Only perform click event when not preceded by a drag (googlearchive#78)

Author: fritz-c

CONTRIBUTORS

@@ -13,3 +13,4 @@ Luke Mahé <lukem@google.com>
 Brendan Kenny <bckenny@google.com>
 Moisés Arcos <moiarcsan@gmail.com>
 Peter Grassberger <petertheone@gmail.com>
+Chris Fritz <us.chrisf@gmail.com>

src/markerclusterer.js

@@ -1075,8 +1075,18 @@ ClusterIcon.prototype.onAdd = function() {
   panes.overlayMouseTarget.appendChild(this.div_);
 
   var that = this;
+  var isDragging = false;
   google.maps.event.addDomListener(this.div_, 'click', function(event) {
-    that.triggerClusterClick(event);
+    // Only perform click when not preceded by a drag
+    if (!isDragging) {
+      that.triggerClusterClick(event);
+    }
+  });
+  google.maps.event.addDomListener(this.div_, 'mousedown', function() {
+    isDragging = false;
+  });
+  google.maps.event.addDomListener(this.div_, 'mousemove', function() {
+    isDragging = true;
   });
 };