+                                  .getAccessibleValue();
+        // Select second tab using a11y API.
+        if (p2a.setCurrentAccessibleValue(1)) {
+            if (pane.getSelectedIndex() != 1) {
+                throw new RuntimeException("Can not change tab selection using a11y API");
+            }
+        }
+
+        // Try to deselect it - that should not be allowed
+        if (p2a.setCurrentAccessibleValue(0)) {
+            throw new RuntimeException("We should not be able to deselect "
+                    + "currently selected tab via a11y API");
+        }
+    }
+}