The old logic was always picking the last baseline, but this should only
happen for inline-blocks.
Since replaced elements and flex containers aren't currently setting
their baselines, this is only an improvement for inline-tables.
The old logic was assuming that all whitespace was a break opportunity,
and that no newlines would be preserved.
Note that text shaping considers the advance of a newline to be the same
as a space. This was problematic because if we have a segment with a
preserved space and newline, only the advance of the space should
contrinute to the size of the block container. Therefore, I'm changing
the breaker logic in other to have newline characters in their own
segment.
Then glyph_run_is_whitespace_ending_with_preserved_newline can just be
renamed to glyph_run_is_preserved_newline.
This patch is still not perfect because it doesn't check allow_wrap(),
so `nowrap` is treated like `normal`, and `pre-wrap` like `pre`.
This brings the version of WebRender used in Servo up-to-date with Gecko
upstream. The big change here is that HiDPI is no longer handled via
WebRender. Instead this happens via a scale applied to the root layer in
the compositor. In addition to this change, various changes are made to
Servo to adapt to the new WebRender API.
Co-authored-by: Mukilan Thiyagarajan <mukilan@igalia.com>
Marking all IFCs as containing floats shouldn't change layout results,
but does prevent parallel layout in some cases. This change fixes an
issue where we were marking all IFCs as containing floats.
Fixes#31540.
At the root of an inline formatting context, we used its vertical-align
in order to compute the strut. That was wrong, since vertical-align
on a block container shouldn't affect the contents, it should only
affect the alignment of the block container (if it's inline-level)
within the parent IFC.
This was only working well if the block container was block-level, since
effective_vertical_align_for_inline_layout returned `baseline` for
block-level boxes.
Instead of the outer display type, this patch changes the logic to check
whether we are at the root of the IFC.
The specification gives instructions for how these values should be
propagated. The other big changs here is that they aren't applied to the
`<body>`.
Co-authored-by: Oriol Brufau <obrufau@igalia.com>
* make margin in pbm use app unit
* Simplification
* Consistently resolve inline margins as Au, like block margins
---------
Co-authored-by: Oriol Brufau <obrufau@igalia.com>
This doesn't really have observable behavior right now, as much as I
tried to trigger some kind of bug. On the other hand, it's just wrong
and is very obvious when you dump the Fragment tree. If you create a
`display: table-cell` that is a child of the `<body>` all parts of the
anonymous table are flagged as if they are the `<body>` element.
* Fix size of tables in flow layout
The contents of a table can make it bigger than what we would expect
from its 'width', 'min-width', 'height' and ' min-height' properties.
Also, 'width: auto' doesn't stretch it to fill the containing block.
We had to refactor the resolution of margins to happen after layout,
otherwise 'auto' margins wouldn't align correctly.
Co-authored-by: Martin Robinson <mrobinson@igalia.com>
* Feedback
* Consistently use `containing_block_for_table` in table layout
* Update test result
---------
Co-authored-by: Martin Robinson <mrobinson@igalia.com>
Synthetic small caps is supported by the font subsystem, but this is
disabled in Layout 2020. We can turn this on to bring support to parity
with the old layout system.
In addition to turning on synthetic small-caps this change also improves
the way that they work. Before, synthetic small caps meant that every
character was a small version of capitalized character. After this
change, capital letters are larger than small caps versions of small
letters -- matching other browsers and the common expectation of how
small caps works.
In quirks mode, preserved segment breaks should add line height to
lines. This matches the behavior of WebKit and Blink, but not Gecko.
This also handles the special-case of `<br>` elements, which are
implemented with preserved segment breaks via `white-space: pre-line`.
This is an implementation detail though because `<br>` has a special
behavior if the line isn't empty -- it doesn't add any line height in
this case.
Absolutes need to be placed at their hypothetical position as if the
position value was static. This position differs based on the value they
had before blockification. The code for placing absolutes was taking
into account the original display for the inline value, but not for the
block value. A static `display: block` box would placed at a new block
position past the end of the linebox.
As per HTML [1], <div align="..."> and <center> should behave as if they
had the text-align property set to the corresponding value.
Servo implements that as internal text-align values because there should
the extra effect of aligning block descendants, but that part has not
been implemented yet. This patch only adds support for inline layout.
[1]: https://html.spec.whatwg.org/multipage/rendering.html#flow-content-3
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 deviates from css2, but it's mandated by css-align, and matches
what other browsers do when no margin is 'auto'.
When some margin is 'auto', this should keep the proper round-tripping
behavior that Gecko and WebKit lack, and Blink recently adopted.
This adds support for table rows, columns, rowgroups and colgroups.
There are few additions here:
1. The createion of fragments, which allows script queries and hit
testing to work properly. These fragments are empty as all cells are
still direct descendants of the table fragment.
2. Properly handling size information from tracks and track groups as
well as frustrating rules about reordering rowgroups.
3. Painting a background seemlessly across track groups and groups. This
is a thing that isn't done in legacy layout (nor WebKit)!
Co-authored-by: Oriol Brufau <obrufau@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>
This adds an initial implementation of font fallback, on part with the
one used in legacy layout. There are still issues. For instance, font
matching is done per unicode character rather than based on graphemes or
the shape first approach of Chrome. The idea is that these changes can
be made later.
This implements a very naive row height allocation approach. It has just
enough to implement `vertical-align` in table cells. Rowspanned cells
get enough space for their content, with the extra space necessary being
allocated to the last row. There's still a lot missing here, including
proper distribution of row height to rowspanned cells.
Co-authored-by: Oriol Brufau <obrufau@igalia.com>
Instead of using the border widths from the style, use the ones recorded
by the `BoxFragment`. This is necessary because inline layout can
override these border widths during fragmentation. For instance, when a
box is split across two lines only one fragment should have an inline
start border.
Instead of tracking justification opportunities during line layout, wait
until the line is about to be laid out and justification is about
happen. This makes the logic for tracking justification opportunities
simpler. In particular, we no longer have to carefully adjust them when
trimming whitespace. Additionally, this avoids a bit of work unless
justification is turned on.
This also includes a small cleanup of the justification code.
This change starts collecting the starting baseline set for fragments,
which is necessary for some layout modes (flex and tables, namely) as
well as being important for the implementation of `align-items`. In
addition, it converts baseline measurement to use `Au` everywhere.
Co-authored-by: Oriol Brufau <obrufau@igalia.com>
* use app unit in replaced elements
* more app unit usage
* Avoid unnecessary into()
* Run ./mach fmt
* use scaleby
* update
---------
Co-authored-by: Oriol Brufau <obrufau@igalia.com>
* layout: Implement computation of table column widths
This change implements the various steps of table column width
computation, ignoring features that don't exist yet (such as separated
borders, column elements, and colgroups).
Co-authored-by: Oriol Brufau <obrufau@igalia.com>
* Fix an issue with the assignment of column percent width
* Respond to review comments
---------
Co-authored-by: Oriol Brufau <obrufau@igalia.com>
Shape text during InlineFormattingContext construction rather than doing
it twice during fragment tree construction. This is a step on the way
toward proper font fallback.
This also moves all `TextRun` related code into `text_run.rs` to try to
trim down the size of `inline.rs`.
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Before counting whitepsace-only `GlyphStore`s where counted as a single
justification opportunity when trimming whitespace from the front and
back of lines. This isn't correct, instead count the actual number of
word seperators of the trimmed `GlyphStore`s.
These two counts can be different in the case where whitespace collapse
isn't happening yet (flexbox). In addition, using word seperators means
the code is making less assumptions about the contents of the line and
is more robust.
This fixes some crashes in flexbox tests on debug builds.
Co-authored-by: Rakhi Sharma <atbrakhi@igalia.com>
Instead of a tricky stack of enum iterators expose a `foreach()`
function on InlineFormattingContext, which takes a `FnMut`. This
prevents callers wanting to iterate from keeping a stack of iterators
and will potentially allow a future version of this function to avoid
borrowing the ArcRefCell<...> of inline boxes for every iteration
(presumably using something like OwnedRef).
Convert `inline_content_sizes` to use this new `foreach()` function and
move the `Computation` out of the function body to
`ContentSizesComputation`. This reduces the stack depth of inline size
computation, because `foreach()` is iterative and not recursive.
This is a preliminary change to removing the second round of text shaping
during layout, because shaping will use this new iterator.
