This patch doesn't change behavior, and eliminates copy construction of
nsFrameList via utilizing const-references to store the return value of
`GetChildList()`.
nsFrameList::Clone() is added in case the caller wants a copy of a list.
This is the first step toward making nsFrameList a move-only class.
Differential Revision: https://phabricator.services.mozilla.com/D160013
This patch doesn't change behavior, and eliminates copy construction of
nsFrameList via utilizing const-references to store the return value of
`GetChildList()`. This is the first step toward making nsFrameList a move-only
class.
Differential Revision: https://phabricator.services.mozilla.com/D160013
After this patch, we still need nsFrameList::Enumerator to iterate
nsFrameList::Slice. We might enhance nsFrameList::Iterator to support Slice, but
I'll leave this for another day.
Differential Revision: https://phabricator.services.mozilla.com/D158809
RemoveFramesAfter and ExtractTail have similar purpose, so we really should keep
one of them to avoid confusion.
They have the following minor differences:
1. RemoveFramesAfter() keeps aFrame in the list, while ExtractTail() returns it.
2. If aFrame is empty, RemoveFramesAfter() returns the entire list, while
ExtractTail returns an empty list.
It's more convenient for the existing callers to use the RemoveFramesAfter(), so
ExtractTail is unneeded.
After this patch, both RemoveFramesAfter() and RemoveFramesBefore() return the
entire list if aFrame is nullptr.
Rename RemoveFramesAfter() to TakeFramesAfter() for symmetry with
TakeFramesBefore().
This change shouldn't change the behavior.
Differential Revision: https://phabricator.services.mozilla.com/D158807
I feel it's hard to understand the purpose of ExtractHead(), especially where
aFrame is going after the call. Therefore, I rename it to TakeFramesBefore(),
and have it complement the existing RemoveFramesAfter(), which will be rename
later. No behavioral change intended.
Also, slightly reword the method's documentation to reflect the its new
name. (Remove the "sibling" wording from the comment since it's an
implementation details that frames are actually a doubly linked list.)
Differential Revision: https://phabricator.services.mozilla.com/D158806
This is a preparation to remove nsFrameList::FrameLinkEnumerator in the next
part.
FrameLinkEnumerator::Find() can be replaced with std::find/std::find_if.
Differential Revision: https://phabricator.services.mozilla.com/D158700
This applies both to the individual mStartPageValue and mEndPageValue fields
of the nsIFrame::PageValues struct, and for the nsIFrame::PageValuesProperty
being null to indicate both mStartPageValue and mEndPageValue are auto.
Fetching this is handled by nsIFrame::GetStartPageValue and
nsIFrame::GetEndPageValue, which also ensure the use of first-in-flow frames.
Differential Revision: https://phabricator.services.mozilla.com/D157873
* Rename `mBreakType` to `mFloatClearType` in nsLineBox and nsReflowStatus and
the methods around it.
* Rename `mBreakType` to `mClear` in nsStyleDisplay.
* Many other method parameters or local variables rename such as from
`aBreakType` to `aClearType`.
Differential Revision: https://phabricator.services.mozilla.com/D158276
Before this patch, StyleClear::Line indicates that the nsLineBox has break-after
but no float clearance (note we don't allow line break-before with clear:none);
StyleClear::None indicates the line has no break-before nor break-after.
In this patch, I added `mHasForcedLineBreak` bit in nsLineBox to indicate the
line has a break so that StyleClear can serve its original meaning -- the float
clearance. In Part 6, I'll rename more existing methods and variables related to
float clearance.
Now, instead of using StyleClear::None to clear the line break status, the
caller should use ClearForcedLineBreak(); Similar to set
SetInlineLineBreakBeforeAndReset() and SetInlineLineBreakAfter on
nsReflowStatus, SetBreakTypeBefore/SetBreakTypeAfter on nsLineBox always sets
break status with an optional float clearance parameter.
This patch shouldn't change the behavior.
Differential Revision: https://phabricator.services.mozilla.com/D158224
This patch shouldn't change the behavior.
* Rename BlockReflowState's `mFloatBreakType` to `mTrailingClearFromPIF` since
it's the cached result of `FindTrailingClear()` from the block's prev-in-flow.
Note that `mTrailingClearFromPIF` can have `StyleClear::Line`, which is
not a float clear value. We'll remove `StyleClear::Line` in a later part to
make this 100% correct.
* Rename `nsLayoutUtils::CombineBreakType` to `CombineClearType` as well as its
arguments.
* Simplify FindTrailingClear()'s implementation.
Differential Revision: https://phabricator.services.mozilla.com/D158221
Nowadays, nsFloatCache stores no extra information but `nsIFrame*`, which makes
nsFloatCacheList and nsFloatCacheFreeList are just singly and doubly linked
list of frames, respectively.
Most of this patch is a plain rewrite to use nsTArray APIs. There are two
rewrite that need more explanation.
1. `BlockReflowState::mFloatCacheFreeList` is served as a temporarily list to
avoid extra allocations of nsFloatCache. It takes the ownership of floats
from a line via FreeFloats(), and later reuses the cache in AddFloat().
We don't need this anymore, so we remove it.
2. In `PlaceBelowCurrentLineFloats()`, the old code removes a float which
needs to be pushed to next continuation from `mBelowCurrentLineFloats`.
After looking through all of the floats, the remaining of
`mBelowCurrentLineFloats` are moved to the line because they belong to the
line. In this patch, rather than removing the pushed floats one by one from
`mBelowCurrentLineFloats`, I use a new list to collect the floats that need
to be added to the line, and just clear `mBelowCurrentLineFloats` at the
end of the method.
Differential Revision: https://phabricator.services.mozilla.com/D157976
This also properly handles placeholder frames, and ensures that when checking
next/prev sibling we ignore placeholder frames.
To properly test this for multiple levels of page value propagation, we also
need to use FirstInFlow to get page values when checking for breaks in block
frames.
Differential Revision: https://phabricator.services.mozilla.com/D157175
Some anonymous children are important for properly sizing their parents
even when those parents hide content with `content-visibility`. This is
shown by regressions in the proper layout of some form elements with
`content-visibility`.
This change introduces a more conservative approach for avoiding layout
of hidden content. Instead of leaving all children dirty during reflow,
reflow anonymous frames (and nsComboboxDisplayFrame, a specialized kind
of anonymous frame). This change means that frames may only lay out some
of their children, so it must introduce some more changes to assumptions
during line layout.
In addition, this change renames `content-visibility` related methods in
nsIFrame in order to make it more obvious what they do.
Differential Revision: https://phabricator.services.mozilla.com/D157306
Some anonymous children are important for properly sizing their parents
even when those parents hide content with `content-visibility`. This is
shown by regressions in the proper layout of some form elements with
`content-visibility`.
This change introduces a more conservative approach for avoiding layout
of hidden content. Instead of leaving all children dirty during reflow,
reflow anonymous frames (and nsComboboxDisplayFrame, a specialized kind
of anonymous frame). This change means that frames may only lay out some
of their children, so it must introduce some more changes to assumptions
during line layout.
In addition, this change renames `content-visibility` related methods in
nsIFrame in order to make it more obvious what they do.
Differential Revision: https://phabricator.services.mozilla.com/D157306
This also adds a small post-processing step for frame-construction to ensure
that replaced frames (or more generally frames with content but no children)
have the auto page-name set on them.
When page-name value tracking is switched to be lazy, this post-processing step
will likely be redundant and can be removed.
Differential Revision: https://phabricator.services.mozilla.com/D152701
Some anonymous children are important for properly sizing their parents
even when those parents hide content with `content-visibility`. This is
shown by regressions in the proper layout of some form elements with
`content-visibility`.
This change introduces a more conservative approach for avoiding layout
of hidden content. Instead of leaving all children dirty during reflow,
reflow anonymous frames (and nsComboboxDisplayFrame, a specialized kind
of anonymous frame). This change means that frames may only lay out some
of their children, so it must introduce some more changes to assumptions
during line layout.
In addition, this change renames `content-visibility` related methods in
nsIFrame in order to make it more obvious what they do.
Differential Revision: https://phabricator.services.mozilla.com/D156473
This also adds a small post-processing step for frame-construction to ensure
that replaced frames (or more generally frames with content but no children)
have the auto page-name set on them.
When page-name value tracking is switched to be lazy, this post-processing step
will likely be redundant and can be removed.
Differential Revision: https://phabricator.services.mozilla.com/D152701
It's always true, so remove it.
Add another pref to allow -webkit-line-clamp to work on all blocks
rather than just legacy -webkit-boxes, which seems something we should
try to look into, eventually.
Depends on D155181
Differential Revision: https://phabricator.services.mozilla.com/D155182
This is a hack, sorta, similar to Chromium's:
https://source.chromium.org/chromium/chromium/src/+/main:third_party/blink/renderer/core/layout/layout_object.cc;l=356;drc=312b74e385e6aba98ab31fd911238c0dc16b396c
except at computed-value rather than used-value time, because it's both
simpler to reason about and prevents lying in the computed style.
This fixes the relevant test-case, and matches closer what Chromium does,
by not creating anonymous flex items for all elements inside the
line-clamp context.
The behavior change is covered by the test changes. I had to also fix a
couple pre-existing bugs that were caught by tests, now that the
line-clamped block is the -webkit-box-styled element rather than an anonymous
flex item (and thus now had padding).
Depends on D155180
Differential Revision: https://phabricator.services.mozilla.com/D155181
Some sites use text content that consists entirely of whitespace, which can
lead to unexpected rendering in High Contrast Mode - namely, backplating of
invisible characters. This commit adds logic that detects text nodes consisting
entirely of whitespace and reports their text area as 0. This commit also adds
a test for the behavior, and modifies an existing test to reflect the new
behavior.
Differential Revision: https://phabricator.services.mozilla.com/D155248
We can move a float frame into its block parent's PushedFloatsList during column
balancing when it cannot fit in the available block-size.
Later, when the column balancing algorithm reflows the last column in an
unconstrained block-size (in the very last reflow if needed [1]), we have to
reflow the line which contains the float's placeholder. The old code uses
`GetPrevInFlow() || GetNextInFlow()` to detect this scenario, which is
insufficient because the float's block parent might not have any continuation.
This patch uses `NS_FRAME_HAS_MULTI_COLUMN_ANCESTOR` bit to detect this instead.
[1] https://searchfox.org/mozilla-central/rev/5c04fc7016eb7f52cf835d482f1125c8f139c959/layout/generic/nsColumnSetFrame.cpp#1144-1154
Differential Revision: https://phabricator.services.mozilla.com/D154860
In the description of the mTruncated bit, its purpose is the same as calling
SetInlineLineBreakBeforeAndReset(). We've removed all its usages in previous
patches, so the bit is no longer needed.
Differential Revision: https://phabricator.services.mozilla.com/D151461
The old code tweaks mIsTopOfPage in ReflowFloat(). However
`aAvailableSize.ISize()` (in containing block's writing-mode) always equals to
ContentISize() because it is computed via ComputeAvailableSizeForFloat().
Therefore, the only reason the floatRI's mIsTopOfPage can be `false` is when
some floats are already being placed, and we only check this in the
`!earlyFloatReflow` branch.
By tweaking mIsTopOfPage bit in FlowAndPlaceFloat(), we can also remove two
unused parameters in ReflowFloat().
This patch shouldn't change the behavior.
Differential Revision: https://phabricator.services.mozilla.com/D151457
The if-branch is incorrect because ShouldAvoidBreakInside() [1] is called via
the parent block instance with float child's ReflowInput as the argument. In
principle, the child frame should report break-before status if it cannot fit
the page/column and wants to avoid breaking. Removing this if-branch is
potentially a behavior change, but it is the correct thing to do. (Note that
ReflowFloat()'s caller FlowAndPlaceFloat() already handles
IsInlineBreakBefore(). If the float frame type already implements break-avoid,
we are fine.)
The else-if branch can never be reached except when the float is a letter frame,
and we've tested that scenario a few lines just before the this added assertion.
The code coverage also shows this branch in never reached.
https://coverage.moz.tools/#revision=e6e2286d2ac25001127a1cf54a87a95fb435c734&path=layout%2Fgeneric%2FnsBlockFrame.cpp&view=file&line=6682
[1] Note: ShouldAvoidBreakInside() is a protected member function, which can
only be called for concrete frame classes inheriting from nsContainerFrame.
Differential Revision: https://phabricator.services.mozilla.com/D151456
There is some advantage to creating the float's ReflowInput in
FlowAndPlaceFloat().
1. ReflowFloat() doesn't need to output the float's margin and offset via the
output arguments. FlowAndPlaceFloat() can get them from the local ReflowInput
directly.
2. Since we are going to reflow the float, we have to create a ReflowInput
anyway. FloatMarginISize() can take the ReflowInput and be simplified. No need
to waste time to create a separate SizeComputationInput.
Also, delete the comment "Pass floatRS so the frame hierarchy can be
used (redoFloatRS has the same hierarchy)" because I believe it is obsolete.
This patch also lays the foundation for other improvements in the later patches.
Differential Revision: https://phabricator.services.mozilla.com/D151455
