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// SPDX-FileCopyrightText: 2020 Robin Krahl <robin.krahl@ireas.org> // SPDX-License-Identifier: Apache-2.0 or MIT //! User-friendly PDF generator written in pure Rust. //! //! `genpdf` is a high-level PDF generator built ontop of [`printpdf`][] and [`rusttype`][]. It //! takes care of the page layout and text alignment and renders a document tree into a PDF //! document. All of its dependencies are written in Rust, so you don’t need any pre-installed //! libraries or tools. //! //! # Quickstart //! //! To generate a PDF document, create an instance of the [`Document`][] struct and add //! [`Element`][] implementations to it. Then call the [`Document::render_to_file`][] method to //! render the document and to write it to a file. //! //! ```no_run //! // Create a document and set the default font family //! let mut doc = genpdf::Document::new("./fonts", "Liberation") //! .expect("Failed to create PDF document"); //! // Change the default settings //! doc.set_margins(10); //! doc.set_title("Demo document"); //! // Add one or more elements //! doc.push(genpdf::elements::Paragraph::new("This is a demo document.")); //! // Render the document and write it to a file //! doc.render_to_file("output.pdf").expect("Failed to write PDF file"); //! ``` //! //! For a complete example with all supported elements, see the [`examples/demo.rs`][] file that //! generates [this PDF document][]. //! //! # Overview //! //! A [`Document`][] consists of a [`LinearLayout`][] that renders the added elements, a //! [`FontCache`][] instance that keeps track of the loaded fonts and a collection of default //! values for the text style and the page layout. //! //! When creating a [`Document`][] instance, you always have to set the default font family that //! will be used for the document. You can load additional fonts with the //! [`Document::load_font_family`][] method. //! //! The style of a shape or text can be set using the [`Style`][] struct. The style is inherited //! within the document tree. You can set the style of an element by wrapping it in a //! [`StyledElement`][] (see the [`Element::styled`][] method) or – for text elements – with a //! [`StyledString`][]. //! //! For an overview of the available elements, see the [`elements`][] module. You can also //! create custom elements by implementing the [`Element`][] trait. //! //! The actual PDF document is generated from the elements that have been added to the document //! once you call the [`Document::render`][] or [`Document::render_to_file`][] methods. For //! details on the rendering process, see the next section. //! //! In `genpdf`, all lengths are measured in millimeters. The only exceptions are font sizes that //! are measured in points. The [`Mm`][] newtype struct is used for all lengths, and the //! [`Position`][] and [`Size`][] types are used to describe points and rectangles in the PDF //! document. //! //! # Rendering Process //! //! The rendering process is started by calling the [`Document::render`][] or //! [`Document::render_to_file`][] methods. You can only render a document once. Before the //! rendering starts, the PDF document is created and all loaded fonts are embedded into the //! document. //! //! The elements are then rendered by calling the [`Element::render`][] method of the root element, //! a [`LinearLayout`][]. This element will then call the `render` methods of the elements stored //! in the layout, and so on. //! //! The [`Element::render`][] method receives the following arguments: //! - *font_cache* is the [`FontCache`][] instance that keeps track of the loaded fonts and can be //! used to map a [`Style`][] instance to font data. //! - *area* is a view on the area of the current page that can be used by the element. //! - *style* is the [`Style`][] instance for this element. Is is a combination of the default //! style of the [`Document`][] and the style set by [`StyledElement`][] instances that are //! parents of the current element. //! //! The `render` method tries to render the entire element in the provided area. The returned //! [`RenderResult`][] stores the size of the area that has actually been used to render the //! element. If the element did not fit into the provided area, the `has_more` field of the //! [`RenderResult`][] is set to `true`. This causes the `Document` to add a new page to the PDF //! document and then call the `render` method again with an area of the new page. This is //! repeated until all elements have been rendered completely, that means until all elements return //! a [`RenderResult`][] with `has_more == false`. //! //! Elements may print to the provided area using the methods of the [`Area`][] struct, or by //! calling the `render` method of other elements, or both. //! //! The render process is cancelled if an `Element` returns an error, or if no content has been //! rendered to a newly created page. This indicates that an element does not fit on a clear page //! and can’t even be rendered partially, so the rendering process is cancelled. //! //! As the [`Element::render`][] method is called repeatedly until the complete element has been //! rendered, the element has to keep track of the content that has already been rendered. As //! there is only one rendering process per document, elements may discard data that has been //! rendered and that is no longer needed. //! //! # Low-Level Interface //! //! The [`render`][] module contains a low-level interface for creating PDF files. It keeps track //! of page sizes and layers and has utility methods for easier text and shape rendering. But it //! does not provide support for measuring the size of rendered text or for laying out elements. //! If possible, you should always try to use `genpdf`’s high-level interface and implement the //! [`Element`][] trait if you want to customize a document instead of using the low-level //! interface directly. //! //! # Known Issues //! //! - Currently, `genpdf` adds all loaded fonts to the PDF document, even if they are not used. //! `printpdf` then adds all available glyphs for these fonts to the document, even if they are //! not used in the document. This increases the file size by 100–200 KiB per font (500–1000 KiB //! per font family). Until this is fixed, you can pass the generated file through `ps2pdf` to //! significantly reduce its size. //! //! [`printpdf`]: https://docs.rs/printpdf //! [`rusttype`]: https://docs.rs/rusttype //! [`render`]: ./render/ //! [`elements`]: ./elements/ //! [`Document`]: struct.Document.html //! [`Document::render`]: struct.Document.html#method.render //! [`Document::render_to_file`]: struct.Document.html#method.render_to_file //! [`Document::load_font_family`]: struct.Document.html#method.load_font_family //! [`Element`]: trait.Element.html //! [`Element::render`]: trait.Element.html#tymethod.render //! [`Element::styled`]: trait.Element.html#tymethod.styled //! [`RenderResult`]: trait.RenderResult.html //! [`LinearLayout`]: elements/struct.LinearLayout.html //! [`StyledElement`]: elements/StyledElement.html //! [`FontCache`]: fonts/struct.FontCache.html //! [`Area`]: render/struct.Area.html //! [`Mm`]: struct.Mm.html //! [`Size`]: struct.Size.html //! [`Position`]: struct.Position.html //! [`Style`]: style/struct.Style.html //! [`StyledString`]: style/struct.StyledString.html //! [`examples/demo.rs`]: https://git.sr.ht/~ireas/genpdf-rs/tree/master/examples/demo.rs //! [this PDF document]: https://git.sr.ht/~ireas/genpdf-rs/blob/master/examples/demo.pdf #![warn(missing_docs, rust_2018_idioms)] mod wrap; pub mod elements; pub mod error; pub mod fonts; pub mod render; pub mod style; use std::fs; use std::io; use std::path; use std::str; use derive_more::{ Add, AddAssign, Div, DivAssign, From, Into, Mul, MulAssign, Sub, SubAssign, Sum, }; /// A length measured in millimeters. /// /// `genpdf` always uses millimeters as its length unit, except for the font size that is measured /// in points. /// /// If you want to convert pixels or points into millimeters, you can use the [`printpdf::Pt`][] /// and [`printpdf::Px`][] types. /// /// [`printpdf::Pt`]: https://docs.rs/printpdf/0.3.2/printpdf/scale/struct.Pt.html /// [`printpdf::Px`]: https://docs.rs/printpdf/0.3.2/printpdf/scale/struct.Px.html #[derive( Clone, Copy, Debug, Default, PartialEq, PartialOrd, Add, AddAssign, Div, DivAssign, From, Into, Mul, MulAssign, Sub, SubAssign, Sum, )] pub struct Mm(f64); impl Mm { /// Returns the maximum of this value and the given value. pub fn max(self, other: Mm) -> Mm { Mm(self.0.max(other.0)) } } impl From<i8> for Mm { fn from(mm: i8) -> Mm { Mm(mm.into()) } } impl From<i16> for Mm { fn from(mm: i16) -> Mm { Mm(mm.into()) } } impl From<i32> for Mm { fn from(mm: i32) -> Mm { Mm(mm.into()) } } impl From<u8> for Mm { fn from(mm: u8) -> Mm { Mm(mm.into()) } } impl From<u16> for Mm { fn from(mm: u16) -> Mm { Mm(mm.into()) } } impl From<u32> for Mm { fn from(mm: u32) -> Mm { Mm(mm.into()) } } impl From<f32> for Mm { fn from(mm: f32) -> Mm { Mm(mm.into()) } } impl From<printpdf::Mm> for Mm { fn from(mm: printpdf::Mm) -> Mm { Mm(mm.0) } } impl From<printpdf::Pt> for Mm { fn from(pt: printpdf::Pt) -> Mm { let mm: printpdf::Mm = pt.into(); mm.into() } } impl From<Mm> for printpdf::Mm { fn from(mm: Mm) -> printpdf::Mm { printpdf::Mm(mm.0) } } impl From<Mm> for printpdf::Pt { fn from(mm: Mm) -> printpdf::Pt { printpdf::Mm(mm.0).into() } } /// A position on a PDF layer, measured in millimeters. /// /// All positions used by `genpdf` are measured from the top left corner of the reference area. #[derive(Clone, Copy, Debug, Default, PartialEq, PartialOrd, Add, AddAssign, Sub, SubAssign)] pub struct Position { /// The x coordinate of the position, measured from the left border of the reference area. pub x: Mm, /// The y coordinate of the position, measured from the top border of the reference area. pub y: Mm, } impl Position { /// Creates a new position from the given coordinates. pub fn new(x: impl Into<Mm>, y: impl Into<Mm>) -> Position { Position { x: x.into(), y: y.into(), } } } impl From<Position> for printpdf::Point { fn from(pos: Position) -> printpdf::Point { printpdf::Point::new(pos.x.into(), pos.y.into()) } } impl<X: Into<Mm>, Y: Into<Mm>> From<(X, Y)> for Position { fn from(values: (X, Y)) -> Position { Position::new(values.0, values.1) } } /// A size of an area on a PDF layer, measured in millimeters. #[derive(Clone, Copy, Debug, Default, PartialEq, PartialOrd, Add, AddAssign, Sub, SubAssign)] pub struct Size { /// The width of the area. pub width: Mm, /// The height of the area. pub height: Mm, } impl Size { /// Creates a new size from the given width and height. pub fn new(width: impl Into<Mm>, height: impl Into<Mm>) -> Size { Size { width: width.into(), height: height.into(), } } /// Stacks the given size vertically on this size and returns the result. /// /// This means that the width is set to the maximum of the widths and the height is set to the /// sum of the heights. #[must_use] pub fn stack_vertical(mut self, other: Size) -> Size { self.width = self.width.max(other.width); self.height += other.height; self } } impl<W: Into<Mm>, H: Into<Mm>> From<(W, H)> for Size { fn from(values: (W, H)) -> Size { Size::new(values.0, values.1) } } /// A paper size like A4, legal or letter. /// /// This enum provides variants for typical paper sizes that can be converted into [`Size`][] /// instances. /// /// [`Size`]: struct.Size.html #[derive(Clone, Copy, Debug, Eq, Ord, PartialEq, PartialOrd)] pub enum PaperSize { /// The A4 paper size (210x297mm). A4, /// The legal paper size (216x356mm). Legal, /// The letter paper size (216x279mm). Letter, } impl From<PaperSize> for Size { fn from(size: PaperSize) -> Size { match size { PaperSize::A4 => Size::new(210, 297), PaperSize::Legal => Size::new(216, 356), PaperSize::Letter => Size::new(216, 279), } } } /// The margins of an area, measured in millimeters. #[derive(Clone, Copy, Debug, Default, PartialEq, PartialOrd)] pub struct Margins { /// The top margin of the area. top: Mm, /// The right margin of the area. right: Mm, /// The bottom margin of the area. bottom: Mm, /// The left margin of the area. left: Mm, } impl Margins { /// Creates a new `Margins` instance from the given top, right, bottom and left margins. pub fn trbl( top: impl Into<Mm>, right: impl Into<Mm>, bottom: impl Into<Mm>, left: impl Into<Mm>, ) -> Margins { Margins { top: top.into(), right: right.into(), bottom: bottom.into(), left: left.into(), } } /// Creates a new `Margins` instance from the given vertical (top and bottom) and horizontal /// (left and right) margins. pub fn vh(vertical: impl Into<Mm>, horizontal: impl Into<Mm>) -> Margins { let (vertical, horizontal) = (vertical.into(), horizontal.into()); Margins::trbl(vertical, horizontal, vertical, horizontal) } /// Creates a new `Margins` instance with all four margins set to the given value. pub fn all(all: impl Into<Mm>) -> Margins { let all = all.into(); Margins::trbl(all, all, all, all) } } impl<T: Into<Mm>, R: Into<Mm>, B: Into<Mm>, L: Into<Mm>> From<(T, R, B, L)> for Margins { fn from(values: (T, R, B, L)) -> Margins { Margins::trbl(values.0, values.1, values.2, values.3) } } impl<V: Into<Mm>, H: Into<Mm>> From<(V, H)> for Margins { fn from(values: (V, H)) -> Margins { Margins::vh(values.0, values.1) } } impl<T: Into<Mm>> From<T> for Margins { fn from(value: T) -> Margins { Margins::all(value) } } /// A PDF document. /// /// This struct is the entry point for the high-level `genpdf` API. It stores a set of elements /// and default style and layout settings. Add elements to the document by calling the [`push`][] /// method and then render them to a PDF file using the [`render`][] and [`render_to_file`][] /// methods. /// /// The root element of the document is a [`LinearLayout`][] that vertically arranges all elements. /// For details on the rendering process, see the [Rendering Process section of the crate /// documentation](index.html#rendering-process). /// /// # Example /// /// ```no_run /// let mut doc = genpdf::Document::new("./fonts", "Liberation") /// .expect("Failed to create document"); /// doc.push(genpdf::elements::Paragraph::new("Document content")); /// doc.render_to_file("output.pdf").expect("Failed to render document"); /// ``` /// /// [`push`]: #method.push /// [`render`]: #method.render /// [`render_to_file`]: #method.render_to_file /// [`LinearLayout`]: elements/struct.LinearLayout.html pub struct Document { root: elements::LinearLayout, title: String, font_cache: fonts::FontCache, style: style::Style, paper_size: Size, margins: Option<Margins>, conformance: Option<printpdf::PdfConformance>, } impl Document { /// Creates a new document with the font family with the given name in the given directory as /// the default font. /// /// See the documentation of the [`load_font_family`][] method for details on the font loading. /// /// [`load_font_family`]: #method.load_font_family pub fn new( font_dir: impl AsRef<path::Path>, font_name: impl AsRef<str>, ) -> Result<Document, error::Error> { Ok(Document { root: elements::LinearLayout::vertical(), title: String::new(), font_cache: fonts::FontCache::new(font_dir, font_name.as_ref())?, style: style::Style::new(), paper_size: PaperSize::A4.into(), margins: None, conformance: None, }) } /// Loads the font family with the given name from the given directory, adds them to the font /// cache and returns a reference to the loaded font family. /// /// The font is loaded from TTF files in the given directory. It assumes that the following /// files exist and are valid font files: /// - `{dir}/{name}-Regular.ttf` /// - `{dir}/{name}-Bold.ttf` /// - `{dir}/{name}-Italic.ttf` /// - `{dir}/{name}-BoldItalic.ttf` /// /// Note that the returned font reference may only be used for this document. It cannot be /// shared with other `Document` or [`FontCache`][] instances. /// /// [`FontCache`]: fonts/struct.FontCache.html pub fn load_font_family( &mut self, dir: impl AsRef<path::Path>, name: &str, ) -> Result<fonts::FontFamily, error::Error> { self.font_cache.load_font_family(dir, name) } /// Returns the font cache used by this document. /// /// You can use the font cache to get the default font and to query glyph metrics for a font. /// Use the [`load_font_family`][] method instead if you want to add fonts to this document. /// /// [`load_font_family`]: #method.load_font_family pub fn font_cache(&self) -> &fonts::FontCache { &self.font_cache } /// Sets the title of the PDF document. /// /// If this method is not called, the PDF title will be empty. pub fn set_title(&mut self, title: impl Into<String>) { self.title = title.into(); } /// Sets the default font size in points for this document. /// /// If this method is not called, the default value of 12 points is used. pub fn set_font_size(&mut self, font_size: u8) { self.style.set_font_size(font_size); } /// Sets the default line spacing factor for this document. /// /// If this method is not called, the default value of 1 is used. pub fn set_line_spacing(&mut self, line_spacing: f64) { self.style.set_line_spacing(line_spacing); } /// Sets the paper size for all pages of this document. /// /// If this method is not called, the default size [`A4`][] is used. /// /// [`A4`]: enum.PaperSize.html#variant.A4 pub fn set_paper_size(&mut self, paper_size: impl Into<Size>) { self.paper_size = paper_size.into(); } /// Sets the margins for all pages of this document. /// /// If this method is not called, the full page is used. pub fn set_margins(&mut self, margins: impl Into<Margins>) { self.margins = Some(margins.into()); } /// Sets the PDF conformance settings for this document. pub fn set_conformance(&mut self, conformance: printpdf::PdfConformance) { self.conformance = Some(conformance); } /// Sets the minimal PDF conformance settings for this document. /// /// If this method is called, the generation of ICC profiles and XMP metadata is deactivated, /// leading to a smaller file size. pub fn set_minimal_conformance(&mut self) { self.set_conformance(printpdf::PdfConformance::Custom( printpdf::CustomPdfConformance { requires_icc_profile: false, requires_xmp_metadata: false, ..Default::default() }, )); } /// Adds the given element to the document. /// /// The given element is appended to the list of elements that is rendered by the root /// [`LinearLayout`][] once [`render`][] or [`render_to_file`][] is called. /// /// [`LinearLayout`]: elements/struct.LinearLayout.html /// [`render`]: #method.render /// [`render_to_file`]: #method.render_to_file pub fn push<E: Element + 'static>(&mut self, element: E) { self.root.push(element); } /// Renders this document into a PDF file and writes it to the given writer. /// /// The given writer is always wrapped in a buffered writer. For details on the rendering /// process, see the [Rendering Process section of the crate /// documentation](index.html#rendering-process). pub fn render(mut self, w: impl io::Write) -> Result<(), error::Error> { let mut renderer = render::Renderer::new(self.paper_size, &self.title)?; if let Some(conformance) = self.conformance { renderer = renderer.with_conformance(conformance); } self.font_cache.load_pdf_fonts(&renderer)?; loop { let mut area = renderer.last_page().last_layer().area(); if let Some(margins) = self.margins { area.add_margins(margins); } let result = self.root.render(&self.font_cache, area, self.style)?; if result.has_more { if result.size == Size::new(0, 0) { return Err(error::Error::new( "Could not fit an element on a new page", error::ErrorKind::PageSizeExceeded, )); } renderer.add_page(PaperSize::A4); } else { break; } } renderer.write(w) } /// Renders this document into a PDF file at the given path. /// /// If the given file does not exist, it is created. If it exists, it is overwritten. /// /// For details on the rendering process, see the [Rendering Process section of the crate /// documentation](index.html#rendering-process). pub fn render_to_file(self, path: impl AsRef<path::Path>) -> Result<(), error::Error> { let path = path.as_ref(); let file = fs::File::create(path).map_err(|err| { error::Error::new(format!("Could not create file {}", path.display()), err) })?; self.render(file) } } /// The result of the rendering process. /// /// This struct is returned by implementations of the [`Element::render`][] method. It contains /// the size of the area that has been written to (measured from the origin of the area that was /// provided to the render method) and information about additional content that did not fit in the /// provided area. /// /// See the [Rendering Process section of the crate documentation](index.html#rendering-process) /// for more information on the rendering process. /// /// [`Element::render`]: trait.Element.html#tymethod.render #[derive(Clone, Copy, Debug, Default, PartialEq, PartialOrd)] pub struct RenderResult { /// The size of the area that has been written to, starting from the origin of the provided /// area. pub size: Size, /// Indicates whether the element contains more content that did not fit in the provided area. pub has_more: bool, } /// An element of a PDF document. /// /// This trait is implemented by all elements that can be added to a [`Document`][]. Implementors /// have to define the [`render`][] method that writes the content of this element to the generated /// PDF document. /// /// See the [Rendering Process section of the crate documentation](index.html#rendering-process) /// for more information on the rendering process. /// /// [`Document`]: struct.Document.html /// [`render`]: #tymethod.render pub trait Element { /// Renders this element to the given area using the given style and font cache. /// /// For an overview over the rendering process, see the [Rendering Process section of the crate /// documentation](index.html#rendering-process). /// /// This method is called once for every element that has been added to a [`Document`][] once /// the [`render`][] or [`render_to_file`][] methods have been called. If this method is /// called, it should print the element’s content to the given area. If the content does not /// fit in the given area, it should set the `has_more` flag of the returned /// [`RenderResult`][]. It will then be called again with a new area on a new page until it /// returns a [`RenderResult`][] with `has_more == false`. Regardless of whether the content /// fitted in the area or not, the `size` field of the [`RenderResult`][] must always be set to /// the size of the area that has been used, starting at the origin of the provided area. /// /// The following guarantuees are made by `genpdf`’s elements and must be followed by /// implementations of this trait: /// /// - There is only one rendering process per element instance. This means that the first call /// to this method is always the start of the rendering process, and subsequent calls are /// always continuations of the same rendering process. This means that the element does not /// have to reset its state after it has processed all content, and it is allowed to drop /// content that has already been rendered. /// - If a call to this method returns an `Err` value, it will not be called again. /// - After the first call, the method will only be called again if the `has_more` of the last /// [`RenderResult`][] was set to true. /// - If none of the element’s content could be fitted in the provided area, the size of the /// [`RenderResult`][] must be `(0, 0)`. If the size is non-zero, this method must return a /// [`RenderResult`] with `has_more == false` after a finite number of calls. /// /// [`Document`]: struct.Document.html /// [`render`]: struct.Document.html#method.render /// [`render_to_file`]: struct.Document.html#method.render_to_file /// [`RenderResult`]: struct.RenderResult.html fn render( &mut self, font_cache: &fonts::FontCache, area: render::Area<'_>, style: style::Style, ) -> Result<RenderResult, error::Error>; /// Draws a frame around this element. fn framed(self) -> elements::FramedElement<Self> where Self: Sized, { elements::FramedElement::new(self) } /// Adds a padding to this element. fn padded(self, padding: impl Into<Margins>) -> elements::PaddedElement<Self> where Self: Sized, { elements::PaddedElement::new(self, padding) } /// Sets the default style for this element and its children. fn styled(self, style: impl Into<style::Style>) -> elements::StyledElement<Self> where Self: Sized, { elements::StyledElement::new(self, style.into()) } }