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.
Properly size synthesized layers
Layers that are composed of several stacking contexts that need to be
rendered on top of other layered content need synthesized layers.
Previously, these layers were placed into a stacking context that was
the same size as their parent. This patch creates a new type of
PaintLayer which simply holds a display list. The layer is sized to the
bounds of the DisplayList and its children are positioned relative to
the parent stacking context.
This will also be useful in the future, when items outside of
StackingContexts are given their own layer for render order purposes.
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Layers that are composed of several stacking contexts that need to be
rendered on top of other layered content need synthesized layers.
Previously, these layers were placed into a stacking context that was
the same size as their parent. This patch creates a new type of
PaintLayer which simply holds a display list. The layer is sized to the
bounds of the DisplayList and its children are positioned relative to
the parent stacking context.
This will also be useful in the future, when items outside of
StackingContexts are given their own layer for render order purposes.
Check for font_variant equality in LayoutFontGroupCacheKey::eq.
This fixes an issue whereby normal text would intermittently be rendered as
small-caps and vice versa.
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Make it possible for iframes to create their own pipeline ID.
This doesn't change any functionality, but it's the first step towards removing SubpageId.
Adding this change now will allow us to gradually change over code referencing subpage id rather than in one massive PR.
Introduces a namespace for pipeline ID generation - there is a namespace for the constellation thread, and one per script thread.
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This doesn't change any functionality, but it's the first step towards removing SubpageId.
Adding this change now will allow us to gradually change over code referencing subpage id rather than in one massive PR.
Introduces a namespace for pipeline ID generation - there is a namespace for the constellation thread, and one per script thread.
StackingContexts are added to layers when it is necessary to maintain
their ordering on top of other layered StackingContexts. Instead of
tracking the information about a layer scattered around into different
structs, combine it all into LayerInfo. LayerInfo will be used in the
future to hold layer information for DisplayItems that are layerized
independently of StackingContexts.
Make DisplayList hit testing a method on DisplayList
This will allow us to hit test into DisplayLists that are not directly
contained in StackingContexts, but instead are children of PaintLayers.
It also makes things slightly simpler.
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layout: Make the compositor rather than layout determine the position of 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 only the size of an iframe is
determined during layout, and the position is determined by the
compositor. Layout layerizes iframes and marks the iframe layers with
the appropriate subpage ID so that the compositor can place them
correctly.
Closes#7377.
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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.
This will allow us to hit test into DisplayLists that are not directly
contained in StackingContexts, but instead are children of PaintLayers.
It also makes things slightly simpler.
gfx: Fix border-radius panic when a corner has 0px and >0px borders
When one border is 0px and the other is >0px then the border corner
drawing code panics when computing the values to use in drawing the
border corner arcs.
This fixes that bug and makes the `draw_corner` function more robust
by explicitly passing an enum, `BorderCorner`, naming which corner is
being drawn e.g. `BorderCorner::TL`.
Add a ref test,
`border_radius_zero_sizes_a.html/border_radius_zero_sizes_ref.html`.
Fixes https://github.com/servo/servo/issues/7700.
r? @pcwalton or @mbrubeck
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A few small bits of refactoring to prepare for more advanced DisplayList layerization
This will be useful when PaintLayers that contain DisplayLists instead
of StackingContexts need to draw themselves. This is a simple
preparatory refactoring and doesn't change any behavior.
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This will be useful when PaintLayers that contain DisplayLists instead
of StackingContexts need to draw themselves. This is a simple
preparatory refactoring and doesn't change any behavior.
When one border is 0px and the other is >0px then the border corner
drawing code panics when computing the values to use in drawing the
border corner arcs.
This fixes that bug and makes the `draw_corner` function more robust
by explicitly passing an enum, `BorderCorner`, naming which corner is
being drawn e.g. `BorderCorner::TL`.
Add a ref test,
`border_radius_zero_sizes_a.html/border_radius_zero_sizes_ref.html`.
Fixes https://github.com/servo/servo/issues/7700.
