This style value holds a list of CSS filter function calls e.g.
blur(10px) invert() grayscale()
It will be used to implement backdrop-filter, but the same style value
can be used for the image filter property.
(The name is a little awkward but it's referenced to as
filter-value-list in the spec too).
Values that contain percentages require special treatment in various
parts of layout. Previously we had no way of peeking into calc() values
to see if their expression contains one or more percentages. That's the
bulk of what we're adding here.
The only accepted syntax for these seems to be
<color> <length percentage> <length percentage>, no other order.
But that's just gathered from looking at other browsers as though
these are supported by all major browsers, they don't appear in
the W3C spec.
This commit moves both the ImageStyleValue and LinearGradientStyleValue
to a common base class of AbstractImageStyleValue. This abstracts
getting the natural_width/height, loading/resolving, and painting
the image.
Now for 'free' you get:
- Linear gradients working with the various background sizing/repeat
properties.
- Linear gradients working as list-markers :^) -- best feature ever!
P.s. This commit is a little large as it's tricky to make this change
incrementally without breaking things.
Previously the clip rect was not relative to the top/left egdes
of the element, which lead to it being positioned incorrectly.
This fixes the clip-rect-auto-004 and clip-rect-auto-005 web
platform tests.
The -webkit version of linear-gradient does not include the `to`
before a <side or corner>. The angles of the <side or corner>
for the webkit version are also opposite that of the standard one.
So for the standard: linear-gradient(to left, red, blue)
The webkit version is: -webkit-linear-gradient(right, red, blue)
Adding the `to` in the -webkit version is invalid, omitting it in
the standard one is also invalid.
Fixes#14697
Percentages inside `calc()` only got converted to the concrete type
(eg, Length) when added or subtracted with one. So if the `calc
()` doesn't contain any of that type, it would resolve to a
Percentage.
Now, we catch that returned Percentage and convert it to the proper
type. This fixes cases like `width: calc(100% / 2);`.
When a `calc()` is resolved, it can only return a Percentage value if
the requested type is Percentage. In all other cases, it returns a
concrete value.
eg, a `calc()` with Lengths and Percentages in will always resolve to a
Length, never a Percentage. This means we can just return Length
directly instead of LengthPercentage, which simplifies things in a few
places.
Each of these strings would previously rely on StringView's char const*
constructor overload, which would call __builtin_strlen on the string.
Since we now have operator ""sv, we can replace these with much simpler
versions. This opens the door to being able to remove
StringView(char const*).
No functional changes.
Previously, set_needs_display() was passed an empty rectangle in
ImageStyleValue::resource_did_load(). This led to the browser not
doing a repaint when the image loaded.
Fixes#14435
When swapping both values to perform the actual calculation, we need to
consider that `A + B == B + A`, but `A - B != B - A`, so turn it into
`-B + A`.
Co-Authored-By: Sam Atkins <atkinssj@serenityos.org>
Every StyleValue type now has its own `equals()` method, rather than
relying on the default "compare the to_string() output" method, which
has now been removed. This logic is still used by UnresolvedSV and
CalculatedSV, because it's probably the best option for them unless
performance becomes a real issue.
Also took this opportunity to move all the `equals()` implementations
into the .cpp file, which may or may not actually help with compile
times but StyleValue.h is huge and included everywhere, so it can't
hurt.
The `text-shadow` property is almost identical to `box-shadow`:
> Values are interpreted as for box-shadow [CSS-BACKGROUNDS-3].
> (But note that the inset keyword are not allowed.)
So, let's use the same data structures and parsing code for both. :^)
If the current Document is not attached to a Web::Page for whatever
reason, but we're trying to look up a color from the system palette,
let's just fail the lookup instead of crashing the process.
Instead of awkwardly visiting and mutating lengths inside StyleValues,
we now simply create a new StyleValue instead.
This fixes an issue where inherited relative lengths could get
absolutized using a parent as reference, and then not having the correct
values when used in a child context.
For now, we only understand `none`, `normal`, `<image>` and `<string>`.
The various other functions and identifiers can be added later.
We can *almost* use a StyleValueList for this, except it's divided into
two parts - the content, and the optional "alt text". So, I've added a
new StyleValue for it.
Depending on the type of the calc() expression, the percentage_basis has
to be the same dimension type. Several places were already passing `
{}` for this, so let's make that an empty Variant instead of an
undefined Length. :^)
