add termion backend

Cargo.toml

@@ -29,7 +29,7 @@ async-std-dep = { package = "async-std", version = "1.9", optional = true, featu
 [features]
 default = ["crossterm", "ahash"]
 crossterm = ["ui/crossterm"]
-# termion = ["ui/termion"]
+termion = ["ui/termion"]
 # curses = ["ui/curses"]
 tokio = ["tokio-dep", "async-trait", "ui/tokio"]
 smol = ["smol-dep", "async-trait", "ui/smol"]

ui/Cargo.toml

@@ -13,8 +13,8 @@ async-trait = { version = "0.1", optional = true }
 futures = { version = "0.3", optional = true }
 
 crossterm = { version = "0.19", optional = true }
+termion = { version = "1.5", optional = true }
 # TODO: add all of these
-# termion = { version = "1.5", optional = true }
 # easycurses = { version = "0.12", optional = true }
 # pancurses = { version = "0.16", optional = true, features = ["win32a"] }
 

ui/src/backend/crossterm.rs

@@ -1,4 +1,7 @@
-use std::io::{self, Write};
+use std::{
+    cmp::Ordering,
+    io::{self, Write},
+};
 
 use crossterm::{
     cursor, queue,
@@ -75,12 +78,16 @@ impl<W: Write> Backend for CrosstermBackend<W> {
     }
 
     fn scroll(&mut self, dist: i32) -> error::Result<()> {
-        if dist >= 0 {
-            queue!(self.buffer, terminal::ScrollDown(dist as u16))?;
-        } else {
-            queue!(self.buffer, terminal::ScrollUp(-dist as u16))?;
+        match dist.cmp(&0) {
+            Ordering::Greater => {
+                queue!(self.buffer, terminal::ScrollDown(dist as u16))
+            }
+            Ordering::Less => {
+                queue!(self.buffer, terminal::ScrollUp(-dist as u16))
+            }
+            Ordering::Equal => Ok(()),
         }
-        Ok(())
+        .map_err(Into::into)
     }
 
     fn set_attributes(&mut self, attributes: Attributes) -> error::Result<()> {

ui/src/backend/mod.rs

@@ -2,14 +2,18 @@ use crate::error;
 
 pub fn get_backend<W: std::io::Write>(buf: W) -> error::Result<impl Backend> {
     #[cfg(feature = "crossterm")]
-    CrosstermBackend::new(buf)
+    type Backend<W> = CrosstermBackend<W>;
+    #[cfg(feature = "termion")]
+    type Backend<W> = TermionBackend<W>;
+
+    Backend::new(buf)
 }
 
 mod style;
-// #[cfg(feature = "termion")]
-// mod termion;
-// #[cfg(feature = "termion")]
-// pub use self::termion::TermionBackend;
+#[cfg(feature = "termion")]
+mod termion;
+#[cfg(feature = "termion")]
+pub use self::termion::TermionBackend;
 
 #[cfg(feature = "crossterm")]
 mod crossterm;
@@ -85,6 +89,12 @@ fn default_move_cursor<B: Backend + ?Sized>(
     backend: &mut B,
     direction: MoveDirection,
 ) -> error::Result<()> {
+    // There are a lot of `MoveDirection::NextLine(1)`, so this will slightly speed up
+    // the rendering process as the cursor doesn't need to be gotten every time
+    if let MoveDirection::NextLine(1) = direction {
+        return write!(backend, "\n\r").map_err(Into::into);
+    }
+
     let (mut x, mut y) = backend.get_cursor()?;
 
     match direction {

ui/src/backend/termion.rs

@@ -1,135 +1,128 @@
-use super::Backend;
-use crate::{
-    buffer::Cell,
-    layout::Rect,
-    style::{Color, Modifier},
-};
 use std::{
+    cmp::Ordering,
     fmt,
     io::{self, Write},
 };
 
-pub struct TermionBackend<W>
-where
-    W: Write,
-{
-    stdout: W,
+use termion::{
+    clear, color, cursor,
+    raw::{IntoRawMode, RawTerminal},
+    scroll, style,
+};
+
+use super::{Attributes, Backend, ClearType, Color, MoveDirection, Size};
+use crate::error;
+
+pub struct TermionBackend<W: Write> {
+    buffer: RawTerminal<W>,
 }
 
-impl<W> TermionBackend<W>
-where
-    W: Write,
-{
-    pub fn new(stdout: W) -> TermionBackend<W> {
-        TermionBackend { stdout }
+impl<W: Write> TermionBackend<W> {
+    pub fn new(buffer: W) -> error::Result<TermionBackend<W>> {
+        let buffer = buffer.into_raw_mode()?;
+        buffer.suspend_raw_mode()?;
+        Ok(TermionBackend { buffer })
     }
 }
 
-impl<W> Write for TermionBackend<W>
-where
-    W: Write,
-{
+impl<W: Write> Write for TermionBackend<W> {
     fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
-        self.stdout.write(buf)
+        self.buffer.write(buf)
     }
 
     fn flush(&mut self) -> io::Result<()> {
-        self.stdout.flush()
+        self.buffer.flush()
     }
 }
 
-impl<W> Backend for TermionBackend<W>
-where
-    W: Write,
-{
-    /// Clears the entire screen and move the cursor to the top left of the screen
-    fn clear(&mut self) -> io::Result<()> {
-        write!(self.stdout, "{}", termion::clear::All)?;
-        write!(self.stdout, "{}", termion::cursor::Goto(1, 1))?;
-        self.stdout.flush()
+impl<W: Write> Backend for TermionBackend<W> {
+    fn enable_raw_mode(&mut self) -> error::Result<()> {
+        self.buffer.activate_raw_mode().map_err(Into::into)
     }
 
-    /// Hides cursor
-    fn hide_cursor(&mut self) -> io::Result<()> {
-        write!(self.stdout, "{}", termion::cursor::Hide)?;
-        self.stdout.flush()
+    fn disable_raw_mode(&mut self) -> error::Result<()> {
+        self.buffer.suspend_raw_mode().map_err(Into::into)
     }
 
-    /// Shows cursor
-    fn show_cursor(&mut self) -> io::Result<()> {
-        write!(self.stdout, "{}", termion::cursor::Show)?;
-        self.stdout.flush()
+    fn hide_cursor(&mut self) -> error::Result<()> {
+        write!(self.buffer, "{}", cursor::Hide).map_err(Into::into)
     }
 
-    /// Gets cursor position (0-based index)
-    fn get_cursor(&mut self) -> io::Result<(u16, u16)> {
-        termion::cursor::DetectCursorPos::cursor_pos(&mut self.stdout)
+    fn show_cursor(&mut self) -> error::Result<()> {
+        write!(self.buffer, "{}", cursor::Show).map_err(Into::into)
+    }
+
+    fn get_cursor(&mut self) -> error::Result<(u16, u16)> {
+        cursor::DetectCursorPos::cursor_pos(&mut self.buffer)
+            // 0 index the position
             .map(|(x, y)| (x - 1, y - 1))
+            .map_err(Into::into)
     }
 
-    /// Sets cursor position (0-based index)
-    fn set_cursor(&mut self, x: u16, y: u16) -> io::Result<()> {
-        write!(self.stdout, "{}", termion::cursor::Goto(x + 1, y + 1))?;
-        self.stdout.flush()
+    fn set_cursor(&mut self, x: u16, y: u16) -> error::Result<()> {
+        write!(self.buffer, "{}", cursor::Goto(x + 1, y + 1)).map_err(Into::into)
     }
 
-    fn draw<'a, I>(&mut self, content: I) -> io::Result<()>
-    where
-        I: Iterator<Item = (u16, u16, &'a Cell)>,
-    {
-        use std::fmt::Write;
-
-        let mut string = String::with_capacity(content.size_hint().0 * 3);
-        let mut fg = Color::Reset;
-        let mut bg = Color::Reset;
-        let mut modifier = Modifier::empty();
-        let mut last_pos: Option<(u16, u16)> = None;
-        for (x, y, cell) in content {
-            // Move the cursor if the previous location was not (x - 1, y)
-            if !matches!(last_pos, Some(p) if x == p.0 + 1 && y == p.1) {
-                write!(string, "{}", termion::cursor::Goto(x + 1, y + 1)).unwrap();
-            }
-            last_pos = Some((x, y));
-            if cell.modifier != modifier {
-                write!(
-                    string,
-                    "{}",
-                    ModifierDiff {
-                        from: modifier,
-                        to: cell.modifier
-                    }
-                )
-                .unwrap();
-                modifier = cell.modifier;
-            }
-            if cell.fg != fg {
-                write!(string, "{}", Fg(cell.fg)).unwrap();
-                fg = cell.fg;
-            }
-            if cell.bg != bg {
-                write!(string, "{}", Bg(cell.bg)).unwrap();
-                bg = cell.bg;
-            }
-            string.push_str(&cell.symbol);
+    fn move_cursor(&mut self, direction: MoveDirection) -> error::Result<()> {
+        match direction {
+            MoveDirection::Up(n) => write!(self.buffer, "{}", cursor::Up(n))?,
+            MoveDirection::Down(n) => write!(self.buffer, "{}", cursor::Down(n))?,
+            MoveDirection::Left(n) => write!(self.buffer, "{}", cursor::Left(n))?,
+            MoveDirection::Right(n) => write!(self.buffer, "{}", cursor::Right(n))?,
+            _ => super::default_move_cursor(self, direction)?,
         }
-        write!(
-            self.stdout,
-            "{}{}{}{}",
-            string,
-            Fg(Color::Reset),
-            Bg(Color::Reset),
-            termion::style::Reset,
-        )
+
+        Ok(())
     }
 
-    /// Return the size of the terminal
-    fn size(&self) -> io::Result<Rect> {
-        let terminal = termion::terminal_size()?;
-        Ok(Rect::new(0, 0, terminal.0, terminal.1))
+    fn scroll(&mut self, dist: i32) -> error::Result<()> {
+        match dist.cmp(&0) {
+            Ordering::Greater => {
+                write!(self.buffer, "{}", scroll::Down(dist as u16))
+            }
+            Ordering::Less => {
+                write!(self.buffer, "{}", scroll::Up(-dist as u16))
+            }
+            Ordering::Equal => Ok(()),
+        }
+        .map_err(Into::into)
     }
 
-    fn flush(&mut self) -> io::Result<()> {
-        self.stdout.flush()
+    fn set_attributes(&mut self, attributes: Attributes) -> error::Result<()> {
+        set_attributes(attributes, &mut self.buffer)
+    }
+
+    fn remove_attributes(&mut self, attributes: Attributes) -> error::Result<()> {
+        remove_attributes(attributes, &mut self.buffer)
+    }
+
+    fn set_fg(&mut self, color: Color) -> error::Result<()> {
+        write!(self.buffer, "{}", Fg(color)).map_err(Into::into)
+    }
+
+    fn set_bg(&mut self, color: Color) -> error::Result<()> {
+        write!(self.buffer, "{}", Bg(color)).map_err(Into::into)
+    }
+
+    fn clear(&mut self, clear_type: ClearType) -> error::Result<()> {
+        match clear_type {
+            ClearType::All => write!(self.buffer, "{}", clear::All),
+            ClearType::FromCursorDown => {
+                write!(self.buffer, "{}", clear::AfterCursor)
+            }
+            ClearType::FromCursorUp => {
+                write!(self.buffer, "{}", clear::BeforeCursor)
+            }
+            ClearType::CurrentLine => write!(self.buffer, "{}", clear::CurrentLine),
+            ClearType::UntilNewLine => {
+                write!(self.buffer, "{}", clear::UntilNewline)
+            }
+        }
+        .map_err(Into::into)
+    }
+
+    fn size(&self) -> error::Result<Size> {
+        termion::terminal_size().map(Into::into).map_err(Into::into)
     }
 }
 
@@ -137,128 +130,122 @@ struct Fg(Color);
 
 struct Bg(Color);
 
-struct ModifierDiff {
-    from: Modifier,
-    to: Modifier,
-}
-
 impl fmt::Display for Fg {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        use termion::color::Color as TermionColor;
+        use color::Color as TermionColor;
         match self.0 {
-            Color::Reset => termion::color::Reset.write_fg(f),
-            Color::Black => termion::color::Black.write_fg(f),
-            Color::Red => termion::color::Red.write_fg(f),
-            Color::Green => termion::color::Green.write_fg(f),
-            Color::Yellow => termion::color::Yellow.write_fg(f),
-            Color::Blue => termion::color::Blue.write_fg(f),
-            Color::Magenta => termion::color::Magenta.write_fg(f),
-            Color::Cyan => termion::color::Cyan.write_fg(f),
-            Color::Gray => termion::color::White.write_fg(f),
-            Color::DarkGray => termion::color::LightBlack.write_fg(f),
-            Color::LightRed => termion::color::LightRed.write_fg(f),
-            Color::LightGreen => termion::color::LightGreen.write_fg(f),
-            Color::LightBlue => termion::color::LightBlue.write_fg(f),
-            Color::LightYellow => termion::color::LightYellow.write_fg(f),
-            Color::LightMagenta => termion::color::LightMagenta.write_fg(f),
-            Color::LightCyan => termion::color::LightCyan.write_fg(f),
-            Color::White => termion::color::LightWhite.write_fg(f),
-            Color::Indexed(i) => termion::color::AnsiValue(i).write_fg(f),
-            Color::Rgb(r, g, b) => termion::color::Rgb(r, g, b).write_fg(f),
+            Color::Reset => color::Reset.write_fg(f),
+            Color::Black => color::Black.write_fg(f),
+            Color::Red => color::Red.write_fg(f),
+            Color::Green => color::Green.write_fg(f),
+            Color::Yellow => color::Yellow.write_fg(f),
+            Color::Blue => color::Blue.write_fg(f),
+            Color::Magenta => color::Magenta.write_fg(f),
+            Color::Cyan => color::Cyan.write_fg(f),
+            Color::Grey => color::White.write_fg(f),
+            Color::DarkGrey => color::LightBlack.write_fg(f),
+            Color::LightRed => color::LightRed.write_fg(f),
+            Color::LightGreen => color::LightGreen.write_fg(f),
+            Color::LightBlue => color::LightBlue.write_fg(f),
+            Color::LightYellow => color::LightYellow.write_fg(f),
+            Color::LightMagenta => color::LightMagenta.write_fg(f),
+            Color::LightCyan => color::LightCyan.write_fg(f),
+            Color::White => color::LightWhite.write_fg(f),
+            Color::Ansi(i) => color::AnsiValue(i).write_fg(f),
+            Color::Rgb(r, g, b) => color::Rgb(r, g, b).write_fg(f),
         }
     }
 }
 impl fmt::Display for Bg {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        use termion::color::Color as TermionColor;
+        use color::Color as TermionColor;
         match self.0 {
-            Color::Reset => termion::color::Reset.write_bg(f),
-            Color::Black => termion::color::Black.write_bg(f),
-            Color::Red => termion::color::Red.write_bg(f),
-            Color::Green => termion::color::Green.write_bg(f),
-            Color::Yellow => termion::color::Yellow.write_bg(f),
-            Color::Blue => termion::color::Blue.write_bg(f),
-            Color::Magenta => termion::color::Magenta.write_bg(f),
-            Color::Cyan => termion::color::Cyan.write_bg(f),
-            Color::Gray => termion::color::White.write_bg(f),
-            Color::DarkGray => termion::color::LightBlack.write_bg(f),
-            Color::LightRed => termion::color::LightRed.write_bg(f),
-            Color::LightGreen => termion::color::LightGreen.write_bg(f),
-            Color::LightBlue => termion::color::LightBlue.write_bg(f),
-            Color::LightYellow => termion::color::LightYellow.write_bg(f),
-            Color::LightMagenta => termion::color::LightMagenta.write_bg(f),
-            Color::LightCyan => termion::color::LightCyan.write_bg(f),
-            Color::White => termion::color::LightWhite.write_bg(f),
-            Color::Indexed(i) => termion::color::AnsiValue(i).write_bg(f),
-            Color::Rgb(r, g, b) => termion::color::Rgb(r, g, b).write_bg(f),
+            Color::Reset => color::Reset.write_bg(f),
+            Color::Black => color::Black.write_bg(f),
+            Color::Red => color::Red.write_bg(f),
+            Color::Green => color::Green.write_bg(f),
+            Color::Yellow => color::Yellow.write_bg(f),
+            Color::Blue => color::Blue.write_bg(f),
+            Color::Magenta => color::Magenta.write_bg(f),
+            Color::Cyan => color::Cyan.write_bg(f),
+            Color::Grey => color::White.write_bg(f),
+            Color::DarkGrey => color::LightBlack.write_bg(f),
+            Color::LightRed => color::LightRed.write_bg(f),
+            Color::LightGreen => color::LightGreen.write_bg(f),
+            Color::LightBlue => color::LightBlue.write_bg(f),
+            Color::LightYellow => color::LightYellow.write_bg(f),
+            Color::LightMagenta => color::LightMagenta.write_bg(f),
+            Color::LightCyan => color::LightCyan.write_bg(f),
+            Color::White => color::LightWhite.write_bg(f),
+            Color::Ansi(i) => color::AnsiValue(i).write_bg(f),
+            Color::Rgb(r, g, b) => color::Rgb(r, g, b).write_bg(f),
         }
     }
 }
 
-impl fmt::Display for ModifierDiff {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        let remove = self.from - self.to;
-        if remove.contains(Modifier::REVERSED) {
-            write!(f, "{}", termion::style::NoInvert)?;
-        }
-        if remove.contains(Modifier::BOLD) {
-            // XXX: the termion NoBold flag actually enables double-underline on ECMA-48 compliant
-            // terminals, and NoFaint additionally disables bold... so we use this trick to get
-            // the right semantics.
-            write!(f, "{}", termion::style::NoFaint)?;
-
-            if self.to.contains(Modifier::DIM) {
-                write!(f, "{}", termion::style::Faint)?;
-            }
-        }
-        if remove.contains(Modifier::ITALIC) {
-            write!(f, "{}", termion::style::NoItalic)?;
-        }
-        if remove.contains(Modifier::UNDERLINED) {
-            write!(f, "{}", termion::style::NoUnderline)?;
-        }
-        if remove.contains(Modifier::DIM) {
-            write!(f, "{}", termion::style::NoFaint)?;
-
-            // XXX: the NoFaint flag additionally disables bold as well, so we need to re-enable it
-            // here if we want it.
-            if self.to.contains(Modifier::BOLD) {
-                write!(f, "{}", termion::style::Bold)?;
-            }
-        }
-        if remove.contains(Modifier::CROSSED_OUT) {
-            write!(f, "{}", termion::style::NoCrossedOut)?;
-        }
-        if remove.contains(Modifier::SLOW_BLINK)
-            || remove.contains(Modifier::RAPID_BLINK)
-        {
-            write!(f, "{}", termion::style::NoBlink)?;
-        }
-
-        let add = self.to - self.from;
-        if add.contains(Modifier::REVERSED) {
-            write!(f, "{}", termion::style::Invert)?;
-        }
-        if add.contains(Modifier::BOLD) {
-            write!(f, "{}", termion::style::Bold)?;
-        }
-        if add.contains(Modifier::ITALIC) {
-            write!(f, "{}", termion::style::Italic)?;
-        }
-        if add.contains(Modifier::UNDERLINED) {
-            write!(f, "{}", termion::style::Underline)?;
-        }
-        if add.contains(Modifier::DIM) {
-            write!(f, "{}", termion::style::Faint)?;
-        }
-        if add.contains(Modifier::CROSSED_OUT) {
-            write!(f, "{}", termion::style::CrossedOut)?;
-        }
-        if add.contains(Modifier::SLOW_BLINK) || add.contains(Modifier::RAPID_BLINK)
-        {
-            write!(f, "{}", termion::style::Blink)?;
-        }
-
-        Ok(())
+fn set_attributes<W: Write>(attributes: Attributes, mut w: W) -> error::Result<()> {
+    if attributes.contains(Attributes::RESET) {
+        write!(w, "{}", style::Reset)?;
     }
+
+    if attributes.contains(Attributes::REVERSED) {
+        write!(w, "{}", style::Invert)?;
+    }
+    if attributes.contains(Attributes::BOLD) {
+        write!(w, "{}", style::Bold)?;
+    }
+    if attributes.contains(Attributes::ITALIC) {
+        write!(w, "{}", style::Italic)?;
+    }
+    if attributes.contains(Attributes::UNDERLINED) {
+        write!(w, "{}", style::Underline)?;
+    }
+    if attributes.contains(Attributes::DIM) {
+        write!(w, "{}", style::Faint)?;
+    }
+    if attributes.contains(Attributes::CROSSED_OUT) {
+        write!(w, "{}", style::CrossedOut)?;
+    }
+    if attributes.contains(Attributes::SLOW_BLINK)
+        || attributes.contains(Attributes::RAPID_BLINK)
+    {
+        write!(w, "{}", style::Blink)?;
+    }
+
+    Ok(())
+}
+
+fn remove_attributes<W: Write>(
+    attributes: Attributes,
+    mut w: W,
+) -> error::Result<()> {
+    if attributes.contains(Attributes::RESET) {
+        write!(w, "{}", style::Reset)?;
+    }
+
+    if attributes.contains(Attributes::REVERSED) {
+        write!(w, "{}", style::NoInvert)?;
+    }
+    if attributes.contains(Attributes::BOLD) {
+        write!(w, "{}", style::NoBold)?;
+    }
+    if attributes.contains(Attributes::ITALIC) {
+        write!(w, "{}", style::NoItalic)?;
+    }
+    if attributes.contains(Attributes::UNDERLINED) {
+        write!(w, "{}", style::NoUnderline)?;
+    }
+    if attributes.contains(Attributes::DIM) {
+        write!(w, "{}", style::NoFaint)?;
+    }
+    if attributes.contains(Attributes::CROSSED_OUT) {
+        write!(w, "{}", style::NoCrossedOut)?;
+    }
+    if attributes.contains(Attributes::SLOW_BLINK)
+        || attributes.contains(Attributes::RAPID_BLINK)
+    {
+        write!(w, "{}", style::NoBlink)?;
+    }
+
+    Ok(())
 }

ui/src/events/crossterm.rs

@@ -1,6 +1,7 @@
-use crate::error;
 use crossterm::event;
 
+use crate::error;
+
 pub fn next_event() -> error::Result<super::KeyEvent> {
     loop {
         if let event::Event::Key(k) = event::read()? {

ui/src/events/mod.rs

@@ -1,3 +1,6 @@
+#[cfg(feature = "termion")]
+use std::io::{stdin, Stdin};
+
 use crate::error;
 
 crate::cfg_async! {
@@ -14,6 +17,8 @@ pub use win::AsyncEvents;
 
 #[cfg(feature = "crossterm")]
 mod crossterm;
+#[cfg(feature = "termion")]
+mod termion;
 
 bitflags::bitflags! {
     /// Represents key modifiers (shift, control, alt).
@@ -93,20 +98,44 @@ pub enum KeyCode {
     Esc,
 }
 
-#[derive(Default)]
-pub struct Events {}
+pub struct Events {
+    #[cfg(feature = "termion")]
+    events: ::termion::input::Keys<Stdin>,
+}
 
 impl Events {
+    #[cfg(feature = "termion")]
+    pub fn new() -> Self {
+        #[rustfmt::skip]
+        use ::termion::input::TermRead;
+
+        Self {
+            events: stdin().keys(),
+        }
+    }
+
+    #[cfg(not(feature = "termion"))]
     pub fn new() -> Self {
         Self {}
     }
 }
 
+impl Default for Events {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl Iterator for Events {
     type Item = error::Result<KeyEvent>;
 
+    #[cfg(feature = "crossterm")]
     fn next(&mut self) -> Option<Self::Item> {
-        #[cfg(feature = "crossterm")]
         Some(self::crossterm::next_event())
     }
+
+    #[cfg(feature = "termion")]
+    fn next(&mut self) -> Option<Self::Item> {
+        Some(self::termion::next_event(&mut self.events))
+    }
 }

ui/src/events/termion.rs

@@ -0,0 +1,104 @@
+use std::{
+    convert::{TryFrom, TryInto},
+    io::{self, Stdin},
+};
+
+use termion::{event, input};
+
+use crate::error;
+
+pub fn next_event(
+    events: &mut input::Keys<Stdin>,
+) -> error::Result<super::KeyEvent> {
+    let e = events.next().unwrap()?;
+    e.try_into()
+}
+
+impl TryFrom<event::Key> for super::KeyEvent {
+    type Error = error::ErrorKind;
+
+    fn try_from(key: event::Key) -> error::Result<super::KeyEvent> {
+        let key = match key {
+            event::Key::Backspace => super::KeyCode::Backspace.into(),
+            event::Key::Left => super::KeyCode::Left.into(),
+            event::Key::Right => super::KeyCode::Right.into(),
+            event::Key::Up => super::KeyCode::Up.into(),
+            event::Key::Down => super::KeyCode::Down.into(),
+            event::Key::Home => super::KeyCode::Home.into(),
+            event::Key::End => super::KeyCode::End.into(),
+            event::Key::PageUp => super::KeyCode::PageUp.into(),
+            event::Key::PageDown => super::KeyCode::PageDown.into(),
+            event::Key::BackTab => super::KeyCode::BackTab.into(),
+            event::Key::Delete => super::KeyCode::Delete.into(),
+            event::Key::Insert => super::KeyCode::Insert.into(),
+            event::Key::F(n) => super::KeyCode::F(n).into(),
+            event::Key::Char('\n') => super::KeyCode::Enter.into(),
+            event::Key::Char('\t') => super::KeyCode::Tab.into(),
+            event::Key::Char(c) => super::KeyCode::Char(c).into(),
+            event::Key::Alt(c) => parse_char(c, super::KeyModifiers::ALT)?,
+            event::Key::Ctrl(c) => parse_char(c, super::KeyModifiers::CONTROL)?,
+            event::Key::Null => super::KeyCode::Null.into(),
+            event::Key::Esc => super::KeyCode::Esc.into(),
+            _ => unreachable!(),
+        };
+
+        Ok(key)
+    }
+}
+
+fn parse_char(
+    mut c: char,
+    mut modifiers: super::KeyModifiers,
+) -> error::Result<super::KeyEvent> {
+    let code = loop {
+        if c as u32 >= 256 {
+            break super::KeyCode::Char(c);
+        }
+
+        let k = match event::parse_event(c as u8, &mut std::iter::empty())? {
+            event::Event::Key(k) => k,
+            _ => match char::try_from(c as u32) {
+                Ok(c) => break super::KeyCode::Char(c),
+                Err(_) => {
+                    return Err(io::Error::new(
+                        io::ErrorKind::Other,
+                        "Could not parse an event",
+                    )
+                    .into())
+                }
+            },
+        };
+
+        match k {
+            event::Key::Backspace => break super::KeyCode::Backspace,
+            event::Key::Left => break super::KeyCode::Left,
+            event::Key::Right => break super::KeyCode::Right,
+            event::Key::Up => break super::KeyCode::Up,
+            event::Key::Down => break super::KeyCode::Down,
+            event::Key::Home => break super::KeyCode::Home,
+            event::Key::End => break super::KeyCode::End,
+            event::Key::PageUp => break super::KeyCode::PageUp,
+            event::Key::PageDown => break super::KeyCode::PageDown,
+            event::Key::BackTab => break super::KeyCode::BackTab,
+            event::Key::Delete => break super::KeyCode::Delete,
+            event::Key::Insert => break super::KeyCode::Insert,
+            event::Key::F(n) => break super::KeyCode::F(n),
+            event::Key::Char('\n') => break super::KeyCode::Enter,
+            event::Key::Char('\t') => break super::KeyCode::Tab,
+            event::Key::Char(c) => break super::KeyCode::Char(c),
+            event::Key::Alt(new_c) => {
+                modifiers |= super::KeyModifiers::ALT;
+                c = new_c
+            }
+            event::Key::Ctrl(new_c) => {
+                modifiers |= super::KeyModifiers::CONTROL;
+                c = new_c
+            }
+            event::Key::Null => break super::KeyCode::Null,
+            event::Key::Esc => break super::KeyCode::Esc,
+            _ => unreachable!(),
+        }
+    };
+
+    Ok(super::KeyEvent::new(code, modifiers))
+}

ui/src/events/unix.rs

@@ -30,7 +30,6 @@ impl AsyncEvents {
         })
     }
 
-    // #[cfg_attr(feature = "tokio", allow(clippy::unnecessary_wraps))]
     #[cfg(feature = "tokio")]
     fn try_get_events(&mut self, cx: &mut Context<'_>) -> std::io::Result<()> {
         #[cfg(nightly)]
@@ -45,7 +44,7 @@ impl AsyncEvents {
 
         let tty = Pin::new(&mut self.tty);
 
-        if tty.poll_read(cx, &mut buf[..]).is_ready() {
+        if tty.poll_read(cx, &mut buf).is_ready() {
             self.parser.advance(buf.filled(), buf.remaining() == 0);
         }
 

ui/src/sync_input.rs

@@ -194,12 +194,16 @@ impl<P: Prompt, B: Backend> Input<P, B> {
                     if e.modifiers.contains(KeyModifiers::CONTROL) =>
                 {
                     self.exit()?;
+                    // The exit handler does not return the never (`!`) type, as a
+                    // custom exit handler does not have to exit the program
                     return Err(
                         io::Error::new(io::ErrorKind::Other, "CTRL+C").into()
                     );
                 }
                 KeyCode::Null => {
                     self.exit()?;
+                    // The exit handler does not return the never (`!`) type, as a
+                    // custom exit handler does not have to exit the program
                     return Err(
                         io::Error::new(io::ErrorKind::UnexpectedEof, "EOF").into()
                     );
@@ -234,6 +238,9 @@ impl<P, B: Backend> Input<P, B> {
     #[allow(clippy::new_ret_no_self)]
     /// Creates a new Input
     pub fn new(prompt: P, backend: &mut B) -> Input<P, &mut B> {
+        // The method doesn't return self directly, as its always used with a `&mut B`,
+        // and this tells the compiler that it doesn't need to consume the `&mut B`, but
+        // once the Input goes out of scope, it can be used again
         Input {
             prompt,
             backend,