Add overlay gamepad support for keyboard-only mode (#17)

src/renderer/controller-status-indicator.ts

@@ -0,0 +1,69 @@
+import type { ControllerDeviceInfo } from '../types';
+
+type ControllerSnapshot = {
+  connectedGamepads: ControllerDeviceInfo[];
+  activeGamepadId: string | null;
+};
+
+type ControllerStatusIndicatorOptions = {
+  durationMs?: number;
+  setTimeout?: (callback: () => void, delay: number) => ReturnType<typeof setTimeout>;
+  clearTimeout?: (timer: ReturnType<typeof setTimeout> | number) => void;
+};
+
+function getDeviceLabel(device: ControllerDeviceInfo | undefined): string {
+  if (!device) return 'Controller';
+  return device.id || `Gamepad ${device.index}`;
+}
+
+export function createControllerStatusIndicator(
+  dom: {
+    controllerStatusToast: {
+      textContent: string;
+      classList: { add: (...entries: string[]) => void; remove: (...entries: string[]) => void };
+    };
+  },
+  options: ControllerStatusIndicatorOptions = {},
+) {
+  const durationMs = options.durationMs ?? 2200;
+  const scheduleTimeout = options.setTimeout ?? globalThis.setTimeout;
+  const cancelTimeout =
+    options.clearTimeout ??
+    ((timer: ReturnType<typeof setTimeout> | number) =>
+      globalThis.clearTimeout(timer as ReturnType<typeof setTimeout>));
+  let hideTimeout: ReturnType<typeof setTimeout> | number | null = null;
+  let previousConnectedIds = new Set<string>();
+
+  function show(message: string): void {
+    if (hideTimeout !== null) {
+      cancelTimeout(hideTimeout);
+      hideTimeout = null;
+    }
+
+    dom.controllerStatusToast.textContent = message;
+    dom.controllerStatusToast.classList.remove('hidden');
+    hideTimeout = scheduleTimeout(() => {
+      dom.controllerStatusToast.classList.add('hidden');
+      dom.controllerStatusToast.textContent = '';
+      hideTimeout = null;
+    }, durationMs);
+  }
+
+  function update(snapshot: ControllerSnapshot): void {
+    const newDevices = snapshot.connectedGamepads.filter(
+      (device) => !previousConnectedIds.has(device.id),
+    );
+    if (newDevices.length > 0) {
+      const activeDevice = snapshot.connectedGamepads.find(
+        (device) => device.id === snapshot.activeGamepadId,
+      );
+      const announcedDevice =
+        newDevices.find((device) => device.id === snapshot.activeGamepadId) ?? newDevices[0] ?? activeDevice;
+      show(`Controller detected: ${getDeviceLabel(announcedDevice)}`);
+    }
+
+    previousConnectedIds = new Set(snapshot.connectedGamepads.map((device) => device.id));
+  }
+
+  return { update };
+}