fix: refresh diff colors on terminal theme changes

vendor/crossterm/src/event/filter.rs

@@ -0,0 +1,115 @@
+use crate::event::InternalEvent;
+
+/// Interface for filtering an `InternalEvent`.
+pub(crate) trait Filter: Send + Sync + 'static {
+    /// Returns whether the given event fulfills the filter.
+    fn eval(&self, event: &InternalEvent) -> bool;
+}
+
+#[cfg(unix)]
+#[derive(Debug, Clone)]
+pub(crate) struct CursorPositionFilter;
+
+#[cfg(unix)]
+impl Filter for CursorPositionFilter {
+    fn eval(&self, event: &InternalEvent) -> bool {
+        matches!(*event, InternalEvent::CursorPosition(_, _))
+    }
+}
+
+#[cfg(unix)]
+#[derive(Debug, Clone)]
+pub(crate) struct KeyboardEnhancementFlagsFilter;
+
+#[cfg(unix)]
+impl Filter for KeyboardEnhancementFlagsFilter {
+    fn eval(&self, event: &InternalEvent) -> bool {
+        // This filter checks for either a KeyboardEnhancementFlags response or
+        // a PrimaryDeviceAttributes response. If we receive the PrimaryDeviceAttributes
+        // response but not KeyboardEnhancementFlags, the terminal does not support
+        // progressive keyboard enhancement.
+        matches!(
+            *event,
+            InternalEvent::KeyboardEnhancementFlags(_) | InternalEvent::PrimaryDeviceAttributes
+        )
+    }
+}
+
+#[cfg(unix)]
+#[derive(Debug, Clone)]
+pub(crate) struct PrimaryDeviceAttributesFilter;
+
+#[cfg(unix)]
+impl Filter for PrimaryDeviceAttributesFilter {
+    fn eval(&self, event: &InternalEvent) -> bool {
+        matches!(*event, InternalEvent::PrimaryDeviceAttributes)
+    }
+}
+
+#[derive(Debug, Clone)]
+pub(crate) struct EventFilter;
+
+impl Filter for EventFilter {
+    #[cfg(unix)]
+    fn eval(&self, event: &InternalEvent) -> bool {
+        matches!(*event, InternalEvent::Event(_))
+    }
+
+    #[cfg(windows)]
+    fn eval(&self, _: &InternalEvent) -> bool {
+        true
+    }
+}
+
+#[cfg(test)]
+#[cfg(unix)]
+mod tests {
+    use super::{
+        super::Event, CursorPositionFilter, EventFilter, Filter, InternalEvent,
+        KeyboardEnhancementFlagsFilter, PrimaryDeviceAttributesFilter,
+    };
+
+    #[derive(Debug, Clone)]
+    pub(crate) struct InternalEventFilter;
+
+    impl Filter for InternalEventFilter {
+        fn eval(&self, _: &InternalEvent) -> bool {
+            true
+        }
+    }
+
+    #[test]
+    fn test_cursor_position_filter_filters_cursor_position() {
+        assert!(!CursorPositionFilter.eval(&InternalEvent::Event(Event::Resize(10, 10))));
+        assert!(CursorPositionFilter.eval(&InternalEvent::CursorPosition(0, 0)));
+    }
+
+    #[test]
+    fn test_keyboard_enhancement_status_filter_filters_keyboard_enhancement_status() {
+        assert!(!KeyboardEnhancementFlagsFilter.eval(&InternalEvent::Event(Event::Resize(10, 10))));
+        assert!(
+            KeyboardEnhancementFlagsFilter.eval(&InternalEvent::KeyboardEnhancementFlags(
+                crate::event::KeyboardEnhancementFlags::DISAMBIGUATE_ESCAPE_CODES
+            ))
+        );
+        assert!(KeyboardEnhancementFlagsFilter.eval(&InternalEvent::PrimaryDeviceAttributes));
+    }
+
+    #[test]
+    fn test_primary_device_attributes_filter_filters_primary_device_attributes() {
+        assert!(!PrimaryDeviceAttributesFilter.eval(&InternalEvent::Event(Event::Resize(10, 10))));
+        assert!(PrimaryDeviceAttributesFilter.eval(&InternalEvent::PrimaryDeviceAttributes));
+    }
+
+    #[test]
+    fn test_event_filter_filters_events() {
+        assert!(EventFilter.eval(&InternalEvent::Event(Event::Resize(10, 10))));
+        assert!(!EventFilter.eval(&InternalEvent::CursorPosition(0, 0)));
+    }
+
+    #[test]
+    fn test_event_filter_filters_internal_events() {
+        assert!(InternalEventFilter.eval(&InternalEvent::Event(Event::Resize(10, 10))));
+        assert!(InternalEventFilter.eval(&InternalEvent::CursorPosition(0, 0)));
+    }
+}

vendor/crossterm/src/event/read.rs

@@ -0,0 +1,436 @@
+use std::{collections::vec_deque::VecDeque, io, time::Duration};
+
+#[cfg(unix)]
+use crate::event::source::unix::UnixInternalEventSource;
+#[cfg(windows)]
+use crate::event::source::windows::WindowsEventSource;
+#[cfg(feature = "event-stream")]
+use crate::event::sys::Waker;
+use crate::event::{filter::Filter, source::EventSource, timeout::PollTimeout, InternalEvent};
+
+/// Can be used to read `InternalEvent`s.
+pub(crate) struct InternalEventReader {
+    events: VecDeque<InternalEvent>,
+    source: Option<Box<dyn EventSource>>,
+    skipped_events: Vec<InternalEvent>,
+}
+
+impl Default for InternalEventReader {
+    fn default() -> Self {
+        #[cfg(windows)]
+        let source = WindowsEventSource::new();
+        #[cfg(unix)]
+        let source = UnixInternalEventSource::new();
+
+        let source = source.ok().map(|x| Box::new(x) as Box<dyn EventSource>);
+
+        InternalEventReader {
+            source,
+            events: VecDeque::with_capacity(32),
+            skipped_events: Vec::with_capacity(32),
+        }
+    }
+}
+
+impl InternalEventReader {
+    /// Returns a `Waker` allowing to wake/force the `poll` method to return `Ok(false)`.
+    #[cfg(feature = "event-stream")]
+    pub(crate) fn waker(&self) -> Waker {
+        self.source.as_ref().expect("reader source not set").waker()
+    }
+
+    pub(crate) fn poll<F>(&mut self, timeout: Option<Duration>, filter: &F) -> io::Result<bool>
+    where
+        F: Filter,
+    {
+        for event in &self.events {
+            if filter.eval(event) {
+                return Ok(true);
+            }
+        }
+
+        let event_source = match self.source.as_mut() {
+            Some(source) => source,
+            None => {
+                return Err(std::io::Error::new(
+                    std::io::ErrorKind::Other,
+                    "Failed to initialize input reader",
+                ))
+            }
+        };
+
+        let poll_timeout = PollTimeout::new(timeout);
+
+        loop {
+            let maybe_event = match event_source.try_read(poll_timeout.leftover()) {
+                Ok(None) => None,
+                Ok(Some(event)) => {
+                    if filter.eval(&event) {
+                        Some(event)
+                    } else {
+                        self.skipped_events.push(event);
+                        None
+                    }
+                }
+                Err(e) => {
+                    if e.kind() == io::ErrorKind::Interrupted {
+                        return Ok(false);
+                    }
+
+                    return Err(e);
+                }
+            };
+
+            if poll_timeout.elapsed() || maybe_event.is_some() {
+                self.events.extend(self.skipped_events.drain(..));
+
+                if let Some(event) = maybe_event {
+                    self.events.push_front(event);
+                    return Ok(true);
+                }
+
+                return Ok(false);
+            }
+        }
+    }
+
+    pub(crate) fn read<F>(&mut self, filter: &F) -> io::Result<InternalEvent>
+    where
+        F: Filter,
+    {
+        let mut skipped_events = VecDeque::new();
+
+        loop {
+            while let Some(event) = self.events.pop_front() {
+                if filter.eval(&event) {
+                    while let Some(event) = skipped_events.pop_front() {
+                        self.events.push_back(event);
+                    }
+
+                    return Ok(event);
+                } else {
+                    // We can not directly write events back to `self.events`.
+                    // If we did, we would put our self's into an endless loop
+                    // that would enqueue -> dequeue -> enqueue etc.
+                    // This happens because `poll` in this function will always return true if there are events in it's.
+                    // And because we just put the non-fulfilling event there this is going to be the case.
+                    // Instead we can store them into the temporary buffer,
+                    // and then when the filter is fulfilled write all events back in order.
+                    skipped_events.push_back(event);
+                }
+            }
+
+            let _ = self.poll(None, filter)?;
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::io;
+    use std::{collections::VecDeque, time::Duration};
+
+    #[cfg(unix)]
+    use super::super::filter::CursorPositionFilter;
+    use super::{super::Event, EventSource, Filter, InternalEvent, InternalEventReader};
+
+    #[derive(Debug, Clone)]
+    pub(crate) struct InternalEventFilter;
+
+    impl Filter for InternalEventFilter {
+        fn eval(&self, _: &InternalEvent) -> bool {
+            true
+        }
+    }
+
+    #[test]
+    fn test_poll_fails_without_event_source() {
+        let mut reader = InternalEventReader {
+            events: VecDeque::new(),
+            source: None,
+            skipped_events: Vec::with_capacity(32),
+        };
+
+        assert!(reader.poll(None, &InternalEventFilter).is_err());
+        assert!(reader
+            .poll(Some(Duration::from_secs(0)), &InternalEventFilter)
+            .is_err());
+        assert!(reader
+            .poll(Some(Duration::from_secs(10)), &InternalEventFilter)
+            .is_err());
+    }
+
+    #[test]
+    fn test_poll_returns_true_for_matching_event_in_queue_at_front() {
+        let mut reader = InternalEventReader {
+            events: vec![InternalEvent::Event(Event::Resize(10, 10))].into(),
+            source: None,
+            skipped_events: Vec::with_capacity(32),
+        };
+
+        assert!(reader.poll(None, &InternalEventFilter).unwrap());
+    }
+
+    #[test]
+    #[cfg(unix)]
+    fn test_poll_returns_true_for_matching_event_in_queue_at_back() {
+        let mut reader = InternalEventReader {
+            events: vec![
+                InternalEvent::Event(Event::Resize(10, 10)),
+                InternalEvent::CursorPosition(10, 20),
+            ]
+            .into(),
+            source: None,
+            skipped_events: Vec::with_capacity(32),
+        };
+
+        assert!(reader.poll(None, &CursorPositionFilter).unwrap());
+    }
+
+    #[test]
+    fn test_read_returns_matching_event_in_queue_at_front() {
+        const EVENT: InternalEvent = InternalEvent::Event(Event::Resize(10, 10));
+
+        let mut reader = InternalEventReader {
+            events: vec![EVENT].into(),
+            source: None,
+            skipped_events: Vec::with_capacity(32),
+        };
+
+        assert_eq!(reader.read(&InternalEventFilter).unwrap(), EVENT);
+    }
+
+    #[test]
+    #[cfg(unix)]
+    fn test_read_returns_matching_event_in_queue_at_back() {
+        const CURSOR_EVENT: InternalEvent = InternalEvent::CursorPosition(10, 20);
+
+        let mut reader = InternalEventReader {
+            events: vec![InternalEvent::Event(Event::Resize(10, 10)), CURSOR_EVENT].into(),
+            source: None,
+            skipped_events: Vec::with_capacity(32),
+        };
+
+        assert_eq!(reader.read(&CursorPositionFilter).unwrap(), CURSOR_EVENT);
+    }
+
+    #[test]
+    #[cfg(unix)]
+    fn test_read_does_not_consume_skipped_event() {
+        const SKIPPED_EVENT: InternalEvent = InternalEvent::Event(Event::Resize(10, 10));
+        const CURSOR_EVENT: InternalEvent = InternalEvent::CursorPosition(10, 20);
+
+        let mut reader = InternalEventReader {
+            events: vec![SKIPPED_EVENT, CURSOR_EVENT].into(),
+            source: None,
+            skipped_events: Vec::with_capacity(32),
+        };
+
+        assert_eq!(reader.read(&CursorPositionFilter).unwrap(), CURSOR_EVENT);
+        assert_eq!(reader.read(&InternalEventFilter).unwrap(), SKIPPED_EVENT);
+    }
+
+    #[test]
+    fn test_poll_timeouts_if_source_has_no_events() {
+        let source = FakeSource::default();
+
+        let mut reader = InternalEventReader {
+            events: VecDeque::new(),
+            source: Some(Box::new(source)),
+            skipped_events: Vec::with_capacity(32),
+        };
+
+        assert!(!reader
+            .poll(Some(Duration::from_secs(0)), &InternalEventFilter)
+            .unwrap());
+    }
+
+    #[test]
+    fn test_poll_returns_true_if_source_has_at_least_one_event() {
+        let source = FakeSource::with_events(&[InternalEvent::Event(Event::Resize(10, 10))]);
+
+        let mut reader = InternalEventReader {
+            events: VecDeque::new(),
+            source: Some(Box::new(source)),
+            skipped_events: Vec::with_capacity(32),
+        };
+
+        assert!(reader.poll(None, &InternalEventFilter).unwrap());
+        assert!(reader
+            .poll(Some(Duration::from_secs(0)), &InternalEventFilter)
+            .unwrap());
+    }
+
+    #[test]
+    fn test_reads_returns_event_if_source_has_at_least_one_event() {
+        const EVENT: InternalEvent = InternalEvent::Event(Event::Resize(10, 10));
+
+        let source = FakeSource::with_events(&[EVENT]);
+
+        let mut reader = InternalEventReader {
+            events: VecDeque::new(),
+            source: Some(Box::new(source)),
+            skipped_events: Vec::with_capacity(32),
+        };
+
+        assert_eq!(reader.read(&InternalEventFilter).unwrap(), EVENT);
+    }
+
+    #[test]
+    fn test_read_returns_events_if_source_has_events() {
+        const EVENT: InternalEvent = InternalEvent::Event(Event::Resize(10, 10));
+
+        let source = FakeSource::with_events(&[EVENT, EVENT, EVENT]);
+
+        let mut reader = InternalEventReader {
+            events: VecDeque::new(),
+            source: Some(Box::new(source)),
+            skipped_events: Vec::with_capacity(32),
+        };
+
+        assert_eq!(reader.read(&InternalEventFilter).unwrap(), EVENT);
+        assert_eq!(reader.read(&InternalEventFilter).unwrap(), EVENT);
+        assert_eq!(reader.read(&InternalEventFilter).unwrap(), EVENT);
+    }
+
+    #[test]
+    fn test_poll_returns_false_after_all_source_events_are_consumed() {
+        const EVENT: InternalEvent = InternalEvent::Event(Event::Resize(10, 10));
+
+        let source = FakeSource::with_events(&[EVENT, EVENT, EVENT]);
+
+        let mut reader = InternalEventReader {
+            events: VecDeque::new(),
+            source: Some(Box::new(source)),
+            skipped_events: Vec::with_capacity(32),
+        };
+
+        assert_eq!(reader.read(&InternalEventFilter).unwrap(), EVENT);
+        assert_eq!(reader.read(&InternalEventFilter).unwrap(), EVENT);
+        assert_eq!(reader.read(&InternalEventFilter).unwrap(), EVENT);
+        assert!(!reader
+            .poll(Some(Duration::from_secs(0)), &InternalEventFilter)
+            .unwrap());
+    }
+
+    #[test]
+    fn test_poll_propagates_error() {
+        let mut reader = InternalEventReader {
+            events: VecDeque::new(),
+            source: Some(Box::new(FakeSource::new(&[]))),
+            skipped_events: Vec::with_capacity(32),
+        };
+
+        assert_eq!(
+            reader
+                .poll(Some(Duration::from_secs(0)), &InternalEventFilter)
+                .err()
+                .map(|e| format!("{:?}", &e.kind())),
+            Some(format!("{:?}", io::ErrorKind::Other))
+        );
+    }
+
+    #[test]
+    fn test_read_propagates_error() {
+        let mut reader = InternalEventReader {
+            events: VecDeque::new(),
+            source: Some(Box::new(FakeSource::new(&[]))),
+            skipped_events: Vec::with_capacity(32),
+        };
+
+        assert_eq!(
+            reader
+                .read(&InternalEventFilter)
+                .err()
+                .map(|e| format!("{:?}", &e.kind())),
+            Some(format!("{:?}", io::ErrorKind::Other))
+        );
+    }
+
+    #[test]
+    fn test_poll_continues_after_error() {
+        const EVENT: InternalEvent = InternalEvent::Event(Event::Resize(10, 10));
+
+        let source = FakeSource::new(&[EVENT, EVENT]);
+
+        let mut reader = InternalEventReader {
+            events: VecDeque::new(),
+            source: Some(Box::new(source)),
+            skipped_events: Vec::with_capacity(32),
+        };
+
+        assert_eq!(reader.read(&InternalEventFilter).unwrap(), EVENT);
+        assert!(reader.read(&InternalEventFilter).is_err());
+        assert!(reader
+            .poll(Some(Duration::from_secs(0)), &InternalEventFilter)
+            .unwrap());
+    }
+
+    #[test]
+    fn test_read_continues_after_error() {
+        const EVENT: InternalEvent = InternalEvent::Event(Event::Resize(10, 10));
+
+        let source = FakeSource::new(&[EVENT, EVENT]);
+
+        let mut reader = InternalEventReader {
+            events: VecDeque::new(),
+            source: Some(Box::new(source)),
+            skipped_events: Vec::with_capacity(32),
+        };
+
+        assert_eq!(reader.read(&InternalEventFilter).unwrap(), EVENT);
+        assert!(reader.read(&InternalEventFilter).is_err());
+        assert_eq!(reader.read(&InternalEventFilter).unwrap(), EVENT);
+    }
+
+    #[derive(Default)]
+    struct FakeSource {
+        events: VecDeque<InternalEvent>,
+        error: Option<io::Error>,
+    }
+
+    impl FakeSource {
+        fn new(events: &[InternalEvent]) -> FakeSource {
+            FakeSource {
+                events: events.to_vec().into(),
+                error: Some(io::Error::new(io::ErrorKind::Other, "")),
+            }
+        }
+
+        fn with_events(events: &[InternalEvent]) -> FakeSource {
+            FakeSource {
+                events: events.to_vec().into(),
+                error: None,
+            }
+        }
+    }
+
+    impl EventSource for FakeSource {
+        fn try_read(&mut self, _timeout: Option<Duration>) -> io::Result<Option<InternalEvent>> {
+            // Return error if set in case there's just one remaining event
+            if self.events.len() == 1 {
+                if let Some(error) = self.error.take() {
+                    return Err(error);
+                }
+            }
+
+            // Return all events from the queue
+            if let Some(event) = self.events.pop_front() {
+                return Ok(Some(event));
+            }
+
+            // Return error if there're no more events
+            if let Some(error) = self.error.take() {
+                return Err(error);
+            }
+
+            // Timeout
+            Ok(None)
+        }
+
+        #[cfg(feature = "event-stream")]
+        fn waker(&self) -> super::super::sys::Waker {
+            unimplemented!();
+        }
+    }
+}

vendor/crossterm/src/event/source.rs

@@ -0,0 +1,27 @@
+use std::{io, time::Duration};
+
+#[cfg(feature = "event-stream")]
+use super::sys::Waker;
+use super::InternalEvent;
+
+#[cfg(unix)]
+pub(crate) mod unix;
+#[cfg(windows)]
+pub(crate) mod windows;
+
+/// An interface for trying to read an `InternalEvent` within an optional `Duration`.
+pub(crate) trait EventSource: Sync + Send {
+    /// Tries to read an `InternalEvent` within the given duration.
+    ///
+    /// # Arguments
+    ///
+    /// * `timeout` - `None` block indefinitely until an event is available, `Some(duration)` blocks
+    ///   for the given timeout
+    ///
+    /// Returns `Ok(None)` if there's no event available and timeout expires.
+    fn try_read(&mut self, timeout: Option<Duration>) -> io::Result<Option<InternalEvent>>;
+
+    /// Returns a `Waker` allowing to wake/force the `try_read` method to return `Ok(None)`.
+    #[cfg(feature = "event-stream")]
+    fn waker(&self) -> Waker;
+}

vendor/crossterm/src/event/source/unix.rs

@@ -0,0 +1,11 @@
+#[cfg(feature = "use-dev-tty")]
+pub(crate) mod tty;
+
+#[cfg(not(feature = "use-dev-tty"))]
+pub(crate) mod mio;
+
+#[cfg(feature = "use-dev-tty")]
+pub(crate) use self::tty::UnixInternalEventSource;
+
+#[cfg(not(feature = "use-dev-tty"))]
+pub(crate) use self::mio::UnixInternalEventSource;

vendor/crossterm/src/event/source/unix/mio.rs

@@ -0,0 +1,279 @@
+use std::{collections::VecDeque, io, time::Duration};
+
+use mio::{unix::SourceFd, Events, Interest, Poll, Token};
+use signal_hook_mio::v1_0::Signals;
+
+#[cfg(feature = "event-stream")]
+use crate::event::sys::Waker;
+use crate::event::{
+    source::EventSource, sys::unix::parse::parse_event, timeout::PollTimeout, Event, InternalEvent,
+};
+use crate::terminal::sys::file_descriptor::{tty_fd, FileDesc};
+
+// Tokens to identify file descriptor
+const TTY_TOKEN: Token = Token(0);
+const SIGNAL_TOKEN: Token = Token(1);
+#[cfg(feature = "event-stream")]
+const WAKE_TOKEN: Token = Token(2);
+
+// I (@zrzka) wasn't able to read more than 1_022 bytes when testing
+// reading on macOS/Linux -> we don't need bigger buffer and 1k of bytes
+// is enough.
+const TTY_BUFFER_SIZE: usize = 1_024;
+
+pub(crate) struct UnixInternalEventSource {
+    poll: Poll,
+    events: Events,
+    parser: Parser,
+    tty_buffer: [u8; TTY_BUFFER_SIZE],
+    tty_fd: FileDesc<'static>,
+    signals: Signals,
+    #[cfg(feature = "event-stream")]
+    waker: Waker,
+}
+
+impl UnixInternalEventSource {
+    pub fn new() -> io::Result<Self> {
+        UnixInternalEventSource::from_file_descriptor(tty_fd()?)
+    }
+
+    pub(crate) fn from_file_descriptor(input_fd: FileDesc<'static>) -> io::Result<Self> {
+        let poll = Poll::new()?;
+        let registry = poll.registry();
+
+        let tty_raw_fd = input_fd.raw_fd();
+        let mut tty_ev = SourceFd(&tty_raw_fd);
+        registry.register(&mut tty_ev, TTY_TOKEN, Interest::READABLE)?;
+
+        let mut signals = Signals::new([signal_hook::consts::SIGWINCH])?;
+        registry.register(&mut signals, SIGNAL_TOKEN, Interest::READABLE)?;
+
+        #[cfg(feature = "event-stream")]
+        let waker = Waker::new(registry, WAKE_TOKEN)?;
+
+        Ok(UnixInternalEventSource {
+            poll,
+            events: Events::with_capacity(3),
+            parser: Parser::default(),
+            tty_buffer: [0u8; TTY_BUFFER_SIZE],
+            tty_fd: input_fd,
+            signals,
+            #[cfg(feature = "event-stream")]
+            waker,
+        })
+    }
+}
+
+impl EventSource for UnixInternalEventSource {
+    fn try_read(&mut self, timeout: Option<Duration>) -> io::Result<Option<InternalEvent>> {
+        if let Some(event) = self.parser.next() {
+            return Ok(Some(event));
+        }
+
+        let timeout = PollTimeout::new(timeout);
+
+        loop {
+            if let Err(e) = self.poll.poll(&mut self.events, timeout.leftover()) {
+                // Mio will throw an interrupted error in case of cursor position retrieval. We need to retry until it succeeds.
+                // Previous versions of Mio (< 0.7) would automatically retry the poll call if it was interrupted (if EINTR was returned).
+                // https://docs.rs/mio/0.7.0/mio/struct.Poll.html#notes
+                if e.kind() == io::ErrorKind::Interrupted {
+                    continue;
+                } else {
+                    return Err(e);
+                }
+            };
+
+            if self.events.is_empty() {
+                // No readiness events = timeout
+                return Ok(None);
+            }
+
+            for token in self.events.iter().map(|x| x.token()) {
+                match token {
+                    TTY_TOKEN => {
+                        loop {
+                            match self.tty_fd.read(&mut self.tty_buffer) {
+                                Ok(read_count) => {
+                                    if read_count > 0 {
+                                        self.parser.advance(
+                                            &self.tty_buffer[..read_count],
+                                            read_count == TTY_BUFFER_SIZE,
+                                        );
+                                    }
+                                }
+                                Err(e) => {
+                                    // No more data to read at the moment. We will receive another event
+                                    if e.kind() == io::ErrorKind::WouldBlock {
+                                        break;
+                                    }
+                                    // once more data is available to read.
+                                    else if e.kind() == io::ErrorKind::Interrupted {
+                                        continue;
+                                    }
+                                }
+                            };
+
+                            if let Some(event) = self.parser.next() {
+                                return Ok(Some(event));
+                            }
+                        }
+                    }
+                    SIGNAL_TOKEN => {
+                        if self.signals.pending().next() == Some(signal_hook::consts::SIGWINCH) {
+                            // TODO Should we remove tput?
+                            //
+                            // This can take a really long time, because terminal::size can
+                            // launch new process (tput) and then it parses its output. It's
+                            // not a really long time from the absolute time point of view, but
+                            // it's a really long time from the mio, async-std/tokio executor, ...
+                            // point of view.
+                            let new_size = crate::terminal::size()?;
+                            return Ok(Some(InternalEvent::Event(Event::Resize(
+                                new_size.0, new_size.1,
+                            ))));
+                        }
+                    }
+                    #[cfg(feature = "event-stream")]
+                    WAKE_TOKEN => {
+                        return Err(std::io::Error::new(
+                            std::io::ErrorKind::Interrupted,
+                            "Poll operation was woken up by `Waker::wake`",
+                        ));
+                    }
+                    _ => unreachable!("Synchronize Evented handle registration & token handling"),
+                }
+            }
+
+            // Processing above can take some time, check if timeout expired
+            if timeout.elapsed() {
+                return Ok(None);
+            }
+        }
+    }
+
+    #[cfg(feature = "event-stream")]
+    fn waker(&self) -> Waker {
+        self.waker.clone()
+    }
+}
+
+//
+// Following `Parser` structure exists for two reasons:
+//
+//  * mimic anes Parser interface
+//  * move the advancing, parsing, ... stuff out of the `try_read` method
+//
+#[derive(Debug)]
+struct Parser {
+    buffer: Vec<u8>,
+    internal_events: VecDeque<InternalEvent>,
+}
+
+impl Default for Parser {
+    fn default() -> Self {
+        Parser {
+            // This buffer is used for -> 1 <- ANSI escape sequence. Are we
+            // aware of any ANSI escape sequence that is bigger? Can we make
+            // it smaller?
+            //
+            // Probably not worth spending more time on this as "there's a plan"
+            // to use the anes crate parser.
+            buffer: Vec::with_capacity(256),
+            // TTY_BUFFER_SIZE is 1_024 bytes. How many ANSI escape sequences can
+            // fit? What is an average sequence length? Let's guess here
+            // and say that the average ANSI escape sequence length is 8 bytes. Thus
+            // the buffer size should be 1024/8=128 to avoid additional allocations
+            // when processing large amounts of data.
+            //
+            // There's no need to make it bigger, because when you look at the `try_read`
+            // method implementation, all events are consumed before the next TTY_BUFFER
+            // is processed -> events pushed.
+            internal_events: VecDeque::with_capacity(128),
+        }
+    }
+}
+
+impl Parser {
+    fn advance(&mut self, buffer: &[u8], more: bool) {
+        for (idx, byte) in buffer.iter().enumerate() {
+            let more = idx + 1 < buffer.len() || more;
+
+            self.buffer.push(*byte);
+
+            match parse_event(&self.buffer, more) {
+                Ok(Some(ie)) => {
+                    self.internal_events.push_back(ie);
+                    self.buffer.clear();
+                }
+                Ok(None) => {
+                    // Event can't be parsed, because we don't have enough bytes for
+                    // the current sequence. Keep the buffer and process next bytes.
+                }
+                Err(_) => {
+                    // Event can't be parsed (not enough parameters, parameter is not a number, ...).
+                    // Clear the buffer and continue with another sequence.
+                    self.buffer.clear();
+                }
+            }
+        }
+    }
+}
+
+impl Iterator for Parser {
+    type Item = InternalEvent;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.internal_events.pop_front()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Parser;
+    use crate::event::{Event, InternalEvent, KeyCode};
+
+    #[test]
+    fn color_scheme_notifications_preserve_following_keys() {
+        for report in [b"\x1B[?997;1n", b"\x1B[?997;2n"] {
+            for split in 1..report.len() {
+                let mut parser = Parser::default();
+                parser.advance(&report[..split], true);
+                assert_eq!(parser.next(), None);
+                parser.advance(&report[split..], false);
+                parser.advance(b"x", false);
+                assert_eq!(
+                    parser.next(),
+                    Some(InternalEvent::Event(Event::ColorSchemeChanged))
+                );
+                assert_eq!(
+                    parser.next(),
+                    Some(InternalEvent::Event(Event::Key(KeyCode::Char('x').into())))
+                );
+                assert_eq!(parser.next(), None);
+            }
+        }
+    }
+
+    #[test]
+    fn malformed_color_scheme_notifications_do_not_trap_keys() {
+        for report in [
+            b"\x1B[?997n".as_slice(),
+            b"\x1B[?997;0n",
+            b"\x1B[?997;3n",
+            b"\x1B[?997;01n",
+            b"\x1B[?997;1;2n",
+            b"\x1B[?997;1A",
+        ] {
+            let mut parser = Parser::default();
+            parser.advance(report, false);
+            assert_eq!(parser.next(), None);
+            parser.advance(b"x", false);
+            assert_eq!(
+                parser.next(),
+                Some(InternalEvent::Event(Event::Key(KeyCode::Char('x').into())))
+            );
+            assert_eq!(parser.next(), None);
+        }
+    }
+}

vendor/crossterm/src/event/source/unix/tty.rs

@@ -0,0 +1,278 @@
+#[cfg(feature = "libc")]
+use std::os::unix::prelude::AsRawFd;
+use std::{collections::VecDeque, io, os::unix::net::UnixStream, time::Duration};
+
+#[cfg(not(feature = "libc"))]
+use rustix::fd::{AsFd, AsRawFd};
+
+use signal_hook::low_level::pipe;
+
+use crate::event::timeout::PollTimeout;
+use crate::event::Event;
+use filedescriptor::{poll, pollfd, POLLIN};
+
+#[cfg(feature = "event-stream")]
+use crate::event::sys::Waker;
+use crate::event::{source::EventSource, sys::unix::parse::parse_event, InternalEvent};
+use crate::terminal::sys::file_descriptor::{tty_fd, FileDesc};
+
+/// Holds a prototypical Waker and a receiver we can wait on when doing select().
+#[cfg(feature = "event-stream")]
+struct WakePipe {
+    receiver: UnixStream,
+    waker: Waker,
+}
+
+#[cfg(feature = "event-stream")]
+impl WakePipe {
+    fn new() -> io::Result<Self> {
+        let (receiver, sender) = nonblocking_unix_pair()?;
+        Ok(WakePipe {
+            receiver,
+            waker: Waker::new(sender),
+        })
+    }
+}
+
+// I (@zrzka) wasn't able to read more than 1_022 bytes when testing
+// reading on macOS/Linux -> we don't need bigger buffer and 1k of bytes
+// is enough.
+const TTY_BUFFER_SIZE: usize = 1_024;
+
+pub(crate) struct UnixInternalEventSource {
+    parser: Parser,
+    tty_buffer: [u8; TTY_BUFFER_SIZE],
+    tty: FileDesc<'static>,
+    winch_signal_receiver: UnixStream,
+    #[cfg(feature = "event-stream")]
+    wake_pipe: WakePipe,
+}
+
+fn nonblocking_unix_pair() -> io::Result<(UnixStream, UnixStream)> {
+    let (receiver, sender) = UnixStream::pair()?;
+    receiver.set_nonblocking(true)?;
+    sender.set_nonblocking(true)?;
+    Ok((receiver, sender))
+}
+
+impl UnixInternalEventSource {
+    pub fn new() -> io::Result<Self> {
+        UnixInternalEventSource::from_file_descriptor(tty_fd()?)
+    }
+
+    pub(crate) fn from_file_descriptor(input_fd: FileDesc<'static>) -> io::Result<Self> {
+        Ok(UnixInternalEventSource {
+            parser: Parser::default(),
+            tty_buffer: [0u8; TTY_BUFFER_SIZE],
+            tty: input_fd,
+            winch_signal_receiver: {
+                let (receiver, sender) = nonblocking_unix_pair()?;
+                // Unregistering is unnecessary because EventSource is a singleton
+                #[cfg(feature = "libc")]
+                pipe::register(libc::SIGWINCH, sender)?;
+                #[cfg(not(feature = "libc"))]
+                pipe::register(rustix::process::Signal::WINCH.as_raw(), sender)?;
+                receiver
+            },
+            #[cfg(feature = "event-stream")]
+            wake_pipe: WakePipe::new()?,
+        })
+    }
+}
+
+/// read_complete reads from a non-blocking file descriptor
+/// until the buffer is full or it would block.
+///
+/// Similar to `std::io::Read::read_to_end`, except this function
+/// only fills the given buffer and does not read beyond that.
+fn read_complete(fd: &FileDesc, buf: &mut [u8]) -> io::Result<usize> {
+    loop {
+        match fd.read(buf) {
+            Ok(x) => return Ok(x),
+            Err(e) => match e.kind() {
+                io::ErrorKind::WouldBlock => return Ok(0),
+                io::ErrorKind::Interrupted => continue,
+                _ => return Err(e),
+            },
+        }
+    }
+}
+
+impl EventSource for UnixInternalEventSource {
+    fn try_read(&mut self, timeout: Option<Duration>) -> io::Result<Option<InternalEvent>> {
+        let timeout = PollTimeout::new(timeout);
+
+        fn make_pollfd<F: AsRawFd>(fd: &F) -> pollfd {
+            pollfd {
+                fd: fd.as_raw_fd(),
+                events: POLLIN,
+                revents: 0,
+            }
+        }
+
+        #[cfg(not(feature = "event-stream"))]
+        let mut fds = [
+            make_pollfd(&self.tty),
+            make_pollfd(&self.winch_signal_receiver),
+        ];
+
+        #[cfg(feature = "event-stream")]
+        let mut fds = [
+            make_pollfd(&self.tty),
+            make_pollfd(&self.winch_signal_receiver),
+            make_pollfd(&self.wake_pipe.receiver),
+        ];
+
+        while timeout.leftover().map_or(true, |t| !t.is_zero()) {
+            // check if there are buffered events from the last read
+            if let Some(event) = self.parser.next() {
+                return Ok(Some(event));
+            }
+            match poll(&mut fds, timeout.leftover()) {
+                Err(filedescriptor::Error::Poll(e)) | Err(filedescriptor::Error::Io(e)) => {
+                    match e.kind() {
+                        // retry on EINTR
+                        io::ErrorKind::Interrupted => continue,
+                        _ => return Err(e),
+                    }
+                }
+                Err(e) => {
+                    return Err(std::io::Error::new(
+                        std::io::ErrorKind::Other,
+                        format!("got unexpected error while polling: {:?}", e),
+                    ))
+                }
+                Ok(_) => (),
+            };
+            if fds[0].revents & POLLIN != 0 {
+                loop {
+                    let read_count = read_complete(&self.tty, &mut self.tty_buffer)?;
+                    if read_count > 0 {
+                        self.parser.advance(
+                            &self.tty_buffer[..read_count],
+                            read_count == TTY_BUFFER_SIZE,
+                        );
+                    }
+
+                    if let Some(event) = self.parser.next() {
+                        return Ok(Some(event));
+                    }
+
+                    if read_count == 0 {
+                        break;
+                    }
+                }
+            }
+            if fds[1].revents & POLLIN != 0 {
+                #[cfg(feature = "libc")]
+                let fd = FileDesc::new(self.winch_signal_receiver.as_raw_fd(), false);
+                #[cfg(not(feature = "libc"))]
+                let fd = FileDesc::Borrowed(self.winch_signal_receiver.as_fd());
+                // drain the pipe
+                while read_complete(&fd, &mut [0; 1024])? != 0 {}
+                // TODO Should we remove tput?
+                //
+                // This can take a really long time, because terminal::size can
+                // launch new process (tput) and then it parses its output. It's
+                // not a really long time from the absolute time point of view, but
+                // it's a really long time from the mio, async-std/tokio executor, ...
+                // point of view.
+                let new_size = crate::terminal::size()?;
+                return Ok(Some(InternalEvent::Event(Event::Resize(
+                    new_size.0, new_size.1,
+                ))));
+            }
+
+            #[cfg(feature = "event-stream")]
+            if fds[2].revents & POLLIN != 0 {
+                #[cfg(feature = "libc")]
+                let fd = FileDesc::new(self.wake_pipe.receiver.as_raw_fd(), false);
+                #[cfg(not(feature = "libc"))]
+                let fd = FileDesc::Borrowed(self.wake_pipe.receiver.as_fd());
+                // drain the pipe
+                while read_complete(&fd, &mut [0; 1024])? != 0 {}
+
+                return Err(std::io::Error::new(
+                    std::io::ErrorKind::Interrupted,
+                    "Poll operation was woken up by `Waker::wake`",
+                ));
+            }
+        }
+        Ok(None)
+    }
+
+    #[cfg(feature = "event-stream")]
+    fn waker(&self) -> Waker {
+        self.wake_pipe.waker.clone()
+    }
+}
+
+//
+// Following `Parser` structure exists for two reasons:
+//
+//  * mimic anes Parser interface
+//  * move the advancing, parsing, ... stuff out of the `try_read` method
+//
+#[derive(Debug)]
+struct Parser {
+    buffer: Vec<u8>,
+    internal_events: VecDeque<InternalEvent>,
+}
+
+impl Default for Parser {
+    fn default() -> Self {
+        Parser {
+            // This buffer is used for -> 1 <- ANSI escape sequence. Are we
+            // aware of any ANSI escape sequence that is bigger? Can we make
+            // it smaller?
+            //
+            // Probably not worth spending more time on this as "there's a plan"
+            // to use the anes crate parser.
+            buffer: Vec::with_capacity(256),
+            // TTY_BUFFER_SIZE is 1_024 bytes. How many ANSI escape sequences can
+            // fit? What is an average sequence length? Let's guess here
+            // and say that the average ANSI escape sequence length is 8 bytes. Thus
+            // the buffer size should be 1024/8=128 to avoid additional allocations
+            // when processing large amounts of data.
+            //
+            // There's no need to make it bigger, because when you look at the `try_read`
+            // method implementation, all events are consumed before the next TTY_BUFFER
+            // is processed -> events pushed.
+            internal_events: VecDeque::with_capacity(128),
+        }
+    }
+}
+
+impl Parser {
+    fn advance(&mut self, buffer: &[u8], more: bool) {
+        for (idx, byte) in buffer.iter().enumerate() {
+            let more = idx + 1 < buffer.len() || more;
+
+            self.buffer.push(*byte);
+
+            match parse_event(&self.buffer, more) {
+                Ok(Some(ie)) => {
+                    self.internal_events.push_back(ie);
+                    self.buffer.clear();
+                }
+                Ok(None) => {
+                    // Event can't be parsed, because we don't have enough bytes for
+                    // the current sequence. Keep the buffer and process next bytes.
+                }
+                Err(_) => {
+                    // Event can't be parsed (not enough parameters, parameter is not a number, ...).
+                    // Clear the buffer and continue with another sequence.
+                    self.buffer.clear();
+                }
+            }
+        }
+    }
+}
+
+impl Iterator for Parser {
+    type Item = InternalEvent;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.internal_events.pop_front()
+    }
+}

vendor/crossterm/src/event/source/windows.rs

@@ -0,0 +1,100 @@
+use std::time::Duration;
+
+use crossterm_winapi::{Console, Handle, InputRecord};
+
+use crate::event::{
+    sys::windows::{parse::MouseButtonsPressed, poll::WinApiPoll},
+    Event,
+};
+
+#[cfg(feature = "event-stream")]
+use crate::event::sys::Waker;
+use crate::event::{
+    source::EventSource,
+    sys::windows::parse::{handle_key_event, handle_mouse_event},
+    timeout::PollTimeout,
+    InternalEvent,
+};
+
+pub(crate) struct WindowsEventSource {
+    console: Console,
+    poll: WinApiPoll,
+    surrogate_buffer: Option<u16>,
+    mouse_buttons_pressed: MouseButtonsPressed,
+}
+
+impl WindowsEventSource {
+    pub(crate) fn new() -> std::io::Result<WindowsEventSource> {
+        let console = Console::from(Handle::current_in_handle()?);
+        Ok(WindowsEventSource {
+            console,
+
+            #[cfg(not(feature = "event-stream"))]
+            poll: WinApiPoll::new(),
+            #[cfg(feature = "event-stream")]
+            poll: WinApiPoll::new()?,
+
+            surrogate_buffer: None,
+            mouse_buttons_pressed: MouseButtonsPressed::default(),
+        })
+    }
+}
+
+impl EventSource for WindowsEventSource {
+    fn try_read(&mut self, timeout: Option<Duration>) -> std::io::Result<Option<InternalEvent>> {
+        let poll_timeout = PollTimeout::new(timeout);
+
+        loop {
+            if let Some(event_ready) = self.poll.poll(poll_timeout.leftover())? {
+                let number = self.console.number_of_console_input_events()?;
+                if event_ready && number != 0 {
+                    let event = match self.console.read_single_input_event()? {
+                        InputRecord::KeyEvent(record) => {
+                            handle_key_event(record, &mut self.surrogate_buffer)
+                        }
+                        InputRecord::MouseEvent(record) => {
+                            let mouse_event =
+                                handle_mouse_event(record, &self.mouse_buttons_pressed);
+                            self.mouse_buttons_pressed = MouseButtonsPressed {
+                                left: record.button_state.left_button(),
+                                right: record.button_state.right_button(),
+                                middle: record.button_state.middle_button(),
+                            };
+
+                            mouse_event
+                        }
+                        InputRecord::WindowBufferSizeEvent(record) => {
+                            // windows starts counting at 0, unix at 1, add one to replicate unix behaviour.
+                            Some(Event::Resize(
+                                (record.size.x as i32 + 1) as u16,
+                                (record.size.y as i32 + 1) as u16,
+                            ))
+                        }
+                        InputRecord::FocusEvent(record) => {
+                            let event = if record.set_focus {
+                                Event::FocusGained
+                            } else {
+                                Event::FocusLost
+                            };
+                            Some(event)
+                        }
+                        _ => None,
+                    };
+
+                    if let Some(event) = event {
+                        return Ok(Some(InternalEvent::Event(event)));
+                    }
+                }
+            }
+
+            if poll_timeout.elapsed() {
+                return Ok(None);
+            }
+        }
+    }
+
+    #[cfg(feature = "event-stream")]
+    fn waker(&self) -> Waker {
+        self.poll.waker()
+    }
+}

vendor/crossterm/src/event/stream.rs

@@ -0,0 +1,146 @@
+use std::{
+    io,
+    pin::Pin,
+    sync::{
+        atomic::{AtomicBool, Ordering},
+        mpsc::{self, SyncSender},
+        Arc,
+    },
+    task::{Context, Poll},
+    thread,
+    time::Duration,
+};
+
+use futures_core::stream::Stream;
+
+use crate::event::{
+    filter::EventFilter, lock_internal_event_reader, poll_internal, read_internal, sys::Waker,
+    Event, InternalEvent,
+};
+
+/// A stream of `Result<Event>`.
+///
+/// **This type is not available by default. You have to use the `event-stream` feature flag
+/// to make it available.**
+///
+/// It implements the [Stream](futures_core::stream::Stream)
+/// trait and allows you to receive [`Event`]s with [`async-std`](https://crates.io/crates/async-std)
+/// or [`tokio`](https://crates.io/crates/tokio) crates.
+///
+/// Check the [examples](https://github.com/crossterm-rs/crossterm/tree/master/examples) folder to see how to use
+/// it (`event-stream-*`).
+#[derive(Debug)]
+pub struct EventStream {
+    poll_internal_waker: Waker,
+    stream_wake_task_executed: Arc<AtomicBool>,
+    stream_wake_task_should_shutdown: Arc<AtomicBool>,
+    task_sender: SyncSender<Task>,
+}
+
+impl Default for EventStream {
+    fn default() -> Self {
+        let (task_sender, receiver) = mpsc::sync_channel::<Task>(1);
+
+        thread::spawn(move || {
+            while let Ok(task) = receiver.recv() {
+                loop {
+                    if let Ok(true) = poll_internal(None, &EventFilter) {
+                        break;
+                    }
+
+                    if task.stream_wake_task_should_shutdown.load(Ordering::SeqCst) {
+                        break;
+                    }
+                }
+                task.stream_wake_task_executed
+                    .store(false, Ordering::SeqCst);
+                task.stream_waker.wake();
+            }
+        });
+
+        EventStream {
+            poll_internal_waker: lock_internal_event_reader().waker(),
+            stream_wake_task_executed: Arc::new(AtomicBool::new(false)),
+            stream_wake_task_should_shutdown: Arc::new(AtomicBool::new(false)),
+            task_sender,
+        }
+    }
+}
+
+impl EventStream {
+    /// Constructs a new instance of `EventStream`.
+    pub fn new() -> EventStream {
+        EventStream::default()
+    }
+}
+
+struct Task {
+    stream_waker: std::task::Waker,
+    stream_wake_task_executed: Arc<AtomicBool>,
+    stream_wake_task_should_shutdown: Arc<AtomicBool>,
+}
+
+// Note to future me
+//
+// We need two wakers in order to implement EventStream correctly.
+//
+// 1. futures::Stream waker
+//
+// Stream::poll_next can return Poll::Pending which means that there's no
+// event available. We are going to spawn a thread with the
+// poll_internal(None, &EventFilter) call. This call blocks until an
+// event is available and then we have to wake up the executor with notification
+// that the task can be resumed.
+//
+// 2. poll_internal waker
+//
+// There's no event available, Poll::Pending was returned, stream waker thread
+// is up and sitting in the poll_internal. User wants to drop the EventStream.
+// We have to wake up the poll_internal (force it to return Ok(false)) and quit
+// the thread before we drop.
+impl Stream for EventStream {
+    type Item = io::Result<Event>;
+
+    fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
+        let result = match poll_internal(Some(Duration::from_secs(0)), &EventFilter) {
+            Ok(true) => match read_internal(&EventFilter) {
+                Ok(InternalEvent::Event(event)) => Poll::Ready(Some(Ok(event))),
+                Err(e) => Poll::Ready(Some(Err(e))),
+                #[cfg(unix)]
+                _ => unreachable!(),
+            },
+            Ok(false) => {
+                if !self
+                    .stream_wake_task_executed
+                    .compare_exchange(false, true, Ordering::SeqCst, Ordering::SeqCst)
+                    // https://github.com/rust-lang/rust/issues/80486#issuecomment-752244166
+                    .unwrap_or_else(|x| x)
+                {
+                    let stream_waker = cx.waker().clone();
+                    let stream_wake_task_executed = self.stream_wake_task_executed.clone();
+                    let stream_wake_task_should_shutdown =
+                        self.stream_wake_task_should_shutdown.clone();
+
+                    stream_wake_task_should_shutdown.store(false, Ordering::SeqCst);
+
+                    let _ = self.task_sender.send(Task {
+                        stream_waker,
+                        stream_wake_task_executed,
+                        stream_wake_task_should_shutdown,
+                    });
+                }
+                Poll::Pending
+            }
+            Err(e) => Poll::Ready(Some(Err(e))),
+        };
+        result
+    }
+}
+
+impl Drop for EventStream {
+    fn drop(&mut self) {
+        self.stream_wake_task_should_shutdown
+            .store(true, Ordering::SeqCst);
+        let _ = self.poll_internal_waker.wake();
+    }
+}

vendor/crossterm/src/event/sys.rs

@@ -0,0 +1,9 @@
+#[cfg(all(unix, feature = "event-stream"))]
+pub(crate) use unix::waker::Waker;
+#[cfg(all(windows, feature = "event-stream"))]
+pub(crate) use windows::waker::Waker;
+
+#[cfg(unix)]
+pub(crate) mod unix;
+#[cfg(windows)]
+pub(crate) mod windows;

vendor/crossterm/src/event/sys/unix.rs

@@ -0,0 +1,5 @@
+#[cfg(feature = "event-stream")]
+pub(crate) mod waker;
+
+#[cfg(feature = "events")]
+pub(crate) mod parse;

vendor/crossterm/src/event/sys/unix/waker.rs

@@ -0,0 +1,11 @@
+#[cfg(feature = "use-dev-tty")]
+pub(crate) mod tty;
+
+#[cfg(not(feature = "use-dev-tty"))]
+pub(crate) mod mio;
+
+#[cfg(feature = "use-dev-tty")]
+pub(crate) use self::tty::Waker;
+
+#[cfg(not(feature = "use-dev-tty"))]
+pub(crate) use self::mio::Waker;

vendor/crossterm/src/event/sys/unix/waker/mio.rs

@@ -0,0 +1,34 @@
+use std::sync::{Arc, Mutex};
+
+use ::mio::{Registry, Token};
+
+/// Allows to wake up the `mio::Poll::poll()` method.
+/// This type wraps `mio::Waker`, for more information see its documentation.
+#[derive(Clone, Debug)]
+pub(crate) struct Waker {
+    inner: Arc<Mutex<::mio::Waker>>,
+}
+
+impl Waker {
+    /// Create a new `Waker`.
+    pub(crate) fn new(registry: &Registry, waker_token: Token) -> std::io::Result<Self> {
+        Ok(Self {
+            inner: Arc::new(Mutex::new(mio::Waker::new(registry, waker_token)?)),
+        })
+    }
+
+    /// Wake up the [`Poll`] associated with this `Waker`.
+    ///
+    /// Readiness is set to `Ready::readable()`.
+    pub(crate) fn wake(&self) -> std::io::Result<()> {
+        self.inner.lock().unwrap().wake()
+    }
+
+    /// Resets the state so the same waker can be reused.
+    ///
+    /// This function is not impl
+    #[allow(dead_code, clippy::clippy::unnecessary_wraps)]
+    pub(crate) fn reset(&self) -> std::io::Result<()> {
+        Ok(())
+    }
+}

vendor/crossterm/src/event/sys/unix/waker/tty.rs

@@ -0,0 +1,28 @@
+use std::{
+    io::{self, Write},
+    os::unix::net::UnixStream,
+    sync::{Arc, Mutex},
+};
+
+/// Allows to wake up the EventSource::try_read() method.
+#[derive(Clone, Debug)]
+pub(crate) struct Waker {
+    inner: Arc<Mutex<UnixStream>>,
+}
+
+impl Waker {
+    /// Create a new `Waker`.
+    pub(crate) fn new(writer: UnixStream) -> Self {
+        Self {
+            inner: Arc::new(Mutex::new(writer)),
+        }
+    }
+
+    /// Wake up the [`Poll`] associated with this `Waker`.
+    ///
+    /// Readiness is set to `Ready::readable()`.
+    pub(crate) fn wake(&self) -> io::Result<()> {
+        self.inner.lock().unwrap().write_all(&[0])?;
+        Ok(())
+    }
+}

vendor/crossterm/src/event/sys/windows.rs

@@ -0,0 +1,48 @@
+//! This is a WINDOWS specific implementation for input related action.
+
+use std::convert::TryFrom;
+use std::io;
+use std::sync::atomic::{AtomicU64, Ordering};
+
+use crossterm_winapi::{ConsoleMode, Handle};
+
+pub(crate) mod parse;
+pub(crate) mod poll;
+#[cfg(feature = "event-stream")]
+pub(crate) mod waker;
+
+const ENABLE_MOUSE_MODE: u32 = 0x0010 | 0x0080 | 0x0008;
+
+/// This is a either `u64::MAX` if it's uninitialized or a valid `u32` that stores the original
+/// console mode if it's initialized.
+static ORIGINAL_CONSOLE_MODE: AtomicU64 = AtomicU64::new(u64::MAX);
+
+/// Initializes the default console color. It will will be skipped if it has already been initialized.
+fn init_original_console_mode(original_mode: u32) {
+    let _ = ORIGINAL_CONSOLE_MODE.compare_exchange(
+        u64::MAX,
+        u64::from(original_mode),
+        Ordering::Relaxed,
+        Ordering::Relaxed,
+    );
+}
+
+/// Returns the original console color, make sure to call `init_console_color` before calling this function. Otherwise this function will panic.
+fn original_console_mode() -> std::io::Result<u32> {
+    u32::try_from(ORIGINAL_CONSOLE_MODE.load(Ordering::Relaxed))
+        .map_err(|_| io::Error::new(io::ErrorKind::Other, "Initial console modes not set"))
+}
+
+pub(crate) fn enable_mouse_capture() -> std::io::Result<()> {
+    let mode = ConsoleMode::from(Handle::current_in_handle()?);
+    init_original_console_mode(mode.mode()?);
+    mode.set_mode(ENABLE_MOUSE_MODE)?;
+
+    Ok(())
+}
+
+pub(crate) fn disable_mouse_capture() -> std::io::Result<()> {
+    let mode = ConsoleMode::from(Handle::current_in_handle()?);
+    mode.set_mode(original_console_mode()?)?;
+    Ok(())
+}

vendor/crossterm/src/event/sys/windows/parse.rs

@@ -0,0 +1,378 @@
+use crossterm_winapi::{ControlKeyState, EventFlags, KeyEventRecord, ScreenBuffer};
+use winapi::um::{
+    wincon::{
+        CAPSLOCK_ON, LEFT_ALT_PRESSED, LEFT_CTRL_PRESSED, RIGHT_ALT_PRESSED, RIGHT_CTRL_PRESSED,
+        SHIFT_PRESSED,
+    },
+    winuser::{
+        GetForegroundWindow, GetKeyboardLayout, GetWindowThreadProcessId, ToUnicodeEx, VK_BACK,
+        VK_CONTROL, VK_DELETE, VK_DOWN, VK_END, VK_ESCAPE, VK_F1, VK_F24, VK_HOME, VK_INSERT,
+        VK_LEFT, VK_MENU, VK_NEXT, VK_NUMPAD0, VK_NUMPAD9, VK_PRIOR, VK_RETURN, VK_RIGHT, VK_SHIFT,
+        VK_TAB, VK_UP,
+    },
+};
+
+use crate::event::{
+    Event, KeyCode, KeyEvent, KeyEventKind, KeyModifiers, MouseButton, MouseEvent, MouseEventKind,
+};
+
+#[derive(Default)]
+pub struct MouseButtonsPressed {
+    pub(crate) left: bool,
+    pub(crate) right: bool,
+    pub(crate) middle: bool,
+}
+
+pub(crate) fn handle_mouse_event(
+    mouse_event: crossterm_winapi::MouseEvent,
+    buttons_pressed: &MouseButtonsPressed,
+) -> Option<Event> {
+    if let Ok(Some(event)) = parse_mouse_event_record(&mouse_event, buttons_pressed) {
+        return Some(Event::Mouse(event));
+    }
+
+    None
+}
+
+enum WindowsKeyEvent {
+    KeyEvent(KeyEvent),
+    Surrogate(u16),
+}
+
+pub(crate) fn handle_key_event(
+    key_event: KeyEventRecord,
+    surrogate_buffer: &mut Option<u16>,
+) -> Option<Event> {
+    let windows_key_event = parse_key_event_record(&key_event)?;
+    match windows_key_event {
+        WindowsKeyEvent::KeyEvent(key_event) => {
+            // Discard any buffered surrogate value if another valid key event comes before the
+            // next surrogate value.
+            *surrogate_buffer = None;
+            Some(Event::Key(key_event))
+        }
+        WindowsKeyEvent::Surrogate(new_surrogate) => {
+            let ch = handle_surrogate(surrogate_buffer, new_surrogate)?;
+            let modifiers = KeyModifiers::from(&key_event.control_key_state);
+            let key_event = KeyEvent::new(KeyCode::Char(ch), modifiers);
+            Some(Event::Key(key_event))
+        }
+    }
+}
+
+fn handle_surrogate(surrogate_buffer: &mut Option<u16>, new_surrogate: u16) -> Option<char> {
+    match *surrogate_buffer {
+        Some(buffered_surrogate) => {
+            *surrogate_buffer = None;
+            std::char::decode_utf16([buffered_surrogate, new_surrogate])
+                .next()
+                .unwrap()
+                .ok()
+        }
+        None => {
+            *surrogate_buffer = Some(new_surrogate);
+            None
+        }
+    }
+}
+
+impl From<&ControlKeyState> for KeyModifiers {
+    fn from(state: &ControlKeyState) -> Self {
+        let shift = state.has_state(SHIFT_PRESSED);
+        let alt = state.has_state(LEFT_ALT_PRESSED | RIGHT_ALT_PRESSED);
+        let control = state.has_state(LEFT_CTRL_PRESSED | RIGHT_CTRL_PRESSED);
+
+        let mut modifier = KeyModifiers::empty();
+
+        if shift {
+            modifier |= KeyModifiers::SHIFT;
+        }
+        if control {
+            modifier |= KeyModifiers::CONTROL;
+        }
+        if alt {
+            modifier |= KeyModifiers::ALT;
+        }
+
+        modifier
+    }
+}
+
+enum CharCase {
+    LowerCase,
+    UpperCase,
+}
+
+fn try_ensure_char_case(ch: char, desired_case: CharCase) -> char {
+    match desired_case {
+        CharCase::LowerCase if ch.is_uppercase() => {
+            let mut iter = ch.to_lowercase();
+            // Unwrap is safe; iterator yields one or more chars.
+            let ch_lower = iter.next().unwrap();
+            if iter.next().is_none() {
+                ch_lower
+            } else {
+                ch
+            }
+        }
+        CharCase::UpperCase if ch.is_lowercase() => {
+            let mut iter = ch.to_uppercase();
+            // Unwrap is safe; iterator yields one or more chars.
+            let ch_upper = iter.next().unwrap();
+            if iter.next().is_none() {
+                ch_upper
+            } else {
+                ch
+            }
+        }
+        _ => ch,
+    }
+}
+
+// Attempts to return the character for a key event accounting for the user's keyboard layout.
+// The returned character (if any) is capitalized (if applicable) based on shift and capslock state.
+// Returns None if the key doesn't map to a character or if it is a dead key.
+// We use the *currently* active keyboard layout (if it can be determined). This layout may not
+// correspond to the keyboard layout that was active when the user typed their input, since console
+// applications get their input asynchronously from the terminal. By the time a console application
+// can process a key input, the user may have changed the active layout. In this case, the character
+// returned might not correspond to what the user expects, but there is no way for a console
+// application to know what the keyboard layout actually was for a key event, so this is our best
+// effort. If a console application processes input in a timely fashion, then it is unlikely that a
+// user has time to change their keyboard layout before a key event is processed.
+fn get_char_for_key(key_event: &KeyEventRecord) -> Option<char> {
+    let virtual_key_code = key_event.virtual_key_code as u32;
+    let virtual_scan_code = key_event.virtual_scan_code as u32;
+    let key_state = [0u8; 256];
+    let mut utf16_buf = [0u16, 16];
+    let dont_change_kernel_keyboard_state = 0x4;
+
+    // Best-effort attempt at determining the currently active keyboard layout.
+    // At the time of writing, this works for a console application running in Windows Terminal, but
+    // doesn't work under a Conhost terminal. For Conhost, the window handle returned by
+    // GetForegroundWindow() does not appear to actually be the foreground window which has the
+    // keyboard layout associated with it (or perhaps it is, but also has special protection that
+    // doesn't allow us to query it).
+    // When this determination fails, the returned keyboard layout handle will be null, which is an
+    // acceptable input for ToUnicodeEx, as that argument is optional. In this case ToUnicodeEx
+    // appears to use the keyboard layout associated with the current thread, which will be the
+    // layout that was inherited when the console application started (or possibly when the current
+    // thread was spawned). This is then unfortunately not updated when the user changes their
+    // keyboard layout in the terminal, but it's what we get.
+    let active_keyboard_layout = unsafe {
+        let foreground_window = GetForegroundWindow();
+        let foreground_thread = GetWindowThreadProcessId(foreground_window, std::ptr::null_mut());
+        GetKeyboardLayout(foreground_thread)
+    };
+
+    let ret = unsafe {
+        ToUnicodeEx(
+            virtual_key_code,
+            virtual_scan_code,
+            key_state.as_ptr(),
+            utf16_buf.as_mut_ptr(),
+            utf16_buf.len() as i32,
+            dont_change_kernel_keyboard_state,
+            active_keyboard_layout,
+        )
+    };
+
+    // -1 indicates a dead key.
+    // 0 indicates no character for this key.
+    if ret < 1 {
+        return None;
+    }
+
+    let mut ch_iter = std::char::decode_utf16(utf16_buf.into_iter().take(ret as usize));
+    let mut ch = ch_iter.next()?.ok()?;
+    if ch_iter.next().is_some() {
+        // Key doesn't map to a single char.
+        return None;
+    }
+
+    let is_shift_pressed = key_event.control_key_state.has_state(SHIFT_PRESSED);
+    let is_capslock_on = key_event.control_key_state.has_state(CAPSLOCK_ON);
+    let desired_case = if is_shift_pressed ^ is_capslock_on {
+        CharCase::UpperCase
+    } else {
+        CharCase::LowerCase
+    };
+    ch = try_ensure_char_case(ch, desired_case);
+    Some(ch)
+}
+
+fn parse_key_event_record(key_event: &KeyEventRecord) -> Option<WindowsKeyEvent> {
+    let modifiers = KeyModifiers::from(&key_event.control_key_state);
+    let virtual_key_code = key_event.virtual_key_code as i32;
+
+    // We normally ignore all key release events, but we will make an exception for an Alt key
+    // release if it carries a u_char value, as this indicates an Alt code.
+    let is_alt_code = virtual_key_code == VK_MENU && !key_event.key_down && key_event.u_char != 0;
+    if is_alt_code {
+        let utf16 = key_event.u_char;
+        match utf16 {
+            surrogate @ 0xD800..=0xDFFF => {
+                return Some(WindowsKeyEvent::Surrogate(surrogate));
+            }
+            unicode_scalar_value => {
+                // Unwrap is safe: We tested for surrogate values above and those are the only
+                // u16 values that are invalid when directly interpreted as unicode scalar
+                // values.
+                let ch = std::char::from_u32(unicode_scalar_value as u32).unwrap();
+                let key_code = KeyCode::Char(ch);
+                let kind = if key_event.key_down {
+                    KeyEventKind::Press
+                } else {
+                    KeyEventKind::Release
+                };
+                let key_event = KeyEvent::new_with_kind(key_code, modifiers, kind);
+                return Some(WindowsKeyEvent::KeyEvent(key_event));
+            }
+        }
+    }
+
+    // Don't generate events for numpad key presses when they're producing Alt codes.
+    let is_numpad_numeric_key = (VK_NUMPAD0..=VK_NUMPAD9).contains(&virtual_key_code);
+    let is_only_alt_modifier = modifiers.contains(KeyModifiers::ALT)
+        && !modifiers.contains(KeyModifiers::SHIFT | KeyModifiers::CONTROL);
+    if is_only_alt_modifier && is_numpad_numeric_key {
+        return None;
+    }
+
+    let parse_result = match virtual_key_code {
+        VK_SHIFT | VK_CONTROL | VK_MENU => None,
+        VK_BACK => Some(KeyCode::Backspace),
+        VK_ESCAPE => Some(KeyCode::Esc),
+        VK_RETURN => Some(KeyCode::Enter),
+        VK_F1..=VK_F24 => Some(KeyCode::F((key_event.virtual_key_code - 111) as u8)),
+        VK_LEFT => Some(KeyCode::Left),
+        VK_UP => Some(KeyCode::Up),
+        VK_RIGHT => Some(KeyCode::Right),
+        VK_DOWN => Some(KeyCode::Down),
+        VK_PRIOR => Some(KeyCode::PageUp),
+        VK_NEXT => Some(KeyCode::PageDown),
+        VK_HOME => Some(KeyCode::Home),
+        VK_END => Some(KeyCode::End),
+        VK_DELETE => Some(KeyCode::Delete),
+        VK_INSERT => Some(KeyCode::Insert),
+        VK_TAB if modifiers.contains(KeyModifiers::SHIFT) => Some(KeyCode::BackTab),
+        VK_TAB => Some(KeyCode::Tab),
+        _ => {
+            let utf16 = key_event.u_char;
+            match utf16 {
+                0x00..=0x1f => {
+                    // Some key combinations generate either no u_char value or generate control
+                    // codes. To deliver back a KeyCode::Char(...) event we want to know which
+                    // character the key normally maps to on the user's keyboard layout.
+                    // The keys that intentionally generate control codes (ESC, ENTER, TAB, etc.)
+                    // are handled by their virtual key codes above.
+                    get_char_for_key(key_event).map(KeyCode::Char)
+                }
+                surrogate @ 0xD800..=0xDFFF => {
+                    return Some(WindowsKeyEvent::Surrogate(surrogate));
+                }
+                unicode_scalar_value => {
+                    // Unwrap is safe: We tested for surrogate values above and those are the only
+                    // u16 values that are invalid when directly interpreted as unicode scalar
+                    // values.
+                    let ch = std::char::from_u32(unicode_scalar_value as u32).unwrap();
+                    Some(KeyCode::Char(ch))
+                }
+            }
+        }
+    };
+
+    if let Some(key_code) = parse_result {
+        let kind = if key_event.key_down {
+            KeyEventKind::Press
+        } else {
+            KeyEventKind::Release
+        };
+        let key_event = KeyEvent::new_with_kind(key_code, modifiers, kind);
+        return Some(WindowsKeyEvent::KeyEvent(key_event));
+    }
+
+    None
+}
+
+// The 'y' position of a mouse event or resize event is not relative to the window but absolute to screen buffer.
+// This means that when the mouse cursor is at the top left it will be x: 0, y: 2295 (e.g. y = number of cells conting from the absolute buffer height) instead of relative x: 0, y: 0 to the window.
+pub fn parse_relative_y(y: i16) -> std::io::Result<i16> {
+    let window_size = ScreenBuffer::current()?.info()?.terminal_window();
+    Ok(y - window_size.top)
+}
+
+fn parse_mouse_event_record(
+    event: &crossterm_winapi::MouseEvent,
+    buttons_pressed: &MouseButtonsPressed,
+) -> std::io::Result<Option<MouseEvent>> {
+    let modifiers = KeyModifiers::from(&event.control_key_state);
+
+    let xpos = event.mouse_position.x as u16;
+    let ypos = parse_relative_y(event.mouse_position.y)? as u16;
+
+    let button_state = event.button_state;
+
+    let kind = match event.event_flags {
+        EventFlags::PressOrRelease | EventFlags::DoubleClick => {
+            if button_state.left_button() && !buttons_pressed.left {
+                Some(MouseEventKind::Down(MouseButton::Left))
+            } else if !button_state.left_button() && buttons_pressed.left {
+                Some(MouseEventKind::Up(MouseButton::Left))
+            } else if button_state.right_button() && !buttons_pressed.right {
+                Some(MouseEventKind::Down(MouseButton::Right))
+            } else if !button_state.right_button() && buttons_pressed.right {
+                Some(MouseEventKind::Up(MouseButton::Right))
+            } else if button_state.middle_button() && !buttons_pressed.middle {
+                Some(MouseEventKind::Down(MouseButton::Middle))
+            } else if !button_state.middle_button() && buttons_pressed.middle {
+                Some(MouseEventKind::Up(MouseButton::Middle))
+            } else {
+                None
+            }
+        }
+        EventFlags::MouseMoved => {
+            let button = if button_state.right_button() {
+                MouseButton::Right
+            } else if button_state.middle_button() {
+                MouseButton::Middle
+            } else {
+                MouseButton::Left
+            };
+            if button_state.release_button() {
+                Some(MouseEventKind::Moved)
+            } else {
+                Some(MouseEventKind::Drag(button))
+            }
+        }
+        EventFlags::MouseWheeled => {
+            // Vertical scroll
+            // from https://docs.microsoft.com/en-us/windows/console/mouse-event-record-str
+            // if `button_state` is negative then the wheel was rotated backward, toward the user.
+            if button_state.scroll_down() {
+                Some(MouseEventKind::ScrollDown)
+            } else if button_state.scroll_up() {
+                Some(MouseEventKind::ScrollUp)
+            } else {
+                None
+            }
+        }
+        EventFlags::MouseHwheeled => {
+            if button_state.scroll_left() {
+                Some(MouseEventKind::ScrollLeft)
+            } else if button_state.scroll_right() {
+                Some(MouseEventKind::ScrollRight)
+            } else {
+                None
+            }
+        }
+        _ => None,
+    };
+
+    Ok(kind.map(|kind| MouseEvent {
+        kind,
+        column: xpos,
+        row: ypos,
+        modifiers,
+    }))
+}

vendor/crossterm/src/event/sys/windows/poll.rs

@@ -0,0 +1,86 @@
+use std::io;
+use std::time::Duration;
+
+use crossterm_winapi::Handle;
+use winapi::{
+    shared::winerror::WAIT_TIMEOUT,
+    um::{
+        synchapi::WaitForMultipleObjects,
+        winbase::{INFINITE, WAIT_ABANDONED_0, WAIT_FAILED, WAIT_OBJECT_0},
+    },
+};
+
+#[cfg(feature = "event-stream")]
+pub(crate) use super::waker::Waker;
+
+#[derive(Debug)]
+pub(crate) struct WinApiPoll {
+    #[cfg(feature = "event-stream")]
+    waker: Waker,
+}
+
+impl WinApiPoll {
+    #[cfg(not(feature = "event-stream"))]
+    pub(crate) fn new() -> WinApiPoll {
+        WinApiPoll {}
+    }
+
+    #[cfg(feature = "event-stream")]
+    pub(crate) fn new() -> std::io::Result<WinApiPoll> {
+        Ok(WinApiPoll {
+            waker: Waker::new()?,
+        })
+    }
+}
+
+impl WinApiPoll {
+    pub fn poll(&mut self, timeout: Option<Duration>) -> std::io::Result<Option<bool>> {
+        let dw_millis = if let Some(duration) = timeout {
+            duration.as_millis() as u32
+        } else {
+            INFINITE
+        };
+
+        let console_handle = Handle::current_in_handle()?;
+
+        #[cfg(feature = "event-stream")]
+        let semaphore = self.waker.semaphore();
+        #[cfg(feature = "event-stream")]
+        let handles = &[*console_handle, **semaphore.handle()];
+        #[cfg(not(feature = "event-stream"))]
+        let handles = &[*console_handle];
+
+        let output =
+            unsafe { WaitForMultipleObjects(handles.len() as u32, handles.as_ptr(), 0, dw_millis) };
+
+        match output {
+            output if output == WAIT_OBJECT_0 => {
+                // input handle triggered
+                Ok(Some(true))
+            }
+            #[cfg(feature = "event-stream")]
+            output if output == WAIT_OBJECT_0 + 1 => {
+                // semaphore handle triggered
+                let _ = self.waker.reset();
+                Err(io::Error::new(
+                    io::ErrorKind::Interrupted,
+                    "Poll operation was woken up by `Waker::wake`",
+                ))
+            }
+            WAIT_TIMEOUT | WAIT_ABANDONED_0 => {
+                // timeout elapsed
+                Ok(None)
+            }
+            WAIT_FAILED => Err(io::Error::last_os_error()),
+            _ => Err(io::Error::new(
+                io::ErrorKind::Other,
+                "WaitForMultipleObjects returned unexpected result.",
+            )),
+        }
+    }
+
+    #[cfg(feature = "event-stream")]
+    pub fn waker(&self) -> Waker {
+        self.waker.clone()
+    }
+}

vendor/crossterm/src/event/sys/windows/waker.rs

@@ -0,0 +1,40 @@
+use std::sync::{Arc, Mutex};
+
+use crossterm_winapi::Semaphore;
+
+/// Allows to wake up the `WinApiPoll::poll()` method.
+#[derive(Clone, Debug)]
+pub(crate) struct Waker {
+    inner: Arc<Mutex<Semaphore>>,
+}
+
+impl Waker {
+    /// Creates a new waker.
+    ///
+    /// `Waker` is based on the `Semaphore`. You have to use the semaphore
+    /// handle along with the `WaitForMultipleObjects`.
+    pub(crate) fn new() -> std::io::Result<Self> {
+        let inner = Semaphore::new()?;
+
+        Ok(Self {
+            inner: Arc::new(Mutex::new(inner)),
+        })
+    }
+
+    /// Wakes the `WaitForMultipleObjects`.
+    pub(crate) fn wake(&self) -> std::io::Result<()> {
+        self.inner.lock().unwrap().release()?;
+        Ok(())
+    }
+
+    /// Replaces the current semaphore with a new one allowing us to reuse the same `Waker`.
+    pub(crate) fn reset(&self) -> std::io::Result<()> {
+        *self.inner.lock().unwrap() = Semaphore::new()?;
+        Ok(())
+    }
+
+    /// Returns the semaphore associated with the waker.
+    pub(crate) fn semaphore(&self) -> Semaphore {
+        self.inner.lock().unwrap().clone()
+    }
+}

vendor/crossterm/src/event/timeout.rs

@@ -0,0 +1,92 @@
+use std::time::{Duration, Instant};
+
+/// Keeps track of the elapsed time since the moment the polling started.
+#[derive(Debug, Clone)]
+pub struct PollTimeout {
+    timeout: Option<Duration>,
+    start: Instant,
+}
+
+impl PollTimeout {
+    /// Constructs a new `PollTimeout` with the given optional `Duration`.
+    pub fn new(timeout: Option<Duration>) -> PollTimeout {
+        PollTimeout {
+            timeout,
+            start: Instant::now(),
+        }
+    }
+
+    /// Returns whether the timeout has elapsed.
+    ///
+    /// It always returns `false` if the initial timeout was set to `None`.
+    pub fn elapsed(&self) -> bool {
+        self.timeout
+            .map(|timeout| self.start.elapsed() >= timeout)
+            .unwrap_or(false)
+    }
+
+    /// Returns the timeout leftover (initial timeout duration - elapsed duration).
+    pub fn leftover(&self) -> Option<Duration> {
+        self.timeout.map(|timeout| {
+            let elapsed = self.start.elapsed();
+
+            if elapsed >= timeout {
+                Duration::from_secs(0)
+            } else {
+                timeout - elapsed
+            }
+        })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::time::{Duration, Instant};
+
+    use super::PollTimeout;
+
+    #[test]
+    pub fn test_timeout_without_duration_does_not_have_leftover() {
+        let timeout = PollTimeout::new(None);
+        assert_eq!(timeout.leftover(), None)
+    }
+
+    #[test]
+    pub fn test_timeout_without_duration_never_elapses() {
+        let timeout = PollTimeout::new(None);
+        assert!(!timeout.elapsed());
+    }
+
+    #[test]
+    pub fn test_timeout_elapses() {
+        const TIMEOUT_MILLIS: u64 = 100;
+
+        let timeout = PollTimeout {
+            timeout: Some(Duration::from_millis(TIMEOUT_MILLIS)),
+            start: Instant::now() - Duration::from_millis(2 * TIMEOUT_MILLIS),
+        };
+
+        assert!(timeout.elapsed());
+    }
+
+    #[test]
+    pub fn test_elapsed_timeout_has_zero_leftover() {
+        const TIMEOUT_MILLIS: u64 = 100;
+
+        let timeout = PollTimeout {
+            timeout: Some(Duration::from_millis(TIMEOUT_MILLIS)),
+            start: Instant::now() - Duration::from_millis(2 * TIMEOUT_MILLIS),
+        };
+
+        assert!(timeout.elapsed());
+        assert_eq!(timeout.leftover(), Some(Duration::from_millis(0)));
+    }
+
+    #[test]
+    pub fn test_not_elapsed_timeout_has_positive_leftover() {
+        let timeout = PollTimeout::new(Some(Duration::from_secs(60)));
+
+        assert!(!timeout.elapsed());
+        assert!(timeout.leftover().unwrap() > Duration::from_secs(0));
+    }
+}