Add support for restoring previous region

lib/Utils.vala

@@ -404,6 +404,8 @@ namespace Gala {
             return texture;
         }
 
+        private static HashTable<Meta.Window, X.Rectangle?> regions = new HashTable<Meta.Window, X.Rectangle?> (null, null);
+
         public static void x11_set_window_pass_through (Meta.Window window) {
             unowned var x11_display = window.display.get_x11_display ();
 
@@ -414,6 +416,9 @@ namespace Gala {
 #endif
             unowned var xdisplay = x11_display.get_xdisplay ();
 
+            int count, ordering;
+            regions[window] = X.Shape.get_rectangles (xdisplay, x_window, 2, out count, out ordering)[0];
+
             X.Xrectangle rect = {};
             var region = X.Fixes.create_region (xdisplay, {rect});
 
@@ -422,7 +427,7 @@ namespace Gala {
             X.Fixes.destroy_region (xdisplay, region);
         }
 
-        public static void x11_unset_window_pass_through (Meta.Window window) {
+        public static void x11_unset_window_pass_through (Meta.Window window, bool restore_previous_region) {
             unowned var x11_display = window.display.get_x11_display ();
 
 #if HAS_MUTTER46
@@ -432,7 +437,19 @@ namespace Gala {
 #endif
             unowned var xdisplay = x11_display.get_xdisplay ();
 
-            X.Fixes.set_window_shape_region (xdisplay, x_window, 2, 0, 0, (X.XserverRegion) 0);
+            if (restore_previous_region) {
+                var region = regions[window];
+                if (region == null) {
+                    debug ("Cannot unset pass through: window not found.");
+                    return;
+                }
+
+                X.Shape.combine_rectangles (xdisplay, x_window, 2, 0, 0, { region }, 0, 3);
+            } else {
+                X.Fixes.set_window_shape_region (xdisplay, x_window, 2, 0, 0, (X.XserverRegion) 0);
+            }
+
+            regions.remove (window);
         }
 
         /**

meson.build

@@ -94,6 +94,7 @@ gnome_desktop_dep = dependency('gnome-desktop-3.0')
 m_dep = cc.find_library('m', required: false)
 posix_dep = vala.find_library('posix', required: false)
 sqlite3_dep = dependency('sqlite3')
+xext_dep = cc.find_library('Xext', required: true)
 if get_option('systemd')
     systemd_dep = dependency('libsystemd')
 endif
@@ -149,7 +150,7 @@ endif
 add_project_arguments(vala_flags, language: 'vala')
 add_project_link_arguments(['-Wl,-rpath,@0@'.format(mutter_typelib_dir)], language: 'c')
 
-gala_base_dep = [atk_bridge_dep, canberra_dep, glib_dep, gobject_dep, gio_dep, gio_unix_dep, gmodule_dep, gee_dep, gtk_dep, mutter_dep, gnome_desktop_dep, m_dep, posix_dep, sqlite3_dep, config_dep]
+gala_base_dep = [atk_bridge_dep, canberra_dep, glib_dep, gobject_dep, gio_dep, gio_unix_dep, gmodule_dep, gee_dep, gtk_dep, mutter_dep, gnome_desktop_dep, m_dep, posix_dep, sqlite3_dep, xext_dep, config_dep]
 
 if get_option('systemd')
     gala_base_dep += systemd_dep

src/ShellClients/ShellClientsManager.vala

@@ -294,9 +294,19 @@ public class Gala.ShellClientsManager : Object, GestureTarget {
                     make_centered (window);
                     break;
 
+                case "restore-previous-region":
+                    set_restore_previous_x11_region (window);
+                    break;
+
                 default:
                     break;
             }
         }
     }
+
+    private void set_restore_previous_x11_region (Meta.Window window)
+    requires (!Meta.Util.is_wayland_compositor ())
+    requires (window in panel_windows) {
+        panel_windows[window].restore_previous_x11_region = true;
+    }
 }

src/ShellClients/ShellWindow.vala

@@ -7,6 +7,7 @@
 
 public class Gala.ShellWindow : PositionedWindow, GestureTarget {
     public Clutter.Actor? actor { get { return window_actor; } }
+    public bool restore_previous_x11_region { private get; set; default = false; }
 
     private Meta.WindowActor window_actor;
     private double custom_progress = 0;
@@ -85,16 +86,16 @@ public class Gala.ShellWindow : PositionedWindow, GestureTarget {
         var visible = double.max (multitasking_view_progress, custom_progress) < 0.1;
         var animating = animations_ongoing > 0;
 
+        window_actor.visible = animating || visible;
+
         if (!Meta.Util.is_wayland_compositor ()) {
-            if (!visible) {
-                Utils.x11_set_window_pass_through (window);
+            if (window_actor.visible) {
+                Utils.x11_unset_window_pass_through (window, restore_previous_x11_region);
             } else {
-                Utils.x11_unset_window_pass_through (window);
+                Utils.x11_set_window_pass_through (window);
             }
         }
 
-        window_actor.visible = animating || visible;
-
         unowned var manager = ShellClientsManager.get_instance ();
         window.foreach_transient ((transient) => {
             if (manager.is_itself_positioned (transient)) {

vapi/xfixes-4.0.vapi

@@ -12,6 +12,12 @@ namespace X {
 		public static void destroy_region (X.Display display, X.XserverRegion region);
 		[CCode (cheader_filename = "X11/extensions/Xfixes.h", cname = "XFixesSetWindowShapeRegion")]
         public static void set_window_shape_region (X.Display display, X.Window win, int shape_kind, int x_off, int y_off, XserverRegion region);
+	}
+		namespace Shape {
+		[CCode (cheader_filename = "X11/extensions/shape.h", cname = "XShapeGetRectangles")]
+		public static X.Rectangle* get_rectangles (X.Display display, X.Window win, int kind, out int count, out int ordering);
+		[CCode (cheader_filename = "X11/extensions/shape.h", cname = "XShapeCombineRectangles")]
+		public static void combine_rectangles (X.Display display, X.Window win, int kind, int x, int y, [CCode (array_length_cname = "count", type = "XRectangle*")] X.Rectangle[] rectangles, int op, int ordering);
 	}
 	[SimpleType]
 	[CCode (cheader_filename = "X11/extensions/Xfixes.h", cname = "XserverRegion", has_type_id = false)]