style: Support the type() function in image-set

Differential Revision: https://phabricator.services.mozilla.com/D109201
This commit is contained in:
Oriol Brufau 2023-05-17 00:30:20 +02:00
parent 7567ddd262
commit 773ddf31fe
4 changed files with 71 additions and 8 deletions

View file

@ -432,4 +432,11 @@ impl Device {
};
SideOffsets2D::new(top, right, bottom, left)
}
/// Returns true if the given MIME type is supported
pub fn is_supported_mime_type(&self, mime_type: &str) -> bool {
unsafe {
bindings::Gecko_IsSupportedImageMimeType(mime_type.as_ptr(), mime_type.len() as u32)
}
}
}

View file

@ -74,9 +74,20 @@ impl ToComputedValue for specified::ImageSet {
fn to_computed_value(&self, context: &Context) -> Self::ComputedValue {
let items = self.items.to_computed_value(context);
let dpr = context.device().device_pixel_ratio().get();
// If no item have a supported MIME type, the behavior is undefined by the standard
// By default, we select the first item
let mut supported_image = false;
let mut selected_index = 0;
let mut selected_resolution = items[0].resolution.dppx();
for (i, item) in items.iter().enumerate().skip(1) {
for (i, item) in items.iter().enumerate() {
// If the MIME type is not supported, we discard the ImageSetItem
if item.has_mime_type && !context.device().is_supported_mime_type(&item.mime_type) {
continue;
}
let candidate_resolution = item.resolution.dppx();
// https://drafts.csswg.org/css-images-4/#image-set-notation:
@ -97,7 +108,9 @@ impl ToComputedValue for specified::ImageSet {
false
};
if better_candidate() {
// The first item with a supported MIME type is obviously the current best candidate
if !supported_image || better_candidate() {
supported_image = true;
selected_index = i;
selected_resolution = candidate_resolution;
}

View file

@ -132,7 +132,7 @@ pub struct GenericImageSet<Image, Resolution> {
/// An optional percent and a cross fade image.
#[derive(
Clone, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToResolvedValue, ToShmem, ToCss,
Clone, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToResolvedValue, ToShmem,
)]
#[repr(C)]
pub struct GenericImageSetItem<Image, Resolution> {
@ -142,7 +142,33 @@ pub struct GenericImageSetItem<Image, Resolution> {
///
/// TODO: Skip serialization if it is 1x.
pub resolution: Resolution,
// TODO: type() function.
/// The `type(<string>)`
/// (Optional) Specify the image's MIME type
pub mime_type: crate::OwnedStr,
/// True if mime_type has been specified
pub has_mime_type: bool,
}
impl<I: style_traits::ToCss, R: style_traits::ToCss> ToCss for GenericImageSetItem<I, R>
{
fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
where
W: fmt::Write,
{
self.image.to_css(dest)?;
dest.write_str(" ")?;
self.resolution.to_css(dest)?;
if self.has_mime_type {
dest.write_str(" ")?;
dest.write_str("type(")?;
self.mime_type.to_css(dest)?;
dest.write_str(")")?;
}
Ok(())
}
}
pub use self::GenericImageSet as ImageSet;

View file

@ -377,6 +377,13 @@ impl ImageSet {
}
impl ImageSetItem {
fn parse_type<'i>(p: &mut Parser<'i, '_>) -> Result<crate::OwnedStr, ParseError<'i>> {
p.expect_function_matching("type")?;
p.parse_nested_block(|input| {
Ok(input.expect_string()?.as_ref().to_owned().into())
})
}
fn parse<'i, 't>(
context: &ParserContext,
input: &mut Parser<'i, 't>,
@ -393,10 +400,20 @@ impl ImageSetItem {
context, input, cors_mode, /* allow_none = */ false, /* only_url = */ only_url
)?,
};
let resolution = input
.try_parse(|input| Resolution::parse(context, input))
.unwrap_or(Resolution::X(1.0));
Ok(Self { image, resolution })
let mut resolution = input.try_parse(|input| Resolution::parse(context, input)).ok();
let mime_type = input.try_parse(Self::parse_type).ok();
// Try to parse resolution after type().
if mime_type.is_some() && resolution.is_none() {
resolution = input.try_parse(|input| Resolution::parse(context, input)).ok();
}
let resolution = resolution.unwrap_or(Resolution::X(1.0));
let has_mime_type = mime_type.is_some();
let mime_type = mime_type.unwrap_or_default();
Ok(Self { image, resolution, has_mime_type, mime_type })
}
}