1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581
#![cfg_attr(feature="nightly", feature(const_fn))] //! A dead simple ANSI terminal color painting library. //! //! # Usage //! //! Usage is best illustrated via a quick example: //! //! ```rust //! use yansi::Paint; //! use yansi::Color::White; //! //! println!("Testing, {}, {}, {}!", Paint::red(1), //! Paint::green(2).bold().underline(), //! Paint::blue("3").bg(White).italic()); //! ``` //! //! ## `Paint` //! //! The main entry point into this library is the `Paint` type. `Paint` //! encapsulates a value of any type that implements the `Display` or `Debug` //! trait. When a `Paint` is `Display`ed or `Debug`ed, the appropriate ANSI //! escape characters are emitted before and after the wrapped type's `fmt` //! implementation. //! //! `Paint` can be constructed via any of following methods: [`black`], [`red`], //! [`green`], [`yellow`], [`blue`], [`purple`], [`cyan`], [`white`]. Each of //! these methods sets the foreground color of the item to be displayed //! according to the name of the method. Additionally, [`rgb`] and [`fixed`] //! allow you to customize the foreground color to your liking. In addition to //! these constructors, you can also use the [`paint`] method on a given //! [`Color`] value to construct a `Paint` type. Both of these approaches are //! shown below: //! //! ```rust //! use yansi::Paint; //! use yansi::Color::Red; //! //! println!("I'm {}!", Paint::red("red").bold()); //! println!("I'm also {}!", Red.paint("red").bold()); //! ``` //! //! [`black`]: struct.Paint.html#method.black, //! [`red`]: struct.Paint.html#method.red, //! [`green`]: struct.Paint.html#method.green, //! [`yellow`]: struct.Paint.html#method.yellow, //! [`blue`]: struct.Paint.html#method.blue, //! [`purple`]: struct.Paint.html#method.purple, //! [`cyan`]: struct.Paint.html#method.cyan, //! [`white`]: struct.Paint.html#method.white //! [`paint`]: enum.Color.html#method.paint //! [`Color`]: enum.Color.html //! [`rgb`]: struct.Paint.html#method.rgb //! [`fixed`]: struct.Paint.html#method.fixed //! //! Finally, [`new`](struct.Paint.html#method.new) creates a `Paint` item //! _without_ a foreground color applied. //! //! ## Styling //! //! Modifications to the styling of the item can be added via the followiing //! chainable builder methods: [`fg`], [`bg`], [`bold`], [`dimmed`], [`italic`], //! [`underline`], [`blink`], [`invert`], [`hidden`], [`strikethrough`]. //! //! [`fg`]: struct.Paint.html#method.fg //! [`bg`]: struct.Paint.html#method.bg //! [`bold`]: struct.Paint.html#method.bold //! [`dimmed`]: struct.Paint.html#method.dimmed //! [`italic`]: struct.Paint.html#method.italic //! [`underline`]: struct.Paint.html#method.underline //! [`blink`]: struct.Paint.html#method.blink //! [`invert`]: struct.Paint.html#method.invert //! [`hidden`]: struct.Paint.html#method.hidden //! [`strikethrough`]: struct.Paint.html#method.strikethrough //! //! # Disabling //! //! On Rust nightly and with the `nightly` feature enabled, painting can be //! disabled globally via the [`Paint::disable()`] method. When painting is //! disabled, the `Display` and `Debug` implementations for `Paint` will emit //! the `Display` or `Debug` of the contained object and nothing else. Painting //! can be reenabled via the [`Paint::enable()`] method. //! //! One potential use of this feature is to allow users to control color ouput //! via an environment variable. For instance, to disable coloring if the //! `CLICOLOR` variable is set to `0`, you might write: //! //! ```rust //! # #[cfg(feature = "nightly")] //! # { if false { // we don't actually want to disable coloring //! use yansi::Paint; //! //! if let Ok(true) = std::env::var("CLICOLOR").map(|v| v == "0") { //! Paint::disable(); //! } //! # } } //! ``` //! //! [`Paint::disable()`]: struct.Paint.html#method.disable //! [`Paint::enable()`]: struct.Paint.html#method.disable //! //! ## Masking //! //! `Paint` structures can _mask_ arbitrary values. When a value is masked and //! painting is disabled, the `Display` and `Debug` implementations of `Paint` //! write nothing. This allows you to selectively omit output when painting is //! disabled. Values can be masked using the [`mask`] builder method or //! [`Paint::masked()`] constructor. //! //! [`mask`]: struct.Paint.html#method.mask //! [`Paint::masked()`]: struct.Paint.html#method.masked //! //! One use for this feature is to print certain characters only when painting //! is enabled. For instance, you might wish to emit the 🎨 emoji when //! coloring is enabled but not otherwise. This can be accomplished by masking //! the emoji: //! //! ```rust //! use yansi::Paint; //! //! println!("I like colors!{}", Paint::masked(" 🎨")); //! ``` //! //! This will print "I like colors! 🎨" when painting is enabled and "I like //! colors!" when painting is disabled. //! //! # Windows //! //! Since the Windows 10 anniversary update, Windows consoles support ANSII //! escape sequences. This support, however, must be explicitly enabled. `yansi` //! provides the [`Paint::enable_windows_ascii()`] method to enable ASCII //! support on Windows consoles when available. //! //! ```rust //! use yansi::Paint; //! //! // Enable ASCII escape sequence support on Windows consoles. //! Paint::enable_windows_ascii(); //! ``` //! //! [`Paint::enable_windows_ascii()`]: struct.Paint.html#method.enable_windows_ascii //! //! # Why? //! //! Several terminal coloring libraries exist ([`ansi_term`], [`colored`], //! [`term_painter`], to name a few), begging the question: why yet another? //! Here are a few reasons: //! //! * This library is _much_ simpler: there are two types! The complete //! implementation is only about 250 lines of code. //! * Like [`term_painter`], but unlike [`ansi_term`], _any_ type implementing //! `Display` can be stylized, not only strings. //! * Styling can be enabled and disabled on the fly. //! * Typically, only one type needs to be imported: `Paint`. //! * Zero dependencies. It really is simple. //! * The name `yansi` is pretty short. //! //! All that being said, this library borrows the general API from the three //! libraries as well as plenty of code from [`ansi_term`]. //! //! [`ansi_term`]: https://crates.io/crates/ansi_term //! [`colored`]: https://crates.io/crates/colored //! [`term_painter`]: https://crates.io/crates/term-painter use std::fmt::{self, Display}; #[cfg(test)] mod tests; mod windows; #[inline(always)] fn write_spliced<T: Display>(c: &mut bool, f: &mut fmt::Formatter, t: T) -> fmt::Result { if *c { write!(f, ";{}", t) } else { *c = true; write!(f, "{}", t) } } /// An enum representing an ANSI color code. #[derive(Debug, Eq, PartialEq, Ord, PartialOrd, Hash, Copy, Clone)] pub enum Color { /// No color has been set. Nothing is changed when applied. Unset, /// Black #0 (foreground code `30`, background code `40`). Black, /// Red: #1 (foreground code `31`, background code `41`). Red, /// Green: #2 (foreground code `32`, background code `42`). Green, /// Yellow: #3 (foreground code `33`, background code `43`). Yellow, /// Blue: #4 (foreground code `34`, background code `44`). Blue, /// Purple: #5 (foreground code `35`, background code `45`). Purple, /// Cyan: #6 (foreground code `36`, background code `46`). Cyan, /// White: #7 (foreground code `37`, background code `47`). White, /// A color number from 0 to 255, for use in 256-color terminals. Fixed(u8), /// A 24-bit RGB color, as specified by ISO-8613-3. RGB(u8, u8, u8), } impl Color { /// Constructs a new `Paint` structure that encapsulates `item` with the /// foreground color set to the color `self`. /// /// ```rust /// use yansi::Color::Blue; /// /// println!("This is going to be blue: {}", Blue.paint("yay!")); /// ``` #[inline(always)] pub fn paint<T>(self, item: T) -> Paint<T> { Paint::new(item).fg(self) } } #[doc(hidden)] impl fmt::Display for Color { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { match *self { Color::Unset => Ok(()), Color::Black => write!(f, "0"), Color::Red => write!(f, "1"), Color::Green => write!(f, "2"), Color::Yellow => write!(f, "3"), Color::Blue => write!(f, "4"), Color::Purple => write!(f, "5"), Color::Cyan => write!(f, "6"), Color::White => write!(f, "7"), Color::Fixed(num) => write!(f, "8;5;{}", num), Color::RGB(r, g, b) => write!(f, "8;2;{};{};{}", r, g, b) } } } impl Default for Color { #[inline(always)] fn default() -> Self { Color::Unset } } #[repr(packed)] #[derive(Default, Debug, Eq, PartialEq, Ord, PartialOrd, Hash, Copy, Clone)] struct Style { bold: bool, dimmed: bool, italic: bool, underline: bool, blink: bool, invert: bool, hidden: bool, strikethrough: bool, } /// A structure encapsulating all of the styling for a given item. /// /// See the [crate level documentation](./) for usage information. #[derive(Default, Eq, PartialEq, Ord, PartialOrd, Hash, Copy, Clone)] pub struct Paint<T> { item: T, foreground: Color, background: Color, style: Style, masked: bool, } macro_rules! constructors_for { ($T:ty, $($name:ident: $color:ident),*) => ($( /// Constructs a new `Paint` structure that encapsulates `item` with the /// foreground color set to the name of this method. /// /// ```rust /// use yansi::Paint; /// /// println!("This is going to be blue: {}", Paint::blue("yay!")); /// ``` pub fn $name(item: $T) -> Paint<$T> { Paint::new(item).fg(Color::$color) } )*) } macro_rules! style_builder_for { ($T:ty, $($name:ident),*) => ($( /// Enables the styling corresponding to the name of this method. /// /// ```rust /// use yansi::Paint; /// /// println!("Red, underlined: {}", Paint::red("beep.").underline()); /// ``` #[inline(always)] pub fn $name(mut self) -> Paint<$T> { self.style.$name = true; self } )*) } impl<T> Paint<T> { /// Constructs a new `Paint` structure that encapsulates `item`. No styling /// is applied. /// /// ```rust /// use yansi::Paint; /// /// assert_eq!(Paint::new("hello!").to_string(), "hello!".to_string()); /// ``` #[inline(always)] pub fn new(item: T) -> Paint<T> { Paint { item: item, foreground: Color::default(), background: Color::default(), style: Style::default(), masked: false } } /// Constructs a new `Paint` structure that encapsulates `item` and masks /// it. No styling is applied. A masked item is not written out when /// painting is disabled during `Display` or `Debug` invocations. When /// painting is enabled, masking has no effect. /// /// ```rust /// use yansi::Paint; /// /// println!("{}Sprout!", Paint::masked("🌱 ")); /// ``` #[inline(always)] pub fn masked(item: T) -> Paint<T> { Paint::new(item).mask() } constructors_for!(T, black: Black, red: Red, green: Green, yellow: Yellow, blue: Blue, purple: Purple, cyan: Cyan, white: White); /// Constructs a new `Paint` structure that encapsulates `item` with the /// foreground color set RGB color corresponding to `r`, `g`, `b`. /// /// ```rust /// use yansi::Paint; /// /// println!("This is going to be funky: {}", Paint::rgb(70, 130, 122, "hi!")); /// ``` #[inline(always)] pub fn rgb(r: u8, g: u8, b: u8, item: T) -> Paint<T> { Paint::new(item).fg(Color::RGB(r, g, b)) } /// Constructs a new `Paint` structure that encapsulates `item` with the /// foreground color set to the fixed color corresponding to `color`. /// /// ```rust /// use yansi::Paint; /// /// println!("This is going to be funky: {}", Paint::fixed(100, "hi!")); /// ``` #[inline(always)] pub fn fixed(color: u8, item: T) -> Paint<T> { Paint::new(item).fg(Color::Fixed(color)) } /// Sets the foreground to `color`. /// /// ```rust /// use yansi::Paint; /// use yansi::Color::Red; /// /// println!("Red foreground: {}", Paint::new("hi!").fg(Red)); /// ``` #[inline(always)] pub fn fg(mut self, color: Color) -> Paint<T> { self.foreground = color; self } /// Sets the background to `color`. /// /// ```rust /// use yansi::Paint; /// use yansi::Color::Yellow; /// /// println!("Yellow background: {}", Paint::new("hi!").bg(Yellow)); /// ``` #[inline(always)] pub fn bg(mut self, color: Color) -> Paint<T> { self.background = color; self } /// Masks `self`. A masked item is not written out when painting is disabled /// during `Display` or `Debug` invocations. When painting is enabled, /// masking has no effect. /// /// ```rust /// use yansi::Paint; /// /// println!("{}Something happened.", Paint::red("Whoops! ").mask()); /// ``` #[inline(always)] pub fn mask(mut self) -> Paint<T> { self.masked = true; self } style_builder_for!(T, bold, dimmed, italic, underline, blink, invert, hidden, strikethrough); #[inline] fn is_plain(&self) -> bool { self.foreground == Color::default() && self.background == Color::default() && self.style == Style::default() } fn styles(&self) -> [bool; 10] { [false, self.style.bold, self.style.dimmed, self.style.italic, self.style.underline, self.style.blink, false, self.style.invert, self.style.hidden, self.style.strikethrough] } /// Write any ANSI codes that go *before* a piece of text. These should be /// the codes to set the terminal to a different colour or font style. fn write_prefix(&self, f: &mut fmt::Formatter) -> fmt::Result { // A user may just want a code-free string when no styles are applied. if self.is_plain() { return Ok(()); } let mut splice = false; write!(f, "\x1B[")?; for (i, _) in self.styles().iter().enumerate().filter(|&(_, e)| *e) { write_spliced(&mut splice, f, i)?; } if self.background != Color::Unset { write_spliced(&mut splice, f, "4")?; self.background.fmt(f)?; } if self.foreground != Color::Unset { write_spliced(&mut splice, f, "3")?; self.foreground.fmt(f)?; } // All the codes end with an `m`, because reasons. write!(f, "m") } /// Write any ANSI codes that go *after* a piece of text. These should be /// the codes to *reset* the terminal back to its normal colour and style. fn write_suffix(&self, f: &mut fmt::Formatter) -> fmt::Result { if self.is_plain() { return Ok(()); } write!(f, "\x1B[0m") } } #[cfg(feature="nightly")] use std::sync::atomic::AtomicBool; #[cfg(feature="nightly")] use std::sync::atomic::Ordering; #[cfg(feature="nightly")] static DISABLED: AtomicBool = AtomicBool::new(false); impl Paint<()> { /// Disables coloring globally. /// /// This method is only available when the "nightly" feature is enabled. /// /// # Example /// /// ```rust /// use yansi::Paint; /// /// // With coloring enabled, ANSI color codes are emitted. /// assert_ne!(Paint::green("go").to_string(), "go".to_string()); /// /// // With coloring disabled, ANSI color codes are _not_ emitted. /// Paint::disable(); /// assert_eq!(Paint::green("go").to_string(), "go".to_string()); /// ``` #[cfg(feature="nightly")] pub fn disable() { DISABLED.store(true, Ordering::Release); } /// Enables coloring globally. Coloring is enabled by default, so this /// method should only be called to _re_ enable coloring. /// /// This method is only available when the "nightly" feature is enabled. /// /// # Example /// /// ```rust /// use yansi::Paint; /// /// // With coloring disabled, ANSI color codes are _not_ emitted. /// Paint::disable(); /// assert_eq!(Paint::green("go").to_string(), "go".to_string()); /// /// // Reenabling causes color code to be emitted. /// Paint::enable(); /// assert_ne!(Paint::green("go").to_string(), "go".to_string()); /// ``` #[cfg(feature="nightly")] pub fn enable() { DISABLED.store(false, Ordering::Release); } /// Enables ASCII terminal escape sequences on Windows consoles when /// possible. Returns `true` if escape sequence support was successfully /// enabled and `false` otherwise. On non-Windows targets, this method /// always returns `true`. /// /// Support for escape sequences in Windows consoles was added in the /// Windows 10 anniversary update. For targets with older Windows /// installations, this method is expected to return `false`. /// /// # Example /// /// ```rust /// use yansi::Paint; /// /// // A best-effort Windows ASCII terminal support enabling. /// Paint::enable_windows_ascii(); /// ``` #[inline(always)] pub fn enable_windows_ascii() -> bool { windows::enable_ascii_colors() } } fn paint_enabled() -> bool { #[cfg(feature="nightly")] { !DISABLED.load(Ordering::Relaxed) } #[cfg(not(feature="nightly"))] { true } } impl<T: fmt::Display> fmt::Display for Paint<T> { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { if paint_enabled() { self.write_prefix(f)?; self.item.fmt(f)?; self.write_suffix(f) } else if !self.masked { self.item.fmt(f) } else { Ok(()) } } } impl<T: fmt::Debug> fmt::Debug for Paint<T> { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { if paint_enabled() { self.write_prefix(f)?; self.item.fmt(f)?; self.write_suffix(f) } else if !self.masked { self.item.fmt(f) } else { Ok(()) } } }