Bug 535083 - [Wayland] setRegion() and transparent shells don't work.

Platform Part-Drag causes eclipse black-out.

1) Replaced gdk_window_shape_combine_region with
gtk_widget_shape_combine_region wrapper in Control#setRegion.

2) There is a bug in GTK on Wayland where pixels in window outside
shape_region is black instead of transparent when the GtkWidget has
opacity of 1.0. This causes the problem where part-drag rectangles
introduces a black overlay shell covering Eclipse itself. This patch
uses a hack where the opacity of the widget is set to 0.99 whenever we
want to set a custom region.

3) Make the GTK_WINDOW_POPUP overlay in Tracker transient to the parent
if possible to avoid window not mapped warning on Wayland.

Tested on Wayland with Snippet134, Snippet 285, and child Eclipse.

Change-Id: I5f2a1bdd3a7acee87b09ab23f8951da0dbbd5c53
Signed-off-by: Xi Yan <xixiyan@redhat.com>

1 files changed, 65 insertions, 0 deletions

diff --git a/tests/org.eclipse.swt.tests.gtk/ManualNativeCTests/BugSnippets/Bug_535083_Set_Region_Black_Out.c b/tests/org.eclipse.swt.tests.gtk/ManualNativeCTests/BugSnippets/Bug_535083_Set_Region_Black_Out.c
new file mode 100644
index 0000000000..cff800cdff
--- /dev/null
+++ b/tests/org.eclipse.swt.tests.gtk/ManualNativeCTests/BugSnippets/Bug_535083_Set_Region_Black_Out.c
@@ -0,0 +1,65 @@
+/*******************************************************************************
+ * Copyright (c) 2018 Red Hat and others. All rights reserved.
+ * The contents of this file are made available under the terms
+ * of the GNU Lesser General Public License (LGPL) Version 2.1 that
+ * accompanies this distribution (lgpl-v21.txt).  The LGPL is also
+ * available at http://www.gnu.org/licenses/lgpl.html.  If the version
+ * of the LGPL at http://www.gnu.org is different to the version of
+ * the LGPL accompanying this distribution and there is any conflict
+ * between the two license versions, the terms of the LGPL accompanying
+ * this distribution shall govern.
+ *
+ * Contributors:
+ *     Red Hat - initial API and implementation
+ *******************************************************************************/
+
+#include <gtk/gtk.h>
+
+static gboolean delete_event(GtkWidget*, GdkEvent*, gpointer);
+
+static void move_cb(GtkWidget *button, gpointer data) {
+	GtkWidget *window = (GtkWidget *) data;
+	cairo_region_t *region;
+	GdkRectangle rect;
+	rect.x = 0;
+	rect.y = 0;
+	rect.width = 500;
+	rect.height = 300;
+	// gtk_window_move((GtkWindow *) window, 300, 300);
+	region = cairo_region_create_rectangle(&rect);
+	gtk_widget_shape_combine_region(window, region);
+	gtk_window_resize(GTK_WINDOW(window), 1000, 599);
+
+	// NO BLACK AREA IF SET OPACITY TO < 1
+    // gtk_widget_set_opacity(window, 0.99);
+}
+
+int main(int argc, char *argv[]) {
+	GtkWidget *window;
+	GtkWidget *main_vbox;
+	GtkWidget *move_button;
+
+	gtk_init(&argc, &argv);
+
+	window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
+	g_signal_connect(window, "delete_event", G_CALLBACK(delete_event), NULL);
+	gtk_window_resize(GTK_WINDOW(window), 1000, 600);
+
+	main_vbox = gtk_box_new(GTK_ORIENTATION_VERTICAL, 0);
+	gtk_container_add(GTK_CONTAINER(window), main_vbox);
+
+	move_button = gtk_button_new_with_label("Set Region");
+	gtk_box_pack_end(GTK_BOX(main_vbox), move_button, FALSE, TRUE, 0);
+	g_signal_connect(move_button, "clicked", G_CALLBACK(move_cb), window);
+
+	gtk_widget_show_all(window);
+	gtk_main();
+	return 0;
+}
+
+static gboolean delete_event(GtkWidget *widget, GdkEvent *event, gpointer data) {
+	gtk_main_quit();
+	return FALSE;
+}
+
+