This patch refactors the logic for propagating overflow to the viewport,
fixing various issues:
- Now we won't propagate from the root element if it has no box. Note
the fix isn't observable in Servo because we lack scrollbars.
- If the first `<body>` element has no box, we won't keep searching for
other `<body>` elements. This deviates from the spec, but aligns us with
other browsers.
- We won't propagate from the `<body>` if it has no box. We were already
handling `display: none` but not `display: contents`. This deviates from
the spec, but aligns us with other browsers.
Also, when we flag the root or `<body>` as having propagated `overflow`
to the viewport, we retrieve the `LayoutBoxBase`. Therefore, now we get
the computed style from the `LayoutBoxBase` in a single operation,
instead of first retrieving the style from the DOM element and then
getting the `LayoutBoxBase` from the box.
Testing: Adding more tests. We were only failing one of them, but it's
hard to test the fixes given that we don't show scrollbars. The tests
that were already passing are useful too, e.g. Firefox fails one of
them.
Signed-off-by: Oriol Brufau <obrufau@igalia.com>
A LayoutBox typically has one LayoutBoxBase, or none in the case of
`LayoutBox::DisplayContents`. However, `LayoutBox::InlineLevel` can
contain multiple inline items, each one with its base. But since things
like the style or the fragment flags should be the same for all of them,
getting the first base is sometimes enough.
Testing: not needed, no change in behavior.
Signed-off-by: Oriol Brufau <obrufau@igalia.com>
The `overflow-*` values of either the root element or the `<body>` get
propagated to the viewport. However, we were missing this part:
> The element from which the value is propagated must then have a used
`overflow` value of `visible`.
See https://drafts.csswg.org/css-overflow/#overflow-propagation
Testing:
- `css/cssom-view/scrolling-quirks-vs-nonquirks.html`
- `css/css-overflow/overflow-body-propagation-007.html`
- `css/css-overflow/overflow-body-propagation-008.html`
- `css/css-overflow/overflow-body-propagation-009.html`
- `css/css-overflow/scrollable-overflow-with-nested-elements-001.html`
- `css/css-overflow/scrollable-overflow-with-nested-elements-002.html`
- `css/css-overflow/scrollable-overflow-with-nested-elements-003.html`
- `css/css-overflow/scrollable-overflow-with-nested-elements-004.html`
- `css/css-overflow/scrollbar-gutter-scroll-into-view.html`
Failures:
- `css/css-overflow/overflow-body-propagation-010.html`
Failing because of missing support for `contain: paint`.
- `css/css-overflow/scrollable-overflow-with-nested-elements-005.html`
Failing because of wrong `data-expected-height`, but correct
`data-expected-scroll-height` which is core of this PR.
`data-expected-height` can be dealt separately.
Fixes: #38248
---------
Signed-off-by: Shubham Gupta <shubham13297@gmail.com>
Signed-off-by: Oriol Brufau <obrufau@igalia.com>
Co-authored-by: Oriol Brufau <obrufau@igalia.com>
Use `ServoThreadSafeLayoutNode` in more places in layout rather than
`ServoLayoutNode`. The former is meant to be used during layout, but
layout 2020 was written against the latter. In general, this reduces the
amount of conversion to the thread-safe version in many places in
layout.
In addition, an unused iterator from the `script` crate
`ServoThreadSafeLayoutNodeChildrenIterator` is replaced with the child
iterator from `layout`. The `layout` version must be directly in
`script` now as it uses the dangerous variants of `next_sibling` and
`first_child`, which allow encapsulating the unsafe bits into one
module.
This will ultimately be useful for storing the layout data of
pseudo-element children of pseudo-elements properly.
Testing: This should not change any behavior and thus is covered by
existing tests.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Oriol Brufau <obrufau@igalia.com>
When a style change does not chang the structure of the box tree, it is
possible to skip box tree rebuilding for an element. This change adds
support for reusing old box trees when no element has that type of
damage. In order to make this happen, there needs to be a type of
"empty" `LayoutDamage` that just indicates that a fragment tree layout
is necessary.
This is the first step toward incremental fragment tree layout.
Testing: This should not change observable behavior and thus is covered
by
existing WPT tests. Performance numbers to follow.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Oriol Brufau <obrufau@igalia.com>
Layout: Continue support incremental box tree reconstruction for
flex&taffy level box
This change reuse the flex/taffy level box from old box slot if the box
slot is valid and there is no LayoutDamage to the element.
Testing: This should not change observable behavior and is thus covered
by existing WPT tests.
Signed-off-by: sharpshooter_pt <ibluegalaxy_taoj@163.com>
Text decorations have a special kind of propagation. Instead of
propating these during box tree construction, move propagation to
stacking context tree construction. This will allow for using a very
easy type of incremental layout when text decorations change. For
instance, when a link changes color during hovering over it, we can skip
all of box and fragment tree construction.
In addition, propagation works a bit better now and color and style
properly move down from their originating `Fragment`s.
This introduces three new failures, because now we are drawing the
text-decoration with the correct color in more places, which exposes an
issue we have with text-decorations not being drawn in relation to the
baseline (taking into account `vertical-align`).
Testing: There are tests for these changes.
Fixes#31736.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Oriol Brufau <obrufau@igalia.com>
When making last-minute changes to the repaint-only layout pass, damage
propagation was broken, meaning that full layout was always done. This
change fixes that, meaning that times in the `blaster.html` test case
now reflect those described in the original commit message from #36978.
In addition, some style repair is now fixed:
- `InlineFormattingContext`s now keep a `SharedInlineStyles` for the
root of the IFC
which is updated during style repair.
- `BlockFormattingContext`s now properly update their style.
These changes are verified by turning on repaint only layout for more
properties
in Stylo via servo/stylo#183.
Testing: Manual performance testing via `blaster.html`.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
This change adds the simplest kind of incremental layout. When Servo
detects that all style changes only require a repaint, only run stacking
context tree and WebRender display list generation. This means that
these kind of restyles do not need a re-layout. Instead, the existing
box and fragment trees will be used and the styles of damaged nodes will
be updated in their box and fragment tree nodes.
This requires a new style repair DOM traversal for nodes that have had
their style damaged. In addition, careful accounting of all the places
where we store style must happen in order ot update those styles.
Testing: This is covered by existing WPT tests as it should not change
observable behavior.
We have created a test case which shows a 50% speedup when run
in Servo, even though there still a long way to go to match the speed
of other browsers:
https://gist.github.com/mrobinson/44ec87d028c0198917a7715a06dd98a0
Co-authored-by: Oriol Brufau <obrufau@igalia.com>
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Oriol Brufau <obrufau@igalia.com>
`TextRun`s use their parent style to render. Previously, these styles
were cloned and stored directly in the box tree `TextRun` and resulting
`TextFragment`s. This presents a problem for incremental layout.
Wrapping the style in another layer of shared ownership and mutability
will allow updating all `TextFragment`s during repaint-only incremental
layout by simply updating the box tree styles of the original text
parents.
This adds a new set of borrows when accessing text styles, but also
makes it so that during box tree block construction
`InlineFormattingContext`s are created lazily and now
`InlineFormattingContextBuilder::finish` consumes the builder, making
the API make a bit more sense. This should also improve performance of
box tree block construction slightly.
Testing: This should not change observable behavior and thus is covered
by existing WPT tests.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Oriol Brufau <obrufau@igalia.com>
This makes it so that layout is no longer generic on the node type,
depending directly on `script`'s `ServoLayoutNode`. In addition to
greatly simplifying layout, this is necessary because incremental layout
needs to be able to create pseudo-element styles without having a handle
on the original `impl LayoutNode`. We feel this is a reasonable
tradeoff.
Testing: No functional changes, so covered by existing WPT tests.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Oriol Brufau <obrufau@igalia.com>
Now that legacy layout has been removed, the name `layout_2020` doesn't
make much sense any longer, also it's 2025 now for better or worse. The
split between the "layout thread" and "layout" also doesn't make as much
sense since layout doesn't run on it's own thread. There's a possibility
that it will in the future, but that should be something that the user
of the crate controls rather than layout iself.
This is part of the larger layout interface cleanup and optimization
that
@Looriool and I are doing.
Testing: Covered by existing tests as this is just code movement.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
2025-04-19 10:17:03 +00:00
Renamed from components/layout_2020/flexbox/mod.rs (Browse further)
