+#ifdef HAVE_MOUSE
+
+/* Restore mouse tracking enablement. See Ftrack_mouse for the only use
+ of this function. */
+
+static Lisp_Object
+tracking_off (old_value)
+ Lisp_Object old_value;
+{
+ do_mouse_tracking = old_value;
+ if (NILP (old_value))
+ {
+ /* Redisplay may have been preempted because there was input
+ available, and it assumes it will be called again after the
+ input has been processed. If the only input available was
+ the sort that we have just disabled, then we need to call
+ redisplay. */
+ if (!readable_events (READABLE_EVENTS_DO_TIMERS_NOW))
+ {
+ redisplay_preserve_echo_area (6);
+ get_input_pending (&input_pending,
+ READABLE_EVENTS_DO_TIMERS_NOW);
+ }
+ }
+ return Qnil;
+}
+
+DEFUN ("track-mouse", Ftrack_mouse, Strack_mouse, 0, UNEVALLED, 0,
+ doc: /* Evaluate BODY with mouse movement events enabled.
+Within a `track-mouse' form, mouse motion generates input events that
+you can read with `read-event'.
+Normally, mouse motion is ignored.
+usage: (track-mouse BODY ...) */)
+ (args)
+ Lisp_Object args;
+{
+ int count = SPECPDL_INDEX ();
+ Lisp_Object val;
+
+ record_unwind_protect (tracking_off, do_mouse_tracking);
+
+ do_mouse_tracking = Qt;
+
+ val = Fprogn (args);
+ return unbind_to (count, val);
+}
+
+/* If mouse has moved on some frame, return one of those frames.
+ Return 0 otherwise. */
+
+static FRAME_PTR
+some_mouse_moved ()
+{
+ Lisp_Object tail, frame;
+
+ FOR_EACH_FRAME (tail, frame)
+ {
+ if (XFRAME (frame)->mouse_moved)
+ return XFRAME (frame);
+ }
+
+ return 0;
+}
+
+#endif /* HAVE_MOUSE */
+\f