diff --git a/Cargo.toml b/Cargo.toml index 3b086174..d3e3be39 100644 --- a/Cargo.toml +++ b/Cargo.toml @@ -13,14 +13,13 @@ edition = '2021' rust-version = "1.70" [features] -default = ["application"] +default = ["application", "detect-color-scheme"] # Feature required for bat the application. Should be disabled when depending on # bat as a library. application = [ "bugreport", "build-assets", "git", - "detect-color-scheme", "minimal-application", ] # Mainly for developers that want to iterate quickly diff --git a/src/bin/bat/app.rs b/src/bin/bat/app.rs index 4e167a88..9a5621ec 100644 --- a/src/bin/bat/app.rs +++ b/src/bin/bat/app.rs @@ -8,9 +8,7 @@ use crate::{ clap_app, config::{get_args_from_config_file, get_args_from_env_opts_var, get_args_from_env_vars}, }; -use bat::theme::{ - theme, ColorScheme, ColorSchemeDetector, DetectColorScheme, ThemeOptions, ThemeRequest, -}; +use bat::theme::{theme, DetectColorScheme, ThemeOptions, ThemeRequest}; use clap::ArgMatches; use console::Term; @@ -245,7 +243,7 @@ impl App { 4 }, ), - theme: theme(self.theme_options(), &TerminalColorSchemeDetector), + theme: theme(self.theme_options()), visible_lines: match self.matches.try_contains_id("diff").unwrap_or_default() && self.matches.get_flag("diff") { @@ -413,42 +411,3 @@ impl App { } } } - -struct TerminalColorSchemeDetector; - -#[cfg(feature = "detect-color-scheme")] -impl ColorSchemeDetector for TerminalColorSchemeDetector { - fn should_detect(&self) -> bool { - // Querying the terminal for its colors via OSC 10 / OSC 11 requires "exclusive" access - // since we read/write from the terminal and enable/disable raw mode. - // This causes race conditions with pagers such as less when they are attached to the - // same terminal as us. - // - // This is usually only an issue when the output is manually piped to a pager. - // For example: `bat Cargo.toml | less`. - // Otherwise, if we start the pager ourselves, then there's no race condition - // since the pager is started *after* the color is detected. - std::io::stdout().is_terminal() - } - - fn detect(&self) -> Option { - use terminal_colorsaurus::{color_scheme, QueryOptions}; - let colors = color_scheme(QueryOptions::default()).ok()?; - if colors.is_light_on_dark() { - Some(ColorScheme::Dark) - } else { - Some(ColorScheme::Light) - } - } -} - -#[cfg(not(feature = "detect-color-scheme"))] -impl ColorSchemeDetector for TerminalColorSchemeDetector { - fn should_detect(&self) -> bool { - false - } - - fn detect(&self) -> Option { - None - } -} diff --git a/src/theme.rs b/src/theme.rs index 53477939..ab326049 100644 --- a/src/theme.rs +++ b/src/theme.rs @@ -1,35 +1,13 @@ +//! Utilities for choosing an appropriate theme for syntax highlighting. + use std::convert::Infallible; +use std::io::IsTerminal as _; use std::str::FromStr; /// Chooses an appropriate theme or falls back to a default theme /// based on the user-provided options and the color scheme of the terminal. -pub fn theme(options: ThemeOptions, detector: &dyn ColorSchemeDetector) -> String { - // Implementation note: This function is mostly pure (i.e. it has no side effects) for the sake of testing. - // All the side effects (e.g. querying the terminal for its colors) are performed in the detector. - if let Some(theme) = options.theme { - theme.into_theme(ColorScheme::default()) - } else { - let color_scheme = detect(options.detect_color_scheme, detector).unwrap_or_default(); - choose_theme(options, color_scheme) - .map(|t| t.into_theme(color_scheme)) - .unwrap_or_else(|| default_theme(color_scheme).to_owned()) - } -} - -fn choose_theme(options: ThemeOptions, color_scheme: ColorScheme) -> Option { - match color_scheme { - ColorScheme::Dark => options.theme_dark, - ColorScheme::Light => options.theme_light, - } -} - -fn detect(when: DetectColorScheme, detector: &dyn ColorSchemeDetector) -> Option { - let should_detect = match when { - DetectColorScheme::Auto => detector.should_detect(), - DetectColorScheme::Always => true, - DetectColorScheme::Never => false, - }; - should_detect.then(|| detector.detect()).flatten() +pub fn theme(options: ThemeOptions) -> String { + theme_from_detector(options, &TerminalColorSchemeDetector) } /// The default theme, suitable for the given color scheme. @@ -42,6 +20,7 @@ pub const fn default_theme(color_scheme: ColorScheme) -> &'static str { } /// Options for configuring the theme used for syntax highlighting. +/// Used together with [`theme`]. #[derive(Debug, Default)] pub struct ThemeOptions { /// Always use this theme regardless of the terminal's background color. @@ -50,7 +29,7 @@ pub struct ThemeOptions { pub theme_dark: Option, /// The theme to use in case the terminal uses a light background with dark text. pub theme_light: Option, - /// Detect whether or not the terminal is dark or light by querying for its colors. + /// Whether or not to test if the terminal is dark or light by querying for its colors. pub detect_color_scheme: DetectColorScheme, } @@ -84,7 +63,7 @@ impl ThemeRequest { #[derive(Clone, Copy, Debug, Default, PartialEq, Eq)] pub enum DetectColorScheme { - /// Only query the terminal for its colors when appropriate (e.g. when the the output is not redirected). + /// Only query the terminal for its colors when appropriate (i.e. when the the output is not redirected). #[default] Auto, /// Always query the terminal for its colors. @@ -101,12 +80,80 @@ pub enum ColorScheme { Light, } -pub trait ColorSchemeDetector { +fn theme_from_detector(options: ThemeOptions, detector: &dyn ColorSchemeDetector) -> String { + // Implementation note: This function is mostly pure (i.e. it has no side effects) for the sake of testing. + // All the side effects (e.g. querying the terminal for its colors) are performed in the detector. + if let Some(theme) = options.theme { + theme.into_theme(ColorScheme::default()) + } else { + let color_scheme = detect(options.detect_color_scheme, detector).unwrap_or_default(); + choose_theme(options, color_scheme) + .map(|t| t.into_theme(color_scheme)) + .unwrap_or_else(|| default_theme(color_scheme).to_owned()) + } +} + +fn choose_theme(options: ThemeOptions, color_scheme: ColorScheme) -> Option { + match color_scheme { + ColorScheme::Dark => options.theme_dark, + ColorScheme::Light => options.theme_light, + } +} + +fn detect(when: DetectColorScheme, detector: &dyn ColorSchemeDetector) -> Option { + let should_detect = match when { + DetectColorScheme::Auto => detector.should_detect(), + DetectColorScheme::Always => true, + DetectColorScheme::Never => false, + }; + should_detect.then(|| detector.detect()).flatten() +} + +trait ColorSchemeDetector { fn should_detect(&self) -> bool; fn detect(&self) -> Option; } +struct TerminalColorSchemeDetector; + +#[cfg(feature = "detect-color-scheme")] +impl ColorSchemeDetector for TerminalColorSchemeDetector { + fn should_detect(&self) -> bool { + // Querying the terminal for its colors via OSC 10 / OSC 11 requires "exclusive" access + // since we read/write from the terminal and enable/disable raw mode. + // This causes race conditions with pagers such as less when they are attached to the + // same terminal as us. + // + // This is usually only an issue when the output is manually piped to a pager. + // For example: `bat Cargo.toml | less`. + // Otherwise, if we start the pager ourselves, then there's no race condition + // since the pager is started *after* the color is detected. + std::io::stdout().is_terminal() + } + + fn detect(&self) -> Option { + use terminal_colorsaurus::{color_scheme, QueryOptions}; + let colors = color_scheme(QueryOptions::default()).ok()?; + if colors.is_light_on_dark() { + Some(ColorScheme::Dark) + } else { + Some(ColorScheme::Light) + } + } +} + +#[cfg(not(feature = "detect-color-scheme"))] +impl ColorSchemeDetector for TerminalColorSchemeDetector { + fn should_detect(&self) -> bool { + false + } + + fn detect(&self) -> Option { + None + } +} + #[cfg(test)] impl ColorSchemeDetector for Option { fn should_detect(&self) -> bool { @@ -136,7 +183,7 @@ mod tests { detect_color_scheme: Never, ..Default::default() }; - _ = theme(options, &detector); + _ = theme_from_detector(options, &detector); assert!(!detector.was_called.get()); } @@ -151,7 +198,7 @@ mod tests { detect_color_scheme: Always, ..Default::default() }; - _ = theme(options, &detector); + _ = theme_from_detector(options, &detector); assert!(detector.was_called.get()); } } @@ -159,14 +206,14 @@ mod tests { #[test] fn called_for_auto_if_should_detect() { let detector = DetectorStub::should_detect(Some(Dark)); - _ = theme(ThemeOptions::default(), &detector); + _ = theme_from_detector(ThemeOptions::default(), &detector); assert!(detector.was_called.get()); } #[test] fn not_called_for_auto_if_not_should_detect() { let detector = DetectorStub::should_not_detect(); - _ = theme(ThemeOptions::default(), &detector); + _ = theme_from_detector(ThemeOptions::default(), &detector); assert!(!detector.was_called.get()); } } @@ -190,7 +237,7 @@ mod tests { }, ] { let detector = ConstantDetector(color_scheme); - assert_eq!("Theme", theme(options, &detector)); + assert_eq!("Theme", theme_from_detector(options, &detector)); } } } @@ -202,7 +249,7 @@ mod tests { ..Default::default() }; let detector = DetectorStub::should_detect(Some(Dark)); - _ = theme(options, &detector); + _ = theme_from_detector(options, &detector); assert!(!detector.was_called.get()); } } @@ -215,7 +262,7 @@ mod tests { let detector = ConstantDetector(None); assert_eq!( default_theme(ColorScheme::Dark), - theme(ThemeOptions::default(), &detector) + theme_from_detector(ThemeOptions::default(), &detector) ); } @@ -229,7 +276,10 @@ mod tests { ..Default::default() }; let detector = ConstantDetector(color_scheme); - assert_eq!(default_theme(ColorScheme::Dark), theme(options, &detector)); + assert_eq!( + default_theme(ColorScheme::Dark), + theme_from_detector(options, &detector) + ); } } @@ -245,7 +295,10 @@ mod tests { }, ] { let detector = ConstantDetector(Some(color_scheme)); - assert_eq!(default_theme(color_scheme), theme(options, &detector)); + assert_eq!( + default_theme(color_scheme), + theme_from_detector(options, &detector) + ); } } } @@ -263,7 +316,7 @@ mod tests { ..Default::default() }; let detector = ConstantDetector(color_scheme); - assert_eq!("Dark", theme(options, &detector)); + assert_eq!("Dark", theme_from_detector(options, &detector)); } } @@ -275,7 +328,7 @@ mod tests { ..Default::default() }; let detector = ConstantDetector(Some(ColorScheme::Light)); - assert_eq!("Light", theme(options, &detector)); + assert_eq!("Light", theme_from_detector(options, &detector)); } }