Bug 546961 - Scrollbar slider broken after debug hover resize

Added an extra resize for a Shell with custom resize, after triggering a
layout update for child widges of the Shell. This is a workaround for a
bug in GTK+, which results in not painting scrollbar sliders correctly
on scrolling.

Change-Id: I3980af5853c56c58a6e8e41e274d568524683d2b
Signed-off-by: Simeon Andreev <simeon.danailov.andreev@gmail.com>
Reviewed-on: https://git.eclipse.org/r/c/platform/eclipse.platform.swt/+/189427
Tested-by: Platform Bot <platform-bot@eclipse.org>
Tested-by: Andrey Loskutov <loskutov@gmx.de>
Reviewed-by: Andrey Loskutov <loskutov@gmx.de>

1 files changed, 76 insertions, 0 deletions

diff --git a/tests/org.eclipse.swt.tests.gtk/ManualTests/org/eclipse/swt/tests/gtk/snippets/Bug546961_Scrollbar_Slider_Popup_Shell.java b/tests/org.eclipse.swt.tests.gtk/ManualTests/org/eclipse/swt/tests/gtk/snippets/Bug546961_Scrollbar_Slider_Popup_Shell.java
new file mode 100644
index 0000000000..9b3909a12a
--- /dev/null
+++ b/tests/org.eclipse.swt.tests.gtk/ManualTests/org/eclipse/swt/tests/gtk/snippets/Bug546961_Scrollbar_Slider_Popup_Shell.java
@@ -0,0 +1,76 @@
+/*******************************************************************************
+ * Copyright (c) 2022 Simeon Andreev 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:
+ *     Simeon Andreev - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.swt.tests.gtk.snippets;
+
+import org.eclipse.swt.SWT;
+import org.eclipse.swt.layout.FillLayout;
+import org.eclipse.swt.widgets.Composite;
+import org.eclipse.swt.widgets.Display;
+import org.eclipse.swt.widgets.Scrollable;
+import org.eclipse.swt.widgets.Shell;
+import org.eclipse.swt.widgets.Text;
+
+/**
+ * Description: After resizing a pop-up {@link Shell},
+ * scrollbars of {@link Scrollable} child widgets
+ * no longer paint sliders correctly when scrolling.
+ * <p>
+ * Steps to reproduce:
+ * <ol>
+ * <li>Run the snippet.</li>
+ * <li>Resize the pop-up {@link Shell}, so that scrollbars can still be used.</li>
+ * <li>Scroll with mouse drag, observe that the sliders of the scrollbars don't move.</li>
+ * </ol>
+ * </p>
+ * Expected results: Scrollbar sliders move during scrolling.
+ * Actual results: Scrollbar sliders don't move when scrolling.
+ */
+public class Bug546961_Scrollbar_Slider_Popup_Shell {
+
+	public static void main(String[] args) {
+		Display display = new Display();
+		Shell shell = new Shell(display);
+		shell.setSize(400, 300);
+		shell.setText("Bug 546961");
+		shell.setLayout(new FillLayout());
+
+		Shell s = new Shell(shell, SWT.ON_TOP | SWT.RESIZE);
+		s.setLayout(new FillLayout());
+		s.setSize(300, 200);
+		Composite c = new Composite(s, SWT.BORDER);
+		c.setLayout(new FillLayout());
+
+		int n = 30;
+		int m = 30;
+		StringBuilder content  = new StringBuilder();
+		for (int i = 10; i <= n; ++i) {
+			for (int j = 10; j <= m; ++j) {
+				content.append(i + "." + j);
+				content.append(' ');
+			}
+			content.append(System.lineSeparator());
+		}
+		Text text = new Text(c, SWT.MULTI | SWT.H_SCROLL | SWT.V_SCROLL);
+		text.setText(content.toString());
+		s.open();
+
+		shell.open();
+		while (!shell.isDisposed()) {
+			if (!display.readAndDispatch())
+				display.sleep();
+		}
+		display.dispose();
+	}
+
+}