theme: fix button background

1) Added 'no background' if there is only one button and backgrounds
   no more overlap if transparency used.
2) Corrected bug with left button clickable region when window is
   maximized.
Origin: Ubuntu
Bug: https://bugzilla.gnome.org/show_bug.cgi?id=608511
Bug-Ubuntu: https://bugs.launchpad.net/ubuntu/+source/metacity/+bug/535088
Author: Nicolas Desfontaine <noop@free.fr>

2 files changed, 27 insertions, 26 deletions

diff --git a/src/ui/theme.c b/src/ui/theme.c
index ed25877d..a13c7734 100644
--- a/src/ui/theme.c
+++ b/src/ui/theme.c
@@ -729,8 +729,13 @@ meta_frame_layout_calc_geometry (const MetaFrameLayout  *layout,
 
   for (i = 0; i < n_left; i++)
     {
-      if (i == 0) /* prefer left background if only one button */
-        left_bg_rects[i] = &fgeom->left_left_background;
+      if (i == 0) /* For the first button (From left to right) */
+        {
+          if (n_left > 1) /* Set left_left_background if we have more than one button */
+            left_bg_rects[i] = &fgeom->left_left_background;
+          else /* No background if we have only one single button */
+            left_bg_rects[i] = &fgeom->left_single_background;
+        }
       else if (i == (n_left - 1))
         left_bg_rects[i] = &fgeom->left_right_background;
       else
@@ -739,9 +744,13 @@ meta_frame_layout_calc_geometry (const MetaFrameLayout  *layout,
 
   for (i = 0; i < n_right; i++)
     {
-      /* prefer right background if only one button */
-      if (i == (n_right - 1))
-        right_bg_rects[i] = &fgeom->right_right_background;
+      if (i == (n_right - 1)) /* For the first button (From right to left) */
+        {
+          if (n_right > 1) /* Set right_right_background if we have more than one button */
+            right_bg_rects[i] = &fgeom->right_right_background;
+          else /* No background if we have only one single button */
+            right_bg_rects[i] = &fgeom->right_single_background;
+        }
       else if (i == 0)
         right_bg_rects[i] = &fgeom->right_left_background;
       else
@@ -870,9 +879,9 @@ meta_frame_layout_calc_geometry (const MetaFrameLayout  *layout,
           flags & META_FRAME_TILED_RIGHT)
         {
           rect->clickable.x = rect->visible.x;
-          rect->clickable.y = 0;
-          rect->clickable.width = rect->visible.width;
-          rect->clickable.height = button_height + button_y;
+          rect->clickable.y = rect->visible.y;
+          rect->clickable.width = button_width;
+          rect->clickable.height = button_height;
 
           if (i == n_right - 1)
             rect->clickable.width += layout->right_titlebar_edge + layout->right_width + layout->button_border.right;
@@ -908,23 +917,13 @@ meta_frame_layout_calc_geometry (const MetaFrameLayout  *layout,
 
       if (flags & META_FRAME_MAXIMIZED)
         {
-          if (i==0)
-            {
-              rect->clickable.x = 0;
-              rect->clickable.width = button_width + x;
-            }
-          else
-            {
-              rect->clickable.x = rect->visible.x;
-              rect->clickable.width = button_width;
-            }
-
-            rect->clickable.y = 0;
-            rect->clickable.height = button_height + button_y;
-          }
-        else
-          g_memmove (&(rect->clickable), &(rect->visible), sizeof(rect->clickable));
-
+          rect->clickable.x = rect->visible.x;
+          rect->clickable.y = rect->visible.y;
+          rect->clickable.width = button_width;
+          rect->clickable.height = button_height;
+        }
+      else
+        g_memmove (&(rect->clickable), &(rect->visible), sizeof(rect->clickable));
 
       x = rect->visible.x + rect->visible.width + layout->button_border.right;
       if (left_buttons_has_spacer[i])
@@ -4655,7 +4654,7 @@ meta_frame_style_draw_with_style (MetaFrameStyle          *style,
               /* MIDDLE_BACKGROUND type may get drawn more than once */
               if ((j == META_BUTTON_TYPE_RIGHT_MIDDLE_BACKGROUND ||
                    j == META_BUTTON_TYPE_LEFT_MIDDLE_BACKGROUND) &&
-                  middle_bg_offset < MAX_MIDDLE_BACKGROUNDS)
+                  (middle_bg_offset < (MAX_MIDDLE_BACKGROUNDS - 1)))
                 {
                   ++middle_bg_offset;
                 }
diff --git a/src/ui/theme.h b/src/ui/theme.h
index cea966c6..5a07d549 100644
--- a/src/ui/theme.h
+++ b/src/ui/theme.h
@@ -246,9 +246,11 @@ struct _MetaFrameGeometry
   MetaButtonSpace unstick_rect;
 
 #define MAX_MIDDLE_BACKGROUNDS (MAX_BUTTONS_PER_CORNER - 2)
+  GdkRectangle left_single_background;
   GdkRectangle left_left_background;
   GdkRectangle left_middle_backgrounds[MAX_MIDDLE_BACKGROUNDS];
   GdkRectangle left_right_background;
+  GdkRectangle right_single_background;
   GdkRectangle right_left_background;
   GdkRectangle right_middle_backgrounds[MAX_MIDDLE_BACKGROUNDS];
   GdkRectangle right_right_background;