Merge pull request #15 from dandavison/14-no-syntax-highlighting

Support --theme=none

3 files changed, 25 insertions, 13 deletions

diff --git a/src/cli.rs b/src/cli.rs
index ad369eb1..5ec01aa9 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -39,7 +39,7 @@ pub struct Opt {
     pub plus_emph_color: Option<String>,
 
     #[structopt(long = "theme")]
-    /// The syntax highlighting theme to use.
+    /// The syntax highlighting theme to use. Use --theme=none to disable syntax highlighting.
     pub theme: Option<String>,
 
     #[structopt(long = "highlight-removed")]
@@ -135,7 +135,7 @@ pub fn process_command_line_arguments<'a>(
         process::exit(1);
     }
     match &opt.theme {
-        Some(theme) => {
+        Some(theme) if theme.to_lowercase() != "none" => {
             if !assets.theme_set.themes.contains_key(theme.as_str()) {
                 eprintln!("Invalid theme: '{}'", theme);
                 process::exit(1);
@@ -157,7 +157,7 @@ pub fn process_command_line_arguments<'a>(
                 process::exit(1);
             }
         }
-        None => (),
+        _ => (),
     };
 
     let terminal_width = Term::stdout().size().1 as usize;
diff --git a/src/config.rs b/src/config.rs
index 2151b086..e1008676 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -7,7 +7,7 @@ use crate::cli;
 use crate::style;
 
 pub struct Config<'a> {
-    pub theme: &'a Theme,
+    pub theme: Option<&'a Theme>,
     pub theme_name: &'a str,
     pub minus_style_modifier: StyleModifier,
     pub minus_emph_style_modifier: StyleModifier,
@@ -39,7 +39,16 @@ pub fn get_config<'a>(
             }
         }
     };
-    let is_light_theme = style::LIGHT_THEMES.contains(&theme_name);
+    let theme = if theme_name.to_lowercase() == "none" {
+        None
+    } else {
+        Some(&theme_set.themes[theme_name])
+    };
+    let is_light_theme = if theme.is_none() {
+        !opt.dark
+    } else {
+        style::LIGHT_THEMES.contains(&theme_name)
+    };
 
     let minus_style_modifier = StyleModifier {
         background: Some(color_from_arg(
@@ -94,7 +103,7 @@ pub fn get_config<'a>(
     };
 
     Config {
-        theme: &theme_set.themes[theme_name],
+        theme,
         theme_name,
         minus_style_modifier,
         minus_emph_style_modifier,
diff --git a/src/paint.rs b/src/paint.rs
index bf873727..543eef95 100644
--- a/src/paint.rs
+++ b/src/paint.rs
@@ -25,24 +25,27 @@ impl<'a> Painter<'a> {
     pub fn new(
         writer: &'a mut Write,
         config: &'a config::Config,
-        assets: &HighlightingAssets,
+        assets: &'a HighlightingAssets,
     ) -> Self {
+        let dummy_highlighter = HighlightLines::new(
+            assets.syntax_set.find_syntax_by_extension("txt").unwrap(),
+            &assets.theme_set.themes[style::DEFAULT_LIGHT_THEME],
+        );
         Self {
             minus_lines: Vec::new(),
             plus_lines: Vec::new(),
             output_buffer: String::new(),
             syntax: None,
-            highlighter: HighlightLines::new(
-                assets.syntax_set.find_syntax_by_extension("txt").unwrap(),
-                config.theme,
-            ),
+            highlighter: dummy_highlighter,
             writer,
             config,
         }
     }
 
     pub fn reset_highlighter(&mut self) {
-        self.highlighter = HighlightLines::new(self.syntax.unwrap(), self.config.theme);
+        if let Some(theme) = self.config.theme {
+            self.highlighter = HighlightLines::new(self.syntax.unwrap(), theme)
+        };
     }
 
     pub fn paint_buffered_lines(&mut self) {
@@ -165,7 +168,7 @@ impl<'a> Painter<'a> {
         config: &config::Config,
         should_syntax_highlight: bool,
     ) -> Vec<(Style, &'a str)> {
-        if should_syntax_highlight {
+        if should_syntax_highlight && config.theme.is_some() {
             highlighter.highlight(line, &config.syntax_set)
         } else {
             vec![(config.no_style, line)]