feat(destination): define destination

src/destination.rs

@@ -0,0 +1,90 @@
+use crate::pdf::PdfObject;
+use crate::Error;
+
+#[derive(Debug, Clone)]
+pub struct Destination {
+    /// Indirect reference to page object.
+    pub page: PdfObject,
+    pub kind: DestinationKind,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq)]
+pub enum DestinationKind {
+    /// Display the page at a scale which just fits the whole page
+    /// in the window both horizontally and vertically.
+    Fit,
+    /// Display the page with the vertical coordinate `top` at the top edge of the window,
+    /// and the magnification set to fit the document horizontally.
+    FitH { top: f32 },
+    /// Display the page with the horizontal coordinate `left` at the left edge of the window,
+    /// and the magnification set to fit the document vertically.
+    FitV { left: f32 },
+    /// Display the page with (`left`, `top`) at the upper-left corner
+    /// of the window and the page magnified by factor `zoom`.
+    XYZ { left: f32, top: f32, zoom: f32 },
+    /// Display the page zoomed to show the rectangle specified by `left`, `bottom`, `right`, and `top`.
+    FitR {
+        left: f32,
+        bottom: f32,
+        right: f32,
+        top: f32,
+    },
+    /// Display the page like `/Fit`, but use the bounding box of the page’s contents,
+    /// rather than the crop box.
+    FitB,
+    /// Display the page like `/FitH`, but use the bounding box of the page’s contents,
+    /// rather than the crop box.
+    FitBH { top: f32 },
+    /// Display the page like `/FitV`, but use the bounding box of the page’s contents,
+    /// rather than the crop box.
+    FitBV { left: f32 },
+}
+
+impl Destination {
+    /// Encode destination into a PDF array.
+    pub(crate) fn encode_into(self, array: &mut PdfObject) -> Result<(), Error> {
+        debug_assert_eq!(array.len()?, 0);
+
+        array.array_push(self.page)?;
+        match self.kind {
+            DestinationKind::Fit => array.array_push(PdfObject::new_name("Fit")?)?,
+            DestinationKind::FitH { top } => {
+                array.array_push(PdfObject::new_name("FitH")?)?;
+                array.array_push(PdfObject::new_real(top)?)?;
+            }
+            DestinationKind::FitV { left } => {
+                array.array_push(PdfObject::new_name("FitV")?)?;
+                array.array_push(PdfObject::new_real(left)?)?;
+            }
+            DestinationKind::XYZ { left, top, zoom } => {
+                array.array_push(PdfObject::new_name("XYZ")?)?;
+                array.array_push(PdfObject::new_real(left)?)?;
+                array.array_push(PdfObject::new_real(top)?)?;
+                array.array_push(PdfObject::new_real(zoom)?)?;
+            }
+            DestinationKind::FitR {
+                left,
+                bottom,
+                right,
+                top,
+            } => {
+                array.array_push(PdfObject::new_name("FitR")?)?;
+                array.array_push(PdfObject::new_real(left)?)?;
+                array.array_push(PdfObject::new_real(bottom)?)?;
+                array.array_push(PdfObject::new_real(right)?)?;
+                array.array_push(PdfObject::new_real(top)?)?;
+            }
+            DestinationKind::FitB => array.array_push(PdfObject::new_name("FitB")?)?,
+            DestinationKind::FitBH { top } => {
+                array.array_push(PdfObject::new_name("FitBH")?)?;
+                array.array_push(PdfObject::new_real(top)?)?;
+            }
+            DestinationKind::FitBV { left } => {
+                array.array_push(PdfObject::new_name("FitBV")?)?;
+                array.array_push(PdfObject::new_real(left)?)?;
+            }
+        }
+
+        Ok(())
+    }
+}

src/lib.rs

@@ -14,6 +14,8 @@ pub mod colorspace;
 pub mod context;
 /// Provide two-way communication between application and library
 pub mod cookie;
+/// Destination
+pub mod destination;
 /// Device interface
 pub mod device;
 /// A way of packaging up a stream of graphical operations
@@ -72,6 +74,7 @@ pub use colorspace::Colorspace;
 pub(crate) use context::context;
 pub use context::Context;
 pub use cookie::Cookie;
+pub use destination::{Destination, DestinationKind};
 pub use device::{BlendMode, Device};
 pub use display_list::DisplayList;
 pub use document::{Document, MetadataName};