From 1dd3dffca6cf256232331fb5183f649a7f3df30e Mon Sep 17 00:00:00 2001
From: Thomas Steur <tsteur@users.noreply.github.com>
Date: Thu, 2 Feb 2017 14:39:35 +1300
Subject: [PATCH 1/2] Fix Piwik UI becomes very slow when having many rows

PR for Piwik 2.x for #11308
---
 plugins/CoreHome/javascripts/dataTable.js | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/plugins/CoreHome/javascripts/dataTable.js b/plugins/CoreHome/javascripts/dataTable.js
index bb892a636c5..aae62b3ad17 100644
--- a/plugins/CoreHome/javascripts/dataTable.js
+++ b/plugins/CoreHome/javascripts/dataTable.js
@@ -95,6 +95,7 @@ $.extend(DataTable.prototype, UIControl.prototype, {
         this.workingDivId = this._createDivId();
         domElem.attr('id', this.workingDivId);
 
+	this.maxNumRowsToHandleEvents = 250;
         this.loadedSubDataTable = {};
         this.isEmpty = $('.pk-emptyDataTable', domElem).length > 0;
         this.bindEventsAndApplyStyle(domElem);
@@ -1502,8 +1503,13 @@ $.extend(DataTable.prototype, UIControl.prototype, {
         $nodes.off('click');
         $nodes.on('click', toggleFooter);
     },
-
+    canHandleRowEvents: function (domElem) {
+        return domElem.find('table > tbody > tr').size() <= this.maxNumRowsToHandleEvents;
+    }, 
     handleColumnHighlighting: function (domElem) {
+        if (!this.canHandleRowEvents(domElem)) {
+            return;
+        }
 
         var maxWidth = {};
         var currentNthChild = null;
@@ -1788,6 +1794,10 @@ $.extend(DataTable.prototype, UIControl.prototype, {
 
     // also used in action data table
     doHandleRowActions: function (trs) {
+	if (!trs || trs.length > this.maxNumRowsToHandleEvents) {
+            return;
+        }
+
         var self = this;
 
         var merged = $.extend({}, self.param, self.props);

From a3d828076c722e8ef62f185b75f75f4b8063dcfb Mon Sep 17 00:00:00 2001
From: Thomas Steur <tsteur@users.noreply.github.com>
Date: Sat, 11 Feb 2017 15:09:55 +1300
Subject: [PATCH 2/2] disable some row features when there are more than 255
 rows

since tr from thead counts as well.
---
 plugins/CoreHome/javascripts/dataTable.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/plugins/CoreHome/javascripts/dataTable.js b/plugins/CoreHome/javascripts/dataTable.js
index aae62b3ad17..6050aa6937c 100644
--- a/plugins/CoreHome/javascripts/dataTable.js
+++ b/plugins/CoreHome/javascripts/dataTable.js
@@ -95,7 +95,7 @@ $.extend(DataTable.prototype, UIControl.prototype, {
         this.workingDivId = this._createDivId();
         domElem.attr('id', this.workingDivId);
 
-	this.maxNumRowsToHandleEvents = 250;
+	this.maxNumRowsToHandleEvents = 255;
         this.loadedSubDataTable = {};
         this.isEmpty = $('.pk-emptyDataTable', domElem).length > 0;
         this.bindEventsAndApplyStyle(domElem);