Hi Armin, hi Michael,
Michael, I have put you an CC, because this is about ODF. Do you prefer
one of the ideas (A)(B)(C)(D) or have a better idea?
Armin Le Grand schrieb am 15.03.2023 um 11:20:
Hi Regina,
{..]
Yes, we cannot change our stuff too far to get to svg definitions - we
will not get rid of these. We will also not have a svg:spreadMethod. The
currently important point is to use existing svg definitions (to not get
even further away from svg as needed) as far as possible, as far in
their svg meaning as possible, too.
For now we need to get the Color-Stops added to 'our' gradients. Do you
have concrete examples/advice how to do that?
I can think of these ways:
(A)
Add a child element <draw:gradient-stop-list> as optional child element
to <draw:gradient>.
Specify that if a <draw:gradient-stop-list> child element is present,
then the attributes draw:start-color, draw:start-intensity,
draw:end-color, draw:end-intensity and draw:gradient-step-count are ignored.
The <draw:gradient-stop-list> element has <svg:stop> child elements, in RNG
<rng:zeroOrMore>
<rng:ref name="svg-stop"/>
</rng:zeroOrMore>
Specify that the rules in 13.2.4 SVG 1.1. for interpreting the
svg:offset values and handling of less than two <svg:stop> elements
shall be followed.
(B)
Add
<rng:zeroOrMore>
<rng:ref name="svg-stop"/>
</rng:zeroOrMore>
as child elements to <draw:gradient> and a boolean attribute
draw:multicolor.
If draw:multicolor is true, then the child elements <svg:stop> are used
and draw:start-color ... are ignored, otherwise draw:start-color ... are
used.
Specify that the rules in 13.2.4 SVG 1.1. ... shall be followed.
(C)
Add total new <draw:multicolor-gradient> element. Define it that way,
that it is suitable to describe OOXML gradFill and suitable to describe
a multi-color version of LO's current <draw:gradient> element. That
includes not only a list of gradient stops but in addition a focus
rectangle and a tile rectangle.
(D)
Add
<rng:zeroOrMore>
<rng:ref name="svg-stop"/>
</rng:zeroOrMore>
as child elements to <draw:gradient>
Add that in case <svg:stop> child elements exist, draw:start-color
together with draw:start-intensity is treated as being a <svg:stop>
element with svg:offset="0%" and svg:opacity="1" before all given
<svg:stop> elements,
and draw:end-color together with draw:end-intensity is treated as being
a svg:stop element with svg:offset="100%" and svg:opacity="1" after all
given <svg:stop> elements,
and draw:gradient-step-count is treated as "0".
Specify that the rules in 13.2.4 SVG 1.1. ... shall be followed.
I would take out from this the StartColor (AKA offset == 0.0) and the
EndColor (AKA offset == 1.0), so in the normal case there would be no
change at all. >
If there are ColorSteps with offset != 0.0 or 1.0 I would create that
extra-entries for these.
What do you mean by "take out"?
Just that for 0% I would use our draw:start-color and for 100% our
draw:end-color. I would only write new entries in svg-conform semantic
for offsets ]0%..100%[. This is to stay as compatible as possible. It
also makes no sense to 'double' the information with having the same
color represented e.g. for StartColor once as draw:start-color and once
as <stop offset="0%"/>.
I think, that would be like I have described as way (D).
Because the introduction of theme colors, it might be needed to extend
<svg:stop> to not only have stop-color attribute in the sense of SVG but
allow a reference to a scheme-color in addition. In case of (D) that
would have to be added for start- and end-color too.
Kind regards,
Regina
