Fixed page numbering (#594)

5 files changed, 23 insertions, 3 deletions

diff --git a/src/doc.rs b/src/doc.rs
index 0f3ade02..aa460bd3 100644
--- a/src/doc.rs
+++ b/src/doc.rs
@@ -609,6 +609,8 @@ pub enum Meta {
     /// An identifiable element that produces something within the area this
     /// metadata is attached to.
     Elem(Content),
+    /// The numbering of the current page.
+    PageNumbering(Value),
     /// Indicates that content should be hidden. This variant doesn't appear
     /// in the final frames as it is removed alongside the content that should
     /// be hidden.
diff --git a/src/eval/methods.rs b/src/eval/methods.rs
index bfe9b0e4..b88bca50 100644
--- a/src/eval/methods.rs
+++ b/src/eval/methods.rs
@@ -154,6 +154,7 @@ pub fn call(
                 match method {
                     "page" => vm.vt.introspector.page(location).into(),
                     "position" => vm.vt.introspector.position(location).into(),
+                    "page-numbering" => vm.vt.introspector.page_numbering(location),
                     _ => return missing(),
                 }
             } else {
@@ -308,7 +309,7 @@ pub fn methods_on(type_name: &str) -> &[(&'static str, bool)] {
         ],
         "function" => &[("where", true), ("with", true)],
         "arguments" => &[("named", false), ("pos", false)],
-        "location" => &[("page", false), ("position", false)],
+        "location" => &[("page", false), ("position", false), ("page-numbering", false)],
         "counter" => &[
             ("display", true),
             ("at", true),
diff --git a/src/export/pdf/page.rs b/src/export/pdf/page.rs
index 8f767e87..636d42c7 100644
--- a/src/export/pdf/page.rs
+++ b/src/export/pdf/page.rs
@@ -298,6 +298,7 @@ fn write_frame(ctx: &mut PageContext, frame: &Frame) {
                 Meta::Link(dest) => write_link(ctx, pos, dest, *size),
                 Meta::Elem(_) => {}
                 Meta::Hide => {}
+                Meta::PageNumbering(_) => {}
             },
         }
     }
diff --git a/src/export/render.rs b/src/export/render.rs
index 89e45b15..18d8a74b 100644
--- a/src/export/render.rs
+++ b/src/export/render.rs
@@ -61,6 +61,7 @@ fn render_frame(
             FrameItem::Meta(meta, _) => match meta {
                 Meta::Link(_) => {}
                 Meta::Elem(_) => {}
+                Meta::PageNumbering(_) => {}
                 Meta::Hide => {}
             },
         }
diff --git a/src/model/introspect.rs b/src/model/introspect.rs
index 31786d5b..31808872 100644
--- a/src/model/introspect.rs
+++ b/src/model/introspect.rs
@@ -5,7 +5,7 @@ use std::num::NonZeroUsize;
 use super::{Content, Selector};
 use crate::diag::StrResult;
 use crate::doc::{Frame, FrameItem, Meta, Position};
-use crate::eval::cast_from_value;
+use crate::eval::{cast_from_value, Value};
 use crate::geom::{Point, Transform};
 use crate::model::Label;
 use crate::util::NonZeroExt;
@@ -84,12 +84,18 @@ impl StabilityProvider {
 pub struct Introspector {
     pages: usize,
     elems: Vec<(Content, Position)>,
+    // Indexed by page number.
+    page_numberings: Vec<Value>,
 }
 
 impl Introspector {
     /// Create a new introspector.
     pub fn new(frames: &[Frame]) -> Self {
-        let mut introspector = Self { pages: frames.len(), elems: vec![] };
+        let mut introspector = Self {
+            pages: frames.len(),
+            elems: vec![],
+            page_numberings: vec![],
+        };
         for (i, frame) in frames.iter().enumerate() {
             let page = NonZeroUsize::new(1 + i).unwrap();
             introspector.extract(frame, page, Transform::identity());
@@ -121,6 +127,9 @@ impl Introspector {
                     let pos = pos.transform(ts);
                     self.elems.push((content.clone(), Position { page, point: pos }));
                 }
+                FrameItem::Meta(Meta::PageNumbering(numbering), _) => {
+                    self.page_numberings.push(numbering.clone());
+                }
                 _ => {}
             }
         }
@@ -184,6 +193,12 @@ impl Introspector {
         self.position(location).page
     }
 
+    /// Gets the page numbering for the given location, if any.
+    pub fn page_numbering(&self, location: Location) -> Value {
+        let page = self.page(location);
+        self.page_numberings.get(page.get() - 1).cloned().unwrap_or_default()
+    }
+
     /// Find the position for the given location.
     pub fn position(&self, location: Location) -> Position {
         self.elems