[kbd] Implement keyboard and adapter

src/device/keyboard.rs

@@ -0,0 +1,68 @@
+use std::sync::mpsc::TryRecvError;
+use crate::util::{EmulatorError, EmulatorResult};
+
+
+// display thread sends these to the device thread.
+
+// device thread updates on key up and down?
+
+
+pub struct Keyboard {
+    bitflags: u16,
+    keyboard_event_receiver: std::sync::mpsc::Receiver<KeyboardEvent>,
+}
+
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub enum KeyboardEvent {
+    KeyUp(u8),
+    KeyDown(u8),
+}
+
+impl Keyboard {
+    pub fn new(keyboard_event_receiver: std::sync::mpsc::Receiver<KeyboardEvent>) -> Keyboard {
+        Keyboard {
+            bitflags: 0,
+            keyboard_event_receiver,
+        }
+    }
+
+    /// Update keyboard based on pending keyboard events
+    pub fn update_keyboard(&mut self) -> EmulatorResult<()> {
+        loop {
+            let keyboard_event_recv_res = self.keyboard_event_receiver.try_recv();
+            match keyboard_event_recv_res {
+                Ok(event) => {
+                    log::warn!("Processing {:?}",event);
+                    self.update_keyboard_state(event);
+                }
+                Err(TryRecvError::Empty) => {
+                    break Ok(());
+                }
+                Err(TryRecvError::Disconnected) => {
+                    break Err(EmulatorError::IOError("Keyboard updater disconnected".into()));
+                }
+            }
+        }
+    }
+
+
+    /// Query if key is down
+    pub fn query_key_down(&self, key_num: u8) -> bool {
+        (self.bitflags | 1 << key_num) == (1 << key_num)
+    }
+
+    fn update_keyboard_state(&mut self, keyboard_event: KeyboardEvent) {
+        match keyboard_event {
+            KeyboardEvent::KeyUp(key) => { self.key_up(key) }
+            KeyboardEvent::KeyDown(key) => { self.key_down(key) }
+        }
+    }
+    fn key_down(&mut self, x: u8) {
+        self.bitflags |= 1 << x;
+        log::trace!("Key Down - state {}",self.bitflags);
+    }
+    fn key_up(&mut self, x: u8) {
+        self.bitflags &= !((1 << x) as u16);
+        log::debug!("Key Up - state {}",self.bitflags);
+    }
+}