Updated utils

app/javascript/gabsocial/utils/element_position.js

@@ -0,0 +1,52 @@
+export const findElementPosition = el => {
+  let box;
+
+  if (el.getBoundingClientRect && el.parentNode) {
+    box = el.getBoundingClientRect();
+  }
+
+  if (!box) {
+    return {
+      left: 0,
+      top: 0,
+    };
+  }
+
+  const docEl = document.documentElement;
+  const body = document.body;
+
+  const clientLeft = docEl.clientLeft || body.clientLeft || 0;
+  const scrollLeft = window.pageXOffset || body.scrollLeft;
+  const left = (box.left + scrollLeft) - clientLeft;
+
+  const clientTop = docEl.clientTop || body.clientTop || 0;
+  const scrollTop = window.pageYOffset || body.scrollTop;
+  const top = (box.top + scrollTop) - clientTop;
+
+  return {
+    left: Math.round(left),
+    top: Math.round(top),
+  };
+};
+
+export const getPointerPosition = (el, event) => {
+  const position = {};
+  const box = findElementPosition(el);
+  const boxW = el.offsetWidth;
+  const boxH = el.offsetHeight;
+  const boxY = box.top;
+  const boxX = box.left;
+
+  let pageY = event.pageY;
+  let pageX = event.pageX;
+
+  if (event.changedTouches) {
+    pageX = event.changedTouches[0].pageX;
+    pageY = event.changedTouches[0].pageY;
+  }
+
+  position.y = Math.max(0, Math.min(1, (pageY - boxY) / boxH));
+  position.x = Math.max(0, Math.min(1, (pageX - boxX) / boxW));
+
+  return position;
+};