Re: Creating a "borderless" frame (without WM chrome) (was Re: Could x-show-tip be reimplemented in Elisp? How does one create borderless frames from Elisp?)

[martin rudalics <rudalics@gmx.at>]

 > * add a frame parameter to frame_parms in frame.c, say "chromeless"

I'd prefer "decorated" as in gtk_window_set-decorated.

 > * add an x_set_chromeless slot in each of frame_parm_handler x_frame_parm_handlers[], frame_parm_handler w32_frame_parm_handlers[], frame_parm_handler ns_frame_parm_handlers[]; for the last two point to 0 for now; for the first one point to a new function x_set_chromeless.
 > * In x-create-frame, add something like
 >      x_default_parameter (f, parms, Qchromeless, Qnil,
 >                           "chromeless", "Chromeless", RES_TYPE_BOOLEAN);

For X I doubt that it's always possible to add/remove the decorations of
an existing frame.  For Windows the below works here with

x_default_parameter (f, parameters, Qdecorated, Qnil,
                      "decorated", "Decorated", RES_TYPE_SYMBOL);

martin


void
x_set_decorated (struct frame *f, Lisp_Object decorated, Lisp_Object old_decorated)
{
   HWND hwnd = FRAME_W32_WINDOW (f);
   DWORD dwStyle = GetWindowLong (hwnd, GWL_STYLE);

   block_input ();
   if (EQ (decorated, Qnone))
     /* Remove caption and border.  */
     SetWindowLong (hwnd, GWL_STYLE, dwStyle & ~WS_CAPTION & ~WS_THICKFRAME);
   else if (EQ (decorated, Qtip_frame))
     /* Retain 1-pixel wide border.  */
     SetWindowLong (hwnd, GWL_STYLE, (dwStyle & ~WS_CAPTION & ~WS_THICKFRAME) | WS_POPUPWINDOW);
   else
     /* Restore decoration.  */
     SetWindowLong (hwnd, GWL_STYLE, dwStyle | WS_CAPTION | WS_THICKFRAME);

   /* Preserve outer position and size as well as Z-order.  */
   SetWindowPos (hwnd, NULL, 0, 0, 0, 0, SWP_FRAMECHANGED | SWP_NOMOVE
		| SWP_NOSIZE | SWP_NOZORDER | SWP_NOOWNERZORDER);
   unblock_input ();
}