Make outstanding window moves work with the new model

We now copy outstanding window moves directly on the window and
not to an intermediary pixmap, this means our previous code to
combine window copies was wrong (it relied on each copy not
destroying the source date).

Furthermore, we can't just remove all the update area from the
destination of the outstanding moves, as sometimes things get
copied into that area and then used as the source of another
copy.

We replace the previous window copy combining with a naive
version that just queues each move, just to get things right.
Further work to optimize copies is possible.

Also, we don't remove copy destinations that are used as source
for later copies.

We also clean up the memory management by not having
move_region_on_impl taking ownership of the passed in region.

diff --git a/gdk/gdkwindow.c b/gdk/gdkwindow.c
index 5aeb9ef71d403addf61cb3e5d4740b8f6faaeda8..d8ced4d0058f1b468544d27180bc158fa2e81f1e 100644 (file)
--- a/gdk/gdkwindow.c
+++ b/gdk/gdkwindow.c
@@ -2219,10 +2219,25 @@ gdk_window_begin_paint_region (GdkWindow       *window,
     gdk_region_union (implicit_paint->region, paint->region);
 
   /* No need to do any moves that will end up over the exposed area */
-  for (l = impl_window->outstanding_moves; l != NULL; l = l->next)
+  if (impl_window->outstanding_moves)
     {
-      move = l->data;
-      gdk_region_subtract (move->region, paint->region);
+      GdkRegion *remove;
+
+      remove = gdk_region_copy (paint->region);
+      for (l = g_list_last (impl_window->outstanding_moves); l != NULL; l = l->prev)
+       {
+         move = l->data;
+         /* Don't need this area */
+         gdk_region_subtract (move->region, remove);
+
+         /* However if any of the destination we do need has a source
+            in the updated region we do need that as a destination for
+            the earlier moves */
+         gdk_region_offset (move->region, -move->dx, -move->dy);
+         gdk_region_subtract (remove, move->region);
+         gdk_region_offset (move->region, move->dx, move->dy);
+       }
+      gdk_region_destroy (remove);
     }
   
   /* Convert back to normal coords */
@@ -2521,79 +2536,33 @@ append_move_region (GdkWindowObject *impl_window,
                    GdkRegion *region,
                    int dx, int dy)
 {
-  GList *moves_to_add, *l, *s;
-  GdkRegion *intersection;
-  GdkWindowRegionMove *move, *new_move, *existing_move;
-  
+  GdkWindowRegionMove *move;
+      
   move = g_slice_new (GdkWindowRegionMove);
-  move->region  = region;
+  move->region  = gdk_region_copy (region);
   move->dx = dx;
   move->dy = dy;
 
-  moves_to_add = g_list_prepend (NULL, move);
-
-  for (l = impl_window->outstanding_moves; l != NULL; l = l->next)
-    {
-      existing_move = l->data;
-      
-      for (s = moves_to_add; s != NULL; s = s->next)
-       {
-         move = s->data;
-
-         intersection = gdk_region_copy (move->region);
-         gdk_region_offset (intersection, -move->dx, -move->dy);
-         gdk_region_intersect (intersection, existing_move->region);
-         gdk_region_offset (intersection, move->dx, move->dy);
-
-         if (!gdk_region_empty (intersection))
-           {
-             
-             new_move = g_slice_new (GdkWindowRegionMove);
-             new_move->region  = intersection;
-             new_move->dx = move->dx + existing_move->dx;
-             new_move->dy = move->dy + existing_move->dy;
-             moves_to_add = g_list_prepend (moves_to_add, new_move);
-
-             gdk_region_subtract (move->region, intersection);
-             gdk_region_subtract (existing_move->region, intersection);
-           }
-         else
-           gdk_region_destroy (intersection);
-       }
-    }
-
-  impl_window->outstanding_moves = g_list_concat (impl_window->outstanding_moves,
-                                                 moves_to_add);
-  
+  impl_window->outstanding_moves =
+    g_list_prepend (impl_window->outstanding_moves, move);
 }
 
-/* Moves bits and update area by dx/dy in impl window
- * Takes ownership of region.
- */
+/* Moves bits and update area by dx/dy in impl window */
 static void
 move_region_on_impl (GdkWindowObject *private,
                     GdkRegion *region, /* In impl window coords */
                     int dx, int dy)
 {
   GdkWindowObject *impl_window;
-  gboolean free_region;
 
   if ((dx == 0 && dy == 0) ||
       gdk_region_empty (region))
-    {
-      gdk_region_destroy (region);
-      return;
-    }
+    return;
   
-  free_region = TRUE;
   impl_window = gdk_window_get_impl_window (private);
 
   if (1) /* Enable flicker free handling of moves. */
-    {
-      free_region = FALSE;
-
-      append_move_region (impl_window, region, dx, dy);
-    }
+    append_move_region (impl_window, region, dx, dy);
   else
     do_move_region_bits_on_impl (private,
                                 region, dx, dy);
@@ -2608,14 +2577,12 @@ move_region_on_impl (GdkWindowObject *private,
       gdk_region_offset (update_area, -dx, -dy);
       gdk_region_intersect (update_area, impl_window->update_area);
       gdk_region_subtract (impl_window->update_area, update_area);
+
       /* Convert back */
       gdk_region_offset (update_area, dx, dy);
       gdk_region_union (impl_window->update_area, update_area);
       gdk_region_destroy (update_area);
     }
-
-  if (free_region)
-    gdk_region_destroy (region);
 }
 
 /* Flushes all outstanding changes to the window, call this
@@ -6221,7 +6188,7 @@ gdk_window_move_resize_internal (GdkWindow *window,
       /* convert from parent coords to impl */
       gdk_region_offset (copy_area, private->abs_x - private->x, private->abs_y - private->y);
 
-      move_region_on_impl (private, copy_area, dx, dy); /* Takes ownership of copy_area */
+      move_region_on_impl (private, copy_area, dx, dy);
 
       /* Invalidate affected part in the parent window
        *  (no higher window should be affected)
@@ -6232,6 +6199,7 @@ gdk_window_move_resize_internal (GdkWindow *window,
 
       gdk_region_destroy (old_region);
       gdk_region_destroy (new_region);
+      gdk_region_destroy (copy_area);
     }
 
   if (old_native_child_region)
@@ -6427,11 +6395,12 @@ gdk_window_scroll (GdkWindow *window,
   /* convert from window coords to impl */
   gdk_region_offset (copy_area, private->abs_x, private->abs_y);
 
-  move_region_on_impl (private, copy_area, dx, dy); /* Takes ownership of copy_area */
+  move_region_on_impl (private, copy_area, dx, dy);
    
   /* Invalidate not copied regions */
   gdk_window_invalidate_region (window, noncopy_area, TRUE);
 
+  gdk_region_destroy (copy_area);
   gdk_region_destroy (noncopy_area);
 
   if (old_native_child_region)
@@ -6504,8 +6473,9 @@ gdk_window_move_region (GdkWindow       *window,
   /* convert from window coords to impl */
   gdk_region_offset (copy_area, private->abs_x, private->abs_y);
   
-  move_region_on_impl (private, copy_area, dx, dy); /* Takes ownership of copy_area */
+  move_region_on_impl (private, copy_area, dx, dy);
 
+  gdk_region_destroy (copy_area);
   gdk_region_destroy (source_area);
 }