8090647: Mnemonics : on windows we should cancel the underscore latch when an app loses focus.

Reviewed-by: angorya, aghaisas

Author: hjohn

modules/javafx.graphics/src/main/java/javafx/scene/Scene.java

@@ -2123,6 +2123,10 @@ private void setWindowFocused(boolean value) {
         if (windowFocused && accessible != null) {
             accessible.sendNotification(AccessibleAttribute.FOCUS_NODE);
         }
+
+        if (!windowFocused) {
+            getInternalEventDispatcher().getKeyboardShortcutsHandler().setMnemonicsDisplayEnabled(false);
+        }
     }
 
     /**

modules/javafx.graphics/src/test/java/test/javafx/scene/SceneTest.java

@@ -25,7 +25,9 @@
 
 package test.javafx.scene;
 
+import com.sun.javafx.scene.KeyboardShortcutsHandler;
 import com.sun.javafx.scene.NodeHelper;
+import com.sun.javafx.scene.SceneEventDispatcher;
 import com.sun.javafx.scene.SceneHelper;
 import javafx.beans.value.ChangeListener;
 import javafx.beans.value.ObservableValue;
@@ -1065,4 +1067,29 @@ public void testAddNullPostLayoutPulseListener() {
 
         JMemoryBuddy.assertCollectable(ref);
     }
+
+    @Test
+    public void sceneShouldSet_MnemonicsDisplayEnabled_ToFalseWhenWindowFocusIsLost() {
+        Group root = new Group();
+
+        root.setFocusTraversable(true);
+
+        Scene scene = new Scene(root);
+        SceneEventDispatcher dispatcher = (SceneEventDispatcher) scene.getEventDispatcher();
+        KeyboardShortcutsHandler keyboardShortcutsHandler = dispatcher.getKeyboardShortcutsHandler();
+
+        stage.setScene(scene);
+        stage.show();
+        stage.requestFocus();
+
+        assertFalse(keyboardShortcutsHandler.isMnemonicsDisplayEnabled());
+
+        keyboardShortcutsHandler.setMnemonicsDisplayEnabled(true);
+
+        assertTrue(keyboardShortcutsHandler.isMnemonicsDisplayEnabled());
+
+        stage.close();
+
+        assertFalse(keyboardShortcutsHandler.isMnemonicsDisplayEnabled());
+    }
 }