Re: mouse-face and help echo support for xterm mouse

[Jared Finder via "Emacs development discussions." <emacs-devel@gnu.org>]

On 2020-11-01 5:39 am, Stefan Monnier wrote:
> Hi Jared,
> 
> I really like this new feature but have just one comment/question?
> 
>> +  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);
>> +    }
> 
> I see this exact same code in other C files.
> Could we move it to a file where we can share it instead of having
> N copies?

I completely agree, not just for this code but also for mouse handling 
in general.  I think there should be a shared mouse interface with 
individual C functions for each type of mouse event: mouse move, mouse 
click, etc.  Translating OS-specific events to this shared functionality 
would continue to be OS-specific, but the actual handling of these 
events, such as this logic, would be fully shared.  For example, this 
would unify the different codepaths between TTY menus for GPM, 
xterm-mouse, and NT Emacs.

I would be happy to help with this next.  However I need some help.  I 
can only locally build and test for Linux terminal with xterm-mouse or 
GPM handling the mouse.  Is there someone who can help for other 
platforms?  And should the GUI platforms be included as well?  (I 
suspect yes is the right answer.)

   -- MJF