You are viewing a plain text version of this content. The canonical link for it is here.
Posted to fop-dev@xmlgraphics.apache.org by gerhard oettl <ge...@oesoft.at> on 2006/01/12 21:10:09 UTC
table-columns and number-columns-spanned
Hello
AFAICS number-columns-spanned are not recognized for
table-columns.
A) Specification:
The first question for me is of overlapping is allowed here? I
did not find an explicit comment on this - maybe I looked not
hard enough.
At a first glance (when reading the spec to from-table-column) it
looks like it was allowed and that only the pair of column-number
+ number-columns-spanned has to be unique to handle something
like that:
<fo:table-column text-align="left"/>
<fo:table-column text-align="right"/>
<fo:table-column column-number="1"
number-columns-spanned="2" text-align="center"/>
But I think it is not true.
B) Implementation:
Currently it is ignored and this fragment
<fo:table-column column-number="1" number-columns-spanned="2"/>
<fo:table-column column-number="3"/>
throws a gap-error, but should not.
B1) I filed a bug (38244) of a possible including of
number-columns-spanned into the addColumn (in a early state i
have to confess) that only changes two things:
B1a) Incorporate the number-columns-spanned for the calculation
of the following cell for number-columns-repeated according
to spec 7.26.12.
B1b) Using the same rule even if no number-culumns-repeated is
given. If no overlapping is allowed there is no other chance
for implicit column-number to work with number-columns-spanned.
B1c) Mark all columns spanned with the used-flag.
B1d) The TableColumn will be cloned (commented out for now)
The main con is that in the columns list of the table object the
positions that are spanned (except the first) are empty (null)
and all layoutmanagers that need information from the
table-column have to handle it by their own to get the value from
the initial column of the spanned range.
C) An alternative idea is to implement number-columns-spanned in
a kind of number-columns-repeated fake, so that a
<fo:table-column column-number="1" number-columns-spanned="3"/>
would end up in three TableColumn objects
<fo:table-column column-number="1" number-columns-spanned="3"/>
<fo:table-column column-number="2" number-columns-spanned="2"/>
<fo:table-column column-number="3" number-columns-spanned="1"/>
For my goal (from-table-column) both are equal but i want to do it
in that way that fits best (or does not break) the layoutmanagers.
gerhard
--
.''`. gerhard oettl on Debian/Gnu Linux
: :' :
`. `'` gpg key: 1024D/D59131AA 2002-06-18
`-
Re: table-columns and number-columns-spanned
Posted by Simon Pepping <sp...@leverkruid.nl>.
On Thu, Jan 12, 2006 at 09:55:57PM +0100, gerhard oettl wrote:
> <fo:table-column number-columns-spanned="2"
> number-columns-repeated="2"/> [ initial colnum = default = "1" ]
> would be expanded according to b) to:
> <fo:table-column number-columns-spanned="2"/> [ colnum = "1" ]
> <fo:table-column number-columns-spanned="2"/> [ colnum = "3" ]
> <fo:table-column number-columns-spanned="2"/> [ colnum = "5" ]
The above represents number-columns-repeated="3".
<fo:table-column number-columns-spanned="2"/> is equivalent to
<fo:table-column number-columns-spanned="2"
number-columns-repeated="1"/> (initial value).
Simon
--
Simon Pepping
home page: http://www.leverkruid.nl
Re: table-columns and number-columns-spanned
Posted by gerhard oettl <ge...@oesoft.at>.
On Sun, Jan 15, 2006 at 11:56:54AM +0100, Andreas L Delmelle wrote:
>On Jan 12, 2006, at 21:55, gerhard oettl wrote:
>
>>>from Andreas L. Delmelle
>>
>>>I see you made the same mistake (?) in interpretation of the
>>>Rec that I initially made: the Rec states literally that "the
>>>column-number for a fo:table-column is 1 plus the column-number
>>>of the previous column"
>>
>>Literaly you are absolutly right especially if reading the spec
>>to column-number (7.26.8) first. My main argument against this is
>>the description of number-columns-repeated (7.26.12) that says:
>>
>Yeah, I remember we discussed this at the time I was implementing
>these in the FOTree,
I expected this and searched, but did not succeed.
The MARC archive findes nothing (but also not this thread) and the
apache eyebrowse link points to a non-existent page. So if you
know the timeframe (some month more or less don't matter) where
I can look in the archive it would be nice to let me know.
>and we took this to be an inconsistency in the Rec...
Here I can fully agree.
But the implementation of fop should not ;-) I can life with every
sight, but want to show some pros and cons and want to know which
part of the inconsitent Rec should be canceled to adopt the
from-table-column function.
I see the spec a little overcrowded here by trying to put two
features into the table-column element in general and to the
number-columns-spanned property in special:
I) background information (pointing to "column groups" in CSS2
for determining the background - in the notes for fo:table)
II) as a container for informations that can be used by
from-table-column.
For II) it would be best to have all column-number /
number-columns-spanned pairs allowed (what was in contrast to the
table-cell spec not explicitly forbidden and what would mean to
have the same column-number used more than once) but I think it a
nightmare for I) because how to decide which background-color to use?
- and it was not explicitly allowed too.
On the other hand the "first fallback" described in the
from-table-column function (retry with
number-columns-spanned="1") is useless if every column-number can
only be used once. If there is a table-column with the same
column-number as the table-cell has you always end at this
table-column regardless of the number-columns-spanned on the
table-column or on the table-cell. It only would make sense if
there are more table-columns with the same column-number but with
different number-columns-spanned. Could make everything more
complicated than it is already ;-)
I am astonished that XSL 1.1 does not clarify anything here.
>The main issue, I think, that kept me from following the definition
>under 7.26.12, is that you could end up with a situation where a
>given table-cell has column-number="2", while there is no column that
>has that column-number...
>
>In your example, the column-number "2" is not assigned to any column.
>What would you do if a bit further down in the tree, there is a
>fo:table-cell with column-number="2" ?
IMHO it should take the information from the spanned range, if it
spannes 1 column or otherwise the default value for the property in
question. My base is the (maybe also to freely interpreted) sentence
from 7.26.13 that says: 'For an fo:table-column the
"number-columns-spanned" property specifies the number of columns
spanned by table-cells that may use properties from this
fo:table-column formatting object using the from-table-column()
function.' - which i read "every cell that has a spanned range
(begincol to endcol) that is within the range spanned by the
table-column" - and which I used as "second fallback".
>With number-columns-repeated="N", you create the effect of separate
>columns occupying column-numbers "I" to "I + N - 1", where I is the
>initial-value (the parent FO's currentColumnIndex = the previous
>column's number plus 1). I would distinguish number-columns-
>spanned="M", precisely by having it not occupy M column indices.
Though I argue against, I have to say that it is a fully legal
point of view.
>If not, what would be the point in having two separate properties?
Very right. This is a question I asked myself more than once without
any realy answer. The only case I could think where they differ is:
<fo:table-column column-number="1" number-columns-spanned="5"
text-align="center"/>
<fo:table-column column-number="6" number-columns-spanned="2"/>
<etc/>
<fo:table-cell column-number="4" number-columns-spanned="3">
<fo:block text-align="from-table-column()">
Here not all columns spanned by the cell (column 4 to 6) are
spanned by the first table-column definition and no table-column
with the column-number "4" exists (first fallback-rule for
from-table-colum), so it falls back to the default ("start").
With the current implementation of number-columns-repeated it
would end up with "center".
>Any table-cell having column-number="1" will occupy the first two
>columns (because of number-columns-spanned="2" on its corresponding
>table-column). If no cell has been assigned column-number="1", then a
>cell having column-number="2" will occupy column 2 and the next,
>whatever column-span (or column-number!) is specified on that next
>column.
Sorry, but here I do not understand what you would like to
show. Neither with the current implementation nor by using the
explicit rule of 7.26.12 is the colspan of the table-cell
affected by the number-columns-spanned of the table-column.
Looks like I overrated the usefullness of the from-table-column
construct and it is hard to say goodby to all the possibilities I
saw there.
Nevertheless - the from-table-column patch follows (tomorrow).
regards
gerhard
--
.''`. gerhard oettl on Debian/Gnu Linux
: :' :
`. `'` gpg key: 1024D/D59131AA 2002-06-18
`-
Re: table-columns and number-columns-spanned
Posted by Andreas L Delmelle <a_...@pandora.be>.
On Jan 12, 2006, at 21:55, gerhard oettl wrote:
>> from Andreas L. Delmelle
>
>> I see you made the same mistake (?) in interpretation of the
>> Rec that I initially made: the Rec states literally that "the
>> column-number for a fo:table-column is 1 plus the column-number
>> of the previous column"
>
> Literaly you are absolutly right especially if reading the spec
> to column-number (7.26.8) first. My main argument against this is
> the description of number-columns-repeated (7.26.12) that says:
>
> a) The "number-columns-repeated" property specifies the
> repetition of a table-column specification n times; with the same
> effect as if the fo:table-column formatting object had been
> repeated n times in the result treewith the same effect as if the
> fo:table-column formatting object had been repeated n times in
> the result tree.
Yeah, I remember we discussed this at the time I was implementing
these in the FOTree, and we took this to be an inconsistency in the
Rec...
The main issue, I think, that kept me from following the definition
under 7.26.12, is that you could end up with a situation where a
given table-cell has column-number="2", while there is no column that
has that column-number...
In your example, the column-number "2" is not assigned to any column.
What would you do if a bit further down in the tree, there is a
fo:table-cell with column-number="2" ?
With number-columns-repeated="N", you create the effect of separate
columns occupying column-numbers "I" to "I + N - 1", where I is the
initial-value (the parent FO's currentColumnIndex = the previous
column's number plus 1). I would distinguish number-columns-
spanned="M", precisely by having it not occupy M column indices. If
not, what would be the point in having two separate properties?
> and b) The "column-number" property, for all but the first, is
> the column-number of the previous one plus its value of the
> "number-columns-spanned" property.
>
> now verify a)
>
> <fo:table-column number-columns-spanned="2"
> number-columns-repeated="2"/> [ initial colnum = default = "1" ]
> would be expanded according to b) to:
> <fo:table-column number-columns-spanned="2"/> [ colnum = "1" ]
> <fo:table-column number-columns-spanned="2"/> [ colnum = "3" ]
Stop! number-columns-repeated="N" means "insert a column node like
this one N times, where 1 is the default/initial value".
> in comparison with:"with the same effect as if the
> fo:table-column formatting object had been repeated n times in
> the result tree"
>
> <fo:table-column number-columns-spanned="2"/> [ colnum = "1" ]
> <fo:table-column number-columns-spanned="2"/> [ colnum = "2" ]
>
> You see the two parts of the spec are not compatible and for this
> case i would prefere the rule that was given at
> column-numbers-repeat. As a side-effect the verification-example
> would produce overlapping table-columns.
Hmm... I still think I like the latter more :-)
Any table-cell having column-number="1" will occupy the first two
columns (because of number-columns-spanned="2" on its corresponding
table-column). If no cell has been assigned column-number="1", then a
cell having column-number="2" will occupy column 2 and the next,
whatever column-span (or column-number!) is specified on that next
column.
> My sight could be wrong, but I think it is a good argument ;-)
So could mine... Maybe others have anything to add to all of this?
Cheers,
Andreas
Re: table-columns and number-columns-spanned
Posted by gerhard oettl <ge...@oesoft.at>.
>>B1) I filed a bug (38244) of a possible including of
>> number-columns-spanned into the addColumn (in a early state i
>> have to confess) that only changes two things:
> from Andreas L. Delmelle
> I see you made the same mistake (?) in interpretation of the
> Rec that I initially made: the Rec states literally that "the
> column-number for a fo:table-column is 1 plus the column-number
> of the previous column"
Literaly you are absolutly right especially if reading the spec
to column-number (7.26.8) first. My main argument against this is
the description of number-columns-repeated (7.26.12) that says:
a) The "number-columns-repeated" property specifies the
repetition of a table-column specification n times; with the same
effect as if the fo:table-column formatting object had been
repeated n times in the result treewith the same effect as if the
fo:table-column formatting object had been repeated n times in
the result tree.
and b) The "column-number" property, for all but the first, is
the column-number of the previous one plus its value of the
"number-columns-spanned" property.
now verify a)
<fo:table-column number-columns-spanned="2"
number-columns-repeated="2"/> [ initial colnum = default = "1" ]
would be expanded according to b) to:
<fo:table-column number-columns-spanned="2"/> [ colnum = "1" ]
<fo:table-column number-columns-spanned="2"/> [ colnum = "3" ]
<fo:table-column number-columns-spanned="2"/> [ colnum = "5" ]
in comparison with:"with the same effect as if the
fo:table-column formatting object had been repeated n times in
the result tree"
<fo:table-column number-columns-spanned="2"/> [ colnum = "1" ]
<fo:table-column number-columns-spanned="2"/> [ colnum = "2" ]
<fo:table-column number-columns-spanned="2"/> [ colnum = "3" ]
You see the two parts of the spec are not compatible and for this
case i would prefere the rule that was given at
column-numbers-repeat. As a side-effect the verification-example
would produce overlapping table-columns.
My sight could be wrong, but I think it is a good argument ;-)
gerhard
--
.''`. gerhard oettl on Debian/Gnu Linux
: :' :
`. `'` gpg key: 1024D/D59131AA 2002-06-18
`-