Added flowchart stuff

src/simple-flowchart/assets/utilty/position.js

@@ -0,0 +1,36 @@
+
+
+/**
+ * @param element {HTMLElement}
+ * @return {{top: number, left: number}}
+ */
+function getOffsetRect (element) {
+  let box = element.getBoundingClientRect()
+
+  let scrollTop = window.pageYOffset
+  let scrollLeft = window.pageXOffset
+
+  let top = box.top + scrollTop
+  let left = box.left + scrollLeft
+
+  return {top: Math.round(top), left: Math.round(left)}
+}
+/**
+ * @param event {MouseEvent}
+ * @param element {HTMLElement}
+ * @return {{x: number, y: number}}
+ */
+function getMousePosition (element, event) {
+  let mouseX = event.pageX || event.clientX + document.documentElement.scrollLeft
+  let mouseY = event.pageY || event.clientY + document.documentElement.scrollTop
+
+  let offset = getOffsetRect(element)
+  let x = mouseX - offset.left
+  let y = mouseY - offset.top
+ 
+  return [x, y];
+}
+
+export {
+  getMousePosition, getOffsetRect
+}