We cannot port over Optional<FlyString> until the IDL generator supports
passing that through as an argument (as opposed to an Optional<String>).
Change to FlyString where possible, and resolve any fallout as a result.
This commit removes DeprecatedString's "null" state, and replaces all
its users with one of the following:
- A normal, empty DeprecatedString
- Optional<DeprecatedString>
Note that null states of DeprecatedFlyString/StringView/etc are *not*
affected by this commit. However, DeprecatedString::empty() is now
considered equal to a null StringView.
Renaming the DeprecatedString version of this function to
Element::get_deprecated_attribute.
While performing this rename, port over functions where it is trivial to
do so to the Optional<String> version of this function.
It calls Element::get_attribute which takes a StringView. Ultimately,
this should be taking a FlyString, but to help in porting away from
DeprecatedString, just leave a FIXME for that for now.
Unfortunately we can't port these functions entirely over to FlyString
from DeprecatedString as Document includes NonElementParentNode and has
not yet been ported over to new AK string. In the mean time, this should
help up in porting over NonElementParentNode itself.
This implements the stop-opacity, fill-opacity, and stroke-opacity
properties (in CSS). This replaces the existing more ad-hoc
fill-opacity attribute handling.
This is the base class for all SVG gradient types. This supports:
- The `gradientUnits` attribute
- The `gradientTransform` attribute
- And following `xlink:hrefs` for inheriting <stops>/attributes
