Balance word spacing within the consecutive lines
to get uniform grayness and less rivers for better
readability, enabled by the new paragraph property
com::sun::star::text::ParaComposer
and the following developments:
* Add Paragraph Composer checkbox on Alignment pane of the
paragraph formatting dialog window (not default yet);
* Implement paragraph composer: big word spacing of a
line is decreased by shifting the last word from the
previous line, only if the word spacing is better, than
before, and the increased word spacing in the previous
line doesn't exceed the Maximum word spacing (limited
paragraph composer);
* When Maximum word spacing is not greater than the Desired
word spacing, shifting of the last word is not limited
by the Maximum word spacing (unlimited paragraph composer)
* Add loext:paragraph-composer attribute, as LibreOffice
ODF extension;
* Add ODF unit tests for the limited and not limited
paragraph composer.
Note: "Smart justify" line breaking algorithm chooses
space shrinking (limited by Minimum word spacing)
only if shifting the last word isn't better based
on the desired word spacing. This was still a greedy
line breaking algorithm, resulting big word spacing
in the lines before a longer word.
The paragraph composer shifts the last word (or the
first part of the hyphenated last word) from the previous
line to decrease big word spacing in the actual line.
Note: balancing very big word spacing in narrow consecutive
lines can result vertical rivers. To avoid this, use limited
paragraph composer by setting maximum word spacing.
Follow-up to "smart justify", word spacing, letter spacing
and glyph scaling developments. Selected commits:
commit 529755f091 "tdf#166113
sw smart justify: adjust algorithm for interoperability",
commit 7d08767b89 "tdf#130088
"tdf#119908 smart justify: fix DOCX line count + compat opt.",
commit 7d6696757d "tdf#159923
sw cui offapi xmloff: add custom word spacing",
commit 5a48070f59 "tdf#126154
sw offapi xmloff cui: add min/max word spacing",
commit f83a04c510 "tdf#167648
cui offapi xmloff sw: add DTP-feature maximum letter spacing",
commit 3c53797210 "tdf#167648
sw letter spacing: implement minimum letter spacing",
commit 45ec7bd761 "tdf#168251
cui offapi xmloff sw glyph scaling: extend UNO/UX/ODF".
Change-Id: I727caad70536c86be524bc9d9b52bc71208c202a
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/203288
Reviewed-by: László Németh <nemeth@numbertext.org>
Tested-by: Jenkins
László Németh
62aecba14c