feat: some shit

src/helpers/normalizeWheel.ts

@@ -0,0 +1,49 @@
+
+// Reasonable defaults
+var PIXEL_STEP = 10;
+var LINE_HEIGHT = 40;
+var PAGE_HEIGHT = 800;
+
+export default function normalizeWheel(/*object*/ event) /*object*/ {
+  var sX = 0, sY = 0,       // spinX, spinY
+    pX = 0, pY = 0;       // pixelX, pixelY
+
+  // Legacy
+  if ('detail' in event) { sY = event.detail; }
+  if ('wheelDelta' in event) { sY = -event.wheelDelta / 120; }
+  if ('wheelDeltaY' in event) { sY = -event.wheelDeltaY / 120; }
+  if ('wheelDeltaX' in event) { sX = -event.wheelDeltaX / 120; }
+
+  // side scrolling on FF with DOMMouseScroll
+  if ('axis' in event && event.axis === event.HORIZONTAL_AXIS) {
+    sX = sY;
+    sY = 0;
+  }
+
+  pX = sX * PIXEL_STEP;
+  pY = sY * PIXEL_STEP;
+
+  if ('deltaY' in event) { pY = event.deltaY; }
+  if ('deltaX' in event) { pX = event.deltaX; }
+
+  if ((pX || pY) && event.deltaMode) {
+    if (event.deltaMode == 1) {          // delta in LINE units
+      pX *= LINE_HEIGHT;
+      pY *= LINE_HEIGHT;
+    } else {                             // delta in PAGE units
+      pX *= PAGE_HEIGHT;
+      pY *= PAGE_HEIGHT;
+    }
+  }
+
+  // Fall-back if spin cannot be determined
+  if (pX && !sX) { sX = (pX < 1) ? -1 : 1; }
+  if (pY && !sY) { sY = (pY < 1) ? -1 : 1; }
+
+  return {
+    spinX: sX,
+    spinY: sY,
+    pixelX: pX,
+    pixelY: pY
+  };
+}