We cache the state of any live HTMLCollection, keeping track of
a) the optional cached length of the collection, and
b) an optional cursor into the collection (a node in the collection plus its index).
The cache is invalidated based on the version number of the node.
We use these caches for speeding up random access to the collection.
When returning coll[i], we search from the cursor, if it exists,
and otherwise search from the front of the collection.
In particular, both a forward for-loop and a backward for-loop
through the collection will now have each access take O(1)
time rather than O(n) time.
This gets 1000x speed-up on the relevant Dromaeo DOM query tests.
For some reason when I wrote this code I mixed up the rules for pseudo-elements
(rightmost, maximum of one) with those of pseudo-classes (which have no such
restriction). This caused a correctness issue which can be demonstrated with the
associated reftest modification.
Properly resize iframe root layers
When a layer containing an iframe changes, we also need to resize the
root layer of the subpage. This ensures that content from the child
layer tree is masked to the new size.
Fixes#8301.
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Mix stacking contexts into the positioned content list
Sometimes positioned content needs to be layered on top of stacking
contexts. The layer synthesis code can do this, but the current design
prevents it because stacking contexts are stored in a separate struct
member. In order to preserve tree order, mix stacking contexts into the
positioned content list, by adding a new StackingContextClass
DisplayItem. Such items do not have a base DisplayItem.
In some ways this simplifies the code, because we no longer have to
have a separate code path in the StackingContextLayerCreator.
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Sometimes positioned content needs to be layered on top of stacking
contexts. The layer synthesis code can do this, but the current design
prevents it because stacking contexts are stored in a separate struct
member. In order to preserve tree order, mix stacking contexts into the
positioned content list, by adding a new StackingContextClass
DisplayItem. Such items do not have a base DisplayItem.
In some ways this simplifies the code, because we no longer have to
have a separate code path in the StackingContextLayerCreator.
Fixes#7779.
Fixes#7983.
Fixes#8122.
Fixes#8310.
When a layer containing an iframe changes, we also need to resize the
root layer of the subpage. This ensures that content from the child
layer tree is masked to the new size.
Fixes#8301.
Compute value of float according to position value
According to CSS2 Section 9.7, if 'position' has a value of 'absolute'
or 'fixed' the computed value of 'float' should be 'none'.
This changes the float to a single_keyword_computed which checks the
positioned value of the element to compute the float value.
Fixes#8002
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Add destructors to some WebGL objects, remove duplicated glutin dependency and try to enable the webgl reftests
The first commit allows to cleanup the gl resources of the webgl task earlier if they aren't being used.
Right now all resources were cleaned up when the context was destroyed, so I think this is
a slightly better approach.
The second commit bumps rust-offscreen-rendering-context to remove the duplicated glutin dependency.
The third one tries to reenable the webgl reftests.
Since the errored builds are deleted, It's the only way I can try to troubleshoot it.
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Before passing these layers to the paint task, expand them to pixel
boundaries. This ensures that subpixel edges of the layer will not be
clipped away and helps prevent rounding issues with layer contents.
Fixes#8166.
Made block type pattern match less inclusive
Given the comments above the match statement, it seems that fixed-pos check should match only block elements in this case. Doing this change seems to partially resolve the issue where list items with `position:fixed;` styling are not displaying their bullet points. This change only resolves the issue for list items with `list-style-position: inside`, outside positioning is still not functioning correctly.
https://github.com/servo/servo/issues/8001#issuecomment-149781613
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