JBR-2639 [win] jcef does not recognize vertical mouse wheel events

added regression test

(cherry picked from commit e8e4741bb0)

test/jdk/jb/java/jcef/MouseWheelEventTest.java

@@ -0,0 +1,90 @@
+// Copyright 2000-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+
+import javax.swing.*;
+import java.awt.*;
+import java.awt.event.MouseAdapter;
+import java.awt.event.MouseWheelEvent;
+import java.awt.event.WindowAdapter;
+import java.awt.event.WindowEvent;
+import java.lang.reflect.InvocationTargetException;
+
+/**
+ * @test
+ * @key headful
+ * @summary Regression test for JBR-2639. The test checks that mouse wheel action is handled on jcef browser.
+ * @run main/othervm MouseWheelEventTest
+ */
+
+public class MouseWheelEventTest {
+
+    public static void main(String[] args) throws InvocationTargetException, InterruptedException {
+        final int width = 400;
+        final int height = 400;
+        CefBrowserFrame browserFrame = new CefBrowserFrame(width, height);
+
+        try {
+            Robot r = new Robot();
+            SwingUtilities.invokeAndWait(browserFrame::initUI);
+            r.waitForIdle();
+
+            r.mouseMove(browserFrame.getLocationOnScreen().x + width/2,
+                    browserFrame.getLocationOnScreen().y + height/2);
+            r.delay(100);
+            r.mouseWheel(1);
+            r.delay(100);
+
+            if (browserFrame.isMouseWheelMoved()) {
+                System.out.println("Test PASSED");
+            } else {
+                throw new RuntimeException("Test FAILED. Mouse wheel action was not handled.");
+            }
+        } catch (AWTException e) {
+            e.printStackTrace();
+        } finally {
+            browserFrame.getBrowser().dispose();
+            JBCefApp.getInstance().getCefApp().dispose();
+            SwingUtilities.invokeAndWait(browserFrame::dispose);
+        }
+    }
+}
+
+
+class CefBrowserFrame extends JFrame {
+
+    private volatile boolean mouseWheelMoved = false;
+    private final JBCefBrowser browser = new JBCefBrowser();
+    private int width, height;
+
+    public CefBrowserFrame(int width, int height) {
+        this.width = width;
+        this.height = height;
+    }
+
+    public void initUI() {
+        browser.getComponent().addMouseWheelListener(new MouseAdapter() {
+            @Override
+            public void mouseWheelMoved(MouseWheelEvent e) {
+                mouseWheelMoved = true;
+                System.out.println("mouseWheelMoved");
+            }
+        });
+        getContentPane().add(browser.getCefBrowser().getUIComponent());
+        setSize(width, height);
+        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
+        addWindowListener(new WindowAdapter() {
+            @Override
+            public void windowClosed(WindowEvent e) {
+                browser.dispose();
+            }
+        });
+        setVisible(true);
+    }
+
+    public JBCefBrowser getBrowser() {
+        return browser;
+    }
+
+    public boolean isMouseWheelMoved() {
+        return mouseWheelMoved;
+    }
+}