From 4a64a717e8ff19d4be1dc97ab37bf6e4f1ab8db5 Mon Sep 17 00:00:00 2001
From: Tobias Schmitz <tobiasschmitz2001@gmail.com>
Date: Tue, 17 Jun 2025 17:00:33 +0200
Subject: [PATCH] WIP [no ci]

---
 crates/typst-library/src/model/outline.rs |  1 +
 crates/typst-pdf/src/link.rs              |  8 ++---
 crates/typst-pdf/src/tags.rs              | 36 +++++++++--------------
 3 files changed, 19 insertions(+), 26 deletions(-)

diff --git a/crates/typst-library/src/model/outline.rs b/crates/typst-library/src/model/outline.rs
index 746a8ae06..a13e0c859 100644
--- a/crates/typst-library/src/model/outline.rs
+++ b/crates/typst-library/src/model/outline.rs
@@ -422,6 +422,7 @@ impl Show for Packed<OutlineEntry> {
         let context = Context::new(None, Some(styles));
         let context = context.track();
 
+        // TODO: prefix should be wrapped in a `Lbl` structure element
         let prefix = self.prefix(engine, context, span)?;
         let body = self.body().at(span)?;
         let page = self.page(engine, context, span)?;
diff --git a/crates/typst-pdf/src/link.rs b/crates/typst-pdf/src/link.rs
index c78ca389f..1fe2c701a 100644
--- a/crates/typst-pdf/src/link.rs
+++ b/crates/typst-pdf/src/link.rs
@@ -74,12 +74,12 @@ pub(crate) fn handle_link(
 
     let placeholder = gc.tags.reserve_placeholder();
     let mut node = TagNode::Placeholder(placeholder);
-    let (parent_tag, _) = gc.tags.parent_nodes();
-    if !matches!(parent_tag, Some(Tag::Link | Tag::Reference)) {
-        node = TagNode::Group(Link, )
+    let (parent_tag, _) = gc.tags.parent();
+    if !matches!(parent_tag, Some(Tag::Link)) {
+        node = TagNode::Group(Tag::Link, vec![node]);
     }
     // Prepend so the link annotation is the first child.
-    gc.tags.prepend();
+    gc.tags.prepend(node);
 
     fc.push_annotation(
         placeholder,
diff --git a/crates/typst-pdf/src/tags.rs b/crates/typst-pdf/src/tags.rs
index 1c5b0bef0..780a88418 100644
--- a/crates/typst-pdf/src/tags.rs
+++ b/crates/typst-pdf/src/tags.rs
@@ -67,20 +67,22 @@ impl Tags {
             .expect("initialized placeholder node")
     }
 
-    pub(crate) fn push(&mut self, node: TagNode) {
-        if let Some((_, _, nodes)) = self.stack.last_mut() {
-            nodes.push(node);
+    /// Returns the current parent's list of children and the structure type ([Tag]).
+    /// In case of the document root the structure type will be `None`.
+    pub(crate) fn parent(&mut self) -> (Option<&mut Tag>, &mut Vec<TagNode>) {
+        if let Some((_, tag, parent_nodes)) = self.stack.last_mut() {
+            (Some(tag), parent_nodes)
         } else {
-            self.tree.push(node);
+            (None, &mut self.tree)
         }
     }
 
+    pub(crate) fn push(&mut self, node: TagNode) {
+        self.parent().1.push(node);
+    }
+
     pub(crate) fn prepend(&mut self, node: TagNode) {
-        if let Some((_, _, nodes)) = self.stack.last_mut() {
-            nodes.insert(0, node);
-        } else {
-            self.tree.insert(0, node);
-        }
+        self.parent().1.insert(0, node);
     }
 
     pub(crate) fn build_tree(&mut self) -> TagTree {
@@ -109,15 +111,6 @@ impl Tags {
         }
     }
 
-    /// Returns the current parent's list of children and whether it is the tree root.
-    pub(crate) fn parent_nodes(&mut self) -> (Option<&mut Tag>, &mut Vec<TagNode>) {
-        if let Some((_, tag, parent_nodes)) = self.stack.last_mut() {
-            (Some(tag), parent_nodes)
-        } else {
-            (None, &mut self.tree)
-        }
-    }
-
     fn context_supports(&self, _tag: &Tag) -> bool {
         // TODO: generate using: https://pdfa.org/resource/iso-ts-32005-hierarchical-inclusion-rules/
         true
@@ -245,9 +238,9 @@ pub(crate) fn handle_end(gc: &mut GlobalContext, surface: &mut Surface, loc: &Lo
 
     surface.end_tagged();
 
-    let (is_root, parent_nodes) = gc.tags.parent_nodes();
+    let (parent_tag, parent_nodes) = gc.tags.parent();
     parent_nodes.push(TagNode::Group(tag, nodes));
-    if !is_root {
+    if parent_tag.is_some() {
         // TODO: somehow avoid empty marked-content sequences
         let id = surface.start_tagged(ContentTag::Other);
         parent_nodes.push(TagNode::Leaf(id));
@@ -258,8 +251,7 @@ fn start_artifact(gc: &mut GlobalContext, surface: &mut Surface, kind: ArtifactK
     let ty = artifact_type(kind);
     let id = surface.start_tagged(ContentTag::Artifact(ty));
 
-    let (_, parent_nodes) = gc.tags.parent_nodes();
-    parent_nodes.push(TagNode::Leaf(id));
+    gc.tags.push(TagNode::Leaf(id));
 }
 
 fn artifact_type(kind: ArtifactKind) -> ArtifactType {