Use async input for termion backend

This enables async refresh, fixing the `logs` and `progress` examples.

src/backend/termion.rs

@@ -2,22 +2,28 @@ extern crate termion;
 
 use ::backend;
 use ::event::{Event, Key};
-use self::termion::color;
+use self::termion::color as tcolor;
 use self::termion::event::Key as TKey;
 use self::termion::input::TermRead;
-use self::termion::style;
 use self::termion::raw::IntoRawMode;
+use self::termion::style as tstyle;
 use std::cell::Cell;
 use std::collections::BTreeMap;
-use std::io::Write;
 use std::fmt;
+use std::io::Write;
+use std::sync::mpsc;
+use std::thread;
+use std::time;
 
 use ::theme;
 
 pub struct Concrete {
     terminal: termion::raw::RawTerminal<::std::io::Stdout>,
     current_style: Cell<theme::ColorStyle>,
-    colors: BTreeMap<i16, (Box<color::Color>, Box<color::Color>)>,
+    colors: BTreeMap<i16, (Box<tcolor::Color>, Box<tcolor::Color>)>,
+
+    input: mpsc::Receiver<Event>,
+    timeout: Option<time::Duration>,
 }
 
 trait Effectable {
@@ -25,10 +31,9 @@ trait Effectable {
     fn off(&self);
 }
 
-struct ColorRef<'a>(&'a color::Color);
-
-impl <'a> color::Color for ColorRef<'a> {
+struct ColorRef<'a>(&'a tcolor::Color);
 
+impl<'a> tcolor::Color for ColorRef<'a> {
     #[inline]
     fn write_fg(&self, f: &mut fmt::Formatter) -> fmt::Result {
         self.0.write_fg(f)
@@ -38,27 +43,26 @@ impl <'a> color::Color for ColorRef<'a> {
     fn write_bg(&self, f: &mut fmt::Formatter) -> fmt::Result {
         self.0.write_bg(f)
     }
-
 }
 
 impl Effectable for theme::Effect {
     fn on(&self) {
         match *self {
             theme::Effect::Simple => (),
-            theme::Effect::Reverse => print!("{}", style::Invert),
+            theme::Effect::Reverse => print!("{}", tstyle::Invert),
         }
     }
 
     fn off(&self) {
         match *self {
             theme::Effect::Simple => (),
-            theme::Effect::Reverse => print!("{}", style::NoInvert),
+            theme::Effect::Reverse => print!("{}", tstyle::NoInvert),
         }
     }
 }
 
-fn apply_colors(fg: &color::Color, bg: &color::Color) {
-    print!("{}{}", color::Fg(ColorRef(fg)), color::Bg(ColorRef(bg)));
+fn apply_colors(fg: &tcolor::Color, bg: &tcolor::Color) {
+    print!("{}{}", tcolor::Fg(ColorRef(fg)), tcolor::Bg(ColorRef(bg)));
 }
 
 impl Concrete {
@@ -71,18 +75,33 @@ impl Concrete {
 impl backend::Backend for Concrete {
     fn init() -> Self {
         print!("{}", termion::cursor::Hide);
+        let terminal = ::std::io::stdout().into_raw_mode().unwrap();
+        let (sender, receiver) = mpsc::channel();
+
+        // TODO: use signal_chan crate
+
+        thread::spawn(move || {
+            for key in ::std::io::stdin().keys() {
+                if let Ok(key) = key {
+                    if sender.send(map_key(key)).is_err() {
+                        break;
+                    }
+                }
+            }
+        });
 
         let backend = Concrete {
-            terminal: ::std::io::stdout().into_raw_mode().unwrap(),
+            terminal: terminal,
             current_style: Cell::new(theme::ColorStyle::Background),
             colors: BTreeMap::new(),
+            input: receiver,
+            timeout: None,
         };
 
         backend
     }
 
     fn finish(&mut self) {
-        // Maybe we should clear everything?
         print!("{}{}", termion::cursor::Show, termion::cursor::Goto(1, 1));
         self.clear();
     }
@@ -148,83 +167,90 @@ impl backend::Backend for Concrete {
         // TODO: handle async refresh, when no input is entered.
         // Could be done with a timeout on the event polling,
         // if it was supportedd.
+        self.timeout = Some(time::Duration::from_millis(1000 / fps as u64));
     }
 
     fn poll_event(&self) -> Event {
-        // TODO: parse input
-        if let Some(key) = ::std::io::stdin().keys().next() {
-            match key.unwrap() {
-                TKey::Esc => Event::Key(Key::Esc),
-                TKey::Backspace => Event::Key(Key::Backspace),
-                TKey::Left => Event::Key(Key::Left),
-                TKey::Right => Event::Key(Key::Right),
-                TKey::Up => Event::Key(Key::Up),
-                TKey::Down => Event::Key(Key::Down),
-                TKey::Home => Event::Key(Key::Home),
-                TKey::End => Event::Key(Key::End),
-                TKey::PageUp => Event::Key(Key::PageUp),
-                TKey::PageDown => Event::Key(Key::PageDown),
-                TKey::Delete => Event::Key(Key::Del),
-                TKey::Insert => Event::Key(Key::Ins),
-                TKey::F(i) if i < 12 => Event::Key(Key::from_f(i)),
-                TKey::F(j) => Event::Unknown(-(j as i32)),
-                TKey::Char('\n') => Event::Key(Key::Enter),
-                TKey::Char('\t') => Event::Key(Key::Tab),
-                TKey::Char(c) => Event::Char(c),
-                TKey::Ctrl('c') => panic!("Ctrl-C pressed"),
-                TKey::Ctrl(c) => Event::CtrlChar(c),
-                TKey::Alt(c) => Event::AltChar(c),
-                _ => Event::Unknown(-1),
-            }
+        // TODO: select! on the input and SIGWINCH signal channel.
+        // TODO: also handle timeout... recv_timeout?
+        if let Some(timeout) = self.timeout {
+            self.input.recv_timeout(timeout).unwrap_or(Event::Refresh)
         } else {
-            Event::Refresh
+            self.input.recv().unwrap()
         }
     }
 }
 
-fn colour_to_termion_colour(clr: &theme::Color) -> Box<color::Color> {
+fn map_key(key: TKey) -> Event {
+    match key {
+        TKey::Esc => Event::Key(Key::Esc),
+        TKey::Backspace => Event::Key(Key::Backspace),
+        TKey::Left => Event::Key(Key::Left),
+        TKey::Right => Event::Key(Key::Right),
+        TKey::Up => Event::Key(Key::Up),
+        TKey::Down => Event::Key(Key::Down),
+        TKey::Home => Event::Key(Key::Home),
+        TKey::End => Event::Key(Key::End),
+        TKey::PageUp => Event::Key(Key::PageUp),
+        TKey::PageDown => Event::Key(Key::PageDown),
+        TKey::Delete => Event::Key(Key::Del),
+        TKey::Insert => Event::Key(Key::Ins),
+        TKey::F(i) if i < 12 => Event::Key(Key::from_f(i)),
+        TKey::F(j) => Event::Unknown(-(j as i32)),
+        TKey::Char('\n') => Event::Key(Key::Enter),
+        TKey::Char('\t') => Event::Key(Key::Tab),
+        TKey::Char(c) => Event::Char(c),
+        TKey::Ctrl('c') => Event::Exit,
+        TKey::Ctrl(c) => Event::CtrlChar(c),
+        TKey::Alt(c) => Event::AltChar(c),
+        _ => Event::Unknown(-1),
+    }
+
+}
+
+fn colour_to_termion_colour(clr: &theme::Color) -> Box<tcolor::Color> {
     match *clr {
-        theme::Color::Dark(theme::BaseColor::Black) => Box::new(color::Black),
-        theme::Color::Dark(theme::BaseColor::Red) => Box::new(color::Red),
-        theme::Color::Dark(theme::BaseColor::Green) => Box::new(color::Green),
+        theme::Color::Dark(theme::BaseColor::Black) => Box::new(tcolor::Black),
+        theme::Color::Dark(theme::BaseColor::Red) => Box::new(tcolor::Red),
+        theme::Color::Dark(theme::BaseColor::Green) => Box::new(tcolor::Green),
         theme::Color::Dark(theme::BaseColor::Yellow) => {
-            Box::new(color::Yellow)
+            Box::new(tcolor::Yellow)
         }
-        theme::Color::Dark(theme::BaseColor::Blue) => Box::new(color::Blue),
+        theme::Color::Dark(theme::BaseColor::Blue) => Box::new(tcolor::Blue),
         theme::Color::Dark(theme::BaseColor::Magenta) => {
-            Box::new(color::Magenta)
+            Box::new(tcolor::Magenta)
         }
-        theme::Color::Dark(theme::BaseColor::Cyan) => Box::new(color::Cyan),
-        theme::Color::Dark(theme::BaseColor::White) => Box::new(color::White),
+        theme::Color::Dark(theme::BaseColor::Cyan) => Box::new(tcolor::Cyan),
+        theme::Color::Dark(theme::BaseColor::White) => Box::new(tcolor::White),
 
         theme::Color::Light(theme::BaseColor::Black) => {
-            Box::new(color::LightBlack)
+            Box::new(tcolor::LightBlack)
         }
         theme::Color::Light(theme::BaseColor::Red) => {
-            Box::new(color::LightRed)
+            Box::new(tcolor::LightRed)
         }
         theme::Color::Light(theme::BaseColor::Green) => {
-            Box::new(color::LightGreen)
+            Box::new(tcolor::LightGreen)
         }
         theme::Color::Light(theme::BaseColor::Yellow) => {
-            Box::new(color::LightYellow)
+            Box::new(tcolor::LightYellow)
         }
         theme::Color::Light(theme::BaseColor::Blue) => {
-            Box::new(color::LightBlue)
+            Box::new(tcolor::LightBlue)
         }
         theme::Color::Light(theme::BaseColor::Magenta) => {
-            Box::new(color::LightMagenta)
+            Box::new(tcolor::LightMagenta)
         }
         theme::Color::Light(theme::BaseColor::Cyan) => {
-            Box::new(color::LightCyan)
+            Box::new(tcolor::LightCyan)
         }
         theme::Color::Light(theme::BaseColor::White) => {
-            Box::new(color::LightWhite)
+            Box::new(tcolor::LightWhite)
         }
 
-        theme::Color::Rgb(r, g, b) => Box::new(color::Rgb(r, g, b)),
+        theme::Color::Rgb(r, g, b) => Box::new(tcolor::Rgb(r, g, b)),
         theme::Color::RgbLowRes(r, g, b) => {
-            Box::new(color::AnsiValue::rgb(r, g, b))
+            Box::new(tcolor::AnsiValue::rgb(r, g, b))
         }
     }
 }