Re: [CSSOM] does CaretPosition need a "before/after" hint?

On Tue, May 10, 2011 at 8:48 AM, Ryosuke Niwa <rniwa@webkit.org> wrote:

> On Tue, May 10, 2011 at 8:43 AM, Ojan Vafai <ojan@chromium.org> wrote:
>
>> On Tue, May 10, 2011 at 12:45 AM, Robert O'Callahan <robert@ocallahan.org
>> > wrote:
>>
>>> Gecko's internal equivalent of CaretPosition has a flag that we use to
>>> disambiguate "the caret is after character N-1 of the text node" and "the
>>> character is before character N of the text node". This matters because in
>>> bidi situations the screen positions of those caret locations can be
>>> different. For example, consider the text node "Latin HEBREW" rendered as
>>> Latin WERBEH
>>> If the caret is after the space, then it should be displayed in the
>>> middle of the line. If the caret is before the H, it should be displayed at
>>> the end of the line.
>>>
>>> Does the CSSOM CaretPosition need to expose something similar?
>>>
>>
> While WebKit does NOT currently support hinted-caret, we're planning to
> implement such a feature in the future.  For this purpose, exposing the
> bidi-level rather than a flag might be more useful.
>

For those of us less familiar with bidi (e.g. me), what is bidi-level and
how is it different from a flag? Specifically, what are some cases where a
flag is insufficient?


> Also, if we're adding this flag/bidi-level, we probably need to expose
> visual ordering of text as well.  Is there any mechanism proposed to do
> such?
>

This sounds like a whole separate discussion, but I'm not sure what you mean
by a mechanism to "expose visual ordering of text."