More colors!

The user_choice() function was a bit weird because it needed a
"formatted" item for every item to select (not using the Display of the
item), but it also didn't support colored output. This change fixes that
by introducing a new trait that does colored output and by making
user_choice() use that trait to output the lines.

4 files changed, 74 insertions, 23 deletions

diff --git a/src/fancyfmt.rs b/src/fancyfmt.rs
new file mode 100644
index 0000000..6c631b3
--- /dev/null
+++ b/src/fancyfmt.rs
@@ -0,0 +1,55 @@
+//! This module provides some methods for "fancily" formatting data.
+//!
+//! This mainly exists so that we can have a version of [`std::fmt::Display`] that can use the
+//! colors provided by [`termcolor`].
+use std::io::Write;
+
+use anyhow::Result;
+use modderbaas::{contentdb::ContentMeta, World};
+use termcolor::{Color, ColorSpec, StandardStream, WriteColor};
+
+/// A trait for objects to output them to a (possibly) colored stream.
+pub trait ColoredDisplay {
+    /// Output the object to the colored stream.
+    fn fmt(&self, output: &mut StandardStream) -> Result<()>;
+}
+
+impl<T: ColoredDisplay> ColoredDisplay for &T {
+    fn fmt(&self, output: &mut StandardStream) -> Result<()> {
+        (*self).fmt(output)
+    }
+}
+
+impl ColoredDisplay for &str {
+    fn fmt(&self, output: &mut StandardStream) -> Result<()> {
+        write!(output, "{}", *self)?;
+        Ok(())
+    }
+}
+
+impl ColoredDisplay for String {
+    fn fmt(&self, output: &mut StandardStream) -> Result<()> {
+        (self as &str).fmt(output)
+    }
+}
+
+impl ColoredDisplay for World {
+    fn fmt(&self, output: &mut StandardStream) -> Result<()> {
+        write!(output, "{}", self)?;
+        Ok(())
+    }
+}
+
+impl ColoredDisplay for ContentMeta {
+    fn fmt(&self, output: &mut StandardStream) -> Result<()> {
+        output.set_color(ColorSpec::new().set_fg(Some(Color::Yellow)))?;
+        write!(output, "{}", self.title)?;
+        output.reset()?;
+        write!(output, " by ")?;
+        output.set_color(ColorSpec::new().set_fg(Some(Color::Cyan)))?;
+        write!(output, "{}", self.author)?;
+        output.reset()?;
+        write!(output, " - {}", self.short_description)?;
+        Ok(())
+    }
+}
diff --git a/src/install.rs b/src/install.rs
index 56754d3..e34ffc3 100644
--- a/src/install.rs
+++ b/src/install.rs
@@ -69,21 +69,12 @@ impl<'o, 'p> Installer for InteractiveInstaller<'o, 'p> {
         } else if candidates.len() == 1 {
             Ok(Source::Http(candidates.into_iter().next().unwrap().url))
         } else {
-            let items = candidates
-                .into_iter()
-                .map(|c| {
-                    (
-                        format!("{} by {} - {}", c.title, c.author, c.short_description),
-                        c,
-                    )
-                })
-                .collect::<Vec<_>>();
             writeln!(
                 &mut self.output,
                 "{} candidates found, please select one:",
-                items.len()
+                candidates.len()
             )?;
-            let candidate = user_choice(&items, self.output)?;
+            let candidate = user_choice(&candidates, self.output)?;
             Ok(Source::Http(candidate.url.clone()))
         }
     }
diff --git a/src/main.rs b/src/main.rs
index 5390479..20e8653 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -8,6 +8,8 @@ use termcolor::{Color, ColorChoice, ColorSpec, StandardStream, WriteColor};
 
 use modderbaas::{baas::Baas, MineMod, Snapshot, World};
 
+mod fancyfmt;
+
 mod uiutil;
 use uiutil::{ask_continue, user_choice};
 
@@ -137,8 +139,11 @@ fn select_world(
     }
 
     // Here, we cannot do an automatic selection, so ask the user:
-    let mut worlds = worlds.iter().collect::<Vec<_>>();
-    worlds.sort_by_key(|i| i.0);
+    let worlds = worlds
+        .iter()
+        .sorted_by_key(|i| i.0)
+        .map(|i| i.1)
+        .collect::<Vec<_>>();
     writeln!(
         output,
         "The following worlds were found, please select one:"
diff --git a/src/uiutil.rs b/src/uiutil.rs
index 188e20c..0cc88a9 100644
--- a/src/uiutil.rs
+++ b/src/uiutil.rs
@@ -1,22 +1,22 @@
 //! Utility functions for user interaction.
-use std::{
-    fmt::Display,
-    io::{self, Write},
-};
+use std::io::{self, Write};
 
 use anyhow::{bail, Result};
 use termcolor::{Color, ColorSpec, StandardStream, WriteColor};
 
+use super::fancyfmt::ColoredDisplay;
+
 /// Presents the user with a choice of items and awaits a selection.
-pub fn user_choice<'i, L: Display, I>(
-    items: &'i [(L, I)],
+pub fn user_choice<'i, I: ColoredDisplay>(
+    items: &'i [I],
     output: &mut StandardStream,
 ) -> Result<&'i I> {
-    for (i, (label, _)) in items.iter().enumerate() {
+    for (i, item) in items.iter().enumerate() {
         output.set_color(ColorSpec::new().set_fg(Some(Color::Blue)))?;
-        write!(output, "[{}]", i)?;
+        write!(output, "[{}] ", i)?;
         output.reset()?;
-        writeln!(output, " {}", label)?;
+        item.fmt(output)?;
+        writeln!(output)?;
     }
 
     let stdin = io::stdin();
@@ -27,7 +27,7 @@ pub fn user_choice<'i, L: Display, I>(
         stdin.read_line(&mut buffer)?;
         if let Ok(number) = buffer.trim().parse::<usize>() {
             if number < items.len() {
-                return Ok(&items[number].1);
+                return Ok(&items[number]);
             }
         }
     }