Fix dummy & blt backends

src/backend/blt.rs

@@ -28,6 +28,9 @@ enum ColorRole {
 pub struct Backend {
     buttons_pressed: HashSet<MouseButton>,
     mouse_position: Vec2,
+
+    inner_sender: Sender<Option<Event>>,
+    inner_receiver: Receiver<Option<Event>>,
 }
 
 impl Backend {
@@ -45,9 +48,13 @@ impl Backend {
             },
         ]);
 
+        let (inner_sender, inner_receiver) = crossbeam_channel::bounded(1);
+
         let c = Backend {
             buttons_pressed: HashSet::new(),
             mouse_position: Vec2::zero(),
+            inner_sender,
+            inner_receiver,
         };
 
         Box::new(c)
@@ -307,10 +314,23 @@ impl backend::Backend for Backend {
         terminal::print_xy(pos.x as i32, pos.y as i32, text);
     }
 
-    fn prepare_input(
-        &mut self, event_sink: &Sender<Option<Event>>,
-        input_request: backend::InputRequest,
+    fn start_input_thread(
+        &mut self, event_sink: Sender<Option<Event>>,
+        input_request: Receiver<backend::InputRequest>,
     ) {
+        let receiver = self.inner_receiver.clone();
+
+        thread::spawn(move || {
+            for _ in input_requests {
+                match receiver.recv() {
+                    None => return,
+                    Some(event) => event_sink.send(event),
+                }
+            }
+        });
+    }
+
+    fn prepare_input(&mut self, input_request: backend::InputRequest) {
         match input_request {
             backend::InputRequest::Peek => event_sink.send(self.parse_next()),
             backend::InputRequest::Block => {
@@ -323,7 +343,7 @@ impl backend::Backend for Backend {
                         return;
                     }
                 }
-                event_sink.send(Some(Event::Refresh));
+                self.inner_sender.send(Some(Event::Refresh));
             }
         }
     }

src/backend/dummy.rs

@@ -1,19 +1,28 @@
 //! Dummy backend
+use std::thread;
+
+use crossbeam_channel::{self, Receiver, Sender};
+
 use backend;
-use event;
+use event::Event;
 use theme;
 use vec::Vec2;
 
-use crossbeam_channel::Sender;
-
-pub struct Backend;
+pub struct Backend {
+    inner_sender: Sender<Option<Event>>,
+    inner_receiver: Receiver<Option<Event>>,
+}
 
 impl Backend {
     pub fn init() -> Box<backend::Backend>
     where
         Self: Sized,
     {
-        Box::new(Backend)
+        let (inner_sender, inner_receiver) = crossbeam_channel::bounded(1);
+        Box::new(Backend {
+            inner_sender,
+            inner_receiver,
+        })
     }
 }
 
@@ -30,11 +39,24 @@ impl backend::Backend for Backend {
         (1, 1).into()
     }
 
-    fn prepare_input(
-        &mut self, event_sink: &Sender<Option<event::Event>>,
-        _input_request: backend::InputRequest,
+    fn prepare_input(&mut self, _input_request: backend::InputRequest) {
+        self.inner_sender.send(Some(Event::Exit));
+    }
+
+    fn start_input_thread(
+        &mut self, event_sink: Sender<Option<Event>>,
+        input_requests: Receiver<backend::InputRequest>,
     ) {
-        event_sink.send(Some(event::Event::Exit))
+        let receiver = self.inner_receiver.clone();
+
+        thread::spawn(move || {
+            for _ in input_requests {
+                match receiver.recv() {
+                    None => return,
+                    Some(event) => event_sink.send(event),
+                }
+            }
+        });
     }
 
     fn print_at(&self, _: Vec2, _: &str) {}

src/backend/mod.rs

@@ -57,13 +57,9 @@ pub trait Backend {
     ///
     /// This is only required for non-thread-safe backends like BearLibTerminal
     /// where we cannot collect input in a separate thread.
-    fn prepare_input(
-        &mut self, event_sink: &Sender<Option<Event>>,
-        input_request: InputRequest,
-    ) {
+    fn prepare_input(&mut self, input_request: InputRequest) {
         // Dummy implementation for most backends.
         // Little trick to avoid unused variables.
-        let _ = event_sink;
         let _ = input_request;
     }
 

src/cursive.rs

@@ -605,8 +605,7 @@ impl Cursive {
         }
 
         self.input_trigger.send(backend::InputRequest::Peek);
-        self.backend
-            .prepare_input(&self.event_sink, backend::InputRequest::Peek);
+        self.backend.prepare_input(backend::InputRequest::Peek);
         self.event_source.recv().unwrap().map(Interruption::Event)
     }
 
@@ -616,8 +615,7 @@ impl Cursive {
     fn poll(&mut self) -> Option<Interruption> {
         if !self.expecting_event {
             self.input_trigger.send(backend::InputRequest::Block);
-            self.backend
-                .prepare_input(&self.event_sink, backend::InputRequest::Block);
+            self.backend.prepare_input(backend::InputRequest::Block);
             self.expecting_event = true;
         }
 
@@ -765,7 +763,6 @@ impl Cursive {
     fn handle_interruption(&mut self, interruption: Interruption) {
         match interruption {
             Interruption::Event(event) => {
-                // eprintln!("{:?}, {:?}", event, self.screen_size());
                 if event == Event::Exit {
                     self.quit();
                 }