Add support for tracking containing blocks when doing inline layout.
This requires setting up a PositioningContext for inline boxes when
necessary. Instead of using the PositioningContext helper methods
and we reuse the contexts between line breaks.
Fixes#25279.
Add a few helper methods which allow removing duplicate code in
PositioningContext. These methods will also be used to properly
implement hoisting in inline layout.
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.
Generate ::before and ::after content from url() for layout2020
- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] There are tests for these changes
This method doesn't actually do any layout, but converts this block to a
HoistedAbsolutelyPositionedBox which is hoisted and then laid-out with
its containing block later. This makes the code a little easier to read.
Add initial support for transforms to layout_2020
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Take origin from current window instead of creating a new one in event of reflow
Everytime a new `LayoutContext` was created, it created a new origin which
caused endless stream of image loads to occur in case of reflow. The reason
for this was that the existing image, although cached successfully, was not
used because the entry in hashmap did not match because of different(new)
origin.
This is solved by storing the origin of a window in enum `ScriptReflow` and
used in creating new `LayoutContext` in case of reflow.
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r?@jdm
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- [X] These changes fix#24720 (GitHub issue number if applicable)
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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.
It's not possible anymore, in the presence of min() / max(), to split a
<length-percentage> value into a <length> and a <percentage> component.
Tweak word_spacing to do what Gecko does (resolving it in advance).
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.
