Enabling Xterm-Mouse-Mode

Enabling Xterm-Mouse-Mode

[Philip Kaludercic]

Is there a reason that we do not enable `xterm-mouse-mode' in emacs -nw
by default?  Are there issues with the implementation that prevent the
change?

Re: Enabling Xterm-Mouse-Mode

[Eli Zaretskii]

> From: Philip Kaludercic <philipk@posteo.net>
> Date: Fri, 06 Dec 2024 08:51:01 +0000
> 
> 
> Is there a reason that we do not enable `xterm-mouse-mode' in emacs -nw
> by default?  Are there issues with the implementation that prevent the
> change?

Users might not expect that?  Certain escape sequences might not
really be mouse-related?

I've added Jared to this discussion.

Re: Enabling Xterm-Mouse-Mode

[Philip Kaludercic]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Philip Kaludercic <philipk@posteo.net>
>> Date: Fri, 06 Dec 2024 08:51:01 +0000
>> 
>> 
>> Is there a reason that we do not enable `xterm-mouse-mode' in emacs -nw
>> by default?  Are there issues with the implementation that prevent the
>> change?
>
> Users might not expect that?  Certain escape sequences might not
> really be mouse-related?

From observing people (often accidentally) using Emacs in my computer
labs, they do them to expect that.  Clicking to move the point is
something that people appear to do very intuitively, and the TUI menus
hint toward mouse-usage as well.

> I've added Jared to this discussion.

Re: Enabling Xterm-Mouse-Mode

[Jared Finder]

On 2024-12-06 03:50, Philip Kaludercic wrote:
> Eli Zaretskii <eliz@gnu.org> writes:
> 
>>> From: Philip Kaludercic <philipk@posteo.net>
>>> Date: Fri, 06 Dec 2024 08:51:01 +0000
>>> 
>>> 
>>> Is there a reason that we do not enable `xterm-mouse-mode' in emacs 
>>> -nw
>>> by default?  Are there issues with the implementation that prevent 
>>> the
>>> change?
>> 
>> Users might not expect that?  Certain escape sequences might not
>> really be mouse-related?
> 
> From observing people (often accidentally) using Emacs in my computer
> labs, they do them to expect that.  Clicking to move the point is
> something that people appear to do very intuitively, and the TUI menus
> hint toward mouse-usage as well.
> 
>> I've added Jared to this discussion.

As long as we can defer actually sending the mouse tracking escape 
sequence until after init file load I think this is fine. All terminals 
I've worked with work fine with xterm-mouse-mode's defaults, but since 
there's so many different terminals I want to ensure user compatibility 
variables still work (currently just xterm-mouse-utf-8, I expect to 
create a new one for bug #73469).

Also, I expect this would only be done when the envvar TERM indicates 
the user is on an xterm-compatible terminal.

   -- MJF

Re: Enabling Xterm-Mouse-Mode

[Richard Stallman]

[[[ To any NSA and FBI agents reading my email: please consider    ]]]
[[[ whether defending the US Constitution against all enemies,     ]]]
[[[ foreign or domestic, requires you to follow Snowden's example. ]]]

I get the impression that Xterm Mouse mode is meant for running
Emacs in an exterm.

What happens if you enable it when using a Linux console?

-- 
Dr Richard Stallman (https://stallman.org)
Chief GNUisance of the GNU Project (https://gnu.org)
Founder, Free Software Foundation (https://fsf.org)
Internet Hall-of-Famer (https://internethalloffame.org)

Re: Enabling Xterm-Mouse-Mode

[Eli Zaretskii]

> Date: Sat, 07 Dec 2024 16:37:46 -0800
> From: Jared Finder <jared@finder.org>
> Cc: Eli Zaretskii <eliz@gnu.org>, Emacs-devel@gnu.org
> 
> On 2024-12-06 03:50, Philip Kaludercic wrote:
> > Eli Zaretskii <eliz@gnu.org> writes:
> > 
> >>> From: Philip Kaludercic <philipk@posteo.net>
> >>> Date: Fri, 06 Dec 2024 08:51:01 +0000
> >>> 
> >>> 
> >>> Is there a reason that we do not enable `xterm-mouse-mode' in emacs 
> >>> -nw
> >>> by default?  Are there issues with the implementation that prevent 
> >>> the
> >>> change?
> >> 
> >> Users might not expect that?  Certain escape sequences might not
> >> really be mouse-related?
> > 
> > From observing people (often accidentally) using Emacs in my computer
> > labs, they do them to expect that.  Clicking to move the point is
> > something that people appear to do very intuitively, and the TUI menus
> > hint toward mouse-usage as well.
> > 
> >> I've added Jared to this discussion.
> 
> As long as we can defer actually sending the mouse tracking escape 
> sequence until after init file load I think this is fine. All terminals 
> I've worked with work fine with xterm-mouse-mode's defaults, but since 
> there's so many different terminals I want to ensure user compatibility 
> variables still work (currently just xterm-mouse-utf-8, I expect to 
> create a new one for bug #73469).

So this would require some changes in the code, to make sure the
escape sequences are delayed?

> Also, I expect this would only be done when the envvar TERM indicates 
> the user is on an xterm-compatible terminal.

How do we know which ones are compatible?

Re: Enabling Xterm-Mouse-Mode

[Philip Kaludercic]

Richard Stallman <rms@gnu.org> writes:

> [[[ To any NSA and FBI agents reading my email: please consider    ]]]
> [[[ whether defending the US Constitution against all enemies,     ]]]
> [[[ foreign or domestic, requires you to follow Snowden's example. ]]]
>
> I get the impression that Xterm Mouse mode is meant for running
> Emacs in an exterm.

Not just Xterm, but most terminal emulators.  But I guess that is a given.

> What happens if you enable it when using a Linux console?

From some superficial testing, it doesn't appear to affect anything.  I
know that there are TTYs with some kind of mouse support, I can try and
see if I can get that running on my system to test it out.

Re: Enabling Xterm-Mouse-Mode

[Jared Finder]

On 2024-12-07 22:07, Eli Zaretskii wrote:
>> Date: Sat, 07 Dec 2024 16:37:46 -0800
>> From: Jared Finder <jared@finder.org>
>> Cc: Eli Zaretskii <eliz@gnu.org>, Emacs-devel@gnu.org
>> 
>> As long as we can defer actually sending the mouse tracking escape
>> sequence until after init file load I think this is fine. All 
>> terminals
>> I've worked with work fine with xterm-mouse-mode's defaults, but since
>> there's so many different terminals I want to ensure user 
>> compatibility
>> variables still work (currently just xterm-mouse-utf-8, I expect to
>> create a new one for bug #73469).
> 
> So this would require some changes in the code, to make sure the
> escape sequences are delayed?

Yes, some changes, though they are straightforward.

>> Also, I expect this would only be done when the envvar TERM indicates
>> the user is on an xterm-compatible terminal.
> 
> How do we know which ones are compatible?

If Emacs decided to load term/xterm.el then the terminal advertised 
itself as xterm compatible and I think we could enable xterm-mouse-mode. 
There's no termcap entry for mouse support, sadly.

   -- MJF

Re: Enabling Xterm-Mouse-Mode

[Jared Finder]

On 2024-12-08 01:55, Philip Kaludercic wrote:
> Richard Stallman <rms@gnu.org> writes:
> 
>> [[[ To any NSA and FBI agents reading my email: please consider    ]]]
>> [[[ whether defending the US Constitution against all enemies,     ]]]
>> [[[ foreign or domestic, requires you to follow Snowden's example. ]]]
>> 
>> I get the impression that Xterm Mouse mode is meant for running
>> Emacs in an exterm.
> 
> Not just Xterm, but most terminal emulators.  But I guess that is a 
> given.
> 
>> What happens if you enable it when using a Linux console?
> 
> From some superficial testing, it doesn't appear to affect anything.  I
> know that there are TTYs with some kind of mouse support, I can try and
> see if I can get that running on my system to test it out.

Are you talking about GPM? That's what is used on Linux. In a pure Linux 
terminal ($TERM set to "linux"), xterm-mouse-mode doesn't appear to have 
any effect.

   -- MJF

Re: Enabling Xterm-Mouse-Mode

[Jared Finder]

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On 2024-12-08 08:35, Jared Finder wrote:
> On 2024-12-07 22:07, Eli Zaretskii wrote:
>>> Date: Sat, 07 Dec 2024 16:37:46 -0800
>>> From: Jared Finder <jared@finder.org>
>>> Cc: Eli Zaretskii <eliz@gnu.org>, Emacs-devel@gnu.org
>>> 
>>> As long as we can defer actually sending the mouse tracking escape
>>> sequence until after init file load I think this is fine. All 
>>> terminals
>>> I've worked with work fine with xterm-mouse-mode's defaults, but 
>>> since
>>> there's so many different terminals I want to ensure user 
>>> compatibility
>>> variables still work (currently just xterm-mouse-utf-8, I expect to
>>> create a new one for bug #73469).
>> 
>> So this would require some changes in the code, to make sure the
>> escape sequences are delayed?
> 
> Yes, some changes, though they are straightforward.
> 
>>> Also, I expect this would only be done when the envvar TERM indicates
>>> the user is on an xterm-compatible terminal.
>> 
>> How do we know which ones are compatible?
> 
> If Emacs decided to load term/xterm.el then the terminal advertised 
> itself as xterm compatible and I think we could enable 
> xterm-mouse-mode. There's no termcap entry for mouse support, sadly.

Relying on term/xterm.el being loaded made the patch very 
straightforward because it gets loaded after user init files.  Patch 
attached.

   -- MJF

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From eecc931e8dc58487cd710ef158fe1e216da0a717 Mon Sep 17 00:00:00 2001
From: Jared Finder <jared@finder.org>
Date: Mon, 9 Dec 2024 22:16:40 -0800
Subject: [PATCH] Enable xterm-mouse-mode by default in xterm

* lisp/xt-mouse.el (xterm-mouse-mode): Change default value of
xterm-mouse-mode to t.
* lisp/term/xterm.el (xterm--init): Enable xterm-mouse-mode if
the default value is still set.
* etc/NEWS: Document new behavior.
---
 etc/NEWS           | 6 ++++++
 lisp/term/xterm.el | 2 ++
 lisp/xt-mouse.el   | 2 ++
 3 files changed, 10 insertions(+)

diff --git a/etc/NEWS b/etc/NEWS
index 3efce149dbf..aebcf30d84a 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -41,6 +41,12 @@ why the mark trace buffer is enabled by default.
 \f
 * Startup Changes in Emacs 31.1
 
+** When run inside xterm, 'xterm-mouse-mode' is turned on by default.
+This means that the mouse will work by default inside xterm terminals.
+If your terminal does not behave properly with xterm mouse tracking
+enabled, you can disable mouse tracking by putting '(xterm-mouse-mode
+-1)' in your init file.
+
 \f
 * Changes in Emacs 31.1
 
diff --git a/lisp/term/xterm.el b/lisp/term/xterm.el
index 82f9a60b53b..c4f33cd0faa 100644
--- a/lisp/term/xterm.el
+++ b/lisp/term/xterm.el
@@ -907,6 +907,8 @@ xterm--init
 
   (when xterm-set-window-title
     (xterm--init-frame-title))
+  (when xterm-mouse-mode
+    (xterm-mouse-mode 1))
   ;; Unconditionally enable bracketed paste mode: terminals that don't
   ;; support it just ignore the sequence.
   (xterm--init-bracketed-paste-mode)
diff --git a/lisp/xt-mouse.el b/lisp/xt-mouse.el
index 8cbb44ece14..c77d763702c 100644
--- a/lisp/xt-mouse.el
+++ b/lisp/xt-mouse.el
@@ -358,6 +358,8 @@ xterm-mouse-mode
 mouse functionality for such clicks is still available by holding
 down the SHIFT key while pressing the mouse button."
   :global t :group 'mouse
+  :init-value t
+  :version "31.1"
   (funcall (if xterm-mouse-mode 'add-hook 'remove-hook)
            'terminal-init-xterm-hook
            'turn-on-xterm-mouse-tracking-on-terminal)
-- 
2.39.5

Re: Enabling Xterm-Mouse-Mode

[Richard Stallman]

[[[ To any NSA and FBI agents reading my email: please consider    ]]]
[[[ whether defending the US Constitution against all enemies,     ]]]
[[[ foreign or domestic, requires you to follow Snowden's example. ]]]

  > Are you talking about GPM? That's what is used on Linux.

I don't recognize the name GPM.  As far as I know, I am using the
default tty that I can get to by tyming Meta-F1, Meta-F2, and so on.

-- 
Dr Richard Stallman (https://stallman.org)
Chief GNUisance of the GNU Project (https://gnu.org)
Founder, Free Software Foundation (https://fsf.org)
Internet Hall-of-Famer (https://internethalloffame.org)

Re: Enabling Xterm-Mouse-Mode

[Jared Finder]

On 2024-12-10 23:33, Richard Stallman wrote:
> [[[ To any NSA and FBI agents reading my email: please consider    ]]]
> [[[ whether defending the US Constitution against all enemies,     ]]]
> [[[ foreign or domestic, requires you to follow Snowden's example. ]]]
> 
>   > Are you talking about GPM? That's what is used on Linux.
> 
> I don't recognize the name GPM.  As far as I know, I am using the
> default tty that I can get to by tyming Meta-F1, Meta-F2, and so on.

Those are terminals provided by the Linux kernel. They report themselves 
as TERM=linux and so Emacs loads term/linux.el at startup. This wouldn't 
be affected by enabling xterm-mouse-mode for xterm, which instead loads 
term/xterm.el.

   -- MJF