This is a improved version of a73cd88f0c
The old commit was reverted in 552dd18696
The new version only paints an element into a new layer if background
blend modes other than normal are used. The rasterization performance
of most websites should therefore not suffer.
Co-Authored-By: Alexander Kalenik <kalenik.aliaksandr@gmail.com>
This reverts commit a73cd88f0c.
Emitting SaveLayer for each paintable made rasterization a lot slower
on every website because now Skia has to allocate enormous amounts of
temporary surfaces. Let's revert it for now and figure how to implement
it with less aggressive SaveLayer usage.
Before this change, an element masked with 'mask-image: url(...)' would
show the mask, but 'mask: url(...)' would not. On e.g. dialogic.nl it
would show white boxes instead of the actual images in the top
navigation bar. We still do not support many of the other mask
properties, but with this change at least the masks show up in both
cases.
When setting `font-family: monospace;` in CSS, we have to interpret
the keyword font sizes (small, medium, large, etc) as slightly smaller
for historical reasons. Normally the medium font size is 16px, but
for monospace it's 13px.
The way this needs to behave is extremely strange:
When encountering `font-family: monospace`, we have to go back and
replay the CSS cascade as if the medium font size had been 13px all
along. Otherwise relative values like 2em/200%/etc could have gotten
lost in the inheritance chain.
We implement this in a fairly naive way by explicitly checking for
`font-family: monospace` (note: it has to be *exactly* like that,
it can't be `font-family: monospace, Courier` or similar.)
When encountered, we simply walk the element ancestors and re-run the
cascade for the font-size property. This is clumsy and inefficient,
but it does work for the common cases.
Other browsers do more elaborate things that we should eventually care
about as well, such as user-configurable font settings, per-language
behavior, etc. For now, this is just something that allows us to handle
more WPT tests where things fall apart due to unexpected font sizes.
To learn more about the wonders of font-size, see this blog post:
https://manishearth.github.io/blog/2017/08/10/font-size-an-unexpectedly-complex-css-property/
Implemented by reusing AddMask display list item that was initially
added for `background-clip` property.
Progress on flashlight effect on https://null.com/games/athena-crisis
Gap values are now represented by Variant<LengthPercentage, NormalGap>.
NormalGap is just an empty struct to represent the `normal` keyword.
This fixes a long-standing issue where we were incorrectly storing gaps
as CSS::Size, which led to us allowing a bunch of invalid gap values.
Similar to LadybirdBrowser/ladybird#1714.
We don't implement the linejoin values `miter-clip` and `arcs`, because
according to the SVG 2 spec:
> The values miter-clip and arcs of the stroke-linejoin property are at
> risk. There are no known browser implementations. See issue Github
> issue w3c/svgwg#592.
Nothing uses this yet. The next step is to change
SVGPathPaintable::paint() to read `graphics_element.stroke_linejoin()`
and `graphics_element.stroke_miterlimit()` when painting.
Previously we would serialize these as the empty string. eg, this:
```
<div style="grid-auto-columns: auto"></div>
```
would have a computed `grid-auto-columns` value of ``.
CSS Fonts level 4 renames font-stretch to font-width, with font-stretch
being left as a legacy alias. Unfortunately the other specs have not yet
been updated, so both terms are used in different places.
When a property is a "legacy name alias", any time it is used in CSS or
via the CSSOM its aliased name is used instead.
(See https://drafts.csswg.org/css-cascade-5/#legacy-name-alias)
This means we only care about the alias when parsing a string as a
PropertyID - and we can just return the PropertyID it is an alias for.
No need for a distinct PropertyID for it, and no need for LibWeb to
care about it at all.
Previously, we had a bunch of these properties, which misused our code
for "logical aliases", some of which I've discovered were not even
fully implemented. But with this change, all that code can go away, and
making a legacy alias is just a case of putting it in the JSON. This
also shrinks `StyleProperties` as it doesn't need to contain data for
these aliases, and removes a whole load of `-webkit-*` spam from the
style inspector.
Instead of switching on the PropertyID and doing a boatload of
comparisons, we reorder the PropertyID enum so that all inherited
properties are in two contiguous ranges (one for shorthands,
one for longhands).
This replaces the switch statement with two simple range checks.
Note that the property order change is observable via
window.getComputedStyle(), but the order of those properties is
implementation defined anyway.
Removes a 1.5% item from the profile when loading https://hemnet.se/
The `start` and `end` value set the text alignment based on the computed
value of `direction`. The default value of `text-align` is now `start`
instead of `left`.
