Add ability to change macOS WM theme (bug#27973)

* src/frame.c (make_frame, frame_parms, syms_of_frame)
[NS_IMPL_COCOA]: Add ns-appearance and ns-transparent-titlebar
options.
* src/frame.h (ns_appearance_type) [NS_IMPL_COCOA]: Add enum to
represent NSAppearance options.
(struct frame) [NS_IMPL_COCOA]: Add ns_appearance and
ns_transparent_titlebar frame parameters.
* src/nsfns.m (ns_frame_parm_handlers) [NS_IMPL_COCOA]: Add
ns_set_appearance and ns_set_transparent_titlebar handlers.
(Sx_create_frame): Handle ns-appearance and ns-transparent-titlebar
frame parameters.
(Qdark): Add new symbol for use with ns-appearance.
* src/nsterm.h (ns_set_appearance, ns_set_transparent_titlebar)
[NS_IMPL_COCOA]: Add prototypes.
* src/nsterm.m (ns_set_appearance, ns_set_transparent_titlebar)
[NS_IMPL_COCOA]: New functions.
(initFrameFromEmacs) [NS_IMPL_COCOA]: Handle ns-appearance and
ns-transparent-titlebar frame parameters.
* doc/lispref/frames.texi (Window Management Parameters): Document
ns-apperance and ns-transparent-titlebar.

1 files changed, 18 insertions, 0 deletions

diff --git a/src/frame.h b/src/frame.h
index 154dc9a3bb4..4b7e448b543 100644
--- a/src/frame.h
+++ b/src/frame.h
@@ -65,6 +65,14 @@ enum internal_border_part
    INTERNAL_BORDER_BOTTOM_EDGE,
    INTERNAL_BORDER_BOTTOM_LEFT_CORNER,
   };
+
+#ifdef NS_IMPL_COCOA
+enum ns_appearance_type
+  {
+   ns_appearance_aqua,
+   ns_appearance_vibrant_dark
+  };
+#endif
 #endif /* HAVE_WINDOW_SYSTEM */
 
 /* The structure representing a frame.  */
@@ -563,6 +571,12 @@ struct frame
   /* All display backends seem to need these two pixel values.  */
   unsigned long background_pixel;
   unsigned long foreground_pixel;
+
+#ifdef NS_IMPL_COCOA
+  /* NSAppearance theme used on this frame.  */
+  enum ns_appearance_type ns_appearance;
+  bool_bf ns_transparent_titlebar;
+#endif
 };
 
 /* Most code should use these functions to set Lisp fields in struct frame.  */
@@ -953,6 +967,10 @@ default_pixels_per_inch_y (void)
 #define FRAME_Z_GROUP_ABOVE_SUSPENDED(f)        \
   ((f)->z_group == z_group_above_suspended)
 #define FRAME_Z_GROUP_BELOW(f) ((f)->z_group == z_group_below)
+#ifdef NS_IMPL_COCOA
+#define FRAME_NS_APPEARANCE(f) ((f)->ns_appearance)
+#define FRAME_NS_TRANSPARENT_TITLEBAR(f) ((f)->ns_transparent_titlebar)
+#endif
 #else /* not HAVE_WINDOW_SYSTEM */
 #define FRAME_UNDECORATED(f) ((void) (f), 0)
 #define FRAME_OVERRIDE_REDIRECT(f) ((void) (f), 0)