src/app.rs

@@ -349,7 +349,10 @@ fn process_gamepad_input(mappings: MappingProvider, proxy: EventLoopProxy<UserEv
             let Some(gamepad) = gilrs.connected_gamepad(event.id) else {
                 continue;
             };
-            mappings.map_gamepad(SimId::Player1, &gamepad);
+            mappings.handle_gamepad_connect(&gamepad);
+        }
+        if event.event == EventType::Disconnected {
+            mappings.handle_gamepad_disconnect(event.id);
         }
         if proxy.send_event(UserEvent::GamepadEvent(event)).is_err() {
             // main thread has closed! we done

src/input.rs

@@ -11,6 +11,14 @@ use crate::emulator::{SimId, VBKey};
 #[derive(Clone, Copy, PartialEq, Eq, Hash)]
 struct DeviceId(u16, u16);
 
+#[derive(Clone)]
+pub struct GamepadInfo {
+    pub id: GamepadId,
+    pub name: String,
+    device_id: DeviceId,
+    pub bound_to: Option<SimId>,
+}
+
 pub struct GamepadMapping {
     buttons: HashMap<Code, VBKey>,
     axes: HashMap<Code, (VBKey, VBKey)>,
@@ -106,6 +114,7 @@ impl InputMapping {
 pub struct MappingProvider {
     device_mappings: Arc<RwLock<HashMap<DeviceId, Arc<RwLock<GamepadMapping>>>>>,
     sim_mappings: HashMap<SimId, Arc<RwLock<InputMapping>>>,
+    gamepad_info: Arc<RwLock<HashMap<GamepadId, GamepadInfo>>>,
 }
 
 impl MappingProvider {
@@ -136,6 +145,7 @@ impl MappingProvider {
         mappings.insert(SimId::Player2, Arc::new(RwLock::new(p2_mappings)));
         Self {
             device_mappings: Arc::new(RwLock::new(HashMap::new())),
+            gamepad_info: Arc::new(RwLock::new(HashMap::new())),
             sim_mappings: mappings,
         }
     }
@@ -144,24 +154,101 @@ impl MappingProvider {
         self.sim_mappings.get(&sim_id).unwrap()
     }
 
-    pub fn map_gamepad(&self, sim_id: SimId, gamepad: &Gamepad) {
+    pub fn handle_gamepad_connect(&self, gamepad: &Gamepad) {
         let device_id = DeviceId(
             gamepad.vendor_id().unwrap_or_default(),
             gamepad.product_id().unwrap_or_default(),
         );
         let mut lock = self.device_mappings.write().unwrap();
-        let gamepad_mapping = match lock.entry(device_id) {
+        let mappings = match lock.entry(device_id) {
-            Entry::Occupied(entry) => entry.get().clone(),
             Entry::Vacant(entry) => {
                 let mappings = GamepadMapping::for_gamepad(gamepad);
-                entry.insert(Arc::new(RwLock::new(mappings))).clone()
+                entry.insert(Arc::new(RwLock::new(mappings)))
             }
-        };
+            Entry::Occupied(entry) => entry.into_mut(),
+        }
+        .clone();
         drop(lock);
+        let mut lock = self.gamepad_info.write().unwrap();
+        let bound_to = SimId::values()
+            .into_iter()
+            .find(|sim_id| lock.values().all(|info| info.bound_to != Some(*sim_id)));
+        if let Entry::Vacant(entry) = lock.entry(gamepad.id()) {
+            let info = GamepadInfo {
+                id: *entry.key(),
+                name: gamepad.name().to_string(),
+                device_id,
+                bound_to,
+            };
+            entry.insert(info);
+        }
+        drop(lock);
+        if let Some(sim_id) = bound_to {
+            self.for_sim(sim_id)
+                .write()
+                .unwrap()
+                .gamepads
+                .insert(gamepad.id(), mappings);
+        }
+    }
+
+    pub fn handle_gamepad_disconnect(&self, gamepad_id: GamepadId) {
+        let mut lock = self.gamepad_info.write().unwrap();
+        let Some(info) = lock.remove(&gamepad_id) else {
+            return;
+        };
+        if let Some(sim_id) = info.bound_to {
+            self.for_sim(sim_id)
+                .write()
+                .unwrap()
+                .gamepads
+                .remove(&gamepad_id);
+        }
+    }
+
+    pub fn assign_gamepad(&self, gamepad_id: GamepadId, sim_id: SimId) {
+        self.unassign_gamepad(gamepad_id);
+        let mut lock = self.gamepad_info.write().unwrap();
+        let Some(info) = lock.get_mut(&gamepad_id) else {
+            return;
+        };
+        info.bound_to = Some(sim_id);
+        let device_id = info.device_id;
+        drop(lock);
+        let Some(device_mappings) = self
+            .device_mappings
+            .write()
+            .unwrap()
+            .get(&device_id)
+            .cloned()
+        else {
+            return;
+        };
         self.for_sim(sim_id)
             .write()
             .unwrap()
             .gamepads
-            .insert(gamepad.id(), gamepad_mapping);
+            .insert(gamepad_id, device_mappings);
+    }
+
+    pub fn unassign_gamepad(&self, gamepad_id: GamepadId) {
+        let mut lock = self.gamepad_info.write().unwrap();
+        let Some(info) = lock.get_mut(&gamepad_id) else {
+            return;
+        };
+        if let Some(sim_id) = info.bound_to {
+            let mut sim_mapping = self.for_sim(sim_id).write().unwrap();
+            sim_mapping.gamepads.remove(&gamepad_id);
+        }
+        info.bound_to = None;
+    }
+
+    pub fn gamepad_info(&self) -> Vec<GamepadInfo> {
+        self.gamepad_info
+            .read()
+            .unwrap()
+            .values()
+            .cloned()
+            .collect()
     }
 }

src/window/input.rs

@@ -42,7 +42,7 @@ impl InputWindow {
         }
     }
 
-    fn render_key_bindings(&mut self, ui: &mut Ui, sim_id: SimId) {
+    fn show_key_bindings(&mut self, ui: &mut Ui, sim_id: SimId) {
         let mappings = self.mappings.for_sim(sim_id);
         let binding_names = {
             let mapping = mappings.read().unwrap();
@@ -86,6 +86,37 @@ impl InputWindow {
                 }
             });
     }
+
+    fn show_gamepads(&mut self, ui: &mut Ui) {
+        let mut gamepads = self.mappings.gamepad_info();
+        gamepads.sort_by_key(|g| usize::from(g.id));
+
+        if gamepads.is_empty() {
+            ui.label("No gamepads connected.");
+            return;
+        }
+
+        for (index, gamepad) in gamepads.into_iter().enumerate() {
+            ui.horizontal(|ui| {
+                ui.label(format!("Gamepad {index}: {}", gamepad.name));
+                let mut bound_to = gamepad.bound_to;
+                let mut rebind = false;
+                rebind |= ui
+                    .selectable_value(&mut bound_to, Some(SimId::Player1), "Player 1")
+                    .changed();
+                rebind |= ui
+                    .selectable_value(&mut bound_to, Some(SimId::Player2), "Player 2")
+                    .changed();
+                rebind |= ui.selectable_value(&mut bound_to, None, "Nobody").changed();
+                if rebind {
+                    match bound_to {
+                        Some(sim_id) => self.mappings.assign_gamepad(gamepad.id, sim_id),
+                        None => self.mappings.unassign_gamepad(gamepad.id),
+                    }
+                }
+            });
+        }
+    }
 }
 
 impl AppWindow for InputWindow {
@@ -104,12 +135,14 @@ impl AppWindow for InputWindow {
             ui.horizontal(|ui| {
                 ui.selectable_value(&mut self.active_tab, InputTab::Player1, "Player 1");
                 ui.selectable_value(&mut self.active_tab, InputTab::Player2, "Player 2");
+                ui.selectable_value(&mut self.active_tab, InputTab::Gamepads, "Gamepads");
             });
         });
         CentralPanel::default().show(ctx, |ui| {
             match self.active_tab {
-                InputTab::Player1 => self.render_key_bindings(ui, SimId::Player1),
+                InputTab::Player1 => self.show_key_bindings(ui, SimId::Player1),
-                InputTab::Player2 => self.render_key_bindings(ui, SimId::Player2),
+                InputTab::Player2 => self.show_key_bindings(ui, SimId::Player2),
+                InputTab::Gamepads => self.show_gamepads(ui),
             };
         });
     }
@@ -130,4 +163,5 @@ impl AppWindow for InputWindow {
 enum InputTab {
     Player1,
     Player2,
+    Gamepads,
 }