Re: Making TTY menus more visual

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

On 2020-10-03 1:50 am, Eli Zaretskii wrote:
>> Date: Fri, 02 Oct 2020 17:16:55 -0700
>> From: Jared Finder <jared@finder.org>
>> Cc: emacs-devel@gnu.org
>> 
>> I see the following things that need to change:
>> 
>> 1. Add a new command that calls menu-bar-open with the right value for
>> initial-x. (this is the patch 001 in the root of the thread)
> 
> But patch 001 also includes unrelated parts, the tmm-menubar-item-at-x
> function etc., right?

tmm-menubar-item-at-x is a new function to share the conversion of a 
mouse X to a specific menu item between tmm-menubar and the newly added 
command, menu-bar-open-mouse.

There's no new code there, it's the existing logic in tmm-menubar.

>> 2. In read_menu_input in term.c, additional logic needs to be added to
>> handle xterm mouse clicks since the focused menu item will not be
>> necessarily the one clicked on.
> 
> I'm not sure I understand how this can happen.  Can you describe the
> sequence of events that could lead to this, assuming tmm-menubar is
> NOT involved?  When TTY menus drop down from the menu bar, the focused
> item and the one clicked on should always coincide.  Any click on
> another item is a click "outside of the popped up menu", and that
> should dismiss the menu.
> 
>> Also, a user may click outside of the popped up menu, which they
>> would expect to dismiss the menu. (this is patch 002 in the root of
>> the thread, not yet complete)
> 
> This should already work; it does in the MS-Windows build when Emacs
> is invoked with -nw.  Please tell more why you think any changes there
> are needed.  Perhaps you could take me through the code there and
> explain what is missing and why.  (And why do you call posn-x-y in the
> patch when X and Y are already known and used by that code? is that
> because mouse_get_xy does not yet support xterm-mouse? if so, that
> support should be added via the terminal's mouse_position_hook.)

 From injecting debug logs into read_menu_input, I can observe that 
tty-menu-mouse-movement is never received so the highlighted item never 
changes except due to keyboard input. And from tracing 
xterm-mouse--read-event-sequence, it appears that Emacs normally does 
not receive xterm mouse motion events unless a button is pressed.

This appears to be due to xt-mouse sending event code 1002 instead of 
1003 (see 
https://invisible-island.net/xterm/ctlseqs/ctlseqs.html#h2-Mouse-Tracking).

Just sending 1003 instead doesn't just work, but I do see mouse events 
now coming through. Let me do some more investigation here and I will 
get back to you.

   -- MJF