Re: Shadow DOM and Fallback contents for images

On Fri, Oct 18, 2013 at 3:56 AM, Jonas Sicking <jonas@sicking.cc> wrote:

> On Thu, Oct 17, 2013 at 1:55 AM, Hajime Morrita <morrita@google.com>
> wrote:
> >
> >
> >
> > On Thu, Oct 17, 2013 at 5:01 PM, Ryosuke Niwa <rniwa@apple.com> wrote:
> >>
> >> On Oct 16, 2013, at 9:47 PM, Hajime Morrita <morrita@google.com> wrote:
> >>
> >> D. "H[ello Shado]w World" - selection spans outside to inside.
> >>
> >>
> >> Suppose we allowed this selection. Then how does one go about pasting
> this
> >> content elsewhere?
> >>
> >> Most likely, whatever other content editable area, mail client, or some
> >> random app (e.g. MS Word) into which the user is going to paste wouldn’t
> >> support shadow DOM and most certainly wouldn’t have the component the
> >> original page happened to have.
> >
> >
> > We have to define how Range.cloneContents() or extractContents() works
> > against shadow-selecting range, assuming selection is built on top of DOM
> > Range. This doesn't seem that complicated. As cloned element drops its
> > shadow, these range-generated nodes won't have shadow either.
>
> Oh, sounds like you are suggesting that we expand the Range API such
> that it can have awareness of spanning parts of a shadow DOM tree.
> While still keeping the existing endpoints "in the same root"?
>
> That like that idea!
>

No, that isn't what I meant. I just want to make it explicit that Range API
works well with shadow trees.
However it happened to be taken by you in some interesting way, and I'm
fine with this  ;-)

So what does this mean?

The "subranges" property exposes the selections of containing ShadowRoots?
That sounds reasonable.

Although I don't think Blink supports this in short term because it only
has per-document selection and doesn't have per-tree ones,
it is rather a lack of features which can be improved eventually than
something totally incompatible and hurting the Web.

Let me confirm what we're talking about.

1. Each shadow tree has its own selection. Each selection spans nodes in
the owning tree only.
2. User initiated selection operation (like dragging) can operate multiple
selections in different trees seamlessly
    as if it is single selection crossing boundaries.
3. Range and/or Selection API could expose sub-selections/sub-ranges of
containing trees.

Going back to the example,

> C. "H[ello Shadow Worl]d" - selection stays outside shadow, but its range
contains a node with shadow.

This turns something like

C2: "H[ello (Shadow) Worl]d" - There are two selections - "[]" for outside
tree and "()" for inside tree.

And this this one

> D. "H[ello Shado]w World" - selection spans outside to inside.

turns

D2: "H[ello] (Shado)w World"

Is is correct?




> Though I'd also be interested to hear how other implementations feel
> about the Gecko solution of allowing selection to be comprised of
> multiple DOM Ranges.
>
> / Jonas
>



-- 
morrita