From e2cd841fe893654f9d2b42b37160c45551185020 Mon Sep 17 00:00:00 2001
From: TheSisb <TheSisb@users.noreply.github.com>
Date: Wed, 14 May 2014 15:25:05 -0700
Subject: [PATCH] Handling mousemove more delicately

Mousemove fires very frequently and is a sure way of killing any app's FPS.  This tweak makes sure it is only bound when it is in fact needed.
---
 select2.js | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/select2.js b/select2.js
index 580d32ed..1769fbc0 100644
--- a/select2.js
+++ b/select2.js
@@ -193,10 +193,6 @@ the specific language governing permissions and limitations under the Apache Lic
         });
     }
 
-    $document.on("mousemove", function (e) {
-        lastMousePosition.x = e.pageX;
-        lastMousePosition.y = e.pageY;
-    });
 
     /**
      * filters mouse events so an event is fired only if the mouse moved.
@@ -1343,6 +1339,12 @@ the specific language governing permissions and limitations under the Apache Lic
 
             this.opening();
 
+            // Only bind the document mousemove when the dropdown is visible
+            $document.on("mousemove.select2Event", function (e) {
+                lastMousePosition.x = e.pageX;
+                lastMousePosition.y = e.pageY;
+            });
+            
             return true;
         },
 
@@ -1439,6 +1441,8 @@ the specific language governing permissions and limitations under the Apache Lic
             this.container.removeClass("select2-dropdown-open").removeClass("select2-container-active");
             this.results.empty();
 
+            // Now that the dropdown is closed, unbind the global document mousemove event
+            $document.off("mousemove.select2Event");
 
             this.clearSearch();
             this.search.removeClass("select2-active");