Bug 336238 - Shell.setBounds sometimes fails to set the right location

Calling gtk_widget_show for the first time before gtk_widget_resize
assumes the initial default size for any subsequent calls to
gtk_widget_move. This causes issue with shell.setBounds where the
location can only be moved to a limited bound on the screen
corresponding to the default size by the window manager, even when the
new resized shell is smaller and is able to move to further x, y
position without being cutoff by the screen. The fix is to set the
default size to the smallest possible (1, 1) before gtk_widget_show.

Tested with attached JUnit test.

Change-Id: I3f20a6aaed5972bfda3775816aab96202bae7e5d
Signed-off-by: Xi Yan <xixiyan@redhat.com>

2 files changed, 66 insertions, 1 deletions

diff --git a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Shell.java b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Shell.java
index 39c0c8a7d9..d2710b6031 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Shell.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Shell.java
@@ -2443,11 +2443,30 @@ public void setVisible (boolean visible) {
 		* unminimized or shown on the desktop.
 		*/
 		mapped = false;
+		/*
+		 * Bug/Feature in GTK: calling gtk_widget_show for the first time before
+		 * gtk_widget_resize assumes the initial default size for any subsequent calls
+		 * to gtk_widget_move. This causes issue with shell.setBounds where the
+		 * location can only be moved to a limited bound on the screen corresponding
+		 * to the default size by the window manager, even when the new resized shell
+		 * is smaller and is able to move to further x, y position without being cutoff by
+		 * the screen. The fix is to set the default size to the smallest possible (1, 1)
+		 * before gtk_widget_show.
+		 */
+		if (oldWidth == 0 && oldHeight == 0) {
+			int [] init_width = new int[1], init_height = new int[1];
+			GTK.gtk_window_get_size(shellHandle, init_width, init_height);
+			GTK.gtk_window_resize(shellHandle, 1, 1);
+			GTK.gtk_widget_show (shellHandle);
+			GTK.gtk_window_resize(shellHandle, init_width[0], init_height[0]);
+			resizeBounds (init_width[0], init_height[0], false);
+		} else {
+			GTK.gtk_widget_show (shellHandle);
+		}
 		/**
 		 *  Feature in GTK: This handles grabbing the keyboard focus from a SWT.ON_TOP window
 		 *  if it has editable fields and is running Wayland. Refer to bug 515773.
 		 */
-		GTK.gtk_widget_show (shellHandle);
 		if (enableWindow != 0) GDK.gdk_window_raise (enableWindow);
 		if (isDisposed ()) return;
 		if (!(OS.isX11() && GTK.GTK_IS_PLUG (shellHandle))) {
diff --git a/tests/org.eclipse.swt.tests.gtk/ManualTests/org/eclipse/swt/tests/gtk/snippets/Bug336238_ShellSetBoundFailTest.java b/tests/org.eclipse.swt.tests.gtk/ManualTests/org/eclipse/swt/tests/gtk/snippets/Bug336238_ShellSetBoundFailTest.java
new file mode 100644
index 0000000000..12f501d398
--- /dev/null
+++ b/tests/org.eclipse.swt.tests.gtk/ManualTests/org/eclipse/swt/tests/gtk/snippets/Bug336238_ShellSetBoundFailTest.java
@@ -0,0 +1,46 @@
+/*******************************************************************************
+ * Copyright (c) 2018 Red Hat and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Red Hat - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.swt.tests.gtk.snippets;
+
+import static org.junit.Assert.assertEquals;
+
+import org.eclipse.swt.widgets.Shell;
+import org.junit.Test;
+
+public class Bug336238_ShellSetBoundFailTest {
+
+	static int cycles = 100;
+
+	@Test
+	public void testSetBounds() {
+
+		int x;
+		int y;
+		int width = 100;
+		int height = 100;
+
+		for (int i = 0; i < cycles; i++) {
+
+			x = (new Double(Math.random() * 1000)).intValue();
+			y = (new Double(Math.random() * 1000)).intValue() + 27;
+
+			Shell testShell = new Shell();
+			testShell.open();
+
+			testShell.setBounds(x, y, width, height);
+
+			assertEquals(x, testShell.getLocation().x);
+			assertEquals(y, testShell.getLocation().y);
+			testShell.close();
+		}
+	}
+
+}