frames: apply shapes in different way

upstream commit:
https://gitlab.gnome.org/GNOME/metacity/commit/cd383e72

2 files changed, 53 insertions, 4 deletions

diff --git a/src/ui/frames.c b/src/ui/frames.c
index c9b0bfb4..953736a5 100644
--- a/src/ui/frames.c
+++ b/src/ui/frames.c
@@ -686,6 +686,7 @@ meta_frames_manage_window (MetaFrames *frames,
   frame->title = NULL;
   frame->expose_delayed = FALSE;
   frame->shape_applied = FALSE;
+  frame->dest_kind = ShapeBounding;
   frame->prelit_control = META_FRAME_CONTROL_NONE;
 
   meta_core_grab_buttons (GDK_DISPLAY_XDISPLAY (gdk_display_get_default ()), frame->xwindow);
@@ -1055,6 +1056,20 @@ get_client_region (MetaFrameGeometry *fgeom,
   return cairo_region_create_rectangle (&rect);
 }
 
+static cairo_region_t *
+get_frame_region (int window_width,
+                  int window_height)
+{
+  cairo_rectangle_int_t rect;
+
+  rect.x = 0;
+  rect.y = 0;
+  rect.width = window_width;
+  rect.height = window_height;
+
+  return cairo_region_create_rectangle (&rect);
+}
+
 void
 meta_frames_apply_shapes (MetaFrames *frames,
                           Window      xwindow,
@@ -1068,6 +1083,8 @@ meta_frames_apply_shapes (MetaFrames *frames,
   MetaFrameGeometry fgeom;
   cairo_region_t *window_region;
   Display *display;
+  gboolean compositing_manager;
+  int dest_kind;
 
   frame = meta_frames_lookup_window (frames, xwindow);
   g_return_if_fail (frame != NULL);
@@ -1090,6 +1107,8 @@ meta_frames_apply_shapes (MetaFrames *frames,
 
           XShapeCombineMask (display, frame->xwindow,
                              ShapeBounding, 0, 0, None, ShapeSet);
+          XShapeCombineMask (display, frame->xwindow,
+                             ShapeClip, 0, 0, None, ShapeSet);
           frame->shape_applied = FALSE;
         }
       else
@@ -1102,6 +1121,18 @@ meta_frames_apply_shapes (MetaFrames *frames,
       return; /* nothing to do */
     }
 
+  compositing_manager = meta_prefs_get_compositing_manager ();
+
+  dest_kind = ShapeClip;
+  if (!compositing_manager)
+    dest_kind = ShapeBounding;
+
+  if (frame->dest_kind != dest_kind)
+    {
+      XShapeCombineMask (display, frame->xwindow,
+                         frame->dest_kind, 0, 0, None, ShapeSet);
+    }
+
   window_region = get_visible_region (frames,
                                       frame,
                                       &fgeom,
@@ -1119,7 +1150,9 @@ meta_frames_apply_shapes (MetaFrames *frames,
       XSetWindowAttributes attrs;
       Window shape_window;
       Window client_window;
+      cairo_region_t *frame_region;
       cairo_region_t *client_region;
+      cairo_region_t *tmp_region;
       GdkScreen *screen;
       int screen_number;
 
@@ -1159,16 +1192,22 @@ meta_frames_apply_shapes (MetaFrames *frames,
       /* Punch the client area out of the normal frame shape,
        * then union it with the shape_window's existing shape
        */
+      frame_region = get_frame_region (new_window_width,
+                                       new_window_height);
       client_region = get_client_region (&fgeom,
                                          new_window_width,
                                          new_window_height);
 
-      cairo_region_subtract (window_region, client_region);
+      tmp_region = compositing_manager ? frame_region : window_region;
+
+      cairo_region_subtract (tmp_region, client_region);
 
       cairo_region_destroy (client_region);
 
       apply_cairo_region_to_window (GDK_DISPLAY_XDISPLAY (gdk_display_get_default ()), shape_window,
-                                    window_region, ShapeBounding, ShapeUnion);
+                                    tmp_region, ShapeBounding, ShapeUnion);
+
+      cairo_region_destroy (frame_region);
 
       /* Now copy shape_window shape to the real frame */
       XShapeCombineShape (GDK_DISPLAY_XDISPLAY (gdk_display_get_default ()), frame->xwindow, ShapeBounding,
@@ -1178,6 +1217,13 @@ meta_frames_apply_shapes (MetaFrames *frames,
                           ShapeSet);
 
       XDestroyWindow (GDK_DISPLAY_XDISPLAY (gdk_display_get_default ()), shape_window);
+
+      if (compositing_manager)
+        {
+          apply_cairo_region_to_window (display,
+                                        frame->xwindow, window_region,
+                                        dest_kind, ShapeSet);
+        }
     }
   else
     {
@@ -1187,10 +1233,12 @@ meta_frames_apply_shapes (MetaFrames *frames,
                   "Frame 0x%lx has shaped corners\n",
                   frame->xwindow);
 
-      apply_cairo_region_to_window (GDK_DISPLAY_XDISPLAY (gdk_display_get_default ()), frame->xwindow,
-                                    window_region, ShapeBounding, ShapeSet);
+      apply_cairo_region_to_window (display,
+                                    frame->xwindow, window_region,
+                                    dest_kind, ShapeSet);
     }
 
+  frame->dest_kind = dest_kind;
   frame->shape_applied = TRUE;
 
   cairo_region_destroy (window_region);
diff --git a/src/ui/frames.h b/src/ui/frames.h
index cde51e60..5019aaad 100644
--- a/src/ui/frames.h
+++ b/src/ui/frames.h
@@ -83,6 +83,7 @@ struct _MetaUIFrame
   char *title; /* NULL once we have a layout */
   guint expose_delayed : 1;
   guint shape_applied : 1;
+  int dest_kind;
 
   /* FIXME get rid of this, it can just be in the MetaFrames struct */
   MetaFrameControl prelit_control;