Implement `follow-tooltip' on NS as well

* lisp/term/ns-win.el (x-begin-drag): Pass `follow-tooltip'.
* src/nsfns.m (Fx_show_tip): Record last dx and dy.
(syms_of_nsfns): New staticpros.
* src/nsmenu.m ([EmacsTooltip moveTo:]): New method.

* src/nsselect.m (Fns_begin_drag): New parameter
`follow-tooltip'.

* src/nsterm.h (@interface EmacsWindow):
(EmacsTooltip): Update prototypes.
* src/nsterm.m ([EmacsWindow draggedImage:movedTo:]): Move any
tooltip to the right location.
([EmacsWindow beginDrag:forPasteboard...]): New parameter
`followTooltip'.

1 files changed, 8 insertions, 4 deletions

diff --git a/src/nsselect.m b/src/nsselect.m
index 6831090aa20..c46bfeaf42a 100644
--- a/src/nsselect.m
+++ b/src/nsselect.m
@@ -703,7 +703,7 @@ ns_dnd_action_from_operation (NSDragOperation operation)
     }
 }
 
-DEFUN ("ns-begin-drag", Fns_begin_drag, Sns_begin_drag, 3, 5, 0,
+DEFUN ("ns-begin-drag", Fns_begin_drag, Sns_begin_drag, 3, 6, 0,
        doc: /* Begin a drag-and-drop operation on FRAME.
 
 FRAME must be a window system frame.  PBOARD is an alist of (TYPE
@@ -729,9 +729,12 @@ other non-nil value means to do the same, but to wait for the mouse to
 leave FRAME first.
 
 If ALLOW-SAME-FRAME is nil, dropping on FRAME will result in the drop
-being ignored.  */)
+being ignored.
+
+FOLLOW-TOOLTIP means the same thing it does in `x-begin-drag'.  */)
   (Lisp_Object frame, Lisp_Object pboard, Lisp_Object action,
-   Lisp_Object return_frame, Lisp_Object allow_same_frame)
+   Lisp_Object return_frame, Lisp_Object allow_same_frame,
+   Lisp_Object follow_tooltip)
 {
   struct frame *f, *return_to;
   NSPasteboard *pasteboard;
@@ -761,7 +764,8 @@ being ignored.  */)
                   forPasteboard: pasteboard
                        withMode: mode
                   returnFrameTo: &return_to
-                   prohibitSame: (BOOL) NILP (allow_same_frame)];
+                   prohibitSame: (BOOL) NILP (allow_same_frame)
+                  followTooltip: (BOOL) !NILP (follow_tooltip)];
 
   if (return_to)
     {