Add --width and --max-width options

This patch adds the --width option to select a fixed output width and
the --max-width to set a maximum output width if the width is
dynamically set using the terminal size.

CHANGELOG.md

@@ -19,6 +19,8 @@ SPDX-License-Identifier: MIT
     configuration file can be used to set defaults for the command-line
     options.
   - Add the `--config-file [file]` option to set a custom configuration file.
+- Add the `--width [width]` option to set a fixed output width and the
+  `--max-width [max]` option to set the maximum output width.
 - Improve line break rendering when displaying code.
 - Add integration test suite.
 

src/args.rs

@@ -96,6 +96,21 @@ pub struct ViewerArgs {
     /// Default value: base16-eighties.dark.
     #[structopt(long)]
     pub theme: Option<String>,
+
+    /// The width of the text output
+    ///
+    /// Per default, rusty-man sets the width of the text output based on the width of the terminal
+    /// with the maximum width given by --max-width.  If this option is set, it uses the given
+    /// width instead.
+    #[structopt(long)]
+    pub width: Option<usize>,
+
+    /// The maximum width of the text output
+    ///
+    /// Unless the --width option is set, rusty-man sets the width of the text output based on the
+    /// width of the terminal with the maximum width set with this optioj.
+    #[structopt(long, default_value = "100")]
+    pub max_width: usize,
 }
 
 impl Args {

src/viewer/mod.rs

@@ -40,10 +40,12 @@ pub fn get_default() -> Box<dyn Viewer> {
     }
 }
 
-pub fn get_line_length() -> usize {
-    if let Ok((cols, _)) = crossterm::terminal::size() {
-        cmp::min(cols.into(), 100)
+pub fn get_line_length(args: &args::ViewerArgs) -> usize {
+    if let Some(width) = args.width {
+        width
+    } else if let Ok((cols, _)) = crossterm::terminal::size() {
+        cmp::min(cols.into(), args.max_width)
     } else {
-        100
+        args.max_width
     }
 }

src/viewer/text/plain.rs

@@ -21,9 +21,9 @@ struct Decorator {
 }
 
 impl super::Printer for PlainTextRenderer {
-    fn new(_args: args::ViewerArgs) -> anyhow::Result<Self> {
+    fn new(args: args::ViewerArgs) -> anyhow::Result<Self> {
         Ok(Self {
-            line_length: viewer::get_line_length(),
+            line_length: viewer::get_line_length(&args),
         })
     }
 

src/viewer/text/rich.rs

@@ -65,7 +65,7 @@ impl super::Printer for RichTextRenderer {
             .remove(theme_name)
             .with_context(|| format!("Could not find theme {}", theme_name))?;
         Ok(Self {
-            line_length: viewer::get_line_length(),
+            line_length: viewer::get_line_length(&args),
             highlight: !args.no_syntax_highlight,
             syntax_set: syntect::parsing::SyntaxSet::load_defaults_newlines(),
             theme,

tests/output.rs

@@ -38,6 +38,7 @@ fn run(args: &[&str]) -> assert_cmd::assert::Assert {
         .args(&["--no-default-sources", "--source"])
         .arg(dir.path().join("doc"))
         .args(&["--viewer", "plain"])
+        .args(&["--width", "100"])
         .args(args)
         .assert()
 }