EWW: Face property changes around newlines

EWW: Face property changes around newlines

[T.V Raman]

In general, font-lock in emacs tends to set properties  like so:

If you have a doc string that is multiline, the whitespace in that
comment -- including the newline chars-- get the  same font/face property.

EWW appears to work differently -- if you take a plain paragraph that
spans multiple lines, the text uses "variable-pitch" as  the face
property -- except that that property is not set on the newline
characters within the paragraph. 

I'm sure this makes no visible difference to the layout -- but it
affects Emacspeak's logic for breaking content into meaningful
clauses. Could EWW be made consistent with the rest of Emacs' font-lock
in this regard?
-- 
Id: kg:/m/0285kf1 

Re: EWW: Face property changes around newlines

[Stefan Monnier]

> EWW appears to work differently -- if you take a plain paragraph that
> spans multiple lines, the text uses "variable-pitch" as  the face
> property -- except that that property is not set on the newline
> characters within the paragraph.

I'm not sure how hard/easy it may be to change SHR (used by EWW) to do
that, but I have the impression that it may be non-trivial.

> I'm sure this makes no visible difference to the layout -- but it
> affects Emacspeak's logic for breaking content into meaningful
> clauses.

Maybe it would be simpler to change Emacspeak so it ignores face
properties on whitespace?


        Stefan

Re: EWW: Face property changes around newlines

[T.V Raman]

Stefan Monnier <monnier@iro.umontreal.ca> writes:


Hi Stefan --

Here is the problem; it's not that easy from the emacspeak side -- see
below.

Emacspeak uses the following algorithm to split text into chunks before
sending to the TTS engine.

1. Split by clauses -- where "clause" is determined by the buffer's
syntax table.

2. Next, split the clause into chunks based on property changes -- since
"changing voice params on any TTS engine triggres a clause boundary.
3. (2) is achieved by calling next-single-property-change

4. Result -- in EWW buffers, next-single-property-change always goes to
the newline  char when on text that isn't otherwise decorated
i.e. variable-pitch->nil for the 'face property.

For now I discovered the shr-use-fonts option and turned it off --- that
appears to fix my problem in large part. 

>> EWW appears to work differently -- if you take a plain paragraph that
>> spans multiple lines, the text uses "variable-pitch" as  the face
>> property -- except that that property is not set on the newline
>> characters within the paragraph.
>
> I'm not sure how hard/easy it may be to change SHR (used by EWW) to do
> that, but I have the impression that it may be non-trivial.
>
>> I'm sure this makes no visible difference to the layout -- but it
>> affects Emacspeak's logic for breaking content into meaningful
>> clauses.
>
> Maybe it would be simpler to change Emacspeak so it ignores face
> properties on whitespace?
>
>
>         Stefan
>
>

-- 

Re: EWW: Face property changes around newlines

[Stefan Monnier]

> 2. Next, split the clause into chunks based on property changes -- since
> "changing voice params on any TTS engine triggres a clause boundary.
> 3. (2) is achieved by calling next-single-property-change

What I was thinking is that after calling next-single-property-change,
skip the subsequent whitespace and check to see if the property is back
to its previous value after the whitespace.


        Stefan

Re: EWW: Face property changes around newlines

[T.V Raman]

Yes, that would work --- 
Stefan Monnier writes:
 > > 2. Next, split the clause into chunks based on property changes -- since
 > > "changing voice params on any TTS engine triggres a clause boundary.
 > > 3. (2) is achieved by calling next-single-property-change
 > 
 > What I was thinking is that after calling next-single-property-change,
 > skip the subsequent whitespace and check to see if the property is back
 > to its previous value after the whitespace.
 > 
 > 
 >         Stefan

-- 
Id: kg:/m/0285kf1 

-- 
Id: kg:/m/0285kf1 

Re: bug#34018: EWW: Face property changes around newlines

[Lars Ingebrigtsen]

"T.V Raman" <raman@google.com> writes:

> Yes, that would work --- 

OK; seems like this doesn't require any changes in eww, then, so I'm
closing the bug report.

(The reason shr doesn't apply (some of the) face properties to the
newline character is that that things like underline would then extend
to the end of the line, which looks very ugly.)

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no