Merge pull request #453 from sharkdp/line-highlight

Line highlight

src/app.rs

@@ -77,7 +77,11 @@ pub struct Config<'a> {
     /// Command to start the pager
     pub pager: Option<&'a str>,
 
+    /// Whether or not to use ANSI italics
     pub use_italic_text: bool,
+
+    /// Lines to highlight
+    pub highlight_lines: Vec<usize>,
 }
 
 fn is_truecolor_terminal() -> bool {
@@ -264,6 +268,11 @@ impl App {
                 Some("always") => true,
                 _ => false,
             },
+            highlight_lines: self
+                .matches
+                .values_of("highlight-line")
+                .and_then(|ws| ws.map(|w| w.parse().ok()).collect())
+                .unwrap_or_default(),
         })
     }
 

src/clap_app.rs

@@ -175,6 +175,7 @@ pub fn build_app(interactive_output: bool) -> ClapApp<'static, 'static> {
         .arg(
             Arg::with_name("line-range")
                 .long("line-range")
+                .short("r")
                 .multiple(true)
                 .takes_value(true)
                 .number_of_values(1)
@@ -188,6 +189,19 @@ pub fn build_app(interactive_output: bool) -> ClapApp<'static, 'static> {
                      '--line-range 40:' prints lines 40 to the end of the file",
                 ),
         )
+        .arg(
+            Arg::with_name("highlight-line")
+                .long("highlight-line")
+                .short("H")
+                .takes_value(true)
+                .number_of_values(1)
+                .multiple(true)
+                .value_name("N")
+                .help("Highlight the given line.")
+                .long_help(
+                    "Highlight the N-th line with a different background color",
+                ),
+        )
         .arg(
             Arg::with_name("color")
                 .long("color")

src/printer.rs

@@ -7,6 +7,7 @@ use ansi_term::Style;
 use console::AnsiCodeIterator;
 
 use syntect::easy::HighlightLines;
+use syntect::highlighting::Color;
 use syntect::highlighting::Theme;
 use syntect::parsing::SyntaxSet;
 
@@ -79,6 +80,7 @@ pub struct InteractivePrinter<'a> {
     pub line_changes: Option<LineChanges>,
     highlighter: Option<HighlightLines<'a>>,
     syntax_set: &'a SyntaxSet,
+    background_color_highlight: Option<Color>,
 }
 
 impl<'a> InteractivePrinter<'a> {
@@ -90,6 +92,8 @@ impl<'a> InteractivePrinter<'a> {
     ) -> Self {
         let theme = assets.get_theme(&config.theme);
 
+        let background_color_highlight = theme.settings.line_highlight;
+
         let colors = if config.colored_output {
             Colors::colored(theme, config.true_color)
         } else {
@@ -156,6 +160,7 @@ impl<'a> InteractivePrinter<'a> {
             line_changes,
             highlighter,
             syntax_set: &assets.syntax_set,
+            background_color_highlight,
         }
     }
 
@@ -287,6 +292,17 @@ impl<'a> Printer for InteractivePrinter<'a> {
         let mut cursor_total: usize = 0;
         let mut panel_wrap: Option<String> = None;
 
+        // Line highlighting
+        let highlight_this_line = self
+            .config
+            .highlight_lines
+            .iter()
+            .any(|&l| l == line_number);
+
+        let background_color = self
+            .background_color_highlight
+            .filter(|_| highlight_this_line);
+
         // Line decorations.
         if self.panel_width > 0 {
             let decorations = self
@@ -313,9 +329,29 @@ impl<'a> Printer for InteractivePrinter<'a> {
                 write!(
                     handle,
                     "{}",
-                    as_terminal_escaped(style, text_trimmed, true_color, colored_output, italics,)
+                    as_terminal_escaped(
+                        style,
+                        text_trimmed,
+                        true_color,
+                        colored_output,
+                        italics,
+                        background_color
+                    )
                 )?;
-                write!(handle, "{}", &text[text_trimmed.len()..])?;
+
+                if text.len() != text_trimmed.len() {
+                    if let Some(background_color) = background_color {
+                        let mut ansi_style = Style::default();
+                        ansi_style.background = Some(to_ansi_color(background_color, true_color));
+                        let width = if cursor_total <= cursor_max {
+                            cursor_max - cursor_total + 1
+                        } else {
+                            0
+                        };
+                        write!(handle, "{}", ansi_style.paint(" ".repeat(width)))?;
+                    }
+                    write!(handle, "{}", &text[text_trimmed.len()..])?;
+                }
             }
 
             if line.bytes().next_back() != Some(b'\n') {
@@ -370,7 +406,8 @@ impl<'a> Printer for InteractivePrinter<'a> {
                                             ),
                                             self.config.true_color,
                                             self.config.colored_output,
-                                            self.config.use_italic_text
+                                            self.config.use_italic_text,
+                                            background_color
                                         )
                                     )?;
                                     break;
@@ -410,7 +447,8 @@ impl<'a> Printer for InteractivePrinter<'a> {
                                         ),
                                         self.config.true_color,
                                         self.config.colored_output,
-                                        self.config.use_italic_text
+                                        self.config.use_italic_text,
+                                        background_color
                                     ),
                                     panel_wrap.clone().unwrap()
                                 )?;
@@ -423,6 +461,17 @@ impl<'a> Printer for InteractivePrinter<'a> {
                 }
             }
 
+            if let Some(background_color) = background_color {
+                let mut ansi_style = Style::default();
+                ansi_style.background =
+                    Some(to_ansi_color(background_color, self.config.true_color));
+
+                write!(
+                    handle,
+                    "{}",
+                    ansi_style.paint(" ".repeat(cursor_max - cursor))
+                )?;
+            }
             write!(handle, "\n")?;
         }
 

src/terminal.rs

@@ -19,8 +19,9 @@ pub fn as_terminal_escaped(
     true_color: bool,
     colored: bool,
     italics: bool,
+    background_color: Option<highlighting::Color>,
 ) -> String {
-    let style = if !colored {
+    let mut style = if !colored {
         Style::default()
     } else {
         let color = to_ansi_color(style.foreground, true_color);
@@ -36,5 +37,6 @@ pub fn as_terminal_escaped(
         }
     };
 
+    style.background = background_color.map(|c| to_ansi_color(c, true_color));
     style.paint(text).to_string()
 }