stack: change how we choose default focus window

Commit f628d8f8901f46fa9e00707ae9d7ccfd1e85f427 changed how we
choose the default focus window from the MRU to the topmost in the
stack. Unfortunately most of the time this gives unexpected result
if there are windows in META_LAYER_TOP and/or META_LAYER_FULLSCREEN
layers.

Re-sort windows using only stack position with one exception, keep
windows in META_LAYER_DESKTOP layer last and apply two rules when
choosing default window:
- fullscreen window should not get focus if it is not on the same
  monitor as not_this_one window. If fullscreen window is on other
  monitor then windows under it also should not get focus.
- desktop window should be always last choice.

1 files changed, 79 insertions, 7 deletions

diff --git a/src/core/stack.c b/src/core/stack.c
index dc96d818..8ca11cde 100644
--- a/src/core/stack.c
+++ b/src/core/stack.c
@@ -1155,6 +1155,53 @@ window_contains_point (MetaWindow *window,
   return POINT_IN_RECT (root_x, root_y, rect);
 }
 
+static int
+compare_default_focus_window_layer (MetaWindow *a,
+                                    MetaWindow *b)
+{
+  if (a->layer == META_LAYER_DESKTOP ||
+      b->layer == META_LAYER_DESKTOP)
+    {
+      if (a->layer < b->layer)
+        return 1;
+      else if (a->layer > b->layer)
+        return -1;
+    }
+
+  return 0;
+}
+
+static int
+compare_default_focus_window_position (MetaWindow *a,
+                                       MetaWindow *b)
+{
+  if (a->stack_position < b->stack_position)
+    return 1;
+  else if (a->stack_position > b->stack_position)
+    return -1;
+
+  return 0;
+}
+
+static int
+compare_default_focus_window_func (gconstpointer a,
+                                   gconstpointer b)
+{
+  MetaWindow *window_a;
+  MetaWindow *window_b;
+  int result;
+
+  window_a = (MetaWindow *) a;
+  window_b = (MetaWindow *) b;
+
+  result = compare_default_focus_window_layer (window_a, window_b);
+
+  if (result == 0)
+    result = compare_default_focus_window_position (window_a, window_b);
+
+  return result;
+}
+
 static MetaWindow*
 get_default_focus_window (MetaStack     *stack,
                           MetaWorkspace *workspace,
@@ -1163,20 +1210,28 @@ get_default_focus_window (MetaStack     *stack,
                           int            root_x,
                           int            root_y)
 {
+  MetaWindow *default_focus_window;
+  GList *tmp;
+  GList *l;
+
   /* Find the topmost, focusable, mapped, window.
    * not_this_one is being unfocused or going away, so exclude it.
    */
 
-  GList *l;
+  default_focus_window = NULL;
 
   stack_ensure_sorted (stack);
 
-  /* top of this layer is at the front of the list */
-  for (l = stack->sorted; l != NULL; l = l->next)
+  tmp = g_list_copy (stack->sorted);
+  tmp = g_list_sort (tmp, compare_default_focus_window_func);
+
+  for (l = tmp; l != NULL; l = l->next)
     {
-      MetaWindow *window = l->data;
+      MetaWindow *window;
+
+      window = l->data;
 
-      if (!window)
+      if (window == NULL)
         continue;
 
       if (window == not_this_one)
@@ -1200,10 +1255,27 @@ get_default_focus_window (MetaStack     *stack,
       if (window->type == META_WINDOW_DOCK)
         continue;
 
-      return window;
+      if (window->fullscreen &&
+          not_this_one != NULL &&
+          default_focus_window == NULL &&
+          windows_on_different_monitor (window, not_this_one))
+        {
+          default_focus_window = window;
+          continue;
+        }
+
+      if (default_focus_window != NULL &&
+          (!windows_on_different_monitor (window, default_focus_window) ||
+           window->layer == META_LAYER_DESKTOP))
+        continue;
+
+      default_focus_window = window;
+      break;
     }
 
-  return NULL;
+  g_list_free (tmp);
+
+  return default_focus_window;
 }
 
 MetaWindow*