Add page label object

src/object/page.rs

@@ -1,7 +1,9 @@
 use crate::serialize::{Object, RegisterableObject, SerializerContext};
 use crate::stream::Stream;
 use crate::util::RectExt;
-use pdf_writer::{Chunk, Finish, Ref};
+use pdf_writer::types::NumberingStyle;
+use pdf_writer::{Chunk, Finish, Ref, TextStr};
+use std::num::{NonZeroI32, NonZeroU32};
 use tiny_skia_path::{Rect, Size};
 
 /// A page.
@@ -57,14 +59,61 @@ impl Object for Page {
 
 impl RegisterableObject for Page {}
 
+// TODO: Make sure that page 0 is always included.
+
+/// A page label.
+#[derive(Debug, Hash, Eq, PartialEq)]
+pub(crate) struct PageLabel {
+    /// The numbering style of the page label.
+    style: NumberingStyle,
+    /// The prefix of the page label.
+    prefix: Option<String>,
+    /// The start numeric value of the page label.
+    offset: NonZeroI32,
+}
+
+impl PageLabel {
+    pub fn new(style: NumberingStyle, prefix: Option<String>, offset: NonZeroI32) -> Self {
+        Self {
+            style,
+            prefix,
+            offset,
+        }
+    }
+}
+
+impl Object for PageLabel {
+    fn serialize_into(self, _: &mut SerializerContext, root_ref: Ref) -> Chunk {
+        let mut chunk = Chunk::new();
+        let mut label = chunk
+            .indirect(root_ref)
+            .start::<pdf_writer::writers::PageLabel>();
+        label.style(self.style);
+
+        if let Some(prefix) = &self.prefix {
+            label.prefix(TextStr(prefix));
+        }
+
+        label.offset(self.offset.get());
+
+        label.finish();
+
+        chunk
+    }
+}
+
+impl RegisterableObject for PageLabel {}
+
 #[cfg(test)]
 mod tests {
-    use crate::object::page::Page;
+    use crate::object::page::{Page, PageLabel};
     use crate::rgb::Rgb;
     use crate::serialize::{SerializeSettings, SerializerContext};
     use crate::surface::StreamBuilder;
     use crate::test_utils::check_snapshot;
     use crate::Fill;
+    use pdf_writer::types::NumberingStyle;
+    use std::num::NonZeroI32;
     use tiny_skia_path::{PathBuilder, Rect, Size};
 
     #[test]
@@ -113,4 +162,19 @@ mod tests {
 
         check_snapshot("page/page_with_resources", sc.finish().as_bytes());
     }
+
+    #[test]
+    fn page_label() {
+        let mut sc = SerializerContext::new(SerializeSettings::default_test());
+
+        let page_label = PageLabel::new(
+            NumberingStyle::Arabic,
+            Some("P".to_string()),
+            NonZeroI32::new(2).unwrap(),
+        );
+
+        sc.add(page_label);
+
+        check_snapshot("page/page_label", sc.finish().as_bytes());
+    }
 }

src/resource.rs

@@ -7,12 +7,9 @@ use crate::object::ext_g_state::ExtGState;
 use crate::object::image::Image;
 use crate::object::shading_function::ShadingFunction;
 use crate::object::shading_pattern::ShadingPattern;
-use crate::object::tiling_pattern::TilingPattern;
 use crate::object::xobject::XObject;
 use crate::serialize::{hash_item, Object, RegisterableObject, SerializerContext};
 use crate::util::NameExt;
-use pdf_writer::traits::ResourcesExt;
-use pdf_writer::writers::Resources;
 use pdf_writer::{Chunk, Dict, Finish, Ref};
 use std::collections::HashMap;
 use std::fmt::Debug;
@@ -108,7 +105,7 @@ impl RegisterableObject for XObjectResource {}
 #[derive(Debug, Hash, Eq, PartialEq, Clone)]
 pub enum PatternResource {
     ShadingPattern(ShadingPattern),
-    TilingPattern(TilingPattern),
+    TilingPattern(crate::object::tiling_pattern::TilingPattern),
 }
 
 impl ResourceTrait for PatternResource {
@@ -404,3 +401,41 @@ impl ResourceTrait for FontResource {
         "f"
     }
 }
+
+use pdf_writer::writers::{FormXObject, Page, Pages, Resources, TilingPattern, Type3Font};
+
+/// A trait for getting the resource dictionary of an object.
+pub trait ResourcesExt {
+    /// Return the resources dictionary of the object.
+    fn resources(&mut self) -> Resources<'_>;
+}
+
+impl ResourcesExt for FormXObject<'_> {
+    fn resources(&mut self) -> Resources<'_> {
+        self.resources()
+    }
+}
+
+impl ResourcesExt for TilingPattern<'_> {
+    fn resources(&mut self) -> Resources<'_> {
+        self.resources()
+    }
+}
+
+impl ResourcesExt for Type3Font<'_> {
+    fn resources(&mut self) -> Resources<'_> {
+        self.resources()
+    }
+}
+
+impl ResourcesExt for Pages<'_> {
+    fn resources(&mut self) -> Resources<'_> {
+        self.resources()
+    }
+}
+
+impl ResourcesExt for Page<'_> {
+    fn resources(&mut self) -> Resources<'_> {
+        self.resources()
+    }
+}

src/serialize.rs

@@ -416,3 +416,5 @@ fn hex_encode(data: &[u8]) -> Vec<u8> {
         .collect::<String>()
         .into_bytes()
 }
+
+pub struct PageLabel {}

tests/snapshots/page/page_label.txt

@@ -0,0 +1,12 @@
+%PDF-1.7
+%AAAA
+
+3 0 obj
+<<
+  /Type /PageLabel
+  /S /D
+  /P (P)
+  /St 2
+>>
+endobj
+