Add new paragraph justification options "Minimum glyph scaling"
and "Maximum glyph scaling" to improve typography, like DTP software
do, allowing to typeset visually better paragraphs, especially narrow
columns without unacceptably big word spacing.
* Add spin boxes to Alignment in paragraph formatting dialog window;
* Store properties in paragraph model:
css::style::ParagraphProperties::ParaPropScaleWidthMinimum
css::style::ParagraphProperties::ParaPropScaleWidthMaximum
Note: desired glyph scaling is already supported by ODF/UNO,
see css::style::CharacterProperties::CharScaleWidth.
* Implement visual layout of minimum and maximum glyph scaling,
limited by the available extra word spacing and letter spacing,
too.
Note: last line can exceed the paragraph width, because minimum
glyph scaling, also minimum letter scaling of the last line
haven't been applied there, yet.
* Add ODF import/export (loext:text-scale-maximum and
loext:text-scale-minimum, where style:text-scale is for the
desired text scaling).
* Add ODF unit test.
Note: hyphenated lines, lines with multiple portions haven't
been using custom glyph scaling, yet.
Note: resolution of glyph scaling is 1 percent, which will
avoid of overgeneration of font types using variable fonts.
Change-Id: I9b4576dde4303437b64e37202c47f888f94c3f67
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/190534
Tested-by: Jenkins
Reviewed-by: László Németh <nemeth@numbertext.org>