A11y: various improvements

src/Sensors/Motion.ts

@@ -0,0 +1,33 @@
+import { UIEventSource } from "../Logic/UIEventSource"
+
+export default class Motion {
+    public static singleton = new Motion()
+    /**
+     * In m/s²
+     */
+    public maxAcc = new UIEventSource<number>(0)
+
+    public lastShakeEvent = new UIEventSource<Date>(undefined)
+
+    private isListening = false
+    private constructor() {
+        this.startListening()
+    }
+
+    private onUpdate(eventData: DeviceMotionEvent) {
+        const acc = eventData.acceleration
+        this.maxAcc.setData(Math.max(acc.x, acc.y, acc.z))
+        if (this.maxAcc.data > 22) {
+            this.lastShakeEvent.setData(new Date())
+        }
+    }
+
+    startListening() {
+        if (this.isListening) {
+            return
+        }
+        this.isListening = true
+        console.log("Listening to motion events", this)
+        window.addEventListener("devicemotion", (e) => this.onUpdate(e))
+    }
+}