Integrate iframes into the display list
Instead of always promoting iframes to StackingContexts, integrate them
into the display list. This prevents stacking bugs when
non-stacking-context elements should be drawn on top of iframes.
To accomplish this, we add another step to ordering layer creation,
where LayeredItems in the DisplayList are added to layers described by
the LayerInfo structures collected at the end of the DisplayList.
Unlayered items that follow these layered items are added to
synthesized layers.
Another result of this change is that iframe layers can be positioned
directly at the location of the iframe fragment, eliminating the need
for the SubpageLayerInfo struct entirely.
Iframes are the first type of content treated this way, but this change
opens up the possibility to properly order canvas and all other layered
content that does not create a stacking context.
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Instead of always promoting iframes to StackingContexts, integrate them
into the display list. This prevents stacking bugs when
non-stacking-context elements should be drawn on top of iframes.
To accomplish this, we add another step to ordering layer creation,
where LayeredItems in the DisplayList are added to layers described by
the LayerInfo structures collected at the end of the DisplayList.
Unlayered items that follow these layered items are added to
synthesized layers.
Another result of this change is that iframe layers can be positioned
directly at the location of the iframe fragment, eliminating the need
for the SubpageLayerInfo struct entirely.
Iframes are the first type of content treated this way, but this change
opens up the possibility to properly order canvas and all other layered
content that does not create a stacking context.
Fixes#7566.
Fixes#7796.
each iframe.
The old code that attempted to do this during layout wasn't able to work
for multiple reasons: it couldn't know where the iframe was going to be
on the page (because of nested iframes), and at the time it was building
the display list for a fragment it couldn't know where that fragment was
going to be in page coordinates.
This patch rewrites that code so that both the sizes and positions of
iframes are determined by the compositor. Layout layerizes all iframes
and marks the iframe layers with the appropriate pipeline and subpage
IDs so that the compositor can place them correctly. This approach is
similar in spirit to Gecko's `RefLayer` infrastructure. The logic that
determines when it is time to take the screenshot for reftests has been
significantly revamped to deal with this change in delegation of
responsibility.
Additionally, this code removes the infrastructure that sends layout
data back to the layout task to be destroyed, since it is now all
thread-safe and can be destroyed on the script task.
The failing tests now fail because of a pre-existing bug related to
intrinsic heights and borders on inline replaced elements. They happened
to pass before because we never rendered the iframes at all, which meant
they never had a chance to draw the red border the tests expect to not
render!
Closes#7377.
layout: Lay absolutely-positioned blocks with inline containing blocks out of flow.
Removes the long space before the site-specific drop-down in the Google SERPs.
r? @glennw
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margins.
* The code that attempted to strip out borders that span multiple
fragments in the same element could go wrong if fragments were
stripped out due to text clumping or whitespace stripping. This patch
rewrites that code to maintain flags in the inline fragment context
specifying whether the node is the beginning or end of the element.
Not only is this easier to maintain, it's closer in spirit to what roc
originally suggested two years ago: it's isomorphic to "begin element,
end element" markers for inline layout.
* Padding and margins for spans containing inline-blocks are now
properly handled via a division of labor between the `InlineBlock`
fragment and the `BlockFlow` that represents the inline-block.
* Unscanned text fragments may not be joined together into a text run if
borders, padding, or margins separate them.
Because Servo now matches the rendering of Gecko and WebKit on the
`input_button_margins_a` reftest, I had to modify it to add some
vertical alignment.
The combined effect of all of these fixes places "Advertising" on the
right place on google.com.
layout: Make overflow calculation take relative percentages into account.
This necessitated changing overflow to be calculated by the parent flow
if relatively positioned children are present. That is because the
overflow regions cannot be calculated without knowing relative offsets,
which themselves cannot be calculated without knowing the parent size
(because of percentages). To accomplish this without sacrificing
parallelism in the non-relative case, this patch splits overflow into
"early" and "late" computation. Late overflow computation cannot be
parallelized across children, while early overflow computation can.
Makes the "Apple Music" text show up over the full-bleed promotional
background on apple.com.
r? @SimonSapin -- would appreciate a look over the iframe test case that was changed.
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account.
This necessitated changing overflow to be calculated by the parent flow
if relatively positioned children are present. That is because the
overflow regions cannot be calculated without knowing relative offsets,
which themselves cannot be calculated without knowing the parent size
(because of percentages). To accomplish this without sacrificing
parallelism in the non-relative case, this patch splits overflow into
"early" and "late" computation. Late overflow computation cannot be
parallelized across children, while early overflow computation can.
Makes the "Apple Music" text show up over the full-bleed promotional
background on apple.com.
layout: Improve our handling of inline absolute containing blocks.
Several issues are addressed in this commit:
* Inline flows now bubble up their absolute descendants instead of
making the inline flow the containing block for them. (In the future,
we will need to make the inline flow *sometimes* be the containing
block for them, but for now it improves sites to unconditionally
bubble up.)
* Fragments now look at their inline fragment context to determine
whether they are positioned.
* Inline flows now push the stacking-relative position of the absolute
containing block down to their inline-block fragments.
* Inline absolute hypothetical fragments can be containing blocks.
* Fixes the logic in
`containing_block_range_for_flow_surrounding_fragment_at_index`. The
condition to determine whether fragments are positioned was inverted!
* `Descendants`/`AbsDescendants` has been refactored in order to become
more friendly to inline absolute containing blocks in the future.
Improves the inline position of the green drop-down arrow in the Google
SERPs. (The block position is still wrong.)
r? @mbrubeck
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Several issues are addressed in this commit:
* Inline flows now bubble up their absolute descendants instead of
making the inline flow the containing block for them. (In the future,
we will need to make the inline flow *sometimes* be the containing
block for them, but for now it improves sites to unconditionally
bubble up.)
* Fragments now look at their inline fragment context to determine
whether they are positioned.
* Inline flows now push the stacking-relative position of the absolute
containing block down to their inline-block fragments.
* Inline absolute hypothetical fragments can be containing blocks.
* Fixes the logic in
`containing_block_range_for_flow_surrounding_fragment_at_index`. The
condition to determine whether fragments are positioned was inverted!
* `Descendants`/`AbsDescendants` has been refactored in order to become
more friendly to inline absolute containing blocks in the future.
Improves the inline position of the green drop-down arrow in the Google
SERPs. (The block position is still wrong.)
This patch makes Servo unconditionally strip whitespace before text run
scanning (assuming that the `white-space` property allows it). Whitespace
stripping during reflow is now only used for handling whitespace at the ends of
lines; reflow now never attempts to handle ignorable whitespace.
Many CSS tests pass now. There are some new failures, however.
The following reference tests now fail due to a pre-existing bug whereby
whitespace is used to calculate the position of inline hypothetical boxes for
elements with `display: inline; position: absolute`:
* `absolute-replaced-height-036.htm`
* `vertical-align-sub-001.htm`
* `vertical-align-super-001.htm`
The following reference tests fail due to a pre-existing bug whereby we don't
handle `font-size: 0` properly in inline reflow:
* `font-size-zero-1.htm`
* `font-size-zero-2.htm`
The following reference test fails due to the fact that it relied on our
incorrect insertion of whitespace to make room for the black background:
* `inline-formatting-context-007.htm`
Known issues:
* Display list optimization can sometimes optimize out elements that
should be shown. This affects the Enyo demo.
* The `overflow: scroll` container doesn't clip the inner layer properly
when borders, border radius, etc. are present.
* `overflow-x: scroll` and `overflow-y: scroll` don't work individually;
elements are scrolled all at once.
* Scrolling only works on absolutely-positioned elements.
at the last known good split point, and use it for `white-space:
nowrap`.
Fixes overflowing tables on Wikipedia.
This infrastructure should form the basis of our fix for inline layout
of fragments that don't themselves constitute valid split points. That
will require some more work, however.
styles of nodes that represent the dirty node, *including its
pseudo-element*.
Fixes lots more jumpiness.
A manual test, `inline-pseudo-repair-jumpiness.html`, has been added. I
was unable to automate it, so I will file a followup issue on that.
It's not possible to correctly determine during the css cascade whether the container height
is explicitly specified. Additionally, the spec https://drafts.csswg.org/css2/visudet.html#the-height-property
says this should affect the *used* height, rather than the computed height.
This significantly improves the layout in #6643.
StrExt::slice_chars is deprecated and will be removed in Rust. This
lifts the implementation from Rust libstd and puts it in util::str.
This fixes a bunch of deprecation warnings in Servo.
