buttons: Fix background functions for non-default layouts

While the configured layout is taken into account for positioning
the buttons, the mapping from button function states to button
position states just assumed the default button layout in LTR
locales.
Do a proper mapping depending on the actual layout instead.

https://bugzilla.gnome.org/show_bug.cgi?id=635686

src/ui/frames.c

@@ -2398,20 +2398,6 @@ meta_frames_paint (MetaFrames   *frames,
     default:
       break;
     }
-
-  /* Map button function states to button position states */
-  button_states[META_BUTTON_TYPE_LEFT_LEFT_BACKGROUND] =
-    button_states[META_BUTTON_TYPE_MENU];
-  button_states[META_BUTTON_TYPE_LEFT_MIDDLE_BACKGROUND] =
-    META_BUTTON_STATE_NORMAL;
-  button_states[META_BUTTON_TYPE_LEFT_RIGHT_BACKGROUND] =
-    META_BUTTON_STATE_NORMAL;
-  button_states[META_BUTTON_TYPE_RIGHT_LEFT_BACKGROUND] =
-    button_states[META_BUTTON_TYPE_MINIMIZE];
-  button_states[META_BUTTON_TYPE_RIGHT_MIDDLE_BACKGROUND] =
-    button_states[META_BUTTON_TYPE_MAXIMIZE];
-  button_states[META_BUTTON_TYPE_RIGHT_RIGHT_BACKGROUND] =
-    button_states[META_BUTTON_TYPE_CLOSE];
   
   meta_core_get (display, frame->xwindow,
                  META_CORE_GET_FRAME_FLAGS, &flags,

src/ui/theme-private.h

@@ -256,6 +256,11 @@ struct _MetaFrameGeometry
   GdkRectangle right_middle_backgrounds[MAX_MIDDLE_BACKGROUNDS];
   GdkRectangle right_right_background;
   /* End of button rects (if changed adjust memset hack) */
+
+  /* Saved button layout */
+  MetaButtonLayout button_layout;
+  int n_left_buttons;
+  int n_right_buttons;
   
   /* Round corners */
   guint top_left_corner_rounded_radius;

src/ui/theme.c

@@ -452,6 +452,38 @@ meta_frame_layout_get_borders (const MetaFrameLayout *layout,
     }
 }
 
+static MetaButtonType
+map_button_function_to_type (MetaButtonFunction  function)
+{
+  switch (function)
+    {
+    case META_BUTTON_FUNCTION_SHADE:
+      return META_BUTTON_TYPE_SHADE;
+    case META_BUTTON_FUNCTION_ABOVE:
+      return META_BUTTON_TYPE_ABOVE;
+    case META_BUTTON_FUNCTION_STICK:
+      return META_BUTTON_TYPE_STICK;
+    case META_BUTTON_FUNCTION_UNSHADE:
+      return META_BUTTON_TYPE_UNSHADE;
+    case META_BUTTON_FUNCTION_UNABOVE:
+      return META_BUTTON_TYPE_UNABOVE;
+    case META_BUTTON_FUNCTION_UNSTICK:
+      return META_BUTTON_TYPE_UNSTICK;
+    case META_BUTTON_FUNCTION_MENU:
+      return META_BUTTON_TYPE_MENU;
+    case META_BUTTON_FUNCTION_MINIMIZE:
+      return META_BUTTON_TYPE_MINIMIZE;
+    case META_BUTTON_FUNCTION_MAXIMIZE:
+      return META_BUTTON_TYPE_MAXIMIZE;
+    case META_BUTTON_FUNCTION_CLOSE:
+      return META_BUTTON_TYPE_CLOSE;
+    case META_BUTTON_FUNCTION_LAST:
+      return META_BUTTON_TYPE_LAST;
+    }
+
+  return META_BUTTON_TYPE_LAST;
+}
+
 static MetaButtonSpace*
 rect_for_function (MetaFrameGeometry *fgeom,
                    MetaFrameFlags     flags,
@@ -808,6 +840,11 @@ meta_frame_layout_calc_geometry (const MetaFrameLayout  *layout,
                     n_left, n_right);
         }
     }
+
+  /* Save the button layout */
+  fgeom->button_layout = *button_layout;
+  fgeom->n_left_buttons = n_left;
+  fgeom->n_right_buttons = n_right;
   
   /* center buttons vertically */
   button_y = (fgeom->top_height -
@@ -4198,6 +4235,64 @@ meta_frame_style_unref (MetaFrameStyle *style)
     }
 }
 
+static MetaButtonState
+map_button_state (MetaButtonType           button_type,
+                  const MetaFrameGeometry *fgeom,
+                  int                      middle_bg_offset,
+                  MetaButtonState          button_states[META_BUTTON_TYPE_LAST])
+{
+  MetaButtonFunction function = META_BUTTON_FUNCTION_LAST;
+
+  switch (button_type)
+    {
+    /* First hande functions, which map directly */
+    case META_BUTTON_TYPE_SHADE:
+    case META_BUTTON_TYPE_ABOVE:
+    case META_BUTTON_TYPE_STICK:
+    case META_BUTTON_TYPE_UNSHADE:
+    case META_BUTTON_TYPE_UNABOVE:
+    case META_BUTTON_TYPE_UNSTICK:
+    case META_BUTTON_TYPE_MENU:
+    case META_BUTTON_TYPE_MINIMIZE:
+    case META_BUTTON_TYPE_MAXIMIZE:
+    case META_BUTTON_TYPE_CLOSE:
+      return button_states[button_type];
+
+    /* Map position buttons to the corresponding function */
+    case META_BUTTON_TYPE_RIGHT_LEFT_BACKGROUND:
+      if (fgeom->n_right_buttons > 0)
+        function = fgeom->button_layout.right_buttons[0];
+      break;
+    case META_BUTTON_TYPE_RIGHT_RIGHT_BACKGROUND:
+      if (fgeom->n_right_buttons > 0)
+        function = fgeom->button_layout.right_buttons[fgeom->n_right_buttons - 1];
+      break;
+    case META_BUTTON_TYPE_RIGHT_MIDDLE_BACKGROUND:
+      if (middle_bg_offset + 1 < fgeom->n_right_buttons)
+        function = fgeom->button_layout.right_buttons[middle_bg_offset + 1];
+      break;
+    case META_BUTTON_TYPE_LEFT_LEFT_BACKGROUND:
+      if (fgeom->n_left_buttons > 0)
+        function = fgeom->button_layout.left_buttons[0];
+      break;
+    case META_BUTTON_TYPE_LEFT_RIGHT_BACKGROUND:
+      if (fgeom->n_left_buttons > 0)
+        function = fgeom->button_layout.left_buttons[fgeom->n_left_buttons - 1];
+      break;
+    case META_BUTTON_TYPE_LEFT_MIDDLE_BACKGROUND:
+      if (middle_bg_offset + 1 < fgeom->n_left_buttons)
+        function = fgeom->button_layout.left_buttons[middle_bg_offset + 1];
+      break;
+    case META_BUTTON_TYPE_LAST:
+      break;
+    }
+
+  if (function != META_BUTTON_FUNCTION_LAST)
+    return button_states[map_button_function_to_type (function)];
+
+  return META_BUTTON_STATE_LAST;
+}
+
 static MetaDrawOpList*
 get_button (MetaFrameStyle *style,
             MetaButtonType  type,
@@ -4540,9 +4635,13 @@ meta_frame_style_draw_with_style (MetaFrameStyle          *style,
           j = 0;
           while (j < META_BUTTON_TYPE_LAST)
             {
+              MetaButtonState button_state;
+
               button_rect (j, fgeom, middle_bg_offset, &rect);
               
-              op_list = get_button (style, j, button_states[j]);
+              button_state = map_button_state (j, fgeom, middle_bg_offset, button_states);
+
+              op_list = get_button (style, j, button_state);
               
               if (op_list)
                 {