This is the variable that says we *need to* rebuild style data. Since
the next patch will introduce a variable that says we're *currently*
rebuilding all style data, renaming this one makes things clearer.
Part of this refactoring involves the ability to start the rebuild-all
process within the processing of restyles. This means we can't pass
parameters directly from RebuildAllStyleData into DoRebuildAllStyleData.
So this continues storing the hints as member variables a little bit
deeper into the process.
(I tried to move in a different direction in this patch queue, and store
these hints in mPendingRestyles, for the root element. But that broke
layout/style/test/test_counter_style.html and
layout/style/test/test_font_loading_api.html, and I didn't want to
figure out why. It would be somewhat better in the long run, since
currently these hints will get processed if we do a rebuild-all on a
RestyleTracker other than mPendingRestyles, which can happen if we have
'rem' units and have a root element font size change in the
animation-only update or in mPendingAnimationRestyles.)
The patches in this series refactor the process of rebuilding all style
data (RestyleManager::RebuildAllStyleData and
RestyleManager::DoRebuildAllStyleData) so that the process of rebuilding
all style data uses the existing restyle processing loops in
ProcessPendingRestyles. (Rebuilding all style data is what we do when
we need to throw away the rule tree because something has invalidated
the cached data in it.) This removes (increasing, especially with bug
960465 coming) code duplicated between the two codepaths, fixes some
omissions from the separate rebuild-all codepath, and (more immediately)
allows fixing lifetime issues of ReframingStyleContexts objects in bug
1110277 so that we can have a single ReframingStyleContexts for all of
the restyle processing in each restyle processing operation. In other
words, the goal is to change the rebuild-all process from a separate
codepath to a few variables that modify the way ProcessPendingRestyles
works (and make it do the extra work).
This is just a small first step in that process, which moves one piece
of code from a chunk of duplicated and to-be-removed code into a chunk
of code that will be preserved.
This patch is not needed to fix the bug, but it seems like it's probably
desirable. It's not needed for this bug because
MaybeReframeForBeforePseudo and MaybeReframeForAfterPseudo are already
called (by ElementRestyler::RestyleChildren) on only the first and last
continuation or ib-split sibling with the same style. So this patch
should only actually change anything for cases like a block-in-inline
split whose initial inline part is inside of a ::first-line (where
different parts of the block-in-inline split chain have different style).
Since the symptom of this bug is (once patch 6 is in the tree) only
causing extra reframes, it can only be tested using the new API (from
bug 1115691) for observing reframes. I confirmed that the test for this
bug fails without the patch and passes with the patch (as noted by the
removal of its todo annotation).
For some kinds of changes we need to update the layer tree even though there is
no change to style. For example, if an animation is paused via the Web
Animations API, we need to remove the animation from the layer even though the
style will not change.
This patch detects such changes by making ElementRestyler check for an
out-of-date animation generation on layers. This is complicated by the fact that
we currently maintain *two* animation generation numbers: one for the set of
animations and one for the set of transitions, but we only have *one* animation
generation number on each layer. This is a known issue (bug 847286).
As a result, until bug 847286 is fixed, we need to be careful to compare against
the greater of the two numbers.
Until we get rid of animation phases in bug 960465, we need to ensure
we're producing style data for the correct animation phase. This makes
this optimization slightly less beneficial until then.
Bug 931668 added the eRestyle_ForceDescendants case for all cases that
go through RebuildAllStyleData, but there is another case that calls
DoRebuildAllStyleData directly, and we should cover that too.
This is needed because when we're rebuilding the rule tree, we need to
create new style contexts for all frames.
I don't know of any bugs caused by this, but it seems worth fixing.
This is just moving one bit of data from the pres context without any
logic change. But given the other refactoring, it seems to make more
sense here now.
The MOZ_DEBUG_RESTYLE_STRUCTS environment variable can be set to a comma-
separated list of style struct names. When restyle logging is enabled,
this will cause the style context tree -- showing cached style struct
pointers for those structs specified -- to be logged before each
individual restyle is processed. It will also show the struct pointer
values involved when swapping structs between style contexts.
For example, set MOZ_DEBUG_RESTYLE_STRUCTS=Font,UserInterface to show
the cached nsStyleFont and nsStyleUserInterface pointers on the style
contexts involved in the restyle process.
Set the MOZ_DEBUG_RESTYLE environment variable and every restyle will have
detailed logging printed to stderr. By default, restyles for animations are
not logged; you can include them by also setting MOZ_DEBUG_RESTYLE_ANIMATIONS.
If you wish to limit restyle logging to a particular change, you can call
nsPresContext::StartRestyleLogging() and nsPresContext::StopRestyleLogging()
at appropriate points. (You might want to add a couple of helper methods
temporarily on nsIDocument and then expose them to your page with Web IDL
to make them easier to call.) You do not need to have set MOZ_DEBUG_RESTYLE
for this to work.
Set the MOZ_DEBUG_RESTYLE environment variable and every restyle will have
detailed logging printed to stderr. By default, restyles for animations are
not logged; you can include them by also setting MOZ_DEBUG_RESTYLE_ANIMATIONS.
If you wish to limit restyle logging to a particular change, you can call
nsPresContext::StartRestyleLogging() and nsPresContext::StopRestyleLogging()
at appropriate points. (You might want to add a couple of helper methods
temporarily on nsIDocument and then expose them to your page with Web IDL
to make them easier to call.) You do not need to have set MOZ_DEBUG_RESTYLE
for this to work.
This is needed because patch 1 and patch 3 did not add a mechanism that
allows restyling pseudo-elements, which would be substantially more work
and very little use (since the only case in which they have style
attributes is for our internal use on the ::-moz-color-swatch
pseudo-element).
RestyleUndisplayedChildren does not need the same fix because it's only
used on elements, and never on pseudo-elements or anonymous boxes.
