diff options
Diffstat (limited to 'src/pdf.rs')
| -rw-r--r-- | src/pdf.rs | 384 |
1 files changed, 81 insertions, 303 deletions
@@ -1,7 +1,9 @@ //! Writing of documents in the _PDF_ format. use std::io::{self, Write}; -use crate::doc::{Document, Text, DocumentFont, Size}; +use crate::doc::{Document, DocumentFont}; +use pdf::{PdfWriter, Id, Rect, Size, Version, DocumentCatalog, PageTree, + Page, PageData, Resource, Font, FontType, Text, Trailer}; /// A type that is a sink for types that can be written conforming @@ -13,332 +15,108 @@ pub trait WritePdf<T> { } impl<W: Write> WritePdf<Document> for W { - fn write_pdf(&mut self, document: &Document) -> io::Result<usize> { - PdfWriter::new(document).write(self) - } -} - -impl<W: Write> WritePdf<Size> for W { - fn write_pdf(&mut self, size: &Size) -> io::Result<usize> { - self.write_str(size.points) - } -} - -/// A type that is a sink for types that can be converted to strings -/// and thus can be written string-like into a byte sink. -pub trait WriteByteString { - /// Write the string-like type into self, returning how many - /// bytes were written. - fn write_str<S: ToString>(&mut self, string_like: S) -> io::Result<usize>; -} - -impl<W: Write> WriteByteString for W { - fn write_str<S: ToString>(&mut self, string_like: S) -> io::Result<usize> { - self.write(string_like.to_string().as_bytes()) - } -} - + fn write_pdf(&mut self, doc: &Document) -> io::Result<usize> { + let mut writer = PdfWriter::new(self); -/// Writes an abstract document into a byte sink in the _PDF_ format. -#[derive(Debug, Clone)] -struct PdfWriter<'d> { - doc: &'d Document, - w: usize, - catalog_id: u32, - page_tree_id: u32, - resources_start: u32, - pages_start: u32, - content_start: u32, - xref_table: Vec<u32>, - offset_xref: u32, -} + // Calculate unique id's for everything + let catalog_id: Id = 1; -impl<'d> PdfWriter<'d> { - /// Create a new pdf writer from a document. - fn new(doc: &'d Document) -> PdfWriter<'d> { - // Calculate unique ids for each object - let catalog_id: u32 = 1; let page_tree_id = catalog_id + 1; let pages_start = page_tree_id + 1; - let resources_start = pages_start + doc.pages.len() as u32; - let content_start = resources_start + doc.fonts.len() as u32; - - PdfWriter { - doc, - catalog_id, - page_tree_id, - resources_start, - pages_start, - content_start, - w: 0, - xref_table: vec![], - offset_xref: 0, - } - } - - /// Write the document into a byte sink. - fn write<W: Write>(&mut self, target: &mut W) -> io::Result<usize> { - self.write_header(target)?; - - self.write_document_catalog(target)?; - self.write_page_tree(target)?; - self.write_pages(target)?; - - self.write_resources(target)?; - - self.write_content(target)?; - // self.write_fonts(target)?; - - self.write_xref_table(target)?; - self.write_trailer(target)?; - self.write_start_xref(target)?; - - Ok(self.w) - } - - /// Write the pdf header. - fn write_header<W: Write>(&mut self, target: &mut W) -> io::Result<usize> { - // Write the magic start - self.w += target.write(b"%PDF-1.7\n")?; - Ok(self.w) - } - - /// Write the document catalog (contains general info about the document). - fn write_document_catalog<W: Write>(&mut self, target: &mut W) -> io::Result<usize> { - self.xref_table.push(self.w as u32); - - self.w += target.write_str(self.catalog_id)?; - self.w += target.write(b" 0 obj\n")?; - self.w += target.write(b"<<\n")?; - self.w += target.write(b"/Type /Catalog\n")?; - - self.w += target.write(b"/Pages ")?; - self.w += target.write_str(self.page_tree_id)?; - self.w += target.write(b" 0 R\n")?; - - self.w += target.write(b">>\n")?; - self.w += target.write(b"endobj\n")?; - - Ok(self.w) - } - - /// Write the page tree (overview over the pages of a document). - fn write_page_tree<W: Write>(&mut self, target: &mut W) -> io::Result<usize> { - self.xref_table.push(self.w as u32); - - // Create page tree - self.w += target.write_str(self.page_tree_id)?; - self.w += target.write(b" 0 obj\n")?; - self.w += target.write(b"<<\n")?; - self.w += target.write(b"/Type /Pages\n")?; - - self.w += target.write(b"/Count ")?; - self.w += target.write_str(self.doc.pages.len())?; - self.w += target.write(b"\n")?; - - self.w += target.write(b"/Kids [")?; - - for id in self.pages_start .. self.pages_start + self.doc.pages.len() as u32 { - self.w += target.write_str(id)?; - self.w += target.write(b" 0 R ")?; - } - - self.w += target.write(b"]\n")?; - - self.w += target.write(b"/Resources\n")?; - self.w += target.write(b"<<\n")?; - - self.w += target.write(b"/Font\n")?; - self.w += target.write(b"<<\n")?; - - let mut font_id = self.resources_start; - for nr in 1 ..= self.doc.fonts.len() as u32 { - self.w += target.write(b"/F")?; - self.w += target.write_str(nr)?; - self.w += target.write(b" ")?; - self.w += target.write_str(font_id)?; - self.w += target.write(b" 0 R\n")?; - font_id += 1; - } - - self.w += target.write(b">>\n")?; - self.w += target.write(b">>\n")?; - - self.w += target.write(b">>\n")?; - self.w += target.write(b"endobj\n")?; - - Ok(self.w) - } - - /// Write the page descriptions. - fn write_pages<W: Write>(&mut self, target: &mut W) -> io::Result<usize> { - let mut page_id = self.pages_start; - let mut content_id = self.content_start; - - for page in &self.doc.pages { - self.xref_table.push(self.w as u32); - - self.w += target.write_str(page_id)?; - self.w += target.write(b" 0 obj\n")?; - self.w += target.write(b"<<\n")?; - self.w += target.write(b"/Type /Page\n")?; - - self.w += target.write(b"/Parent ")?; - self.w += target.write_str(self.page_tree_id)?; - self.w += target.write(b" 0 R\n")?; - - self.w += target.write(b"/MediaBox [0 0 ")?; - self.w += target.write_pdf(&page.size[0])?; - self.w += target.write(b" ")?; - self.w += target.write_pdf(&page.size[1])?; - self.w += target.write(b"]\n")?; - - self.w += target.write(b"/Contents [")?; - - for _ in &page.contents { - self.w += target.write_str(content_id)?; - self.w += target.write(b" 0 R ")?; - - content_id += 1; - } - - self.w += target.write(b"]\n")?; - - self.w += target.write(b">>\n")?; - self.w += target.write(b"endobj\n")?; + let pages_end = pages_start + doc.pages.len() as Id; + + let resources_start = pages_end; + let font_start = resources_start; + let font_end = font_start + doc.fonts.len() as Id; + let resources_end = font_end; + + let content_start = resources_end; + let content_end = content_start + + doc.pages.iter().flat_map(|p| p.contents.iter()).count() as Id; + + writer.write_header(&Version::new(1, 7))?; + + // The document catalog + writer.write_obj(catalog_id, &DocumentCatalog { + page_tree: page_tree_id, + })?; + + let font_resources: Vec<_> = (1 ..= doc.fonts.len() as u32) + .zip(font_start .. font_end) + .map(|(nr, id)| Resource::Font(nr, id)).collect(); + + // Root page tree + writer.write_obj(page_tree_id, &PageTree { + parent: None, + kids: (pages_start .. pages_end).collect(), + data: PageData { + resources: Some(font_resources), + .. PageData::default() + }, + })?; + + // The page objects + let mut id = pages_start; + for page in &doc.pages { + let width = page.size[0].points; + let height = page.size[1].points; + + writer.write_obj(id, &Page { + parent: page_tree_id, + data: PageData { + media_box: Some(Rect::new(0.0, 0.0, width, height)), + contents: Some((content_start .. content_end).collect()), + .. PageData::default() + }, + })?; - page_id += 1; + id += 1; } - Ok(self.w) - } - - /// Write the resources used by the file (fonts and friends). - fn write_resources<W: Write>(&mut self, target: &mut W) -> io::Result<usize> { - let mut id = self.resources_start; - - for font in &self.doc.fonts { - self.xref_table.push(self.w as u32); - - self.w += target.write_str(id)?; - self.w += target.write(b" 0 obj\n")?; - self.w += target.write(b"<<\n")?; - self.w += target.write(b"/Type /Font\n")?; - + // The resources (fonts) + let mut id = font_start; + for font in &doc.fonts { match font { - DocumentFont::Builtin(builtin) => { - self.w += target.write(b"/Subtype /Type1\n")?; - self.w += target.write(b"/BaseFont /")?; - self.w += target.write_str(builtin.name())?; - self.w += target.write(b"\n")?; - }, - DocumentFont::Loaded(font) => { - self.w += target.write(b"/Subtype /TrueType\n")?; - self.w += target.write(b"/BaseFont /")?; - self.w += target.write_str(font.name.as_str())?; - self.w += target.write(b"\n")?; - unimplemented!(); + DocumentFont::Builtin(font) => { + writer.write_obj(id, &Font { + subtype: FontType::Type1, + base_font: font.name().to_owned(), + })?; }, + DocumentFont::Loaded(_) => unimplemented!(), } - self.w += target.write(b">>\n")?; - self.w += target.write(b"endobj\n")?; - id += 1; } - Ok(self.w) - } - - /// Write the page contents. - fn write_content<W: Write>(&mut self, target: &mut W) -> io::Result<usize> { - let mut id = self.content_start; - - for page in &self.doc.pages { + // The page contents + let mut id = content_start; + for page in &doc.pages { for content in &page.contents { - self.xref_table.push(self.w as u32); - - self.w += target.write_str(id)?; - self.w += target.write(b" 0 obj\n")?; - self.w += target.write(b"<<\n")?; - - let mut buffer = Vec::new(); - buffer.write(b"BT/\n")?; - - buffer.write(b"/F1 13 Tf\n")?; - buffer.write(b"108 734 Td\n")?; - buffer.write(b"(")?; - - let Text(string) = content; - buffer.write(string.as_bytes())?; - - buffer.write(b") Tj\n")?; - buffer.write(b"ET\n")?; + let string = &content.0; - self.w += target.write(b"/Length ")?; - self.w += target.write_str(buffer.len())?; - self.w += target.write(b"\n")?; - - self.w += target.write(b">>\n")?; - - self.w += target.write(b"stream\n")?; - self.w += target.write(&buffer)?; - self.w += target.write(b"endstream\n")?; - - self.w += target.write(b"endobj\n")?; + let mut text = Text::new(); + text.set_font(1, Size::from_points(13.0)) + .move_pos(Size::from_points(108.0), Size::from_points(734.0)) + .write_str(&string); + writer.write_obj(id, &text.as_stream())?; id += 1; } } - Ok(self.w) - } - - /// Write the cross-reference table. - fn write_xref_table<W: Write>(&mut self, target: &mut W) -> io::Result<usize> { - self.offset_xref = self.w as u32; - - self.w += target.write(b"xref\n")?; - self.w += target.write(b"0 ")?; - self.w += target.write_str(self.xref_table.len())?; - self.w += target.write(b"\n")?; - - self.w += target.write(b"0000000000 65535 f\r\n")?; - - for offset in &self.xref_table { - self.w += target.write(format!("{:010}", offset).as_bytes())?; - self.w += target.write(b" 00000 n")?; - self.w += target.write(b"\r\n")?; - } - - Ok(self.w) - } + // Cross-reference table + writer.write_xref_table()?; - /// Write the trailer (points to the root object). - fn write_trailer<W: Write>(&mut self, target: &mut W) -> io::Result<usize> { - self.w += target.write(b"trailer\n")?; - self.w += target.write(b"<<\n")?; - - self.w += target.write(b"/Root ")?; - self.w += target.write_str(self.catalog_id)?; - self.w += target.write(b" 0 R\n")?; - - self.w += target.write(b"/Size ")?; - self.w += target.write_str(self.xref_table.len() + 1)?; - self.w += target.write(b"\n")?; - - self.w += target.write(b">>\n")?; - - Ok(self.w) - } + // Trailer + writer.write_trailer(&Trailer { + root: catalog_id, + })?; - /// Write where the cross-reference table starts. - fn write_start_xref<W: Write>(&mut self, target: &mut W) -> io::Result<usize> { - self.w += target.write(b"startxref\n")?; - self.w += target.write_str(self.offset_xref)?; - self.w += target.write(b"\n")?; + // Write where the xref table starts + writer.write_start_xref()?; - Ok(self.w) + Ok(writer.written()) } } |