only cancel touch events if it was the right touch

Author: brianfay

lib/draggable.js

@@ -516,7 +516,7 @@ module.exports = React.createClass({
   handleDragStart: function (e) {
     // Set touch identifier in component state if this is a touch event
     if(e.targetTouches){
-      this.setState({identifier: e.targetTouches[0].identifier});
+      this.setState({touchIdentifier: e.targetTouches[0].identifier});
     }
 
     // Make it possible to attach event handlers on top of this one
@@ -562,6 +562,11 @@ module.exports = React.createClass({
       return;
     }
 
+    // Short circuit if this is not the correct touch event
+    if(e.changedTouches && (e.changedTouches[0].identifier != this.state.touchIdentifier)){
+     return;
+    } 
+
     removeUserSelectStyles(this);
 
     // Turn off dragging
@@ -580,7 +585,7 @@ module.exports = React.createClass({
 
   handleDrag: function (e) {
     // Return if this is a touch event, but not the correct one for this element
-    if(e.targetTouches && (e.targetTouches[0].identifier != this.state.identifier)){
+    if(e.targetTouches && (e.targetTouches[0].identifier != this.state.touchIdentifier)){
       return;
     }
     var dragPoint = getControlPosition(e);