style: add component 'rule' for horizontal file delimiter

src/bin/bat/clap_app.rs

@@ -367,7 +367,7 @@ pub fn build_app(interactive_output: bool) -> ClapApp<'static, 'static> {
                 .validator(|val| {
                     let mut invalid_vals = val.split(',').filter(|style| {
                         !&[
-                            "auto", "full", "plain", "header", "grid", "numbers", "snip",
+                            "auto", "full", "plain", "header", "grid", "rule", "numbers", "snip",
                             #[cfg(feature = "git")]
                                 "changes",
                         ]
@@ -382,7 +382,7 @@ 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, snip).",
+                     (*auto*, full, plain, changes, header, grid, rule, numbers, snip).",
                 )
                 .long_help(
                     "Configure which elements (line numbers, file headers, grid \
@@ -400,6 +400,7 @@ pub fn build_app(interactive_output: bool) -> ClapApp<'static, 'static> {
                      * header: show filenames before the content.\n  \
                      * grid: vertical/horizontal lines to separate side bar\n          \
                        and the header from the content.\n  \
+                     * rule: horizontal lines to delimit files.\n  \
                      * numbers: show line numbers in the side bar.\n  \
                      * snip: draw separation lines between distinct line ranges.",
                 ),

src/pretty_printer.rs

@@ -23,6 +23,7 @@ struct ActiveStyleComponents {
     header: bool,
     vcs_modification_markers: bool,
     grid: bool,
+    rule: bool,
     line_numbers: bool,
     snip: bool,
 }
@@ -179,6 +180,12 @@ impl<'a> PrettyPrinter<'a> {
         self
     }
 
+    /// Whether to paint a horizontal rule to delimit files
+    pub fn rule(&mut self, yes: bool) -> &mut Self {
+        self.active_style_components.rule = yes;
+        self
+    }
+
     /// Whether to show modification markers for VCS changes. This has no effect if
     /// the `git` feature is not activated.
     #[cfg_attr(
@@ -285,6 +292,9 @@ impl<'a> PrettyPrinter<'a> {
         if self.active_style_components.grid {
             style_components.push(StyleComponent::Grid);
         }
+        if self.active_style_components.rule {
+            style_components.push(StyleComponent::Rule);
+        }
         if self.active_style_components.header {
             style_components.push(StyleComponent::Header);
         }

src/printer.rs

@@ -200,13 +200,18 @@ impl<'a> InteractivePrinter<'a> {
         })
     }
 
+    fn print_horizontal_line_term(&mut self, handle: &mut dyn Write, style: Style) -> Result<()> {
+        writeln!(
+            handle,
+            "{}",
+            style.paint("─".repeat(self.config.term_width))
+        )?;
+        Ok(())
+    }
+
     fn print_horizontal_line(&mut self, handle: &mut dyn Write, grid_char: char) -> Result<()> {
         if self.panel_width == 0 {
-            writeln!(
-                handle,
-                "{}",
-                self.colors.grid.paint("─".repeat(self.config.term_width))
-            )?;
+            self.print_horizontal_line_term(handle, self.colors.grid)?;
         } else {
             let hline = "─".repeat(self.config.term_width - (self.panel_width + 1));
             let hline = format!("{}{}{}", "─".repeat(self.panel_width), grid_char, hline);
@@ -251,6 +256,10 @@ impl<'a> Printer for InteractivePrinter<'a> {
         input: &OpenedInput,
         add_header_padding: bool,
     ) -> Result<()> {
+        if add_header_padding && self.config.style_components.rule() {
+            self.print_horizontal_line_term(handle, self.colors.rule)?;
+        }
+
         if !self.config.style_components.header() {
             if Some(ContentType::BINARY) == self.content_type && !self.config.show_nonprintable {
                 writeln!(
@@ -279,7 +288,8 @@ impl<'a> Printer for InteractivePrinter<'a> {
                     .paint(if self.panel_width > 0 { "│ " } else { "" }),
             )?;
         } else {
-            if add_header_padding {
+            // Only pad space between files, if we haven't already drawn a horizontal rule
+            if add_header_padding && !self.config.style_components.rule() {
                 writeln!(handle)?;
             }
             write!(handle, "{}", " ".repeat(self.panel_width))?;
@@ -603,6 +613,7 @@ const DEFAULT_GUTTER_COLOR: u8 = 238;
 #[derive(Debug, Default)]
 pub struct Colors {
     pub grid: Style,
+    pub rule: Style,
     pub filename: Style,
     pub git_added: Style,
     pub git_removed: Style,
@@ -624,6 +635,7 @@ impl Colors {
 
         Colors {
             grid: gutter_color.normal(),
+            rule: gutter_color.normal(),
             filename: Style::new().bold(),
             git_added: Green.normal(),
             git_removed: Red.normal(),

src/style.rs

@@ -9,6 +9,7 @@ pub enum StyleComponent {
     #[cfg(feature = "git")]
     Changes,
     Grid,
+    Rule,
     Header,
     LineNumbers,
     Snip,
@@ -29,6 +30,7 @@ impl StyleComponent {
             #[cfg(feature = "git")]
             StyleComponent::Changes => &[StyleComponent::Changes],
             StyleComponent::Grid => &[StyleComponent::Grid],
+            StyleComponent::Rule => &[StyleComponent::Rule],
             StyleComponent::Header => &[StyleComponent::Header],
             StyleComponent::LineNumbers => &[StyleComponent::LineNumbers],
             StyleComponent::Snip => &[StyleComponent::Snip],
@@ -54,6 +56,7 @@ impl FromStr for StyleComponent {
             #[cfg(feature = "git")]
             "changes" => Ok(StyleComponent::Changes),
             "grid" => Ok(StyleComponent::Grid),
+            "rule" => Ok(StyleComponent::Rule),
             "header" => Ok(StyleComponent::Header),
             "numbers" => Ok(StyleComponent::LineNumbers),
             "snip" => Ok(StyleComponent::Snip),
@@ -81,6 +84,10 @@ impl StyleComponents {
         self.0.contains(&StyleComponent::Grid)
     }
 
+    pub fn rule(&self) -> bool {
+        self.0.contains(&StyleComponent::Rule)
+    }
+
     pub fn header(&self) -> bool {
         self.0.contains(&StyleComponent::Header)
     }