Add functionality to begin parsing grid-template-columns and
grid-template-rows. There are still things to be added, like parsing
functions, but I would say a couple of the major points are already
adressed like length, percentage, and flexible-length.
I believe this is all of them, but I may have missed some.
Several properties technically do not allow negative numbers but the
description says to accept these as valid, and then clamp them
afterwards to the desired range. As such, we don't reject them during
parsing.
This is a change to CSS-TEXT-4, listed here:
https://www.w3.org/TR/2022/WD-css-text-4-20220318/#changes
We don't actually support these properties yet, but it doesn't hurt to
keep them up to date for when they get implemented in the future. :^)
I came across some websites that change an elements CSS "opacity" in
their :hover selectors. That caused us to relayout on hover, which we'd
like to avoid.
With this patch, we now check if a property only affects the stacking
context tree, and if nothing layout-affecting has changed, we only
invalidate the stacking context tree, causing it to be rebuilt on next
paint or hit test.
This makes :hover { opacity: ... } rules much faster. :^)
- background properties
- box-shadow
- cursor
- SVG fill/stroke properties
- image-rendering
- outline properties
- pointer-events
- user-select
This should be basically all of them. I skipped `opacity` and
`transform` since establishing a stacking context feels like a
layout-affecting thing, but I could be very wrong on that!
This patch adds CSS::property_affects_layout(PropertyID) which tells us
whether a CSS property would affect layout if it were changed.
This will be used to avoid unnecessary relayout work when something
changes that really only requires us to repaint the page.
To mark a property as not affecting layout, set "affects-layout" to
false in the corresponding Properties.json entry. Note that all
properties affect layout by default.
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.
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.
It's a little verbose to repeat these in cases like the borders, but if
everything has an initial value, we can guarantee that
`property_initial_value()` will return something! :^)
- `align-items`: `normal` is the initial value in the CSS-ALIGN spec,
but `stretch` is in CSS-FLEXBOX. The FLEXBOX spec is the one we've
actually implemented elsewhere, and ALIGN adds new values with special
syntax, so it's not trivial to add it here.
- `border-spacing`: `0` is equivalent to `0px 0px` and we don't yet
parse the double-value syntax.
- `text-decoration-thickness`: Had the wrong value.
While right now this doesn't save much complexity, it will do once we
care about multiple background layers per node. Then, having a single
repeat value per layer will simplify things.
It also means we can remove the pseudo-property concept entirely! :^)
Previously, `box-shadow: none` would fail to parse, meaning that in this
example:
```css
p {
box-shadow: 20px 10px 5px magenta;
}
p.foo {
box-shadow: none;
}
```
... a `<p class="foo">` would still have a box-shadow, when it should
not have one. Now, we handle the `none` value. :^)
For `number` and `integer` types, you can add a range afterwards to add
a range check, using similar syntax to that used in the CSS specs. For
example:
```json
"font-weight": {
...
"valid-types": [
"number [1,1000]"
],
...
}
```
This limits any numbers to the range `1 <= n <= 1000`.
- The `text-decoration-foo` values now match the spec.
- Added values for `border-foo` since those are needed soon.
- Make `color`'s initial value be `-libweb-palette-base-text`.
