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>
Bumps Stylo to servo/stylo#37
`white-space` is split into `white-space-collapse` and `text-wrap-mode`:
| white-space | white-space-collapse | text-wrap-mode |
| ----------- | -------------------- | -------------- |
| normal | collapse | wrap |
| nowrap | collapse | nowrap |
| pre-wrap | preserve | wrap |
| pre | preserve | nowrap |
| pre-line | preserve-breaks | wrap |
| - | preserve-breaks | nowrap |
Note this introduces a combination that wasn't previously possible,
but I think the existing logic can handle it well enough.
The old `allow_wrap()` is replaced by checking whether `text-wrap-mode`
is set to `wrap`.
The old `preserve_newlines()` is replaced by checking whether
`white-space-collapse` is *not* set to `collapse`.
The old `preserve_spaces()` is replaced by checking whether
`white-space-collapse` is set to `preserve`.
This adds basic support for `text-transform` in a way that is more
complete than legacy layout. There are still many missing elements of
proper `text-transform` support such as:
1. Support for `full-width` and `full-size-kana`
2. Support for grapheme based uppercasing, lowercasing, and
capitalization. These are all done per-code point right now.
3. Support for the language-specific `SpecialCasing.txt` cases for case
mapping such as the ones for Irish and Turkish.
Co-authored-by: Rakhi Sharma <atbrakhi@igalia.com>
This moves white space collapse to right before breaking and shaping
happens, which is more similar to what happens in legacy layout. This is
the first step toward making this procedure more efficient (avoiding
string copies) and also implementing support for `text-transform`.
Co-authored-by: Rakhi Sharma <atbrakhi@igalia.com>
