The spec grammar for `text-decoration-line` is:
`none | [ underline || overline || line-through || blink ]`
Which means that it's either `none`, or any combination of the other
values. This patch makes that parse for `text-decoration-line` and
`text-decoration`, stores the results as a Vector, and adjusts
`paint_text_decoration()` to run as a loop over all the values that are
provided.
As noted, storing a Vector of values is a bit wasteful, as they could be
stored as flags in a single `u8`. But I was getting too confused trying
to do that in a nice way.
As before, this requires deviating from the spec slightly to create the
StyleRule fully-formed instead of creating it empty and then modifying
its internals.
This means deviating slightly from the spec in order to construct a
fully-initialized Declaration instead of creating an empty one and then
poking at its internals.
DeclarationOrAtRule should probably use a Variant, but for now, making
its Declaration member optional is quick and easy.
This means deviating a little from the spec, so that we create a
complete Block in one go instead of creating an empty one and then
poking at its internals.
The goal here is to move the parser-internal classes into this namespace
so they can have more convenient names without causing collisions. The
Parser itself won't collide, and would be more convenient to just
remain `CSS::Parser`, but having a namespace and a class with the same
name makes C++ unhappy.
This is used to skip downloading fonts in formats that we don't support.
Currently we only support TTF as far as I am aware.
The parts of a `src` are in a fixed order, unusually, which makes the
parsing more nesty instead of loopy.
Like, An+B, this is an old construct that does not fit well with modern
CSS syntax, so things get a bit hairy! We have to determine which
tokens match the grammar for `<urange>`, then turn those back into a
string, and then parse the string differently from normal. Thankfully
the spec describes in detail how to do that. :^)
This is not 100% correct, since we are not using the original source
text (referred to in the spec as the "representation") of the tokens,
but just converting them to strings in a manual, ad-hoc way.
Re-engineering the Tokenizer to keep that original text was too much of
a tangent for today. In any case, we do parse `U+4???`, `U+0-100`,
`U+1234`, and similar, so good enough for now!
"Component value" is the term used in the spec, and it doesn't conflict
with any other types, so let's use the shorter name. :^)
Also, this doesn't need to be friends with the Parser any more.
We're calling this in a way that is incorrect, and so the algorithm's
assumption that the next token is an `<ident-token>` is wrong, and we
have to handle that failing. Ideally we would just stop calling this
incorrectly, but until then, let's actually document what is happening.
The code had to change a bit to match. Previously, we appended an empty
sub-list immediately, but now we append it at the end. The difference
is that if there are no tokens, we now correctly return an empty
list-of-lists, instead of a list containing an empty list.
We now correctly call convert_to_rule() outside of this function.
As before, I've renamed `parse_as_rule()` -> `parse_as_css_rule()` to
match the free function that calls it.
This is not actually used by anything currently, but it should be used
for `@media` and other at-rules.
Removed the public parse_as_list_of_rules() because public functions
should be things that outside classes actually need to use.
`parse_a_stylesheet()` should not do any conversion on its rules. This
change corrects that. There are other places where we get this wrong,
but one thing at a time. :^)
CSS Values and Units Module Level 5 defines attr as:
`attr(<q-name> <attr-type>?, <declaration-value>?)`
This implementation does not contain support for the type argument,
effectively supporting `attr(<q-name>, <declaration-value>?)`
When parsing the "style" attribute on elements, we'd previously ask the
CSS parser for a PropertyOwningCSSStyleDeclaration. Then we'd create a
new ElementCSSInlineStyleDeclaration and transfer the properties from
the first object to the second object.
This patch teaches the parser to make ElementCSSInlineStyleDeclaration
objects directly.
When I wrote the An+B parser, it was guaranteed to have no
non-whitespace tokens after it. This is no longer true with the `of
foo` syntax, so this patch corrects the logic when there is no `+B`
segment.
This makes this case shown on Twitter work correctly. :^)
https://twitter.com/simevidas/status/1506657566012678151
`text-shadow` does not support this, so this way we can still use the
same parsing code.
It's OK that we still assign a ShadowPlacement value to the
ShadowStyleValue, since it will just get ignored when painting
text-shadows, but if it appears in the property value then that is a
syntax error.
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. :^)
There's really no reason to use doubles here, except at the time I
wanted to use doubles everywhere in CSS. I now realize that is
excessive, so everything can be floats instead.
There was no real benefit to creating the SimpleSelector early and then
modifying it, and doing so made this code harder to follow than it
needs to be.
The spec says:
> <delim-token> has a value composed of a single code point.
So using StringView is a bit overkill.
This also allows us to use switch statements in the future.
This doesn't have parsing support for multiple languages in the same
selector. Support for language subcodes is not great either. But it
does do the basics.
In Selectors level 4, `:nth-child()` and `:nth-last-child()` can both
optionally take a selector-list argument. This selector-list acts as a
filter, so that only elements matching the list are counted. For
example, this means that the following are equivalent:
```css
:nth-child(2n+1 of p) {}
p:nth-of-type(2n+1) {}
```
`<forgiving-selector-list>` and `<forgiving-relative-selector-list>` are
the same as regular selector-lists, except that an invalid selector
does not make the whole list invalid. The former is used by the `:is()`
pseudo-class.
For example:
```css
/* This entire selector-list is invalid */
.foo, .bar, !?invalid { }
/* This is valid, but the "!?invalid" selector is removed */
:is(.foo, .bar, !?invalid) { }
```
Also as part of this, I've removed the `parse_a_selector(TokenStream)`
and `parse_a_relative_selector(TokenStream)` methods as they don't add
anything useful.
This resolves the ambiguity between whether a single number is a number
or a ratio. :^)
Also removed the "no more tokens" checks from
deea129b8c - that logic was completely
wrong, since there are always tokens after a value in the `(123 < foo <
456)` syntax.
As noted, the Parser can't handle the `<number>` syntax for this - it
gets parsed instead by the `<number>` branch. We can't actually resolve
the ambiguity without making the Parser aware of what type each
media-feature is, but I will get to that soon. :^)
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.
This is the only dimension type besides `<length>` that is used in any
media queries in levels 4 or 5 right now. Others can be included
if/when they're needed.
