Generate ::before and ::after content from url() for layout2020

components/layout_2020/replaced.rs

@@ -2,6 +2,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
+use crate::context::LayoutContext;
 use crate::dom_traversal::NodeExt;
 use crate::fragments::{DebugId, Fragment, ImageFragment};
 use crate::geom::flow_relative::{Rect, Vec2};
@@ -10,9 +11,11 @@ use crate::sizing::ContentSizes;
 use crate::style_ext::ComputedValuesExt;
 use crate::ContainingBlock;
 use net_traits::image::base::Image;
+use net_traits::image_cache::{ImageOrMetadataAvailable, UsePlaceholder};
 use servo_arc::Arc as ServoArc;
 use std::sync::Arc;
 use style::properties::ComputedValues;
+use style::servo::url::ComputedUrl;
 use style::values::computed::{Length, LengthOrAuto};
 use style::values::CSSFloat;
 use style::Zero;
@@ -70,6 +73,39 @@ impl ReplacedContent {
         None
     }
 
+    pub fn from_image_url<'dom>(
+        element: impl NodeExt<'dom>,
+        context: &LayoutContext,
+        image_url: &ComputedUrl,
+    ) -> Option<Self> {
+        if let ComputedUrl::Valid(image_url) = image_url {
+            let (image, width, height) = match context.get_or_request_image_or_meta(
+                element.as_opaque(),
+                image_url.clone(),
+                UsePlaceholder::No,
+            ) {
+                Some(ImageOrMetadataAvailable::ImageAvailable(image, _)) => {
+                    (Some(image.clone()), image.width as f32, image.height as f32)
+                },
+                Some(ImageOrMetadataAvailable::MetadataAvailable(metadata)) => {
+                    (None, metadata.width as f32, metadata.height as f32)
+                },
+                None => return None,
+            };
+
+            return Some(Self {
+                kind: ReplacedContentKind::Image(image),
+                intrinsic: IntrinsicSizes {
+                    width: Some(Length::new(width)),
+                    height: Some(Length::new(height)),
+                    // FIXME https://github.com/w3c/csswg-drafts/issues/4572
+                    ratio: Some(width / height),
+                },
+            });
+        }
+        None
+    }
+
     fn flow_relative_intrinsic_size(&self, style: &ComputedValues) -> Vec2<Option<Length>> {
         let intrinsic_size = PhysicalSize::new(self.intrinsic.width, self.intrinsic.height);
         Vec2::from_physical_size(&intrinsic_size, style.writing_mode)