Bug 545403: [GTK3] MouseWheel event only reports GDK.GDK_SCROLL_UP

gdk_event_get_scroll_direction() will return false if GDK_SMOOTH is
enabled. The fix is to check if this function returns false, and then
call gdk_event_get_scroll_deltas() to get the scroll delta.

Change-Id: I27bb15b61d9da4c5e749e71d6bb27bbcfc63b879
Signed-off-by: Eric Williams <ericwill@redhat.com>

1 files changed, 39 insertions, 0 deletions

diff --git a/tests/org.eclipse.swt.tests.gtk/ManualTests/org/eclipse/swt/tests/gtk/snippets/Bug545403_ScrollDirection.java b/tests/org.eclipse.swt.tests.gtk/ManualTests/org/eclipse/swt/tests/gtk/snippets/Bug545403_ScrollDirection.java
new file mode 100644
index 0000000000..718ead0126
--- /dev/null
+++ b/tests/org.eclipse.swt.tests.gtk/ManualTests/org/eclipse/swt/tests/gtk/snippets/Bug545403_ScrollDirection.java
@@ -0,0 +1,39 @@
+/*******************************************************************************
+ * Copyright (c) 2019 Red Hat and others.
+ *
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     Red Hat - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.swt.tests.gtk.snippets;
+
+import org.eclipse.swt.SWT;
+import org.eclipse.swt.widgets.Display;
+import org.eclipse.swt.widgets.Shell;
+
+public class Bug545403_ScrollDirection {
+
+	public static void main(String[] args) {
+		final Display display = new Display();
+
+		final Shell shell = new Shell(display);
+		shell.addListener(SWT.MouseWheel, event -> System.out.println(event.count));
+
+		shell.setSize(300, 200);
+		shell.open();
+
+		while (!shell.isDisposed()) {
+			if (!display.readAndDispatch()) {
+				display.sleep();
+			}
+		}
+
+		display.dispose();
+	}
+}
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