Add new style component to separate multiple '--line-range's

src/clap_app.rs

@@ -111,7 +111,7 @@ pub fn build_app(interactive_output: bool) -> ClapApp<'static, 'static> {
                 .validator(|val| {
                     let mut invalid_vals = val.split(',').filter(|style| {
                         !&[
-                            "auto", "full", "plain", "changes", "header", "grid", "numbers",
+                            "auto", "full", "plain", "changes", "header", "grid", "numbers", "snip"
                         ]
                         .contains(style)
                     });
@@ -124,7 +124,7 @@ pub fn build_app(interactive_output: bool) -> ClapApp<'static, 'static> {
                 })
                 .help(
                     "Comma-separated list of style elements to display \
-                     (*auto*, full, plain, changes, header, grid, numbers).",
+                     (*auto*, full, plain, changes, header, grid, numbers, snip).",
                 )
                 .long_help(
                     "Configure which elements (line numbers, file headers, grid \
@@ -134,7 +134,7 @@ pub fn build_app(interactive_output: bool) -> ClapApp<'static, 'static> {
                      pre-defined style ('full'). To set a default style, add the \
                      '--style=\"..\"' option to the configuration file or export the \
                      BAT_STYLE environment variable (e.g.: export BAT_STYLE=\"..\"). \
-                     Possible values: *auto*, full, plain, changes, header, grid, numbers.",
+                     Possible values: *auto*, full, plain, changes, header, grid, numbers, snip.",
                 ),
         )
         .arg(

src/controller.rs

@@ -98,14 +98,29 @@ impl<'b> Controller<'b> {
         let mut line_buffer = Vec::new();
         let mut line_number: usize = 1;
 
+        let mut first_range: bool = true;
+        let mut mid_range: bool = false;
+
         while reader.read_line(&mut line_buffer)? {
             match line_ranges.check(line_number) {
                 RangeCheckResult::OutsideRange => {
                     // Call the printer in case we need to call the syntax highlighter
                     // for this line. However, set `out_of_range` to `true`.
                     printer.print_line(true, writer, line_number, &line_buffer)?;
+                    mid_range = false;
                 }
+
                 RangeCheckResult::InRange => {
+                    if self.config.output_components.snip() {
+                        if first_range {
+                            first_range = false;
+                            mid_range = true;
+                        } else if !mid_range {
+                            mid_range = true;
+                            printer.print_snip(writer)?;
+                        }
+                    }
+
                     printer.print_line(false, writer, line_number, &line_buffer)?;
                 }
                 RangeCheckResult::AfterLastRange => {

src/printer.rs

@@ -32,6 +32,9 @@ use crate::terminal::{as_terminal_escaped, to_ansi_color};
 pub trait Printer {
     fn print_header(&mut self, handle: &mut dyn Write, file: InputFile) -> Result<()>;
     fn print_footer(&mut self, handle: &mut dyn Write) -> Result<()>;
+
+    fn print_snip(&mut self, handle: &mut dyn Write) -> Result<()>;
+
     fn print_line(
         &mut self,
         out_of_range: bool,
@@ -58,6 +61,10 @@ impl Printer for SimplePrinter {
         Ok(())
     }
 
+    fn print_snip(&mut self, _handle: &mut Write) -> Result<()> {
+        Ok(())
+    }
+
     fn print_line(
         &mut self,
         out_of_range: bool,
@@ -182,6 +189,24 @@ impl<'a> InteractivePrinter<'a> {
         Ok(())
     }
 
+    fn create_fake_panel(&self, text: &str) -> String {
+        if self.panel_width == 0 {
+            "".to_string()
+        } else {
+            let text_truncated: String = text.chars().take(self.panel_width - 1).collect();
+            let text_filled: String = format!(
+                "{}{}",
+                text_truncated,
+                " ".repeat(self.panel_width - 1 - text_truncated.len())
+            );
+            if self.config.output_components.grid() {
+                format!("{} │ ", text_filled)
+            } else {
+                format!("{}", text_filled)
+            }
+        }
+    }
+
     fn preprocess(&self, text: &str, cursor: &mut usize) -> String {
         if self.config.tab_width > 0 {
             expand_tabs(text, self.config.tab_width, cursor)
@@ -271,6 +296,31 @@ impl<'a> Printer for InteractivePrinter<'a> {
         }
     }
 
+    fn print_snip(&mut self, handle: &mut Write) -> Result<()> {
+        let panel = self.create_fake_panel(" ...");
+        let panel_count = panel.chars().count();
+
+        let title = "8<";
+        let title_count = title.chars().count();
+
+        let snip_left =
+            "─ ".repeat((self.config.term_width - panel_count - (title_count / 2)) / 4);
+        let snip_left_count = snip_left.chars().count(); // Can't use .len() with Unicode.
+
+        let snip_right = " ─"
+            .repeat((self.config.term_width - panel_count - snip_left_count - title_count) / 2);
+
+        write!(
+            handle,
+            "{}\n",
+            self.colors
+                .grid
+                .paint(format!("{}{}{}{}", panel, snip_left, title, snip_right))
+        )?;
+
+        Ok(())
+    }
+
     fn print_line(
         &mut self,
         out_of_range: bool,

src/style.rs

@@ -10,6 +10,7 @@ pub enum OutputComponent {
     Grid,
     Header,
     Numbers,
+    Snip,
     Full,
     Plain,
 }
@@ -34,11 +35,13 @@ impl OutputComponent {
             OutputComponent::Grid => &[OutputComponent::Grid],
             OutputComponent::Header => &[OutputComponent::Header],
             OutputComponent::Numbers => &[OutputComponent::Numbers],
+            OutputComponent::Snip => &[OutputComponent::Snip],
             OutputComponent::Full => &[
                 OutputComponent::Changes,
                 OutputComponent::Grid,
                 OutputComponent::Header,
                 OutputComponent::Numbers,
+                OutputComponent::Snip,
             ],
             OutputComponent::Plain => &[],
         }
@@ -55,6 +58,7 @@ impl FromStr for OutputComponent {
             "grid" => Ok(OutputComponent::Grid),
             "header" => Ok(OutputComponent::Header),
             "numbers" => Ok(OutputComponent::Numbers),
+            "snip" => Ok(OutputComponent::Snip),
             "full" => Ok(OutputComponent::Full),
             "plain" => Ok(OutputComponent::Plain),
             _ => Err(format!("Unknown style '{}'", s).into()),
@@ -82,6 +86,10 @@ impl OutputComponents {
         self.0.contains(&OutputComponent::Numbers)
     }
 
+    pub fn snip(&self) -> bool {
+        self.0.contains(&OutputComponent::Snip)
+    }
+
     pub fn plain(&self) -> bool {
         self.0.iter().all(|c| c == &OutputComponent::Plain)
     }