If the parent BFC can come up with a nice stretch-fit width for the flex
container, it will have already done so *before* even entering flex
layout. There's no need to do it again, midway through the flex layout
algorithm.
This wasn't just unnecessary, but we were also doing it incorrectly and
not taking margins into account when calculating the amount of available
space for stretch-fit. This led to oversized flex containers in the
presence of negative margins.
Fixes#18614
`calculate_max_content_height` expects the available width as the
second argument. However, the available height was mistakenly passed
before. This did not seem to cause any problems because TFC currently
does not respect height sizing constraints but still needs to be fixed.
The root element font metrics were getting queried again and again
during style computation. Before this change we would do some work to
recalculate them each time.
This patch simply caches them in a StyleComputer member. Since style
updates always start with the root element, we know that it'll be
up-to-date by the time we look at any other element.
Before this change, we were spending ~5% of CPU time on Google Groups
in root_element_font_metrics().
This is an oversized hammer for sure, but we have to make sure the
layout tree gets rebuilt in case the object representation changes.
Since "throw out the entire layout tree" is the finest tool we have
right now, it'll have to do.
This fixes an issue where the eyes on Acid2 would sometimes not show up
until the next layout invalidation occurred.
Layout will be identical for both of those values, so only a repaint is
necessary. If it changes to/from "collapse" however, we do need to
relayout. This means we can't simply use the "affects-layout" mechanism.
We have to write a little bit of custom code.
This makes Google Groups (and surely many other sites) significantly
more responsive by avoiding large amounts of layout work.
Fixes incorrect thread highlighting for ResourceGraph panels.
Prior to FrameStyles, these graphs were painted as faux-panels,
this is, sunken containers with a thickness of 1, and weren't
subject to the bug.
If something else has already caused a layout, there's no need to force
a new relayout when the layout timer fires.
This avoids a lot of redundant work on many pages. :^)
The Font class now remembers the results of kerning lookups in a
HashMap. This fixes an issue where text-heavy UI (like WidgetGallery)
would lag when using a UI font with kerning data.
Instead of testing all possible code to find the good symbol, we use a
lookup table to directly find the expected symbol. This method is used
by most Huffman decoder (gzip or libjpeg-turbo).
In order to use the correct key when peeking a constant number of bits
from the stream, we generate duplicates in the table. As an example, for
the code 110, all entries with that pattern 110***** will be set to
110's symbol. So, when you read this code plus garbage from following
codes, you still find the correct symbol.
Advantages of encapsulation are really obvious here:
- Put related code together
- Prevent external functions to modify the object
- Abstract the implementation
No functional changes intended.
A compressed ALPH chunk is a lossless webp bitstream, but without
the 5 byte "header" that stores width, height, is-alpha-channel-used
(it never is for an ALPH chunk since the ALPH chunk gets the alpha
data out of the lossless webp's green channel), and version fields.
For that reason, this cuts decode_webp_chunk_VP8L() into the
header-reading part and the remaining part, so that the remaining
part can be called by the ALPH reading routine.
Lossy webp files with a (losslessly) compressed alpha channel can
be found in the wild. Since we can't decode lossy webp data yet,
change the `#if 0` in decode_webp_chunk_VP8() to `#if 1` to test this.
ALPH chunks are only used to give lossy webp frames an alpha channel,
and lossy decompression isn't implemented yet. So this can currently
never be hit in practice -- but for debugging and testing, I put in
some code behind `#if 0` for now that fake-decompresses a lossy webp
frame by returning an empty bitmap.
But this also doesn't implement compressed ALPH chunks yet, and I
couldn't find any lossy-webp-with-alpha files that use uncompressed
alpha channels. So the code here isn't really tested.
If someone comes along who wants to implement lossy webp decoding,
they now only need to implement decode_webp_chunk_VP8() and everything
might Just Work.
It also makes it possible to implement alpha chunk decoding before
implementing lossy decoding (by making decode_webp_chunk_VP8()
return an empty black bitmap for testing).
That way, animated and non-animated webp files use the same code path
to decode images. That will make it easier to add handling for lossy
decompression and for alpha chunk handling.
No behavior change.
Width of table wrapper need to be set to to calculate width of table
box inside. Otherwise TFC will set wrong width assuming width of
containing block is 0.
There is a NOTE in our implementation of these steps which states that
the effective overload set only contains overloads with the correct
number of arguments. While this is true, we should not skip the steps to
clamp the inspected argument count to that correct number. Otherwise, we
will dereference past the end of the overload set's type list as we
blindly iterate over the user-provided arguments.
Fixes#18670.
