• Use std::io::IsTerminal rather than the external atty crate.

Released 2026-03-07

• Updated terminal_size dependency.

Released 2025-10-05

• Breaking change: Render no longer has a blanket implementation for Display: you can no longer use a string, integer, or some object that implements Display as a model directly. You can instead implement Render explicitly, or opt in to this behavior using the new nutmeg::models::DisplayModel.

  It seems that the Display implementation is often not a very satisfactory progress bar, and the presence of the blanket implementation causes confusing error messages when Render is not implemented correctly.

• Change back to std::sync::Mutex from parking_lot, to keep dependencies smaller.

• When painting multi-line progress, clear to the end of each line as it's painted, rather than previously clearing to the end of the screen. This reduces flickering on large multi-line progress bars.

Released 2023-09-23

• New: Support and documentation for sending tracing updates through a Nutmeg view.

• New: View::new is now const, so that a static view can be constructed in a global variable: you no longer need to wrap them in an Arc. See examples/static_view.

Released 2023-05-24

• New: [View::clear] temporarily removes the progress view if it is drawn, but allows it to pop back when the model is next updated.

• New: [Options] can be constructed as a static value: there's a new const fn [Options::new] constructor and the functions to set fields are also const.

• New: [View::message_bytes] as a convenience for callers who already have a [u8] or Bytes or similar.

Released 2022-07-27

• API change: Removed View::new_stderr and View::write_to. Instead, the view can be drawn on stderr or output can be captured using [Options::destination]. This is better aligned with the idea that programs might have a central function that constructs a [Options], as they will probably want to consistently write to either stdout or stderr.

• New: Output can be captured for inspection in tests using [Options::destination], [Destination::Capture], and [View::captured_output].

• Improved: Nutmeg avoids redrawing if the model renders identical output to what is already displayed, to avoid flicker.

Released 2022-03-22

• API change: [View::message] takes the message as an AsRef<str>, meaning it may be either a &str or String. This makes the common case where the message is the result of format! a little easier.

Released 2022-03-22

• API change: The "Write" type representing the destination is no longer part of the visible public signature of [View], to hide complexity and since it is not helpful to most callers.

• API change: Renamed View::to_stderr to View::new_stderr.

• New: [percent_done] and [estimate_remaining] functions to help in rendering progress bars.

• New: The [models] mod provides some generally-useful basic models, specifically [models::StringPair], [models::UnboundedModel] and [models::LinearModel]. These build only on the public interface of Nutmeg, so also constitute examples of what can be done in application-defined models.

• New: [View::finish] removes the progress bar (if painted) and returns the [Model]. [View::abandon] now also returns the model.

• New: [Model::final_message] to let the model render a message to be printed when work is complete.

• New: The callback to [View::update] may return a value, and this is passed back to the caller of [View::update].

• New: [models::BasicModel] allows simple cases to supply both an initial value and a render function inline in the [View] constructor call, avoiding any need to define a [Model] struct.

• New: [View::inspect_model] gives its callback a &mut to the model.

• New: Progress bars constructed by [View::new] and View::new_stderr are disabled when $TERM=dumb.

Released 2022-03-07

• API change: Renamed nutmeg::ViewOptions to just nutmeg::Options.

• Fixed: A bug that caused leftover text when multi-line bars shrink in width.

• Fixed: The output from bars created with [View::new] and View::to_stderr in Rust tests is captured with the test output rather than leaking through to cargo's output.

• New method [View::message] to print a message to the terminal, as an alternative to using write!().

• New example/multithreaded.rs showing how a View and Model can be shared across threads.

• Rate-limit updates to the terminal, controlled by ViewOptions::update_interval and ViewOptions::print_holdoff.

• Fix a bug where the bar was sometimes not correctly erased by [View::suspend].

• Change to parking_lot mutexes in the implementation.

• The application has complete control of styling, including coloring etc.
• Draw and erase progress bars.
• Write messages "under" the progress bar with writeln!(view, ...). The bar is automatically suspended and restored. If the message has no final newline, the bar remains suspended until the line is completed.