The two flags combined used to be represented by just RENDER_IGNORE_VIEWPORT_SCROLLING. Until http://hg.mozilla.org/mozilla-central/rev/99279c1c33cc (bug 590294) split RENDER_DOCUMENT_RELATIVE out. It split out the requested rect to be document relative. But it also split out the part about "drawing the document as if it had not been scrolled" with the new flag, but the comments for that part didn't get updated.
The names of the flags are perhaps inaccurate, but changing that requires changing a lot more code.
We may want to do this for fixed pos frames in all documents (not just root documents). However, this patch only maintains the previous behaviour on purpose.
Instead of returning the root scroll frame if we encountered the root frame (which is the parent of the root scroll frame).
This allows the use of GetNearestScrollableFrame to walk up the frame tree without getting into a infinite loop going from root scroll frame to root frame and back.
This regresses bug 1105823 in that fixed pos frames will no longer find the root scroll frame of their document. The next patch will fix that.
The only other type of frame that will be affected when calling GetNearestScrollableFrame are viewport (root) frames. However, the only user of SCROLLABLE_ALWAYS_MATCH_ROOT (APZCCallbackHelper) calls GetNearestScrollableFrame on the result of a hit test on a display list. Viewport frames never create any display items whose HitTest function could return the viewport frame.
Removing the "stop at ancestor" parameter from functions that compute AGR meant that nsLayoutUtils::GetAnimatedGeometryRootFor could no longer pass the display item's reference frame as the "stop at ancestor" which meant that the AGR could cross the reference frame for the item, which we don't want. So we make transformed frames into AGRs.
This makes the computation of display items whose frames are transformed tricky. We need the AGR of the transform item to be the ancestor AGR, not the underlying frame of the transform item (which is now an AGR). So we modify nsLayoutUtils::GetAnimatedGeometryRootFor to handle this. (The patch from bug 1205087 didn't suffer from this problem because it special cased the computation of the AGR of transform items. Leaving anybody who called nsLayoutUtils::GetAnimatedGeometryRootFor to get the wrong result.)
The computation of the AGR for scroll metadata in ContainerState::ProcessDisplayItems specifically bypassed nsLayoutUtils::GetAnimatedGeometryRootFor to avoid it's special processing of fixed background items. However we do want the AGR for scroll metadata to do this special processing of transform items. So we add a flag to bypass the fixed background behaviour and use it for the scroll metadata AGR.
This removes the "aStopAtAncestor" argument to agr computing functions. In most cases an AGR was passed for the stop at ancestor, so we'd stop at it anyway since it was an AGR. Most of the remaining cases the root reference frame was passed. And in a few cases something else was passed, which we probably don't want (returning something that isn't an AGR and isn't the root reference frame as an AGR).
The ShouldFixToViewport case is a little tricky. We want to get the AGR of the nearest viewport frame, but only if we don't have to cross our root reference frame to get it. This happens in practice for example when a select dropdown has background-attachment: fixed inside it.
Except for the ShouldFixToViewport bit, this patch is a subset of part 3 in bug 1205087 (which has more changes, and has been temporarily backed out, the remaining bits can hopefully land soon).
The ShouldFixToViewport part is by Timothy Nikkel <tnikkel@gmail.com>
The bulk of this commit was generated with a script, executed at the top
level of a typical source code checkout. The only non-machine-generated
part was modifying MFBT's moz.build to reflect the new naming.
CLOSED TREE makes big refactorings like this a piece of cake.
# The main substitution.
find . -name '*.cpp' -o -name '*.cc' -o -name '*.h' -o -name '*.mm' -o -name '*.idl'| \
xargs perl -p -i -e '
s/nsRefPtr\.h/RefPtr\.h/g; # handle includes
s/nsRefPtr ?</RefPtr</g; # handle declarations and variables
'
# Handle a special friend declaration in gfx/layers/AtomicRefCountedWithFinalize.h.
perl -p -i -e 's/::nsRefPtr;/::RefPtr;/' gfx/layers/AtomicRefCountedWithFinalize.h
# Handle nsRefPtr.h itself, a couple places that define constructors
# from nsRefPtr, and code generators specially. We do this here, rather
# than indiscriminantly s/nsRefPtr/RefPtr/, because that would rename
# things like nsRefPtrHashtable.
perl -p -i -e 's/nsRefPtr/RefPtr/g' \
mfbt/nsRefPtr.h \
xpcom/glue/nsCOMPtr.h \
xpcom/base/OwningNonNull.h \
ipc/ipdl/ipdl/lower.py \
ipc/ipdl/ipdl/builtin.py \
dom/bindings/Codegen.py \
python/lldbutils/lldbutils/utils.py
# In our indiscriminate substitution above, we renamed
# nsRefPtrGetterAddRefs, the class behind getter_AddRefs. Fix that up.
find . -name '*.cpp' -o -name '*.h' -o -name '*.idl' | \
xargs perl -p -i -e 's/nsRefPtrGetterAddRefs/RefPtrGetterAddRefs/g'
if [ -d .git ]; then
git mv mfbt/nsRefPtr.h mfbt/RefPtr.h
else
hg mv mfbt/nsRefPtr.h mfbt/RefPtr.h
fi
This commit was generated using the following script, executed at the
top level of a typical source code checkout.
# Don't modify select files in mfbt/ because it's not worth trying to
# tease out the dependencies currently.
#
# Don't modify anything in media/gmp-clearkey/0.1/ because those files
# use their own RefPtr, defined in their own RefCounted.h.
find . -name '*.cpp' -o -name '*.h' -o -name '*.mm' -o -name '*.idl'| \
grep -v 'mfbt/RefPtr.h' | \
grep -v 'mfbt/nsRefPtr.h' | \
grep -v 'mfbt/RefCounted.h' | \
grep -v 'media/gmp-clearkey/0.1/' | \
xargs perl -p -i -e '
s/mozilla::RefPtr/nsRefPtr/g; # handle declarations in headers
s/\bRefPtr</nsRefPtr</g; # handle local variables in functions
s#mozilla/RefPtr.h#mozilla/nsRefPtr.h#; # handle #includes
s#mfbt/RefPtr.h#mfbt/nsRefPtr.h#; # handle strange #includes
'
# |using mozilla::RefPtr;| is OK; |using nsRefPtr;| is invalid syntax.
find . -name '*.cpp' -o -name '*.mm' | xargs sed -i -e '/using nsRefPtr/d'
# RefPtr.h used |byRef| for dealing with COM-style outparams.
# nsRefPtr.h uses |getter_AddRefs|.
# Fixup that mismatch.
find . -name '*.cpp' -o -name '*.h'| \
xargs perl -p -i -e 's/byRef/getter_AddRefs/g'
The change breaks some scenarios with APZ scrolling, in particular the code
that layerizes the scroll handoff chain for deeply nested scrollable frames.
gfxIntSize is just a typedef of gfx::IntSize, so this is very mechanical. The
only tricky part is deciding for each occurrence whether to replace it with
IntSize, gfx::IntSize or mozilla::gfx::IntSize; in all cases I went with the
shortest one that worked given the existing "using namespace" declarations.
Remove WrapPreserve3DList() and replaced it by creating a
nsDisplayTransform item for each transformed frame.
- Add an additional item for each top frame extending 3D context to
separate consequence contexts.
- Effective transform of a layer is the accumulation of ancestors in
the same 3D context.
- The layers creating new context and extended by children need a
temporary buffer if it's effective transform is not 2D.
- Clip rects are accumulated along the context chain.
- Visible rects of items are computed from dirty regions of the frame
creating the context and accumulated transforms.
- Bounds of items are computed from accumulated transforms and
accumulated bounds of the descent frames.
- Backface hidden is handled by compositor and BasicLayerManager.
Remove WrapPreserve3DList() and replaced it by creating a
nsDisplayTransform item for each transformed frame.
- Add an additional item for each top frame extending 3D context to
separate consequence contexts.
- Effective transform of a layer is the accumulation of ancestors in
the same 3D context.
- The layers creating new context and extended by children need a
temporary buffer if it's effective transform is not 2D.
- Clip rects are accumulated along the context chain.
- Visible rects of items are computed from dirty regions of the frame
creating the context and accumulated transforms.
- Bounds of items are computed from accumulated transforms and
accumulated bounds of the descent frames.
- Backface hidden is handled by compositor and BasicLayerManager.
AnimationCollection::HasAnimationOfProperty uses IsFinishedTransition to filter
out transitions that should otherwise be ignored. This is used in the following
places:
1. nsLayoutUtils::HasAnimations
The is only used by nsIFrame::BuildDisplayListForStackingContext to see if
there are any opacity animations
For this case, simply returning *current* animations would be sufficient
(since finished but filling animations should have already filled in the
display opacity)
2. CommonAnimationManager::GetAnimationsForCompositor
This should really only return *current* animations--that is, animations that
are running or scheduled to run. Finished animations never run on the
compositor. Indeed, only *playing* animations run on the compositor but, as
we will see in some of the cases below, it is sometimes useful to know that
an animation *will* run on the compositor in the near future (e.g. so we can
pre-render content).
The places where GetAnimationsForCompositor is used are:
- When building layers to add animations to layers in nsDisplayList--in this
case we skip any animations that aren't playing so if
GetAnimationsForCompositor only returned current animations that would be
more than sufficient.
- In nsLayoutUtils::HasAnimationsForCompositor. This in turn is used:
- In ChooseScaleAndSetTransform to see if the transform is being animated
on the compositor. If so, it calls
nsLayoutUtils::ComputeSuitableScaleForAnimation (which also calls
GetAnimationsForCompositor) and passes the result to
GetMinAndMaxScaleForAnimationProperty which we have already adjusted in
part 4 of this patch series to only deal with *relevant* animations
Relevant animations include both current animations and in effect
animations but we don't run forwards-filling animations on the compositor
so GetAnimationsForCompositor should NOT return them. Current animations
should be enough. In fact, playing animations should be enough but we
might want to pre-render layers at a suitable size during their delay
phase so returning current animations is probably ok.
- In nsDisplayListBuilder::MarkOutOfFlowFrameForDisplay to add a fuzz
factor to the overflow rect for frames undergoing a transform animation
on the compositor. In this case too current animations should be
sufficient.
- In nsDisplayOpacity::NeedsActiveLayer to say "yes" if we are animating
opacity on the compositor. Presumably in this case it would be good to
say "yes" if the animation is in the delay phase too (as it currently
does). After the animation is finished, we should drop the layer, i.e.
current animations should be sufficient.
- In nsDisplayTransform::ShouldPrerenderTransformedContent. As with
nsDisplayOpacity::NeedsActiveLayer, we only need to pre-render
transformed content for animations that are current.
- In nsDisplayTransform::GetLayerState. As with
nsDisplayOpacity::NeedsActiveLayer, we only need to return active here
for current animations.
- In nsIFrame::IsTransformed. Here we test the display style to see if
there is a transform and also check if transform is being animated on the
compositor. As a result, we really only need HasAnimationsForCompositor
to return true for animations that are playing--otherwise the display
style will tell us if we're transformed or not. Returning true for all
current compositor animations (which is a superset of playing), however,
should not cause problems (we already return true for even more than
that).
- In nsIFrame::HasOpacityInternal which is much the same as
nsIFrame::IsTransformed and hence current should be fine.
3. AnimationCollection::CanThrottleAnimation
Here, HasAnimationOfProperty is used when looking for animations that would
disqualify us from throttling the animation by having an out-of-date layer
generation or being a transform animation that affects scroll and so requires
that we do the occasional main thread sample to update scrollbars.
It would seem like current animations are enough here too. One interesting
case is where we *had* a compositor animation but it has finished or been
cancelled. In that case, the animation won't be current and we should not
throttle the animation since we need to take it off its layer.
It turns out checking for current animations is still ok in this case too.
The reasoning is as follows:
- If the animation is newly-finished, we'll pick that up in
Animation::CanThrottle and return false then.
- If the animation is newly-idle then there are two cases:
If the cancelled animation was the only compositor animation then
AnimationCollection::CanPerformOnCompositorThread will notice that there
are no playing compositor animations and return false and
AnimationCollection::CanThrottleAnimation will never be called.
If there are other compositor animations running, then
AnimationCollection::CanThrottleAnimation will still return false because
whatever cancelled the animation will update the animation generation and
we'll notice the mismatch between the layer animation generation and the
animation generation on the collection.
Based on the above analysis it appears that making
AnimationCollection::HasAnimationOfProperty return only current animations (and
simulatneously renaming it to HasCurrentAnimationOfProperty) is safe. Indeed, in
effect, we already do this for transitions but not for animations. This patch
generalizes this behavior to all animations.
This patch also updates test_animations_omta.html since it was incorrectly
testing that a finished opacity animation was still running on the compositor.
Finished animations should not run on the compositor and the changes in this
patch cause that to happen. The reason we don't just update this test to check
for RunningOn.MainThread is that for opacity animations, unlike transform
animations, we can't detect if an opacity on a layer was set by animation or
not. As a result, for opacity animations we typically test the opacity on
either the main thread or compositor in order to allow for the case where an
animation-set opacity is still lingering on the compositor.
