8241840: Memoryleak: Closed focused Stages are not collected with Monocle.

modules/javafx.graphics/src/main/java/com/sun/glass/ui/Window.java

@@ -351,6 +351,9 @@ public void close() {
         if (this.ptr != 0L) {
             _close(this.ptr);
         }
+        if(Window.focusedWindow == this) {
+            Window.focusedWindow = null;
+        }
     }
 
     private boolean isChild() {
@@ -1322,7 +1325,7 @@ protected void notifyFocus(int event) {
 
         if (this.isFocused != focused) {
             this.isFocused = focused;
-            if (this.isFocused) {
+            if (this.isFocused && this.isVisible) {
                 setFocusedWindow(this);
             } else {
                 setFocusedWindow(null);

modules/javafx.graphics/src/main/java/com/sun/glass/ui/monocle/MonocleWindowManager.java

@@ -121,7 +121,7 @@ boolean maximizeWindow(MonocleWindow window) {
 
     boolean requestFocus(MonocleWindow window) {
         int index = getWindowIndex(window);
-        if (index != -1) {
+        if (index != -1 && window.isVisible()) {
             focusedWindow = window;
             window.notifyFocus(WindowEvent.FOCUS_GAINED);
             return true;

tests/system/src/test/java/test/javafx/stage/FocusedWindowTest.java

@@ -0,0 +1,142 @@
+/*
+ * Copyright (c) 2020, 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.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * 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.
+ */
+
+package test.javafx.stage;
+
+import javafx.application.Application;
+import javafx.application.Platform;
+import javafx.scene.Node;
+import javafx.scene.Scene;
+import javafx.scene.control.TextField;
+import javafx.stage.Stage;
+import javafx.stage.WindowEvent;
+
+import java.lang.ref.WeakReference;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+
+import junit.framework.Assert;
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+public class FocusedWindowTest {
+
+    static CountDownLatch startupLatch;
+    static Stage stage = null;
+
+    static {
+        System.setProperty("glass.platform","Monocle");
+        System.setProperty("monocle.platform","Headless");
+    }
+
+    public static class TestApp extends Application {
+
+        @Override
+        public void start(Stage primaryStage) throws Exception {
+            primaryStage.setTitle("Primary Stage");
+            primaryStage.setScene(new Scene(new TextField()));
+
+            primaryStage.setOnShown(l -> {
+                Platform.runLater(() -> startupLatch.countDown());
+            });
+            primaryStage.show();
+            Platform.setImplicitExit(false);
+            stage = primaryStage;
+        }
+    }
+
+    @BeforeClass
+    public static void initFX() throws Exception {
+        startupLatch = new CountDownLatch(1);
+        new Thread(() -> Application.launch(TestApp.class, (String[]) null)).start();
+        Assert.assertTrue("Timeout waiting for FX runtime to start", startupLatch.await(15, TimeUnit.SECONDS));
+        Platform.runLater(() -> stage.close());
+    }
+
+    @Test
+    public void testLeak() throws Exception {
+        int counter = 0;
+        while(counter <= 100) {
+            counter += 1;
+            testLeakOnce();
+        }
+    }
+
+    static WeakReference<Stage> closedFocusedStageWeak = null;
+
+    public void testLeakOnce() throws Exception {
+        CountDownLatch leakLatch = new CountDownLatch(1);
+        closedFocusedStageWeak = null;
+        Platform.runLater(() -> {
+            Stage closedFocusedStage = new Stage();
+            closedFocusedStage.setTitle("Focused Stage");
+            closedFocusedStageWeak = new WeakReference<>(closedFocusedStage);
+            TextField textField = new TextField();
+            closedFocusedStage.setScene(new Scene(textField));
+            Platform.runLater(() -> {
+                closedFocusedStage.show();
+                Platform.runLater(() -> {
+                    closedFocusedStage.close();
+                    Platform.runLater(() -> {
+                        closedFocusedStage.requestFocus();
+                        //textField.requestFocus();
+                        Platform.runLater(() -> {
+                            leakLatch.countDown();
+                        });
+                    });
+                });
+            });
+        });
+
+        Assert.assertTrue("Timeout, waiting for runLater. ", leakLatch.await(15, TimeUnit.SECONDS));
+
+        assertCollectable(closedFocusedStageWeak);
+
+    }
+
+    public static void assertCollectable(WeakReference weakReference) throws Exception {
+        int counter = 0;
+
+        System.gc();
+        System.runFinalization();
+
+        while (counter < 10 && weakReference.get() != null) {
+            Thread.sleep(100);
+            counter = counter + 1;
+            System.gc();
+            System.runFinalization();
+        }
+
+        Assert.assertNull(weakReference.get());
+    }
+
+    @AfterClass
+    public static void teardownOnce() {
+        Platform.runLater(() -> {
+            Platform.exit();
+        });
+    }
+}