* frame.c (x_set_alpha) [NS_IMPL_COCOA]: Call x_set_frame_alpha.

* nsfns.m (ns_frame_parm_handlers): Set alpha handler.
* nsterm.m (x_set_frame_alpha): New function.

src/ChangeLog

+2008-11-28  Seiji Zenitani  <zenitani@mac.com>
+
+	* frame.c (x_set_alpha) [NS_IMPL_COCOA]: Call x_set_frame_alpha.
+
+	* nsfns.m (ns_frame_parm_handlers): Set alpha handler.
+
+	* nsterm.m (x_set_frame_alpha): New function.
+
 2008-11-27  Eli Zaretskii  <eliz@gnu.org>
 
 	* xfaces.c (Fx_font_family_list, syms_of_xfaces): Fix last change.

src/frame.c

@@ -3678,7 +3678,7 @@ x_set_alpha (f, arg, oldval)
   for (i = 0; i < 2; i++)
     f->alpha[i] = newval[i];
 
-#if defined (HAVE_X_WINDOWS) || defined (HAVE_NTGUI)
+#if defined (HAVE_X_WINDOWS) || defined (HAVE_NTGUI) || defined (NS_IMPL_COCOA)
   BLOCK_INPUT;
   x_set_frame_alpha (f);
   UNBLOCK_INPUT;

src/nsfns.m

@@ -1040,7 +1040,7 @@ Turn the input menu (an NSMenu) into a lisp list for tracking on lisp side
   0, /* x_set_wait_for_wm, will ignore */
   0,  /* x_set_fullscreen will ignore */
   x_set_font_backend, /* generic OK */
-  0
+  x_set_alpha
 };
 
 

src/nsterm.m

@@ -964,9 +964,15 @@ Free a pool and temporary objects it refers to (callable from C)
          dpyinfo->x_highlight_frame != old_highlight)
     {
       if (old_highlight)
+	{
           x_update_cursor (old_highlight, 1);
+	  x_set_frame_alpha (old_highlight);
+	}
       if (dpyinfo->x_highlight_frame)
+	{
           x_update_cursor (dpyinfo->x_highlight_frame, 1);
+          x_set_frame_alpha (dpyinfo->x_highlight_frame);
+	}
     }
 }
 
@@ -1634,6 +1640,39 @@ Free a pool and temporary objects it refers to (callable from C)
 }
 
 
+void
+x_set_frame_alpha (struct frame *f)
+/* --------------------------------------------------------------------------
+     change the entire-frame transparency
+   -------------------------------------------------------------------------- */
+{
+  struct ns_display_info *dpyinfo = FRAME_NS_DISPLAY_INFO (f);
+  EmacsView *view = FRAME_NS_VIEW (f);
+  double alpha = 1.0;
+  double alpha_min = 1.0;
+
+  if (dpyinfo->x_highlight_frame == f)
+    alpha = f->alpha[0];
+  else
+    alpha = f->alpha[1];
+
+  if (FLOATP (Vframe_alpha_lower_limit))
+    alpha_min = XFLOAT_DATA (Vframe_alpha_lower_limit);
+  else if (INTEGERP (Vframe_alpha_lower_limit))
+    alpha_min = (XINT (Vframe_alpha_lower_limit)) / 100.0;
+
+  if (alpha < 0.0)
+    return;
+  else if (1.0 < alpha)
+    alpha = 1.0;
+  else if (0.0 <= alpha && alpha < alpha_min && alpha_min <= 1.0)
+    alpha = alpha_min;
+  
+#ifdef NS_IMPL_COCOA
+  [[view window] setAlphaValue: alpha];
+#endif
+}
+
 
 /* ==========================================================================
 
@@ -5009,7 +5048,10 @@ - (void)windowDidResignKey: (NSNotification *)notification
   /* FIXME: for some reason needed on second and subsequent clicks away
             from sole-frame Emacs to get hollow box to show */
   if (!windowClosing && [[self window] isVisible] == YES)
-    x_update_cursor (emacsframe, 1);
+    {
+      x_update_cursor (emacsframe, 1);
+      x_set_frame_alpha (emacsframe);
+    }
 
   if (emacs_event)
     {