vendor/annotate-snippets-0.6.1/src/formatter/style.rs

   1 //! Set of structures required to implement a stylesheet for
   2 //! [DisplayListFormatter](super::DisplayListFormatter).
   3 //!
   4 //! In order to provide additional styling information for the
   5 //! formatter, a structs can implement `Stylesheet` and `Style`
   6 //! traits.
   7 //!
   8 //! Example:
   9 //!
  10 //! ```
  11 //! use annotate_snippets::formatter::style::{Stylesheet, StyleClass, Style};
  12 //!
  13 //! struct HTMLStyle {
  14 //!   prefix: String,
  15 //!   postfix: String,
  16 //! };
  17 //!
  18 //! impl HTMLStyle {
  19 //!   fn new(prefix: &str, postfix: &str) -> Self {
  20 //!     HTMLStyle {
  21 //!       prefix: prefix.into(),
  22 //!       postfix: postfix.into()
  23 //!     }
  24 //!   }
  25 //! };
  26 //!
  27 //! impl Style for HTMLStyle {
  28 //!   fn paint(&self, text: &str) -> String {
  29 //!     format!("{}{}{}", self.prefix, text, self.postfix)
  30 //!   }
  31 //!
  32 //!   fn bold(&self) -> Box<Style> {
  33 //!     Box::new(HTMLStyle {
  34 //!       prefix: format!("{}<b>", self.prefix),
  35 //!       postfix: format!("</b>{}", self.postfix),
  36 //!     })
  37 //!   }
  38 //! }
  39 //!
  40 //! struct HTMLStylesheet {};
  41 //!
  42 //!
  43 //! impl Stylesheet for HTMLStylesheet {
  44 //!   fn get_style(&self, class: StyleClass) -> Box<Style> {
  45 //!     let s = match class {
  46 //!       StyleClass::Error => HTMLStyle::new("<span style='color:red'>", "</span>"),
  47 //!       StyleClass::Warning => HTMLStyle::new("<span style='color:orange'>", "</span>"),
  48 //!       StyleClass::Info => HTMLStyle::new("<span style='color:yellow'>", "</span>"),
  49 //!       StyleClass::Note => HTMLStyle::new("<span style='color:blue'>", "</span>"),
  50 //!       StyleClass::Help => HTMLStyle::new("<span style='color:green'>", "</span>"),
  51 //!       StyleClass::LineNo => HTMLStyle::new("<strong>", "</strong>"),
  52 //!       StyleClass::Emphasis => HTMLStyle::new("<i>", "</i>"),
  53 //!       StyleClass::None => HTMLStyle::new("", ""),
  54 //!     };
  55 //!     Box::new(s)
  56 //!   }
  57 //! }
  58 //! ```
  59
  60 /// StyleClass is a collection of named variants of style classes
  61 /// that DisplayListFormatter uses.
  62 pub enum StyleClass {
  63     /// Message indicating an error.
  64     Error,
  65     /// Message indicating a warning.
  66     Warning,
  67     /// Message indicating an information.
  68     Info,
  69     /// Message indicating a note.
  70     Note,
  71     /// Message indicating a help.
  72     Help,
  73
  74     /// Style for line numbers.
  75     LineNo,
  76
  77     /// Parts of the text that are to be emphasised.
  78     Emphasis,
  79
  80     /// Parts of the text that are regular. Usually a no-op.
  81     None,
  82 }
  83
  84 /// This trait implements a return value for the `Stylesheet::get_style`.
  85 pub trait Style {
  86     /// The method used by the DisplayListFormatter to style the message.
  87     fn paint(&self, text: &str) -> String;
  88     /// The method used by the DisplayListFormatter to display the message
  89     /// in bold font.
  90     fn bold(&self) -> Box<dyn Style>;
  91 }
  92
  93 /// Trait to annotate structs that can provide `Style` implementations for
  94 /// every `StyleClass` variant.
  95 pub trait Stylesheet {
  96     /// Returns a `Style` implementer based on the requested `StyleClass` variant.
  97     fn get_style(&self, class: StyleClass) -> Box<dyn Style>;
  98 }