Which is to return an empty scroll clip (instead of whatever scroll clip was accumulated in the for loop).
This patch is actually even slightly better than what we did before in that we can stop when we hit the root AGR (which is also the root reference frame) instead of the root of the frame tree. These would be different when painting a popup frame, or when not painting to the window.
gfxRect can be implicitly constructed from IntRect, which hides a number of
implicit conversion points, makes Moz2Dification harder, and has some
surprising effects.
This patch removes the implicit constructor and replaces it with an explicit
conversion function:
gfxRect ThebesRect(const IntRect&)
This is the obvious outcome of removing the constructor.
But there is also a second, less obvious outcome: currently we do a number of
IntRect-to-Rect conversions using ToRect(), which (surprisingly) works because
it turns into an implicit IntRect-to-gfxRect conversion (via the implicit
constructor) combined with an explicit gfxRect-to-Rect conversion (via
ToRect()). I.e. we do two conversions, going from a Moz2D type to a Thebes
type and back to a Moz2D type!
So this patch also changes these conversion. It moves this existing function:
Rect ToRect(const IntRect&)
from gfx2DGlue.h -- where it doesn't really belong because it doesn't involve
any Thebes types -- to gfx/2d/Rect.h, templatifying and renaming it as
IntRectToRect() in the process.
The rest of the patch deals with fall-out from these changes. The call sites
change as follows:
- IntRect-to-gfxRect conversions:
- old: implicit
- new: ThebesRect()
- IntRect-to-Rect conversions:
- old: ToRect()
- new: IntRectToRect()
Displayports only get acted upon when painting to the window, and the async scroll clips only get computed when we use a displayport.
In addition we change an assert because if we are painting to the window then our root reference frame is either a root frame, or a popup frame. In either case we should not be able to get to out of flows outside of the frame subtree rooted at the root reference frame by following placeholders.
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>
This change necessitates a few other header changes around the tree:
either places that we relying on FrameLayerBuilder.h to #include
ImageLayers.h for them, or places that were bootlegging headers from
ImageLayers.h.
This change means that we don't have to have the definition of
LayerManager visible when FrameLayerBuilder is declared (which would be
necessary for, e.g. the ctor/dtor of ClippedDisplayItem), which means we
can get rid of the Layers.h include here in a subsequent patch.
Having to include all of Layers.h just to get at the definition of
LayerUserData is inconvenient, especially as most of the interesting
things in Layers.h can be forward-declared. Let's move LayerUserData to
its own header, so clients can include a small header for that,
forward-declare anything else they need from Layers.h, and reduce header
bloat.
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.
