From b7eb78397bc96c0e1bc2d280bd6660bbaa779790 Mon Sep 17 00:00:00 2001
From: Jared Finder <jared@finder.org>
Date: Sat, 31 Oct 2020 21:25:47 -0800
Subject: [PATCH] Face-changing text properties and help-echo now work with
 xterm-mouse.

* src/term.c (handle-lisp-mouse-motion): New function like
handle_one_term_event but only for mouse motion and with no GPM code.
* lisp/xt-mouse.el (xterm-mouse--handle-mouse-motion): New function that
calls 'handle-lisp-mouse-motion'.
(xterm-mouse-translate-1): Call 'xterm-mouse--handle-mouse-motion'.
---
 lisp/xt-mouse.el |  9 +++++++++
 src/term.c       | 28 ++++++++++++++++++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/lisp/xt-mouse.el b/lisp/xt-mouse.el
index f9c08f9a17..37550276f8 100644
--- a/lisp/xt-mouse.el
+++ b/lisp/xt-mouse.el
@@ -77,6 +77,7 @@ xterm-mouse-translate-1
               (copy-sequence event))
 	vec)
        (is-move
+        (xterm-mouse--handle-mouse-motion)
         (if track-mouse vec
           ;; Mouse movement events are currently supposed to be
           ;; suppressed.  Return no event.
@@ -106,8 +107,16 @@ xterm-mouse-translate-1
 	      (if (null track-mouse)
 		  (vector drag)
 		(push drag unread-command-events)
+                (xterm-mouse--handle-mouse-motion)
 		(vector (list 'mouse-movement ev-data))))))))))))
 
+(defun xterm-mouse--handle-mouse-motion ()
+  "Handle mouse motion that was just generated for XTerm mouse."
+  (let ((frame (selected-frame)))
+    (handle-lisp-mouse-motion frame
+                              (terminal-parameter frame 'xterm-mouse-x)
+                              (terminal-parameter frame 'xterm-mouse-y))))
+
 ;; These two variables have been converted to terminal parameters.
 ;;
 ;;(defvar xterm-mouse-x 0
diff --git a/src/term.c b/src/term.c
index ff1aabfed2..710b00e32f 100644
--- a/src/term.c
+++ b/src/term.c
@@ -2617,6 +2617,33 @@ handle_one_term_event (struct tty_display_info *tty, Gpm_Event *event,
   return count;
 }
 
+DEFUN ("handle-lisp-mouse-motion", Fhandle_lisp_mouse_motion,
+       Shandle_lisp_mouse_motion, 3, 3, 0,
+       doc: /* Handle mouse motion detected by Lisp code.
+
+This function should be called when Lisp code detects the mouse has
+moved, even if `track-mouse' is nil.  This handles updates that do not
+not rely on input events such as updating display for mouse-face
+proprties or updating the help echo text.  */)
+  (Lisp_Object frame, Lisp_Object mouse_x, Lisp_Object mouse_y)
+{
+  if (NILP (frame))
+    frame = selected_frame;
+
+  previous_help_echo_string = help_echo_string;
+  help_echo_string = Qnil;
+
+  note_mouse_highlight(XFRAME(frame), XFIXNUM (mouse_x), XFIXNUM (mouse_y));
+
+  if (!NILP (help_echo_string)
+      || !NILP (previous_help_echo_string))
+    {
+      gen_help_event (help_echo_string, frame, help_echo_window,
+                      help_echo_object, help_echo_pos);
+    }
+  return Qnil;
+}
+
 DEFUN ("gpm-mouse-start", Fgpm_mouse_start, Sgpm_mouse_start,
        0, 0, 0,
        doc: /* Open a connection to Gpm.
@@ -4568,6 +4595,7 @@ syms_of_term (void)
   defsubr (&Stty_top_frame);
   defsubr (&Ssuspend_tty);
   defsubr (&Sresume_tty);
+  defsubr (&Shandle_lisp_mouse_motion);
 #ifdef HAVE_GPM
   defsubr (&Sgpm_mouse_start);
   defsubr (&Sgpm_mouse_stop);
-- 
2.20.1