not too happy with Emacs 21 vertical-line dragging when scroll bars present

not too happy with Emacs 21 vertical-line dragging when scroll bars present

[Drew Adams]

GNU Emacs 21.3.50.1 (i386-mingw-nt5.1.2600) of 2004-07-26 on BERATUNG4,
Windows XP SP1.

This may be Windows specific; I don't know.

In Emacs 20, the mode line did not extend under a vertical scroll bar (or
under a vertical line) -- there was a small (~4mm) square that you could
drag with the mouse to resize the window.

In Emacs 21, this small but visible "drag handle" has disappeared. If you
position the mouse _very_ carefully along the mode line at the window
division, you can grab and drag the divider. However, this effective drag
handle is _very_ small and not obvious at all (only the cursor change
indicates its presence).

Also, if you have two horizontally adjacent windows and try to drag the
divider, you actually need to place the mouse slightly to the right of the
divider, so that it is well over the right mode line, not the left (even
though it is the left mode line that extends under the scroll bar). This is
not intuitive at all.

If you try to grab & drag directly under the scroll bar (as in Emacs 20),
you grab the left mode line, and nothing happens (no drag cursor). If you
grab slightly to the right of this, at the right edge of the scroll bar, in
the modeline (that is, _at_ the vertical line that separates the windows),
then you see the drag cursor (so everything looks OK), but you also get this
error message: "Attempt to drag leftmost scrollbar".

There is no reason for this. Intuitively, that is just what you _want_ to
do: drag the "leftmost" scrollbar - that is, drag the only vertical
separation you see between the two windows. You certainly don't want to (and
cannot) drag the _rightmost_ scrollbar/vertical line!

To be able to drag the vertical line, you must in fact grab it slightly to
the right of the visible vertical line, that is, to the right of the right
edge of the scroll bar, so that you are well over the right mode line. The
proper position appears to be at the right edge of the fringe! Dragging here
also activates the right mode line, for no reason that I can see. All of
this is not very intuitive.

__Any chance we can get back the small square of real estate under the
scroll bar as a drag handle?__   It was a great visual clue to the existence
of a drag handle, and it was large enough to function as such. Ideal would
be to put a tiny drag-handle-cursor image (<-->) in this square, and leave
it there all the time.


Related enhancement request: If we had the small, visible drag handle of
Emacs 20 (as suggested above), then we could bind not just
mouse-drag-vertical-line, but a command that does this:

(if (one-window-p t)
    (resize-frame)
  (mouse-drag-vertical-line start-event))

That is, if there is only one window, you can click this spot to resize the
frame to fit the selected window. (`resize-frame' is not yet part of Emacs,
but is available for inclusion --
http://www.emacswiki.org/elisp/resize-frame.el.)

 - Drew

RE: not too happy with Emacs 21 vertical-line dragging when scroll bars present

[Drew Adams]

Update - I don't know why, but I've tried this again and cannot reproduce
the "Attempt to drag leftmost scrollbar" error in another Emacs session. I
still have an Emacs session open that gives me the error (systematically),
but when I try on new sessions (same version of Emacs, and -q in all cases),
I don't get the error message.

Here's the backtrace (although it's not very helpful):
Debugger entered--Lisp error: (error "Attempt to drag leftmost scrollbar")
  signal(error ("Attempt to drag leftmost scrollbar"))
  error("Attempt to drag leftmost scrollbar")
  mouse-drag-vertical-line((down-mouse-1 (#<window 3 on *Help*>
vertical-line (300 . 344) 7448410 nil 342 (0 . 8) nil (0 . 215) (1 . 16))))
  call-interactively(mouse-drag-vertical-line)

In the session with the bug, the only buffers I have are these: *Help*,
*info*, *scratch*, and *Messages*. I have default values for everything, and
I have a single frame split vertically with *info* at the bottom, *Help* at
the top left, and *scratch* at the top right (although I doubt that is
significant). In case it helps, I've included the *Messages* buffer
contents, below.

I don't remember having done anything special, but, as I say, I can't seem
to reproduce it in other Emacs sessions.

Also, in the non-bugged sessions, the drag-handle is closer to  where it
should be: you do not need to grab over the right mode line (in fact, you
cannot); you must grab at the mode-line division or slightly to the left.

In any case, I still would like to see a visible drag handle area, as I
described, even in the case of a single-window frame.

HTH,

 - Drew

-------------------8<---------*Messages* buffer-------------
Searching subfile emacs-5...
Searching subfile emacs-6...
Searching subfile emacs-7...
Searching subfile emacs-8...
Searching subfile emacs-9...
Searching subfile emacs-10...
Searching subfile emacs-11...
Searching subfile emacs-12...
Searching subfile emacs-13...
Searching subfile emacs-14...
Searching subfile emacs-15...
Searching subfile emacs-16...
Searching subfile emacs-17...
Searching subfile emacs-18...
Searching subfile emacs-19...
Searching subfile emacs-20...
Searching subfile emacs-21...
Searching subfile emacs-22...
Searching subfile emacs-23...
Searching subfile emacs-24...
Searching subfile emacs-25...
Searching subfile emacs-26...
Searching subfile emacs-27...
Quit [2 times]
Loading debug...done
Entering debugger...
Back to top level.
Entering debugger...
Back to top level.
nil [2 times]
mouse-drag-vertical-line: Attempt to drag leftmost scrollbar [9 times]
Type C-x 4 b RET to restore the other window.  C-M-v to scroll the help.
mouse-drag-vertical-line: Attempt to drag leftmost scrollbar [2 times]
Note, built-in variable `x-use-underline-position-properties' not bound
Debug on Error enabled
Entering debugger...
mouse-drag-vertical-line: Attempt to drag leftmost scrollbar
Back to top level.
Entering debugger...
Back to top level.
Entering debugger...
Debug on Error enabled
Entering debugger...
Back to top level.
Entering debugger...
byte-code: Buffer is read-only: #<buffer *Help*>
Back to top level.
Debug on Error disabled
mouse-drag-vertical-line: Attempt to drag leftmost scrollbar [5 times]

-------------------8<---------end *Messages* buffer-------------


-----Original Message-----
From: Drew Adams [mailto:drew.adams@oracle.com]
Sent: Wednesday, September 29, 2004 10:54 AM
To: emacs-devel@gnu.org; help-gnu-emacs@gnu.org; bug-gnu-emacs@gnu.org
Subject: not too happy with Emacs 21 vertical-line dragging when scroll
bars present


GNU Emacs 21.3.50.1 (i386-mingw-nt5.1.2600) of 2004-07-26 on BERATUNG4,
Windows XP SP1.

This may be Windows specific; I don't know.

In Emacs 20, the mode line did not extend under a vertical scroll bar (or
under a vertical line) -- there was a small (~4mm) square that you could
drag with the mouse to resize the window.

In Emacs 21, this small but visible "drag handle" has disappeared. If you
position the mouse _very_ carefully along the mode line at the window
division, you can grab and drag the divider. However, this effective drag
handle is _very_ small and not obvious at all (only the cursor change
indicates its presence).

Also, if you have two horizontally adjacent windows and try to drag the
divider, you actually need to place the mouse slightly to the right of the
divider, so that it is well over the right mode line, not the left (even
though it is the left mode line that extends under the scroll bar). This is
not intuitive at all.

If you try to grab & drag directly under the scroll bar (as in Emacs 20),
you grab the left mode line, and nothing happens (no drag cursor). If you
grab slightly to the right of this, at the right edge of the scroll bar, in
the modeline (that is, _at_ the vertical line that separates the windows),
then you see the drag cursor (so everything looks OK), but you also get this
error message: "Attempt to drag leftmost scrollbar".

There is no reason for this. Intuitively, that is just what you _want_ to
do: drag the "leftmost" scrollbar - that is, drag the only vertical
separation you see between the two windows. You certainly don't want to (and
cannot) drag the _rightmost_ scrollbar/vertical line!

To be able to drag the vertical line, you must in fact grab it slightly to
the right of the visible vertical line, that is, to the right of the right
edge of the scroll bar, so that you are well over the right mode line. The
proper position appears to be at the right edge of the fringe! Dragging here
also activates the right mode line, for no reason that I can see. All of
this is not very intuitive.

__Any chance we can get back the small square of real estate under the
scroll bar as a drag handle?__   It was a great visual clue to the existence
of a drag handle, and it was large enough to function as such. Ideal would
be to put a tiny drag-handle-cursor image (<-->) in this square, and leave
it there all the time.


Related enhancement request: If we had the small, visible drag handle of
Emacs 20 (as suggested above), then we could bind not just
mouse-drag-vertical-line, but a command that does this:

(if (one-window-p t)
    (resize-frame)
  (mouse-drag-vertical-line start-event))

That is, if there is only one window, you can click this spot to resize the
frame to fit the selected window. (`resize-frame' is not yet part of Emacs,
but is available for inclusion --
http://www.emacswiki.org/elisp/resize-frame.el.)

 - Drew

Re: not too happy with Emacs 21 vertical-line dragging when scroll bars present

[Richard Stallman]

    Here's the backtrace (although it's not very helpful):
    Debugger entered--Lisp error: (error "Attempt to drag leftmost scrollbar")
      signal(error ("Attempt to drag leftmost scrollbar"))
      error("Attempt to drag leftmost scrollbar")
      mouse-drag-vertical-line((down-mouse-1 (#<window 3 on *Help*>
    vertical-line (300 . 344) 7448410 nil 342 (0 . 8) nil (0 . 215) (1 . 16))))
      call-interactively(mouse-drag-vertical-line)

What happens if you install an interpreted version of
mouse-drag-vertical-line in that session?  Does the bug still happen?
If so, you can get some real info from the backtrace when
it is running interpreted.

RE: not too happy with Emacs 21 vertical-line dragging when scrollbars present

[Drew Adams]

You're right. I should have thought of that.

I'm sorry, but I've since rebooted, so I no longer have that session (and I
can't reproduce that part of the problem).

Again, though, it would still be good to have the entire (small) space under
the vertical scroll bar as drag handle (even for the rightmost window), for
the reasons I mentioned. And there is no reason that the mode line should
seem to be selected or become active, just because you use the drag handle.
IOW, the Emacs 20 behavior is preferable in terms of usability: more
intuitive, more visible feedback (visible affordance), and an easier handle
to grab.

 - Drew

-----Original Message-----
From: Richard Stallman [mailto:rms@gnu.org]
Sent: Thursday, September 30, 2004 9:00 AM
To: Drew Adams
Cc: bug-gnu-emacs@gnu.org
Subject: Re: not too happy with Emacs 21 vertical-line dragging when
scrollbars present


    Here's the backtrace (although it's not very helpful):
    Debugger entered--Lisp error: (error "Attempt to drag leftmost
scrollbar")
      signal(error ("Attempt to drag leftmost scrollbar"))
      error("Attempt to drag leftmost scrollbar")
      mouse-drag-vertical-line((down-mouse-1 (#<window 3 on *Help*>
    vertical-line (300 . 344) 7448410 nil 342 (0 . 8) nil (0 . 215) (1 .
16))))
      call-interactively(mouse-drag-vertical-line)

What happens if you install an interpreted version of
mouse-drag-vertical-line in that session?  Does the bug still happen?
If so, you can get some real info from the backtrace when
it is running interpreted.

Re: not too happy with Emacs 21 vertical-line dragging when scrollbars present

[Richard Stallman]

    The squares where the `.' are were visible drag handles for the windows.

ISTR that we never thought of them as having a purpose; they were
simply unused space.  So we used them to make the mode line bigger,
without realizing anything useful was being taken away.

At Lisp level you could put a different meaning on clicks on the first
two characters of the mode line.  Want to try that?  It would be
desirable to change what those two characters look like, so as to give
a visual hint.

RE: not too happy with Emacs 21 vertical-line dragging when scrollbars present

[Drew Adams]

I'm not surprised that this was not thought of :-).

[ BTW, at one point with Emacs 20 (or 19?) I discovered by chance that I
could bind that small square using `nil' as the key! Later this hack
possibility was removed:
(global-set-key [nil down-mouse-1] 'shrink-frame-to-fit) ]

Anyway... I think you mean the two mode-line characters next to  the scroll
bar. In my case, the scroll bar is on the right, so these would be the last
(rightmost) two characters.

If I understand you correctly, you are saying:

1. Leave the mode line extended under the scroll bar.
2. But change the part of it that is under the scroll bar to show a
drag-handle graphic (image/glyph), indicating that you can drag that spot.

Is that right? If so, that's not a bad suggestion. And it would satisfy
Kim's criterion that we visually associate the scroll bar with its window. I
had been complaining that the drag handle had nothing to do with
(activating) the mode line, but I think your proposal is a good one.

I can take a look at this, if no one else is interested in hacking it.  It
would be better, however, for someone already familiar with programming the
new mode line to take a crack at it. I'll see what I can do, when I get some
time. If this is simple to do, then someone please send the few lines of
code needed.

Also, is it straightforward to use something like the drag-handle mouse
pointer as the glyph for those two mode-line characters? Suggestions
appreciated.

Thanks,

  Drew


-----Original Message-----
From: Richard Stallman [mailto:rms@gnu.org]
Sent: Monday, October 04, 2004 8:19 AM
To: Drew Adams
Cc: emacs-devel@gnu.org
Subject: Re: not too happy with Emacs 21 vertical-line dragging when
scrollbars present


    The squares where the `.' are were visible drag handles for the windows.

ISTR that we never thought of them as having a purpose; they were
simply unused space.  So we used them to make the mode line bigger,
without realizing anything useful was being taken away.

At Lisp level you could put a different meaning on clicks on the first
two characters of the mode line.  Want to try that?  It would be
desirable to change what those two characters look like, so as to give
a visual hint.

Re: not too happy with Emacs 21 vertical-line dragging when scrollbars present

[Miles Bader]

On Mon, Oct 04, 2004 at 11:12:39AM -0700, Drew Adams wrote:
> Also, is it straightforward to use something like the drag-handle mouse
> pointer as the glyph for those two mode-line characters? Suggestions
> appreciated.

I think that would be a bit too visually aggressive -- it's a rarely used
function, so it shouldn't be something that constantly draws one's eye.

-Miles
-- 
"Whatever you do will be insignificant, but it is very important that
 you do it."  Mahatma Ghandi

RE: not too happy with Emacs 21 vertical-line dragging when scrollbars present

[Drew Adams]

The idea is to have something that visually indicates what this small spot
is for. Are you suggesting a different glyph (fine) or none at all? Or what?

Let see ... something that no one can see has rarely been used...
Can you say "self-fulfilling retro-prophecy"?

Reminds me of when a former Gaullist French foreign minister said, of
independendists in New Caledonia, "Ever since we stopped listening to them,
we haven't heard a word from them."  Works every time...

 - Drew

-----Original Message-----
From: Miles Bader [mailto:miles@gnu.org]

> Also, is it straightforward to use something like the drag-handle mouse
> pointer as the glyph for those two mode-line characters? Suggestions
> appreciated.

I think that would be a bit too visually aggressive -- it's a rarely used
function, so it shouldn't be something that constantly draws one's eye.

Re: not too happy with Emacs 21 vertical-line dragging when scrollbars present

[Miles Bader]

"Drew Adams" <drew.adams@oracle.com> writes:
> The idea is to have something that visually indicates what this small spot
> is for. Are you suggesting a different glyph (fine) or none at all? Or what?

I don't know; I'm mainly concerned that it not draw attention to itself.
A different glyph might be suitable, but at least on my system, the drag
cursor is quite large and noticeable.

I don't think that it's easy to get cursor glyphs from X, so I guess
it'd have to be a custom bitmap anyway.

> Let see ... something that no one can see has rarely been used...
> Can you say "self-fulfilling retro-prophecy"?

It doesn't matter.  This feature is not so important that it's worth
making general emacs usage worse to "advertise it"; if it's useful,
people will find it via documentation (incl. tool-tips) and word of
mouth anyway.

Of course, it would be best if there's a compromise:  For instance, a
much lighter-weight version of the usual drag cursor, or something that
looks like the sort of "grab-handle" Gnome themes usually use.

-Miles
-- 
Love is a snowmobile racing across the tundra.  Suddenly it flips over,
pinning you underneath.  At night the ice weasels come.  --Nietzsche

RE: not too happy with Emacs 21 vertical-line dragging when scrollbars present

[Drew Adams]

I'm open wrt what symbol to use, and I'm not arguing that it be obtrusive. I
don't think we disagree.

My question was really about how to do this. I have no experience with the
new mode line or using bitmaps etc. I'll consult the Emacs doc (when I get
around to this), but if someone has a pointer or two now, it would be
appreciated.

 - Drew

-----Original Message-----
From: Miles Bader [mailto:miles@lsi.nec.co.jp]
Sent: Monday, October 04, 2004 6:33 PM
To: Drew Adams
Cc: rms@gnu.org; emacs-devel@gnu.org
Subject: Re: not too happy with Emacs 21 vertical-line dragging when
scrollbars present


"Drew Adams" <drew.adams@oracle.com> writes:
> The idea is to have something that visually indicates what this small spot
> is for. Are you suggesting a different glyph (fine) or none at all? Or
what?

I don't know; I'm mainly concerned that it not draw attention to itself.
A different glyph might be suitable, but at least on my system, the drag
cursor is quite large and noticeable.

I don't think that it's easy to get cursor glyphs from X, so I guess
it'd have to be a custom bitmap anyway.

> Let see ... something that no one can see has rarely been used...
> Can you say "self-fulfilling retro-prophecy"?

It doesn't matter.  This feature is not so important that it's worth
making general emacs usage worse to "advertise it"; if it's useful,
people will find it via documentation (incl. tool-tips) and word of
mouth anyway.

Of course, it would be best if there's a compromise:  For instance, a
much lighter-weight version of the usual drag cursor, or something that
looks like the sort of "grab-handle" Gnome themes usually use.

Re: not too happy with Emacs 21 vertical-line dragging when scrollbars present

[Kim F. Storm]

"Drew Adams" <drew.adams@oracle.com> writes:

> I'm open wrt what symbol to use, and I'm not arguing that it be obtrusive. I
> don't think we disagree.

Personally, I don't think a symbol is needed ...  

Admittedly, it is not very intuitive that you can drag the small line
between mode lines, but the cursor does change to a <-> arrow when over
that line.

It would be much better if we could find a way to just drag the
scroll-bar.

One way would be to always make a tiny area between windows that you
could drag.  But unless we do it by reducing the qscroll bar width,
that would take away space that is now used for text display.

>
> My question was really about how to do this. I have no experience with the
> new mode line or using bitmaps etc. I'll consult the Emacs doc (when I get
> around to this), but if someone has a pointer or two now, it would be
> appreciated.

You can easily make a drag-able area to the left of the modeline, but
one problem with this is that the lisp code expects to be using the
window on the left side of the vertical line, not the right window --
you would have to modify the lisp code to deal with this.

It is much harder (impossible) to make a drag-able area to the right
of the modeline, as there is no fixed right edge of the modeline at the
lisp level [the modeline is simply truncated by redisplay].

But I think we have bigger issues to think about for the next release,
so I suggest that we postpone this discussion...

-- 
Kim F. Storm <storm@cua.dk> http://www.cua.dk

RE: not too happy with Emacs 21 vertical-line dragging when scrollbars present

[Drew Adams]

I still think that a visible affordance would be good; I'm not a fan of
having to discover things by accidentally mousing over them (or searching
for them by mousing around).

I agree that we don't want to reduce window real estate in any way for this.

You & RMS both mentioned a draggable area to the _left_ of the mode line.
Until now, I thought that was a typo. I thought Richard meant the _right_
end of the mode line that is to the _left_ of the scroll bar. Now I
understand that you're both speaking of the _left_ end of the mode line that
is to the _right_ of the scroll bar - is that correct? That is, the proposed
area to resize the left window is to the right of the window's scroll bar,
not underneath the scroll bar.

If so, then I don't think that would be very cool. Usable, but ugly.

Anyway, I agree that we should just forget about this for now -- if there's
no way to recuperate the space under the scroll bar. Perhaps an elegant
solution will make itself evident sometime in the future.

 - Drew

-----Original Message-----
From: Kim F. Storm [mailto:storm@cua.dk]
Sent: Tuesday, October 05, 2004 1:21 AM
To: Drew Adams
Cc: Miles Bader; rms@gnu.org; emacs-devel@gnu.org
Subject: Re: not too happy with Emacs 21 vertical-line dragging when
scrollbars present


"Drew Adams" <drew.adams@oracle.com> writes:

> I'm open wrt what symbol to use, and I'm not arguing that it be obtrusive.
I
> don't think we disagree.

Personally, I don't think a symbol is needed ...

Admittedly, it is not very intuitive that you can drag the small line
between mode lines, but the cursor does change to a <-> arrow when over
that line.

It would be much better if we could find a way to just drag the
scroll-bar.

One way would be to always make a tiny area between windows that you
could drag.  But unless we do it by reducing the qscroll bar width,
that would take away space that is now used for text display.

>
> My question was really about how to do this. I have no experience with the
> new mode line or using bitmaps etc. I'll consult the Emacs doc (when I get
> around to this), but if someone has a pointer or two now, it would be
> appreciated.

You can easily make a drag-able area to the left of the modeline, but
one problem with this is that the lisp code expects to be using the
window on the left side of the vertical line, not the right window --
you would have to modify the lisp code to deal with this.

It is much harder (impossible) to make a drag-able area to the right
of the modeline, as there is no fixed right edge of the modeline at the
lisp level [the modeline is simply truncated by redisplay].

But I think we have bigger issues to think about for the next release,
so I suggest that we postpone this discussion...

--
Kim F. Storm <storm@cua.dk> http://www.cua.dk

Re: not too happy with Emacs 21 vertical-line dragging when scrollbars present

[Richard Stallman]

    I think that would be a bit too visually aggressive -- it's a rarely used
    function, so it shouldn't be something that constantly draws one's eye.

It has to make itself seen somehow, or users won't think of using it.

Re: not too happy with Emacs 21 vertical-line dragging when scrollbars present

[Richard Stallman]

    If I understand you correctly, you are saying:

    1. Leave the mode line extended under the scroll bar.
    2. But change the part of it that is under the scroll bar to show a
    drag-handle graphic (image/glyph), indicating that you can drag that spot.

This is much easier to do right for the default case of scroll bars
on the left.  However, to implement this would require doing it also
for the case of scroll bars on the right.

Re: not too happy with Emacs 21 vertical-line dragging when scrollbars present

[Richard Stallman]

    It would be much better if we could find a way to just drag the
    scroll-bar.

Dragging in the scroll bar has another meaning.

    One way would be to always make a tiny area between windows that you
    could drag.  But unless we do it by reducing the qscroll bar width,
    that would take away space that is now used for text display.

We DID have a tiny area, at the bottom of the scroll bar.  Drew is
complaining that we got rid of it.  It is much easier to use a square
than a very thin rectangle.  It is hard to put the mouse on the
latter.

    It is much harder (impossible) to make a drag-able area to the right
    of the modeline, as there is no fixed right edge of the modeline at the
    lisp level [the modeline is simply truncated by redisplay].

It would be hard to do it at the right using mode-line-format.
It would be easy to add a new feature that would override part
of the mode line at the right when appropriate.

Re: not too happy with Emacs 21 vertical-line dragging when scrollbars present

[Stefan Monnier]

>     It would be much better if we could find a way to just drag the
>     scroll-bar.

> Dragging in the scroll bar has another meaning.

I could imagine distinguishing the act of dragging (vertically) the thumb in
the scrollbar from the act of dragging (horizontally) the actual scrollbar.

Emacs could use different mouse buttons to tell which action is desired.
The problem is that Emacs doesn't see any of those events anyway since
they're all handled directly by the toolkit that provides the scrollbar.


        Stefan

Re: not too happy with Emacs 21 vertical-line dragging when scrollbars present

[Kim F. Storm]

Richard Stallman <rms@gnu.org> writes:

>     It would be much better if we could find a way to just drag the
>     scroll-bar.
>
> Dragging in the scroll bar has another meaning.
>
>     One way would be to always make a tiny area between windows that you
>     could drag.  But unless we do it by reducing the qscroll bar width,
>     that would take away space that is now used for text display.
>
> We DID have a tiny area, at the bottom of the scroll bar.  Drew is
> complaining that we got rid of it.  It is much easier to use a square
> than a very thin rectangle.  It is hard to put the mouse on the
> latter.

That's not correct.  It is easy to put the cursor on that tiny line!  

The code uses a relaxed check so that if the mouse is within ONE
COLUMN on either side of the line, the cursor changes to the <-> drag
cursor.  So there is already a virtual block area there which is TWO
COLUMS wide there.


>
>     It is much harder (impossible) to make a drag-able area to the right
>     of the modeline, as there is no fixed right edge of the modeline at the
>     lisp level [the modeline is simply truncated by redisplay].
>
> It would be hard to do it at the right using mode-line-format.
> It would be easy to add a new feature that would override part
> of the mode line at the right when appropriate.

Personally, I see no reason to make that explicitly stand out more
than it already does...

-- 
Kim F. Storm <storm@cua.dk> http://www.cua.dk

RE: not too happy with Emacs 21 vertical-line dragging when scrollbars present

[Drew Adams]

I don't want to stir this pot much more, but, for clarification:

 - I thought that Kim's original text, quoted by Richard, was talking about
letting you drag the scroll-bar itself, not dragging below it on the
mode-line. Is that right?

 - I thought that Richard's reply was taking about this thin vertical strip
that Kim proposed perhaps adding between windows. Is that right?

 - If so, then I don't understand Kim's reply, saying that we already have
such a feature - that it's easy to use "that thin line" to drag. Is the thin
line in question the current thin line between _mode-lines_, or the tiny
area between _windows_ that Kim proposed adding?

To me, needing to mouse-over the scroll-bar to get the drag handle would be
OK. The scroll-bar is big, obvious, and conceptually that's just what you
want to do: drag the scroll-bar. Needing to mouse-over to find the existing
tiny thin line between _mode-lines_, however, is not good. Intuitively, you
don't go mousing around between two mode-lines to find where to drag the
scroll-bar.

So, just what thin, vertical rectangle are we talking about here: a
potential one to be added between windows or the existing one between
mode-lines?

--

To speak to a different part of this subject, Richard said this:

  It would be hard to do it at the right using mode-line-format.
  It would be easy to add a new feature that would override part
  of the mode line at the right when appropriate.

If I understand this correctly, he is saying that, in effect, that we could
get back the small, visible drag-handle square beneath the scroll-bar that
we had in Emacs 20. That would be good. If, alternatively, a way could be
found to let users drag the scroll-bar itself, that would be even better.

 - Drew

-----Original Message-----
From: Kim F. Storm [mailto:storm@cua.dk]

Richard Stallman <rms@gnu.org> writes:

>     It would be much better if we could find a way to just drag the
>     scroll-bar.
>
> Dragging in the scroll bar has another meaning.
>
>     One way would be to always make a tiny area between windows that you
>     could drag.  But unless we do it by reducing the qscroll bar width,
>     that would take away space that is now used for text display.
>
> We DID have a tiny area, at the bottom of the scroll bar.  Drew is
> complaining that we got rid of it.  It is much easier to use a square
> than a very thin rectangle.  It is hard to put the mouse on the
> latter.

That's not correct.  It is easy to put the cursor on that tiny line!

The code uses a relaxed check so that if the mouse is within ONE
COLUMN on either side of the line, the cursor changes to the <-> drag
cursor.  So there is already a virtual block area there which is TWO
COLUMS wide there.


>
>     It is much harder (impossible) to make a drag-able area to the right
>     of the modeline, as there is no fixed right edge of the modeline at
the
>     lisp level [the modeline is simply truncated by redisplay].
>
> It would be hard to do it at the right using mode-line-format.
> It would be easy to add a new feature that would override part
> of the mode line at the right when appropriate.

Personally, I see no reason to make that explicitly stand out more
than it already does...

Re: not too happy with Emacs 21 vertical-line dragging when scrollbars present

[Kim F. Storm]

"Drew Adams" <drew.adams@oracle.com> writes:

> I don't want to stir this pot much more, but, for clarification:
>
>  - I thought that Kim's original text, quoted by Richard, was talking about
> letting you drag the scroll-bar itself, not dragging below it on the
> mode-line. Is that right?

Yes.

>
>  - I thought that Richard's reply was taking about this thin vertical strip
> that Kim proposed perhaps adding between windows. Is that right?

Richard said that we cannot drag the scroll-bar itself (the scrollbar widget
takes control over the mouse, so that's not possible).

Then he commented on the square area that was between modelines in
20.x that was reduced to a thin line in 21.1.  He said it was easier
to grab the old square than the current thin line.

>
>  - If so, then I don't understand Kim's reply, saying that we already have
> such a feature - that it's easy to use "that thin line" to drag. Is the thin
> line in question the current thin line between _mode-lines_, or the tiny
> area between _windows_ that Kim proposed adding?

My response was that it is just as easy to grab the thin line (between
modelines) in 21.x as it was to grab the square in 20.x

>
> To me, needing to mouse-over the scroll-bar to get the drag handle would be
> OK. The scroll-bar is big, obvious, and conceptually that's just what you
> want to do: drag the scroll-bar. 

As I said, mouse-over for a scroll-bar is out of emacs' control.  If we are
to do something here, we would add a thin line on the side of the scrollbar
and the user would have to be precise to grab that line (like grabbing the
edge of a frame)...

>                                  Needing to mouse-over to find the existing
> tiny thin line between _mode-lines_, however, is not good. Intuitively, you
> don't go mousing around between two mode-lines to find where to drag the
> scroll-bar.

Didn't you have to mouse around in 20.x to discover what the square area did?
I don't see the difference...

>
> So, just what thin, vertical rectangle are we talking about here: a
> potential one to be added between windows or the existing one between
> mode-lines?

The one between mode lines.

>
> --
>
> To speak to a different part of this subject, Richard said this:
>
>   It would be hard to do it at the right using mode-line-format.
>   It would be easy to add a new feature that would override part
>   of the mode line at the right when appropriate.
>
> If I understand this correctly, he is saying that, in effect, that we could
> get back the small, visible drag-handle square beneath the scroll-bar that
> we had in Emacs 20. That would be good. If, alternatively, a way could be
> found to let users drag the scroll-bar itself, that would be even better.
>
>  - Drew
>
> -----Original Message-----
> From: Kim F. Storm [mailto:storm@cua.dk]
>
> Richard Stallman <rms@gnu.org> writes:
>
>>     It would be much better if we could find a way to just drag the
>>     scroll-bar.
>>
>> Dragging in the scroll bar has another meaning.
>>
>>     One way would be to always make a tiny area between windows that you
>>     could drag.  But unless we do it by reducing the qscroll bar width,
>>     that would take away space that is now used for text display.
>>
>> We DID have a tiny area, at the bottom of the scroll bar.  Drew is
>> complaining that we got rid of it.  It is much easier to use a square
>> than a very thin rectangle.  It is hard to put the mouse on the
>> latter.
>
> That's not correct.  It is easy to put the cursor on that tiny line!
>
> The code uses a relaxed check so that if the mouse is within ONE
> COLUMN on either side of the line, the cursor changes to the <-> drag
> cursor.  So there is already a virtual block area there which is TWO
> COLUMS wide there.
>
>
>>
>>     It is much harder (impossible) to make a drag-able area to the right
>>     of the modeline, as there is no fixed right edge of the modeline at
> the
>>     lisp level [the modeline is simply truncated by redisplay].
>>
>> It would be hard to do it at the right using mode-line-format.
>> It would be easy to add a new feature that would override part
>> of the mode line at the right when appropriate.
>
> Personally, I see no reason to make that explicitly stand out more
> than it already does...
>
>

-- 
Kim F. Storm <storm@cua.dk> http://www.cua.dk

RE: not too happy with Emacs 21 vertical-line dragging when scrollbars present

[Drew Adams]

OK, now it's clear.

By mouse-around, I meant mouse-over.

I didn't mouse-over to find the square drag handle in Emacs 20. I saw it,
and mouse-over doesn't change the pointer in Emacs 20, so that wouldn't help
anyway. But your point is that I still had to go looking for it; and you're
right. But there was something _visible_ there to try. I didn't have to
blindly _mouse-over_ every part of the frame to find the hidden "G" spot
(for "grab" ;-) ) that did the trick.

I would prefer the "thin line on the side of the scrollbar" (all the way
up). That is common in many applications. Hopefully, it wouldn't be _too_
difficult to grab, and it would have the big advantage of being where you
expect it, and being pretty obvious (via mouse-over pointer change). You
want to drag the scroll bar? -- well, just drag it (or, that thin line all
along it).

You made the analogy with grabbing a frame edge; that's a good analogy:
everyone is used to doing that -- there is nothing exotic about grabbing and
dragging such a "thin line".

That would be a lot better, IMO, than what we have now.

 - Drew

-----Original Message-----
From: Kim F. Storm

As I said, mouse-over for a scroll-bar is out of emacs' control.  If we are
to do something here, we would add a thin line on the side of the scrollbar
and the user would have to be precise to grab that line (like grabbing the
edge of a frame)...

> Needing to mouse-over to find the existing
> tiny thin line between _mode-lines_, however, is not good. Intuitively,
you
> don't go mousing around between two mode-lines to find where to drag the
> scroll-bar.

Didn't you have to mouse around in 20.x to discover what the square area
did?
I don't see the difference...

Re: not too happy with Emacs 21 vertical-line dragging when scrollbars present

[Kim F. Storm]

"Drew Adams" <drew.adams@oracle.com> writes:

> I would prefer the "thin line on the side of the scrollbar" (all the way
> up). That is common in many applications. Hopefully, it wouldn't be _too_
> difficult to grab, and it would have the big advantage of being where you
> expect it, and being pretty obvious (via mouse-over pointer change). You
> want to drag the scroll bar? -- well, just drag it (or, that thin line all
> along it).
>
> That would be a lot better, IMO, than what we have now.

The current display engine need to position windows on a multiple of
the frame default column width, so it is not trivial to introduce a
'thin line all the way up'.

It is on my plan for 'after next release' to get rid of this restriction.

Once that is done, adding a thin line will be easier, so I don't want
to spend time now on a halfbaked solution.  At least, 21.4 will not be
any worse than 21.3.

-- 
Kim F. Storm <storm@cua.dk> http://www.cua.dk

RE: not too happy with Emacs 21 vertical-line dragging when scrollbars present

[Drew Adams]

We haven't spoken of implementation difficulty until now. What you say makes
sense to me. I'll be happy if the possibility is at least considered at
sometime in the future. - Drew

-----Original Message-----
From: Kim F. Storm

The current display engine need to position windows on a multiple of
the frame default column width, so it is not trivial to introduce a
'thin line all the way up'.

It is on my plan for 'after next release' to get rid of this restriction.

Once that is done, adding a thin line will be easier, so I don't want
to spend time now on a halfbaked solution.  At least, 21.4 will not be
any worse than 21.3.

Re: not too happy with Emacs 21 vertical-line dragging when scrollbars present

[Richard Stallman]

    That's not correct.  It is easy to put the cursor on that tiny line!  

    The code uses a relaxed check so that if the mouse is within ONE
    COLUMN on either side of the line, the cursor changes to the <-> drag
    cursor.  So there is already a virtual block area there which is TWO
    COLUMS wide there.

I see what you mean.  Yes, that is not hard to use.  But we should
document it.

Also, the mouse cursor changes to various other shapes as I drag
the border sideways.  I think that's a bug--could someone fix it
to remain the double-pointed horizontal arrow while dragging
left and right?

Re: not too happy with Emacs 21 vertical-line dragging when scrollbars present

[Richard Stallman]

    My response was that it is just as easy to grab the thin line (between
    modelines) in 21.x as it was to grab the square in 20.x

Yes, after seeing what you were telling me, I agree with you.

    I would prefer the "thin line on the side of the scrollbar" (all the way
    up). That is common in many applications. Hopefully, it wouldn't be _too_
    difficult to grab, and it would have the big advantage of being where you

If we make it artificially easy to grab, as has been done for the line
between mode lines, it would interfere with scrolling using the scroll
bar.

Re: not too happy with Emacs 21 vertical-line dragging when scrollbars present

[Jason Rumney]

Richard Stallman <rms@gnu.org> writes:

> If we make it artificially easy to grab, as has been done for the line
> between mode lines, it would interfere with scrolling using the scroll
> bar.

I think on those toolkits where it is possible to interfere with
scrolling using the scrollbar, dragging the scroll bar sideways
already resizes the windows.

How about letting a mouse-drag in the fringe be used for this purpose?

Re: not too happy with Emacs 21 vertical-line dragging when scrollbars present

[Kim F. Storm]

Richard Stallman <rms@gnu.org> writes:

>     That's not correct.  It is easy to put the cursor on that tiny line!  
>
>     The code uses a relaxed check so that if the mouse is within ONE
>     COLUMN on either side of the line, the cursor changes to the <-> drag
>     cursor.  So there is already a virtual block area there which is TWO
>     COLUMS wide there.
>
> I see what you mean.  Yes, that is not hard to use.  But we should
> document it.

Where ?

>
> Also, the mouse cursor changes to various other shapes as I drag
> the border sideways.  I think that's a bug--could someone fix it
> to remain the double-pointed horizontal arrow while dragging
> left and right?

I installed a fix for that a few days ago...  How old is your emacs?

-- 
Kim F. Storm <storm@cua.dk> http://www.cua.dk

Re: not too happy with Emacs 21 vertical-line dragging when scrollbars present

[Richard Stallman]

    I think on those toolkits where it is possible to interfere with
    scrolling using the scrollbar, dragging the scroll bar sideways
    already resizes the windows.

Is that really true?  For which kinds of toolkits?

If this is how it is, it would be ideal to implement this for the
other remaining kinds of scroll bar, in a compatible way.

Re: not too happy with Emacs 21 vertical-line dragging when scrollbars present

[Richard Stallman]

    > I see what you mean.  Yes, that is not hard to use.  But we should
    > document it.

    Where ?

I am not sure.  Perhaps where C-x 3 is described.  Or where
mode lines are described.

Re: not too happy with Emacs 21 vertical-line dragging when scrollbars present

[Richard Stallman]

    >
    > Also, the mouse cursor changes to various other shapes as I drag
    > the border sideways.  I think that's a bug--could someone fix it
    > to remain the double-pointed horizontal arrow while dragging
    > left and right?

    I installed a fix for that a few days ago...  How old is your emacs?

About 2 weeks.

Re: not too happy with Emacs 21 vertical-line dragging when scrollbars present

[Jason Rumney]

Richard Stallman <rms@gnu.org> writes:

>     I think on those toolkits where it is possible to interfere with
>     scrolling using the scrollbar, dragging the scroll bar sideways
>     already resizes the windows.
>
> Is that really true?  For which kinds of toolkits?

I was under the impression that only GTK, Windows and Mac scroll bars
could not be dragged sideways. Certainly in older versions I have been
able to drag the scroll bars sideways to resize windows, though I have
been using GTK on GNU/Linux recently.

Comments in `mouse-drag-vertical-line' seem to indicate that my memory
is not faulty.

Re: not too happy with Emacs 21 vertical-line dragging when scrollbars present

[Stefan]

>> I think on those toolkits where it is possible to interfere with
>> scrolling using the scrollbar, dragging the scroll bar sideways
>> already resizes the windows.
>> 
>> Is that really true?  For which kinds of toolkits?

> I was under the impression that only GTK, Windows and Mac scroll bars
> could not be dragged sideways. Certainly in older versions I have been
> able to drag the scroll bars sideways to resize windows, though I have
> been using GTK on GNU/Linux recently.

> Comments in `mouse-drag-vertical-line' seem to indicate that my memory
> is not faulty.

It is possible only with the non-toolkit scrollbar (the only one that
existed until Emacs-21).


        Stefan

Re: not too happy with Emacs 21 vertical-line dragging when scrollbars present

[Kim F. Storm]

Richard Stallman <rms@gnu.org> writes:

>     >
>     > Also, the mouse cursor changes to various other shapes as I drag
>     > the border sideways.  I think that's a bug--could someone fix it
>     > to remain the double-pointed horizontal arrow while dragging
>     > left and right?
>
>     I installed a fix for that a few days ago...  How old is your emacs?
>
> About 2 weeks.

That's too old to have the fix.

-- 
Kim F. Storm <storm@cua.dk> http://www.cua.dk

Re: not too happy with Emacs 21 vertical-line dragging when scrollbars present

[Richard Stallman]

    I was under the impression that only GTK, Windows and Mac scroll bars
    could not be dragged sideways.

The built-in scroll bars used with the Lucid widgets can't be dragged
sideways.  Which means that nearly all toolkits do not handle it.

Too bad, it would have been a nice solution, but it is not feasible.
I think we should leave things as they are.

Re: not too happy with Emacs 21 vertical-line dragging when scrollbars present

[David Kastrup]

Richard Stallman <rms@gnu.org> writes:

>     I was under the impression that only GTK, Windows and Mac scroll bars
>     could not be dragged sideways.
>
> The built-in scroll bars used with the Lucid widgets can't be dragged
> sideways.  Which means that nearly all toolkits do not handle it.
>
> Too bad, it would have been a nice solution, but it is not feasible.
> I think we should leave things as they are.

I disagree that being able to drag scrollbars sideways would have
been a nice solution.  One of the most annoying "features" about the
Windows toolkit is that you can "skid off" scrollbars while dragging,
in which case the scrolled area jumps back to where it started until
you move the cursor back onto the scroll bar.

In general, when I am using a scrollbar by dragging in the vertical
direction, I don't want to be forced to keep the horizontal position
of the cursor "correct" as well.

Dragging a scrollbar horizontally when used with an additional
modifier key, like shift or control, might have been a possible idea,
but not in the course of normal operation.

Looking at the thread I am not sure that I understand what this
discussion tries to be actually about: it started by thinking about
whether dragging some vertical structure at the _side_ of the
scrollbar would be possible.  But if we are not clicking on the
scrollbar itself, the toolkit is not involved in the dragging, anyway.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum