Make decorations respect --width

Fixes #61
Fixes #155

3 files changed, 25 insertions, 16 deletions

diff --git a/src/cli.rs b/src/cli.rs
index fc841598..3c3bdd6d 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -1,6 +1,5 @@
 use std::process;
 
-use console::Term;
 use structopt::clap::AppSettings::{ColorAlways, ColoredHelp, DeriveDisplayOrder};
 use structopt::StructOpt;
 
@@ -310,12 +309,6 @@ pub fn process_command_line_arguments<'a>(mut opt: Opt) -> config::Config<'a> {
 
     rewrite::apply_rewrite_rules(&mut opt);
 
-    // We do not use the full width, in case `less --status-column` is in effect. See #41 and #10.
-    // TODO: There seems to be some confusion in the accounting: we are actually leaving 2
-    // characters unused for less at the right edge of the terminal, despite the subtraction of 1
-    // here.
-    let available_terminal_width = (Term::stdout().size().1 - 1) as usize;
-
     let paging_mode = match opt.paging_mode.as_ref() {
         "always" => PagingMode::Always,
         "never" => PagingMode::Never,
@@ -347,7 +340,6 @@ pub fn process_command_line_arguments<'a>(mut opt: Opt) -> config::Config<'a> {
         assets.syntax_set,
         assets.theme_set,
         true_color,
-        available_terminal_width,
         paging_mode,
     )
 }
diff --git a/src/config.rs b/src/config.rs
index 7706679b..e986f478 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -1,3 +1,7 @@
+use std::cmp::min;
+use std::process;
+
+use console::Term;
 use syntect::highlighting::Style as SyntectStyle;
 use syntect::highlighting::{Theme, ThemeSet};
 use syntect::parsing::SyntaxSet;
@@ -29,7 +33,7 @@ pub struct Config<'a> {
     pub file_style: Style,
     pub hunk_header_style: Style,
     pub syntax_set: SyntaxSet,
-    pub terminal_width: usize,
+    pub decorations_width: usize,
     pub true_color: bool,
     pub background_color_extends_to_terminal_width: bool,
     pub tab_width: usize,
@@ -55,10 +59,23 @@ pub fn get_config<'a>(
     syntax_set: SyntaxSet,
     theme_set: ThemeSet,
     true_color: bool,
-    terminal_width: usize,
     paging_mode: PagingMode,
 ) -> Config<'a> {
-    let background_color_extends_to_terminal_width = opt.width != Some("variable".to_string());
+    // Allow one character for e.g. `less --status-column` is in effect. See #41 and #10.
+    let available_terminal_width = (Term::stdout().size().1 - 1) as usize;
+    let (decorations_width, background_color_extends_to_terminal_width) = match opt.width.as_deref()
+    {
+        Some("variable") => (available_terminal_width, false),
+        Some(width) => {
+            let width = width.parse().unwrap_or_else(|_| {
+                eprintln!("Could not parse width as a positive integer: {:?}", width);
+                process::exit(1);
+            });
+            (min(width, available_terminal_width), true)
+        }
+        None => (available_terminal_width, true),
+    };
+
     let theme_name_from_bat_pager = env::get_env_var("BAT_THEME");
     let (is_light_mode, theme_name) = theme::get_is_light_mode_and_theme_name(
         opt.theme.as_ref(),
@@ -122,7 +139,7 @@ pub fn get_config<'a>(
         file_style,
         hunk_header_style,
         true_color,
-        terminal_width,
+        decorations_width,
         background_color_extends_to_terminal_width,
         tab_width: opt.tab_width,
         syntax_set,
diff --git a/src/delta.rs b/src/delta.rs
index 34d66d54..1554cb9a 100644
--- a/src/delta.rs
+++ b/src/delta.rs
@@ -226,7 +226,7 @@ fn handle_commit_meta_header_line(
         painter.writer,
         &format!("{}{}", line, if pad { " " } else { "" }),
         &format!("{}{}", raw_line, if pad { " " } else { "" }),
-        config.terminal_width,
+        config.decorations_width,
         config.commit_style,
         decoration_ansi_term_style,
     )?;
@@ -286,7 +286,7 @@ fn handle_generic_file_meta_header_line(
         painter.writer,
         &format!("{}{}", line, if pad { " " } else { "" }),
         &format!("{}{}", raw_line, if pad { " " } else { "" }),
-        config.terminal_width,
+        config.decorations_width,
         config.file_style,
         decoration_ansi_term_style,
     )?;
@@ -332,7 +332,7 @@ fn handle_hunk_header_line(
             painter.writer,
             &format!("{} ", line),
             &format!("{} ", raw_line),
-            config.terminal_width,
+            config.decorations_width,
             config.hunk_header_style,
             decoration_ansi_term_style,
         )?;
@@ -365,7 +365,7 @@ fn handle_hunk_header_line(
                 painter.writer,
                 &painter.output_buffer,
                 &painter.output_buffer,
-                config.terminal_width,
+                config.decorations_width,
                 config.hunk_header_style,
                 decoration_ansi_term_style,
             )?;