Re: Adjusting column width dynamically to get rid of orphans and widows

[Thomas Widmann <thomas@complexli.com>]

On 20 June 2017 at 20:33, Hans Hagen <pragma@wxs.nl> wrote:
> On 6/20/2017 11:53 AM, Thomas Widmann wrote:
>>
>> On 20 June 2017 at 10:41, Henri Menke <henrimenke@gmail.com> wrote:
>>>
>>>
>>> On Tue, 2017-06-20 at 09:22 +0100, Thomas Widmann wrote:
>>>>
>>>>
>>>> I recently started experimenting with using ConTeXt (mkiv) for
>>>> dictionary typesetting. It's a much
>>>> more attractive option than plain TeX or LaTeX because of the support
>>>> for typesetting on a grid.
>>>>
>>>> However, grid typesetting can easily result in a large number of orphans
>>>> and widows, which really
>>>> doesn't look good in a dictionary.
>>>>
>>>> In an ideal world, I'd want to alter the column width slightly to
>>>> prevent them (because most
>>>> dictionaries aren't justified, this wouldn't be very noticeable).
>>>>
>>>> Would it be possible to use LuaTeX to achieve this?  I.e., could one
>>>> write some code that gets
>>>> triggered by orphans and widows and then alters the current column width
>>>> slightly until the
>>>> problem disappears?  Has somebody already done this?  Or have the
>>>> relevant TeX internals not been
>>>> Luafied yet?
>>>>
>>>> I'd also be interested in other ways to solve this issue – for instance
>>>> changing the looseness
>>>> dynamically instead of the column width.
>>>
>>>
>>> Have a look at \widowpenalty and \clubpenalty.  Also use margin kerning
>>> and font expansion.
>>
>>
>> \widowpenalty and \clubpenalty are almost useless in this context –
>> believe me, I've tried! (I'm typesetting on a grid, with a fixed
>> number of lines per page.) Which is why I'm looking for alternatives.
>>
>> Margin kerning and font expansion are definitely options, but again,
>> my real query would be how to trigger them dynamically to avoid a
>> widow or an orphan.
>
> can you make a small example showing the problem

Sorry about the delay – here you go!

On my computer, the first column goes on for two lines more than the
following column, and it still produces a widow:

%%% document starts here

\mainlanguage[en]

\definefontfeature
  [default][default]
  [
    protrusion=quality,
    expansion=quality,
    onum=yes,
  ]

\definestartstop [negindent] [
  before={%
    \startnarrower[left]%
    \setupindenting[-.5em,yes,first]%
    \setuphead[subject][indentnext=yes]%
  },
  after=\stopnarrower,
]

\setupbodyfont[palatino]

\setupalign[hz,hanging,tolerant]

\startsetups[grid][mypenalties]
    \setdefaultpenalties
    \setpenalties\widowpenalties{2}{10000}
    \setpenalties\clubpenalties {2}{10000}
\stopsetups

\setuplayout[grid=yes, setups=mypenalties]

\righthyphenmin=60
\lefthyphenmin=60

\def\Sblackbold#1{{\bf #1}}
\def\Sdef#1{{#1}}
\def\Sdefrf#1{{\bf #1}}
\def\ShwJNR#1{{\blue\bf #1}}
\def\Spospsmallcaps#1{{\sc #1}}
\def\Spunctuation#1{{#1}}
\def\Sxrefxrhw#1{{\bf #1}}
\def\Sgroupintro#1{{\it #1}}

\def\threeentries{\ShwJNR{headphones}\page[no]\par\-\hskip
.5em\Spospsmallcaps{noun}\Spunctuation{ }\Sdef{a pair of small
speakers that you wear over your
ears}\par\ShwJNR{heard}\page[no]\par\-\hskip
.5em\Spospsmallcaps{verb}\Spunctuation{ }\Sgroupintro{the past tense
and past participle of}\Spunctuation{
}\Sxrefxrhw{hear}\par\ShwJNR{hearing}\page[no]\par\-\hskip
.5em\Spospsmallcaps{noun}\Spunctuation{ }\Sblackbold{2}\Spunctuation{
}\Sdef{If someone gives you a }\Sdefrf{hearing}\Sdef{, they let you
give your point of view and listen to you.\par}}

\def\thirtyentries{\threeentries\threeentries\threeentries\threeentries\threeentries\threeentries\threeentries\threeentries\threeentries\threeentries}

\startdocument

\startmixedcolumns[balance=yes]
\raggedright
\startnegindent

\thirtyentries

\stopnegindent
\stopmixedcolumns
\placefloats
\stopdocument

%%% document ends here

The thing is that there simply isn't a good way to break up a
three-line dictionary entry, and it would be much better to play
around with the column width, the looseness, margin kerning or other
tools rather than having to do so.  Doing it manually is easy enough,
but it would be much nicer if the one or more of these tools could get
triggered automatically.

Regards,

Thomas
-- 
Thomas Widmann
Director
Complexli Limited
+44 789 444 3009
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