feat(download_tracker): use the custom ColorableTerminal and respect related env vars

With this commit, `RUSTUP_TERM_COLOR` and `RUSTUP_PROGRESS_WHEN` are now
being honored.

Author: FranciscoTGouveia

src/cli/download_tracker.rs

@@ -1,9 +1,9 @@
-use indicatif::{ProgressBar, ProgressDrawTarget, ProgressStyle};
+use indicatif::{MultiProgress, ProgressBar, ProgressDrawTarget, ProgressStyle};
 use std::time::Duration;
 
 use crate::dist::Notification as In;
 use crate::notifications::Notification;
-use crate::process::Process;
+use crate::process::{Process, terminalsource::ColorChoice};
 use crate::utils::Notification as Un;
 
 /// Tracks download progress and displays information about it to a terminal.
@@ -14,16 +14,35 @@ pub(crate) struct DownloadTracker {
     /// Whether we display progress or not.
     display_progress: bool,
     stdout_is_a_tty: bool,
-    // Progress bar for the download.
+    /// Whether we display colors or not.
+    use_colors: bool,
+    /// MultiProgress bar for the downloads.
+    multi_progress_bars: MultiProgress,
+    /// ProgressBar for the current download.
     progress_bar: ProgressBar,
 }
 
 impl DownloadTracker {
     /// Creates a new DownloadTracker.
     pub(crate) fn new_with_display_progress(display_progress: bool, process: &Process) -> Self {
+        let t = process.stdout().terminal(process);
+        let is_a_tty = t.is_a_tty();
+        let use_colors = matches!(t.color_choice(), ColorChoice::Auto | ColorChoice::Always);
+        let multi_progress_bars = MultiProgress::with_draw_target(
+            match process.var("RUSTUP_TERM_PROGRESS_WHEN") {
+                Ok(s) if s.eq_ignore_ascii_case("always") => {
+                    ProgressDrawTarget::term_like(Box::new(t))
+                }
+                Ok(s) if s.eq_ignore_ascii_case("never") => ProgressDrawTarget::hidden(),
+                _ if is_a_tty => ProgressDrawTarget::term_like(Box::new(t)),
+                _ => ProgressDrawTarget::hidden(),
+            }
+        );
         Self {
             display_progress,
             stdout_is_a_tty: process.stdout().is_a_tty(process),
+            use_colors,
+            multi_progress_bars,
             progress_bar: ProgressBar::hidden(),
         }
     }
@@ -56,7 +75,11 @@ impl DownloadTracker {
         self.progress_bar.set_length(content_len);
         self.progress_bar.set_style(
             ProgressStyle::with_template(
-                "[{elapsed_precise}] [{bar:40.blue}] {bytes}/{total_bytes} (ETA: {eta})",
+                if self.use_colors {
+                    "[{elapsed_precise}] [{bar:40.blue}] {bytes}/{total_bytes} (ETA: {eta})"
+                } else {
+                    "[{elapsed_precise}] [{bar:40}] {bytes}/{total_bytes} (ETA: {eta})"
+                },
             )
             .unwrap()
             .tick_chars("⠁⠂⠄⡀⢀⠠⠐⠈ "),
@@ -70,15 +93,15 @@ impl DownloadTracker {
             && self.stdout_is_a_tty
             && self.progress_bar.elapsed() >= Duration::from_secs(1)
         {
-            self.progress_bar
-                .set_draw_target(ProgressDrawTarget::stdout());
+            self.multi_progress_bars.add(self.progress_bar.clone());
         }
         self.progress_bar.inc(len as u64);
     }
 
     /// Notifies self that the download has finished.
     pub(crate) fn download_finished(&mut self) {
         self.progress_bar.finish_and_clear();
+        self.multi_progress_bars.remove(&self.progress_bar);
         self.progress_bar = ProgressBar::hidden();
     }
 }