This patch makes the bg-fixed-child-mask.html reftest pass by ensuring
the clips for the test case are all in the correct spots. See the
comments in the patch for a more detailed explanation.
MozReview-Commit-ID: 21MAHr0PJ9B
This patch is not really needed, but it avoids accidental conversion
between FrameMetrics::ViewID (which represents a scrolling clip) and a
uint64_t id for a non-scrolling clip.
MozReview-Commit-ID: JriIfpECHe7
Each layer has a stack of scroll metadata objects, which represent the
set of scrollframes that got flattened into the layer. Effectively the
metadata objects provide the scroll information for the chain of
scrollframes containing that layer's content. Each of these scrollframes
may have a clip, and so we need to push those clips to WR. We need to
take care to insert these clips at the right point in the stack, so that
they are interleaved correctly with the PushScrollLayer calls that we
use to inform WR of the scrolling clips for the scrollframes. This patch
implements this behaviour.
MozReview-Commit-ID: HD3OO5TZHSr
This patch makes the bg-fixed-child-mask.html reftest pass by ensuring
the clips for the test case are all in the correct spots. See the
comments in the patch for a more detailed explanation.
MozReview-Commit-ID: 5HHtsSkcsji
This patch is not really needed, but it avoids accidental conversion
between FrameMetrics::ViewID (which represents a scrolling clip) and a
uint64_t id for a non-scrolling clip.
MozReview-Commit-ID: BU7p4WNocXa
Each layer has a stack of scroll metadata objects, which represent the
set of scrollframes that got flattened into the layer. Effectively the
metadata objects provide the scroll information for the chain of
scrollframes containing that layer's content. Each of these scrollframes
may have a clip, and so we need to push those clips to WR. We need to
take care to insert these clips at the right point in the stack, so that
they are interleaved correctly with the PushScrollLayer calls that we
use to inform WR of the scrolling clips for the scrollframes. This patch
implements this behaviour.
MozReview-Commit-ID: BayxnZuqh4s
This ensures that for layers with both transforms and mask layers, the
mask layer is properly positioned outside of the transform and relative
to the proper stacking context.
MozReview-Commit-ID: 79yvhxQCykW
For various reasons, we want to be pushing the layer's local clip rect
outside of the stacking context rather than inside it. Not only is this
more correct with respect to the semantics of the layer tree, we also
need it in order to properly handle fixed-positioning of layers with
async scrolling.
This patch does the bulk of the work to make this happen. Most of the code
in the individual layer classes to process the layer's local clip rect
is removed, and instead a function in ScrollingLayersHelper is added to
deal with it. There are a couple of places that individual layer classes
still handle this but those will be removed in future patches. Note that
the individual layer classes still need to provide a clip rect of some
sort in order to push their display items, and now they simply use their
visible region bounds for this purpose.
MozReview-Commit-ID: IBmfUdJwYx1
This implements at least enough fixed-positioning support to make the
reftest in layout/reftests/async-scrolling/bg-fixed-child.html pass.
That test implements a simple background-attachment:fixed which is
implemented in the layer tree with a combination of a scrolled clip and
a fixed-position layer. Previous patches in this patchset implemented
support for the scrolled clip, and this patch implements the
fixed-position layer support.
MozReview-Commit-ID: 1Al1YshhUL7
If the layer has a "scrolled clip", that clip scrolls with the content
of the layers (it moves if any of the scrollable frames defined by that
layer are scrolled).
MozReview-Commit-ID: 37hvXWO930f
This adds an RAII helper and uses it in RenderLayer functions. When APZ
is enabled, the RAII helper pushes a scrolling clip for each scrollable
metrics on the layer. It also pops off the scrolling clips on
destruction. Note that this should happen before any other things are
pushed into the WR display list for the rendering of a layer, since
those things should be subjected to the enclosing scrolling clips.
If APZ is disabled, this skips pushing the scrolling clips.
MozReview-Commit-ID: 1qv9egKbbok
