Hi Regina,
Sorry for replying so late.
On 4/26/25 14:53, Regina Henschel wrote:
Hi Kohei,
thank you for looking at it.
Kohei Yoshida schrieb am 23.04.2025 um 04:20:
Hi Regina,
On 4/22/25 11:29, Regina Henschel wrote:
Hi all,
The ODF TC currently discusses OFFICE-2317 "Text distribute
justification" [1]. The issue is about the proposal in the
OASIS-Wiki [2].
I can see myself being the author of this proposal... This was
authored almost 15 years ago. I must say I could have added a bit
more detail in this proposal to make less open to interpretation, but
alas, I can't go back in time to fix it. :-)
The ODF TC makes some house keeping and examines those proposals that
do not yet have a decision whether to accept them.
(A)
The proposal wants to introduce a new attribute "css3t:text-justify"
with values "auto" and "distribute".
Problem is, that the actual CSS3 draft [3] has the values "auto",
"none", "inter-word" and "inter-character". The draft states in
addition, that a UA must additionally support "distribute" and treat
it as "inter-character".
CCS3's "inter-character" appears to correspond with the "distribute"
mode. So I would say ODF can also inherit this "inter-character"
value here instead of the old "distribute" value as specified in the
proposal. When I authored this proposal I chose the value
"distribute" likely because the CSS3 draft proposal available back
then also used that word. The latest CCS2 draft still references the
word "distribute" as the legacy value to support.
We can likely add into the text, that consumers shall accept the value
"distribute" in addition.
(B)
The proposal wants to introduce a special attribute
style:vertical-justify for use in style:vertical-align. There has
been some work on this in bug tdf#45450. On the other hand, bug
tdf#112843 was rejected.
Is such property really needed?
Yes, but only when the text is oriented 90 degrees or 270 degrees
i.e. flows either either top-to-bottom or bottom-to-top, or when the
text is vertically stacked. This feature is useful at least in
Japanese setting. I can't speak for Chinese or Korean settings, but
it may be relevant in those languages as well, or not. I'm not really
sure.
I disagree her. The proposal misunderstands fo:text-align and
style:vertical-align attributes.
The fo:text-align attribute (current values start, end, left, right,
center or justify) always works in line direction and the line
direction is given by the style:writing-mode attribute.
The style:vertical-align attribute is orthogonal to the line
direction. It determines how the entire text content is positioned in
the cell area. Current values are top, middle, bottom or automatic.
Ok. I'm all for using style:writing-mode attribute to make this part
more "ergonomic" and less awkward. No objections there.
If we really want to distribute the lines of the text content, then it
would be enough to add a new value "distributed" to the
style:vertical-align attribute of the <style:table-cell-properties>
without any further attributes. In case the new value "distributed" is
set, any line spacing and margin related attributes of the
<style:paragraph-properties> element assigned to the text in the cell
has to be ignored.
The result of such distribution is ugly for normal text. It might be
useful for "stacked" characters to have something compatible to Excel.
Albeit, currently LibreOffice has no wrap for "stacked" characters in
Calc.
If we have a vertical writing mode (in ODF 1.4 these are tb-rl, tb-lr,
sideways-rl, sideways-lr), then the fo:text-align attribute still
works in line direction and with value 'justify' the text is aligned
with the top and bottom edge of the cell. That does neither require a
new css3t:text-justify nor a new style:vertical-justify attribute.
And in case of paragraph-properties, a value of "justify" for
attribute style:vertical-align makes no sense at all. The attribute
style:vertical-align (20.396.1 ODF 1.4) of a
<style:paragraph-properties> element specifies the position of a
_character_ relative to the line to which the character belongs.
So, I haven't done a deep dive of the current ODF specification text, so
I'll trust you on this one.
When the text flows horizontally i.e. not vertically stacked, the
vertically distributed justification works identically to the normal
vertical justification. There is no difference between these two modes.
You can try this in Calc by putting some Japanese sentence into a
cell, go to the Format Cells dialog, switch to the Alignment tab and
check the "Vertically stacked" check box in the Text Orientation
section. Or leave the check box unchecked, and change the text
orientation to either 90 degrees or 270 degrees. Set the vertical
text alignment to "Distributed" and compare how that differs from the
"Justified" alignment. Change the row height if you have difficulty
seeing the effect of this distributed alignment.
There are two problems:
- The current implementation does not use the attribute
style:writing-mode to describe vertical writing modes, but a
workaround with attributes style:glyph-orientation="auto" and
style:direction="ttb". But this workaround has not the ability to
distinguish whether the block direction is from right-to-left or
left-to-right.
- As far as I see, the values "justified" and "distributed" in the UI
are only different in the way the last line of a paragraph is handled.
But the method for handling the last line is already specified as
style:justify-single-word attribute (20.301 ODF 1.4) and
fo:text-align-last (20.224 ODF 1.4). Only that LibreOffice does not
use these in Calc.
I agree that these can be used in lieu of the current implementation.
You may need to enable Asian language features in the Language
Settings in case it's not there. I'm not sure whether this feature
is visible without the Asian language features enabled.
(C)
LO has implemented something for OFFICE-2317, see around lines #2848
to #2891 in the schema
/core/schema/libreoffice/OpenDocument-v1.4+libreoffice-schema.rng
Is there a UI in LibreOffice for these properties?
When are these properties written to file?
See my reply above. For horizontal distribution, put some Japanese
text into a cell, go to the same dialog location I described above,
and simply set the horizontal text alignment to "Distributed". If
it's hard to see, try widening the column width.
For horizontal Japanese text too, I see only a difference in the last
line of the text.
Yup. That's my observation and understanding of what the distributed
text alignment does.
BTW, Excel seems to be not able to set Japanese vertical writing mode
for a single cell and keep the other cells in a horizontal writing
mode. At least I do not find it in Excel. I only find "vertical Text"
for the cell, but that does not make Japanese vertical writing mode
(tategaki) but stacks all glyphs upright, which is
style:direction="ttb" in ODF.
I believe that stacking of glyphs in vertical direction is essentially
what tategaki mode does. In this mode, the glyphs stay upright (i.e.
not rotated) but the flow of the text becomes vertical.
This article has some screenshots of the relevant UI for tategaki mode:
https://atmarkit.itmedia.co.jp/ait/articles/1912/20/news020.html
Hopefully this helps a bit. Let me know if you need more
clarification on this stuff.
How about becoming a member of the ODF TC?
Well, right now, the time I can spend aside from my life's obligation is
rather limited, so I don't think I can find enough time to dedicate
myself to join the TC. Sorry about this.
Kohei
