[mutter] window: Add a meta_window_get_titlebar_rect

[Jasper St. Pierre <jstpierre src gnome org>]

commit 3a0af0faaebb1af75925c70ad98e73c61e57639b
Author: Jasper St. Pierre <jstpierre mecheye net>
Date:   Thu May 22 16:48:58 2014 -0400

    window: Add a meta_window_get_titlebar_rect

 src/core/constraints.c    |    5 +----
 src/core/place.c          |   29 +++++++++--------------------
 src/core/window-private.h |    2 ++
 src/core/window.c         |   25 +++++++++++++++++++++++--
 4 files changed, 35 insertions(+), 26 deletions(-)
---
diff --git a/src/core/constraints.c b/src/core/constraints.c
index 1a054a6..250de41 100644
--- a/src/core/constraints.c
+++ b/src/core/constraints.c
@@ -637,13 +637,10 @@ update_onscreen_requirements (MetaWindow     *window,
    */
   if (window->frame && window->decorated)
     {
-      MetaFrameBorders borders;
       MetaRectangle titlebar_rect;
 
-      meta_frame_calc_borders (window->frame, &borders);
+      meta_window_get_titlebar_rect (window, &titlebar_rect);
 
-      titlebar_rect = info->current;
-      titlebar_rect.height = borders.visible.top;
       old = window->require_titlebar_visible;
       window->require_titlebar_visible =
         meta_rectangle_overlaps_with_region (info->usable_screen_region,
diff --git a/src/core/place.c b/src/core/place.c
index 4533616..cf246f0 100644
--- a/src/core/place.c
+++ b/src/core/place.c
@@ -82,6 +82,7 @@ find_next_cascade (MetaWindow *window,
   GList *tmp;
   GList *sorted;
   int cascade_x, cascade_y;
+  MetaRectangle titlebar_rect;
   int x_threshold, y_threshold;
   MetaRectangle frame_rect;
   int window_width, window_height;
@@ -102,19 +103,9 @@ find_next_cascade (MetaWindow *window,
    * manually cascade.
    */
 #define CASCADE_FUZZ 15
-  if (window->frame)
-    {
-      MetaFrameBorders borders;
-
-      meta_frame_calc_borders (window->frame, &borders);
-      x_threshold = MAX (borders.visible.left, CASCADE_FUZZ);
-      y_threshold = MAX (borders.visible.top, CASCADE_FUZZ);
-    }
-  else
-    {
-      x_threshold = CASCADE_FUZZ;
-      y_threshold = CASCADE_FUZZ;
-    }
+  meta_window_get_titlebar_rect (window, &titlebar_rect);
+  x_threshold = MAX (titlebar_rect.x, CASCADE_FUZZ);
+  y_threshold = MAX (titlebar_rect.y, CASCADE_FUZZ);
 
   /* Find furthest-SE origin of all workspaces.
    * cascade_x, cascade_y are the target position
@@ -151,13 +142,11 @@ find_next_cascade (MetaWindow *window,
       if (ABS (wx - cascade_x) < x_threshold &&
           ABS (wy - cascade_y) < y_threshold)
         {
-          /* This window is "in the way", move to next cascade
-           * point. The new window frame should go at the origin
-           * of the client window we're stacking above.
-           */
-          meta_window_get_position (w, &wx, &wy);
-          cascade_x = wx;
-          cascade_y = wy;
+          meta_window_get_titlebar_rect (w, &titlebar_rect);
+
+          /* Cascade the window evenly by the titlebar height; this isn't a typo. */
+          cascade_x = wx + titlebar_rect.height;
+          cascade_y = wy + titlebar_rect.height;
 
           /* If we go off the screen, start over with a new cascade */
          if (((cascade_x + window_width) >
diff --git a/src/core/window-private.h b/src/core/window-private.h
index 6c79bbd..a0c1283 100644
--- a/src/core/window-private.h
+++ b/src/core/window-private.h
@@ -703,6 +703,8 @@ Window meta_window_get_toplevel_xwindow (MetaWindow *window);
 
 void meta_window_get_client_area_rect (const MetaWindow      *window,
                                        cairo_rectangle_int_t *rect);
+void meta_window_get_titlebar_rect (MetaWindow    *window,
+                                    MetaRectangle *titlebar_rect);
 
 void meta_window_activate_full (MetaWindow     *window,
                                 guint32         timestamp,
diff --git a/src/core/window.c b/src/core/window.c
index 6100640..44bcc4a 100644
--- a/src/core/window.c
+++ b/src/core/window.c
@@ -4310,6 +4310,28 @@ meta_window_get_client_area_rect (const MetaWindow      *window,
     rect->height = window->rect.height;
 }
 
+void
+meta_window_get_titlebar_rect (MetaWindow    *window,
+                               MetaRectangle *rect)
+{
+  meta_window_get_frame_rect (window, rect);
+
+  /* The returned rectangle is relative to the frame rect. */
+  rect->x = 0;
+  rect->y = 0;
+
+  if (window->frame)
+    {
+      rect->height = window->frame->child_y;
+    }
+  else
+    {
+      /* Pick an arbitrary height for a titlebar. We might want to
+       * eventually have CSD windows expose their borders to us. */
+      rect->height = 15;
+    }
+}
+
 const char*
 meta_window_get_startup_id (MetaWindow *window)
 {
@@ -5381,8 +5403,7 @@ meta_window_titlebar_is_onscreen (MetaWindow *window)
     return TRUE;
 
   /* Get the rectangle corresponding to the titlebar */
-  meta_window_get_frame_rect (window, &titlebar_rect);
-  titlebar_rect.height = window->frame->child_y;
+  meta_window_get_titlebar_rect (window, &titlebar_rect);
 
   /* Run through the spanning rectangles for the screen and see if one of
    * them overlaps with the titlebar sufficiently to consider it onscreen.