From 56ac5a1105d7ff3d1d7135d562003db957ba174b Mon Sep 17 00:00:00 2001
From: gorhill <rhill@raymondhill.net>
Date: Wed, 27 May 2015 15:15:20 -0400
Subject: [PATCH] coalesce mouse move events

---
 src/js/scriptlets/element-picker.js | 26 ++++++++++++++++++++++----
 1 file changed, 22 insertions(+), 4 deletions(-)

diff --git a/src/js/scriptlets/element-picker.js b/src/js/scriptlets/element-picker.js
index bb77b0c0e..7c8c25d7e 100644
--- a/src/js/scriptlets/element-picker.js
+++ b/src/js/scriptlets/element-picker.js
@@ -735,10 +735,28 @@ var elementFromPoint = function(x, y) {
 
 /******************************************************************************/
 
-var onSvgHovered = function(ev) {
-    var elem = elementFromPoint(ev.clientX, ev.clientY);
-    highlightElements(elem ? [elem] : []);
-};
+var onSvgHovered = (function() {
+    var timer = null;
+    var position = { x: 0, y: 0 };
+
+    var onTimer = function() {
+        timer = null;
+        var elem = elementFromPoint(position.x, position.y);
+        highlightElements(elem ? [elem] : []);
+    };
+
+    var onMove = function(ev) {
+        position.x = ev.clientX;
+        position.y = ev.clientY;
+        if ( timer !== null ) {
+            return;
+        }
+
+        timer = vAPI.setTimeout(onTimer, 40);
+    };
+
+    return onMove;
+})();
 
 /******************************************************************************/