fix(dragging): Pooled events to reuse inside setState.

In a previous refactor, the setState methods were changed to use the prevState prop, but this lost the event received on the function, so the needed properties were desesctructured from the original event so it can be used inside the setState.

No breaking changes

src/components/Carousel.js

@@ -299,9 +299,10 @@ export default class Carousel extends Component {
   onMouseDown = (e, index) => {
     e.preventDefault();
     e.stopPropagation();
+    const { pageX } = e;
     this.setState(() => ({
       clicked: index,
-      dragStart: e.pageX,
+      dragStart: pageX,
     }));
   };
 
@@ -310,9 +311,10 @@ export default class Carousel extends Component {
    * @param {event} e event
    */
   onMouseMove = e => {
+    const { pageX } = e;
     if (this.state.dragStart !== null) {
       this.setState(previousState => ({
-        dragOffset: e.pageX - previousState.dragStart,
+        dragOffset: pageX - previousState.dragStart,
       }));
     }
   };
@@ -323,9 +325,10 @@ export default class Carousel extends Component {
    * @param {number} index of the element drag started on
    */
   onTouchStart = (e, index) => {
+    const { changedTouches } = e;
     this.setState(() => ({
       clicked: index,
-      dragStart: e.changedTouches[0].pageX,
+      dragStart: changedTouches[0].pageX,
     }));
   };
 
@@ -338,9 +341,10 @@ export default class Carousel extends Component {
       e.preventDefault();
       e.stopPropagation();
     }
+    const { changedTouches } = e;
     if (this.state.dragStart !== null) {
       this.setState(previousState => ({
-        dragOffset: e.changedTouches[0].pageX - previousState.dragStart,
+        dragOffset: changedTouches[0].pageX - previousState.dragStart,
       }));
     }
   };