This renames the helper method to be a bit more accurate. For elements
with static, relative, and sticky positioning, their containing block is
always formed by their nearest block container ancestor. This method is
really dealing with style that means an element will establish a
containing block for absolutely positioned descendants.
This change adds support for the <iframe> element to Layout 2020. In
addition, certain aspects of the implementation are made the same
between both layout systems.
Store hit testing information in a data structure that sits alongside
the display list in the compositor. This will allow the compositor to
store more information per-node. The data structure also takes care of
de-duplicating information between successive display list entries. In
the future, the data structure can be even more aggressive in producing
smaller side hit testing lists, if necessary.
- Also updates raqote to latest with an upgrade of font-kit to 0.11
applied on as a patch
- Update lyon_geom to the latest version
Major change:
- All matrices are now stored in row major order. This means that
parameters to rotation functions no longer should be negated.
- `post_...()` functions are now named `then()`. `pre_transform()` is removed,
so `then()` is used and the order of operations changed.
Update webrender
These changes reflect changes in webrender's API that make RenderApiSender and RenderApi objects more challenging to share. This PR moves us to a model where:
* the compositor owns the main RenderApi object
* other threads that need to create transactions or manipulate fonts proxy those operations to the compositor (script/layout use IPC, while other threads use non-IPC channels)
* the webgl thread owns its own independent RenderApi
Don't create empty stacking contexts in display lists
A recent change to euclid exposed that our display lists can contain Rects that contain NaN values. These NaNs originate from creating stacking contexts with transforms that scale the horizontal or vertical dimensions to 0. WebRender isn't prepared to handle these, so we need to not produce these empty stacking contexts when building the display list.
---
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- [x] `./mach test-tidy` does not report any errors
- [x] These changes fix#26592 and fix#26590
- [x] There are tests for these changes
We were previously throwing away some boxes hoisted to containing blocks
for all descendants when they were contained by absolutes. This prevents
panics in existing web platform tests that would otherwise be triggered
by the addition of the `unreachable!` statement.
This avoids the use of lookup tables for containing blocks when
constructing the stacking context tree.
This seems to catch some laid-out hoisted fragments that were otherwise
dropped in the previous design. The changes cause one new test to pass
and one to fail. Visual examination of the failing tests reveals that
it's a progression (list markers are appearing when they were previously
not rendered).
layout_2020: Use ArcRefCell in the fragment tree
This will allow mutability which is useful for things like animations.
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Partial text decoration support for layout 2020
- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix#25166
- [X] There are tests for these changes
When calculating scrolling overflow calculation we cannot currently use
the actual containing block in all cases. This change increases the
amount that we do use the containing block.
Instead of painting hoisted position fragments in the order to which
they are hoisted, paint them in tree order and properly incorporate them
into the stacking context.
We do this by creating a placeholder fragment in the original tree position
of hoisted fragments. The ghost fragment contains an atomic id which
links back to the hoisted fragment in the containing block.
While building the stacking context, we keep track of containing blocks
and their children. When encountering a placeholder fragment we look at
the containing block's hoisted children in order to properly paint the
hoisted fragment.
One notable design modification in this change is that hoisted fragments
no longer need an AnonymousFragment as their parent. Instead they are
now direct children of the fragment that establishes their containing block.
This is a feature that was never properly implemented in the previous
layout system. We still need to preserve their in-tree order in the
display list though.
This allows rendering stacking context content in the proper order. We
also need to add a new pseudo stacking context for atomic inlines in
order to preserve proper rendering order in some cases.
This adds very rudimentary support for paint order in stacking context.
In particular z-index is now handled properly, apart from issues with
hoisted fragments.
This adds an intermediary data structure that allows the display list
builder to move through the fragment tree in stacking context painting
order. Spatial nodes are built during this phase and all display list
items are added to the end of the display list.
This makes it so that position:fixed elements do not scroll with the
rest of the contents, but does not tackle the rest of the issues with
their positioning.
