Adding system test using Group and Shape

tests/system/src/test/java/test/javafx/scene/shape/ShapeViewOrderLeakTest.java

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+/*
+ * 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.scene.shape;
+
+import javafx.application.Application;
+import javafx.application.Platform;
+import javafx.scene.Group;
+import javafx.scene.Scene;
+import javafx.scene.layout.StackPane;
+import javafx.scene.shape.Circle;
+import javafx.scene.shape.Rectangle;
+import javafx.scene.shape.Shape;
+import javafx.stage.Stage;
+
+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;
+import test.util.Util;
+
+public class ShapeViewOrderLeakTest extends Application {
+
+    private static CountDownLatch startupLatch;
+    private static StackPane root;
+    private static Stage stage;
+    private static Group group;
+    private static WeakReference<Shape> shapeWeakRef;
+
+    @Override
+    public void start(Stage primaryStage) throws Exception {
+        stage = primaryStage;
+        Shape shape1 = new Rectangle();
+        Shape shape2 = new Circle();
+        shape1.setViewOrder(1);
+        shape2.setViewOrder(0);
+        shapeWeakRef = new WeakReference<>(shape1);
+
+        group = new Group(shape1, shape2);
+        shape1 = null;
+        shape2 = null;
+
+        root = new StackPane(group);
+        Scene scene = new Scene(root);
+        primaryStage.setScene(scene);
+        primaryStage.setOnShown(l -> {
+            startupLatch.countDown();
+        });
+        primaryStage.show();
+    }
+
+    @BeforeClass
+    public static void initFX() {
+        startupLatch = new CountDownLatch(1);
+        new Thread(() -> Application.launch(ShapeViewOrderLeakTest.class, (String[]) null)).start();
+        try {
+            if (!startupLatch.await(15, TimeUnit.SECONDS)) {
+                Assert.fail("Timeout waiting for FX runtime to start");
+            }
+        } catch (InterruptedException ex) {
+            Assert.fail("Unexpected exception: " + ex);
+        }
+    }
+
+    @Test
+    public void testShapeViewOrderLeak() throws Exception {
+        Util.sleep(100);
+        Util.runAndWait(() -> {
+            group.getChildren().clear();
+            root.getChildren().clear();
+        });
+        for (int i = 0; i < 10; i++) {
+            System.gc();
+            System.runFinalization();
+            if (shapeWeakRef.get() == null) {
+                break;
+            }
+            Util.sleep(500);
+        }
+        // Ensure that Shape is GCed.
+        Assert.assertNull("Couldn't collect Shape", shapeWeakRef.get());
+    }
+
+    @AfterClass
+    public static void teardownOnce() {
+        Platform.runLater(() -> {
+            stage.hide();
+            Platform.exit();
+        });
+    }
+}