This accomplishes two things:
1. Makes it easier to iterate through all inline formatting context
items.
2. Will make it possible to easily move back and forth through the tree
of inline boxes, in order to enable reordering and splitting inline
boxes on lines -- necessary for BiDi.
Co-authored-by: Rakhi Sharma <atbrakhi@igalia.com>
Instead of linebreaking inside each single-font text segment, linebreak
the entire inline formatting context at once. This has several benefits:
1. It allows us to use `icu_segmenter` (already in use from style),
which is written against a newer version of the Unicode spec --
preventing breaking emoji clusters.
2. Opens up the possibility of changing the way that linebreaking and
shaping work -- eventually allowing shaping across inline box
boundaries and line breaking *after* shaping.
Co-authored-by: Rakhi Sharma <atbrakhi@igalia.com>
The main change here is that collapsed and `text-transform`'d text is
computed as it's processed by DOM traversal. This single transformed
text is stored in the root of the `InlineFormattingContext`.
This will eventually allow performing linebreaking and shaping of the
entire inline formatting context at once. Allowing for intelligent
processing of linebreaking and also shaping across elements. This
matches more closely what LayoutNG does.
This shouldn't have any (or negligable) behavioral changes, but will
allow us to prevent linebreaking inside of clusters in a followup
change.
Co-authored-by: Rakhi Sharma <atbrakhi@igalia.com>
