More flexible capability to control showing reference (#646)

library/src/meta/heading.rs

@@ -102,6 +102,7 @@ impl Synthesize for HeadingElem {
         self.push_numbering(self.numbering(styles));
         self.push_supplement(self.supplement(styles));
         self.push_outlined(self.outlined(styles));
+        self.push_supplement(self.supplement(styles));
         Ok(())
     }
 }

library/src/meta/reference.rs

@@ -85,12 +85,62 @@ pub struct RefElem {
     /// A synthesized citation.
     #[synthesized]
     pub citation: Option<CiteElem>,
+
+    /// Content of the element, it should be referable.
+    ///
+    /// ```example
+    /// #set heading(numbering: (..nums) => {
+    ///   nums.pos().map(str).join(".")
+    ///   }, supplement: [Chapt])
+    ///
+    /// #show ref: it => {
+    ///   if it.has("element") and it.element.func() == heading {
+    ///     let element = it.element
+    ///     "["
+    ///     element.supplement
+    ///     "-"
+    ///     numbering(element.numbering, ..counter(heading).at(element.location()))
+    ///     "]"
+    ///   } else {
+    ///     it
+    ///   }
+    /// }
+    ///
+    /// = Introduction <intro>
+    /// = Summary <sum>
+    /// == Subsection <sub>
+    /// @intro
+    ///
+    /// @sum
+    ///
+    /// @sub
+    /// ```
+    #[synthesized]
+    pub element: Option<Content>,
 }
 
 impl Synthesize for RefElem {
     fn synthesize(&mut self, vt: &mut Vt, styles: StyleChain) -> SourceResult<()> {
         let citation = self.to_citation(vt, styles)?;
         self.push_citation(Some(citation));
+
+        if !vt.introspector.init() {
+            self.push_element(None);
+            return Ok(());
+        }
+
+        // find the element content
+        let target = self.target();
+        let elem = vt.introspector.query_label(&self.target());
+        // not in bibliography, but in document, then push the element
+        if let (false, Ok(elem)) =
+            (BibliographyElem::has(vt, &target.0), elem.at(self.span()))
+        {
+            self.push_element(Some(elem));
+        } else {
+            self.push_element(None);
+        }
+
         Ok(())
     }
 }

tests/typ/meta/ref.typ

@@ -19,3 +19,104 @@ As seen in @intro, we proceed.
 
 // Error: 1-5 label occurs multiple times in the document
 @foo
+
+---
+
+#show ref: it => {
+  if it.element != none and it.element.func() == figure {
+    let element = it.element
+    "["
+    element.supplement
+    "-"
+    str(element.counter.at(element.location()).at(0))
+    "]"
+    // it
+  } else {
+    it
+  }
+}
+
+#figure(
+  image("/cylinder.svg", height: 3cm),
+  caption: [A sylinder.],
+  supplement: "Fig",
+) <fig1>
+
+#figure(
+  image("/tiger.jpg", height: 3cm),
+  caption: [A tiger.],
+  supplement: "Figg",
+) <fig2>
+
+#figure(
+  $ A = 1 $,
+  kind: "equation",
+  supplement: "Equa",
+
+) <eq1>
+@fig1
+
+@fig2
+
+@eq1
+
+---
+#set heading(numbering: (..nums) => {
+  nums.pos().map(str).join(".")
+  }, supplement: [Chapt])
+
+#show ref: it => {
+  if it.element != none and it.element.func() == heading {
+    let element = it.element
+    "["
+    emph(element.supplement)
+    "-"
+    numbering(element.numbering, ..counter(heading).at(element.location()))
+    "]"
+  } else {
+    it
+  }
+}
+
+= Introduction <intro>
+
+= Summary <sum>
+
+== Subsection <sub>
+
+@intro
+
+@sum
+
+@sub
+
+---
+
+#show ref: it => {
+  if it.element != none {
+    if it.element.func() == text {
+      let element = it.element
+      "["
+      element
+      "]"
+    } else if it.element.func() == underline {
+      let element = it.element
+      "{"
+      element
+      "}"
+    } else {
+      it
+    }
+  } else {
+    it
+  }
+}
+
+@txt
+
+Ref something unreferable <txt>
+
+@under
+#underline[
+Some underline text.
+] <under>