Refactor various classes in the GridTrackSize file for the incoming
named_tracks feature.
Previously the ExplicitTrackSizing had mixed responsiblities with the
newly-named GridRepeat class. This made it so it was not possible to
have multiple repeats within a single 'GridTrackSizeList' definition.
The MetaGridTrackSize class had both the responsibilities of being a
container for minmax values as well as for simple GridSizes. By uniting
the different possible values (repeat, minmax, default) into the
ExplicitGridTrack class are able to be more expressive as to the
different grid size modalities.
The GridTrackSizeList will be useful as compared to a
Vector<ExplicitGridTrack> since this way can keep track of the declared
line names. These same line names are able to be declared within the
values of a repeat function, hence the presence of a GridTrackSizeList
inside the GridRepeat class.
Add classes ExplicitTrackSizing and MetaGridTrackSize which will allow
for managing properties like auto-fill and minmax.
In the following CSS example there are 3 classes that will be used:
grid-template-column: repeat(auto-fill, minmax(50px, 1fr) 75px);
ExplicitTrackSizing - will contain the entire value. e.g.
repeat(auto-fill, minmax(50px, 1fr) 75px)
With a flag if it's a repeat, as well as references to the
MetaGridTrackSizes which is the next step down.
MetaGridTrackSize:
Contain the individual grid track sizes. Here there are two:
minmax(50px, 1fr) as well as 75px.
This way can keep track if it's a minmax function or not, and the
references to both GridTrackSizes in the case it is, or in just the one
if it is not.
GridTrackSize:
Is the most basic element, in this case there are three in total; two of
which are held by the first MetaGridTrackSize, and the third is held by
the second MetaGridTrackSize.
Examples: 50px, 1fr and 75px.
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.
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.
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.
It's probably not in 1:1 as spec says, as it wants us to first upscale
the image to the nearest integer and then downscale it bilinearly.
But this mode still falls into the general description of the value:
> The image is scaled in a way that preserves the pixelated nature of
> the original as much as possible, but allows minor smoothing instead
> of awkward distortion when necessary.
Also, this way we don't have to allocate the memory just for the integer
scale. :^) :^)
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.
"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.
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>?)`
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. :^)
This patch adds support for "crisp-edges", "high-quality" and "smooth"
for the CSS image-rendering property.
"crisp-edges" maps to nearest-neighbor scaling for <canvas> and <img>
elements, while "high-quality" and "smooth" both use bilinear blending.
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.
