Clicks map to wrong line with line-spacing > nil.

Clicks map to wrong line with line-spacing > nil.

[David Koppelman]

Mouse clicks map to the wrong line on recent versions (including
8a7a99) when line-spacing is set to a non-default value. For
example, set

(setq-default line-spacing 10)

and try clicking on a line towards the bottom of the window. The
cursor moves to a point well above the mouse pointer.

Am I the only one setting this variable? Or is there something unusual
about my system? (RHEL 6.)

David

Re: Clicks map to wrong line with line-spacing > nil.

[Eli Zaretskii]

> From: David Koppelman <koppel@ece.lsu.edu>
> Date: Fri, 31 Jul 2015 15:29:12 -0500
> 
> Mouse clicks map to the wrong line on recent versions (including
> 8a7a99) when line-spacing is set to a non-default value. For
> example, set
> 
> (setq-default line-spacing 10)
> 
> and try clicking on a line towards the bottom of the window. The
> cursor moves to a point well above the mouse pointer.

Does the problem go away if you follow the above setting with "M-x
redraw-display RET"?

Re: Clicks map to wrong line with line-spacing > nil.

[David Koppelman]

> Does the problem go away if you follow the above setting with "M-x
> redraw-display RET"?

No. The problem is robust in the sense that it occurs as soon as the
setting is applied (including when set in .emacs) and doesn't seem to go
away.



Eli Zaretskii <eliz@gnu.org> writes:

>> From: David Koppelman <koppel@ece.lsu.edu>
>> Date: Fri, 31 Jul 2015 15:29:12 -0500
>> 
>> Mouse clicks map to the wrong line on recent versions (including
>> 8a7a99) when line-spacing is set to a non-default value. For
>> example, set
>> 
>> (setq-default line-spacing 10)
>> 
>> and try clicking on a line towards the bottom of the window. The
>> cursor moves to a point well above the mouse pointer.
>
> Does the problem go away if you follow the above setting with "M-x
> redraw-display RET"?

Re: Clicks map to wrong line with line-spacing > nil.

[Eli Zaretskii]

> From: David Koppelman <koppel@ece.lsu.edu>
> Cc: emacs-devel@gnu.org
> Date: Fri, 31 Jul 2015 16:29:12 -0500
> 
> > Does the problem go away if you follow the above setting with "M-x
> > redraw-display RET"?
> 
> No. The problem is robust in the sense that it occurs as soon as the
> setting is applied (including when set in .emacs) and doesn't seem to go
> away.

Then I'm afraid I cannot reproduce it.

What I see is that once the expression is evaluated, the window is not
redisplayed, although it should have, with the larger line spacing.
Typing just "M-x" causes redisplay, and then mouse clicks work for me
as expected.

Can you show a reproducible recipe for the problem, starting with
"emacs -Q", and including all the details, like what you have in the
visible portion of the buffer, where you click, and where does the
cursor move?  I suggest to use "M-x report-emacs-bug RET" for that, as
bugs should be discussed and logged there anyway.

Thanks.

Re: Clicks map to wrong line with line-spacing > nil.

[Tassilo Horn]

Eli Zaretskii <eliz@gnu.org> writes:

>> > Does the problem go away if you follow the above setting with "M-x
>> > redraw-display RET"?
>> 
>> No. The problem is robust in the sense that it occurs as soon as the
>> setting is applied (including when set in .emacs) and doesn't seem to
>> go away.
>
> Then I'm afraid I cannot reproduce it.
>
> What I see is that once the expression is evaluated, the window is not
> redisplayed, although it should have, with the larger line spacing.
> Typing just "M-x" causes redisplay, and then mouse clicks work for me
> as expected.
>
> Can you show a reproducible recipe for the problem, starting with
> "emacs -Q", and including all the details, like what you have in the
> visible portion of the buffer, where you click, and where does the
> cursor move?

I can reproduce with emacs -Q and eb0f65b4.  Here's a recipe:

1. emacs -Q
2. C-h h to open the HELLO file
3. M-: (setq line-spacing 50)
   Here, that's immediately visible.
   (window-size nil t) => 96, (window-size) => 47 but actually
   with this spacing there are only 11 lines visible, i.e., I see
   the HELLO portion from line 1 to the second line of the South
   Asia entry.
4. When I click on some word in lines 1-3, point is set on that word.
   In later lines, point ends up on the previous line.  For ex., I
   click on the "examples" in "Non-ASCII examples:" and point is set
   to the beginning of the empty line before.  Clicking on "South" in
   "South Asia:" puts point on "Middle" in "Middle/Near East:".

Doing the same with line-spacing set to 10, the problem becomes worse.
Again, clicking on the first 3 lines works correctly, then on the next
2-3 lines jumps to the line before, then clicking on the next few lines
makes point jump to 2 lines before the click position, etc.  So it
becomes worse for the lines displayed later in a window.

Bye,
Tassilo

Re: Clicks map to wrong line with line-spacing > nil.

[Eli Zaretskii]

> From: Tassilo Horn <tsdh@gnu.org>
> Cc: David Koppelman <koppel@ece.lsu.edu>,  emacs-devel@gnu.org
> Date: Sat, 01 Aug 2015 09:40:44 +0200
> 
> I can reproduce with emacs -Q and eb0f65b4.  Here's a recipe:

Thanks.  I am still not sure what are we talking about.  I can almost
say "not reproducible here", but see below.

First, please try the latest master.

> 1. emacs -Q
> 2. C-h h to open the HELLO file
> 3. M-: (setq line-spacing 50)
>    Here, that's immediately visible.
>    (window-size nil t) => 96, (window-size) => 47 but actually
>    with this spacing there are only 11 lines visible, i.e., I see
>    the HELLO portion from line 1 to the second line of the South
>    Asia entry.

That's not a problem, since window-size reports the height in
canonical character units, disregarding the line-spacing.

> 4. When I click on some word in lines 1-3, point is set on that word.
>    In later lines, point ends up on the previous line.  For ex., I
>    click on the "examples" in "Non-ASCII examples:" and point is set
>    to the beginning of the empty line before.  Clicking on "South" in
>    "South Asia:" puts point on "Middle" in "Middle/Near East:".

Does point get set always on the _previous_ line?  Because the
original report said something different, AFAIU:

> try clicking on a line towards the bottom of the window. The
> cursor moves to a point well above the mouse pointer.
                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

To me, "well above" doesn't sound like the previous line, but several
lines above that.  That I certainly cannot see.

As to setting point to the previous line, are you sure you don't click
on the spacing reserved below the characters of the previous line?
Setting line-spacing to a large value adds that many pixels _below_
the characters, so if you click slightly above the character, you are
actually clicking on the previous line.

> Doing the same with line-spacing set to 10, the problem becomes worse.
> Again, clicking on the first 3 lines works correctly, then on the next
> 2-3 lines jumps to the line before, then clicking on the next few lines
> makes point jump to 2 lines before the click position, etc.  So it
> becomes worse for the lines displayed later in a window.

I don't see the 2-line jump at all.  I sometimes see a 1-line jump,
but I think that's because I click on the spacing below the previous
line.

Could it be that the problem depends on how many empty lines are
between the window start and the location of the click?  If so, this
might be one consequence of bug#21165, which I fixed a few minutes
ago.

Re: Clicks map to wrong line with line-spacing > nil.

[Tassilo Horn]

Eli Zaretskii <eliz@gnu.org> writes:

>> I can reproduce with emacs -Q and eb0f65b4.  Here's a recipe:
>
> Thanks.  I am still not sure what are we talking about.  I can almost
> say "not reproducible here", but see below.
>
> First, please try the latest master.

Ok, I'm on master now (e663cfec5a2dbf69d0f4360e1f8e05f81a037333).

>> 4. When I click on some word in lines 1-3, point is set on that word.
>> In later lines, point ends up on the previous line.  For ex., I click
>> on the "examples" in "Non-ASCII examples:" and point is set to the
>> beginning of the empty line before.  Clicking on "South" in "South
>> Asia:" puts point on "Middle" in "Middle/Near East:".
>
> Does point get set always on the _previous_ line?  Because the
> original report said something different, AFAIU:
>
>> try clicking on a line towards the bottom of the window. The
>> cursor moves to a point well above the mouse pointer.
>                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>
> To me, "well above" doesn't sound like the previous line, but several
> lines above that.  That I certainly cannot see.

With `line-spacing' of 50, it was always the previous line when clicking
in the two last thirds of the window (and the correct line in the 1st
third).  With `line-spacing' of 10, it were more lines too early
depending on how near the end of the window the click position was.

> Could it be that the problem depends on how many empty lines are
> between the window start and the location of the click?  If so, this
> might be one consequence of bug#21165, which I fixed a few minutes
> ago.

Yes, that seems to be it.  At least now with the current master HEAD,
point always jumps to exact the click position regardless of the
`line-spacing' value.

Thanks,
Tassilo

Re: Clicks map to wrong line with line-spacing > nil.

[Eli Zaretskii]

> From: Tassilo Horn <tsdh@gnu.org>
> Cc: koppel@ece.lsu.edu,  emacs-devel@gnu.org
> Date: Sat, 01 Aug 2015 12:18:14 +0200
> 
> > Could it be that the problem depends on how many empty lines are
> > between the window start and the location of the click?  If so, this
> > might be one consequence of bug#21165, which I fixed a few minutes
> > ago.
> 
> Yes, that seems to be it.  At least now with the current master HEAD,
> point always jumps to exact the click position regardless of the
> `line-spacing' value.

OK, thanks.  I will wait for David to confirm that his problem is
solved as well by that commit.

Re: Clicks map to wrong line with line-spacing > nil.

[David Koppelman]

> OK, thanks.  I will wait for David to confirm that his problem is
> solved as well by that commit.

I've tried 08d65696c947b0, and the problem no longer occurs, thanks!

FWIW, the cursor ended up 'well above' the mouse pointer only for
larger values of line-spacing. For the value that I usually use
it was just OB1.

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Tassilo Horn <tsdh@gnu.org>
>> Cc: koppel@ece.lsu.edu,  emacs-devel@gnu.org
>> Date: Sat, 01 Aug 2015 12:18:14 +0200
>> 
>> > Could it be that the problem depends on how many empty lines are
>> > between the window start and the location of the click?  If so, this
>> > might be one consequence of bug#21165, which I fixed a few minutes
>> > ago.
>> 
>> Yes, that seems to be it.  At least now with the current master HEAD,
>> point always jumps to exact the click position regardless of the
>> `line-spacing' value.
>
> OK, thanks.  I will wait for David to confirm that his problem is
> solved as well by that commit.

Re: Clicks map to wrong line with line-spacing > nil.

[Eli Zaretskii]

> From: David Koppelman <koppel@ece.lsu.edu>
> Cc: Tassilo Horn <tsdh@gnu.org>,  emacs-devel@gnu.org
> Date: Sat, 01 Aug 2015 10:31:09 -0500
> 
> > OK, thanks.  I will wait for David to confirm that his problem is
> > solved as well by that commit.
> 
> I've tried 08d65696c947b0, and the problem no longer occurs, thanks!

Thanks, good news.