Performance improvments (#2869)

webapp/components/sidebar.jsx

@@ -47,7 +47,6 @@ export default class Sidebar extends React.Component {
         this.onScroll = this.onScroll.bind(this);
         this.updateUnreadIndicators = this.updateUnreadIndicators.bind(this);
         this.handleLeaveDirectChannel = this.handleLeaveDirectChannel.bind(this);
-        this.handleResize = this.handleResize.bind(this);
 
         this.showMoreChannelsModal = this.showMoreChannelsModal.bind(this);
         this.showNewChannelModal = this.showNewChannelModal.bind(this);
@@ -64,7 +63,6 @@ export default class Sidebar extends React.Component {
         state.newChannelModalType = '';
         state.showDirectChannelsModal = false;
         state.loadingDMChannel = -1;
-        state.windowWidth = Utils.windowWidth();
         this.state = state;
     }
     getTotalUnreadCount() {
@@ -150,8 +148,6 @@ export default class Sidebar extends React.Component {
 
         this.updateTitle();
         this.updateUnreadIndicators();
-
-        window.addEventListener('resize', this.handleResize);
     }
     shouldComponentUpdate(nextProps, nextState) {
         if (!Utils.areObjectsEqual(nextState, this.state)) {
@@ -173,20 +169,12 @@ export default class Sidebar extends React.Component {
         }
     }
     componentWillUnmount() {
-        window.removeEventListener('resize', this.handleResize);
-
         ChannelStore.removeChangeListener(this.onChange);
         UserStore.removeChangeListener(this.onChange);
         UserStore.removeStatusesChangeListener(this.onChange);
         TeamStore.removeChangeListener(this.onChange);
         PreferenceStore.removeChangeListener(this.onChange);
     }
-    handleResize() {
-        this.setState({
-            windowWidth: Utils.windowWidth(),
-            windowHeight: Utils.windowHeight()
-        });
-    }
     onChange() {
         this.setState(this.getStateFromStores());
     }
@@ -492,6 +480,7 @@ export default class Sidebar extends React.Component {
             return (<div/>);
         }
 
+        this.lastBadgesActive = this.badgesActive;
         this.badgesActive = false;
 
         // keep track of the first and last unread channels so we can use them to set the unread indicators
@@ -508,21 +497,23 @@ export default class Sidebar extends React.Component {
         });
 
         // update the favicon to show if there are any notifications
-        var link = document.createElement('link');
-        link.type = 'image/x-icon';
-        link.rel = 'shortcut icon';
-        link.id = 'favicon';
-        if (this.badgesActive) {
-            link.href = redFavicon;
-        } else {
-            link.href = favicon;
+        if (this.lastBadgesActive !== this.badgesActive) {
+            var link = document.createElement('link');
+            link.type = 'image/x-icon';
+            link.rel = 'shortcut icon';
+            link.id = 'favicon';
+            if (this.badgesActive) {
+                link.href = redFavicon;
+            } else {
+                link.href = favicon;
+            }
+            var head = document.getElementsByTagName('head')[0];
+            var oldLink = document.getElementById('favicon');
+            if (oldLink) {
+                head.removeChild(oldLink);
+            }
+            head.appendChild(link);
         }
-        var head = document.getElementsByTagName('head')[0];
-        var oldLink = document.getElementById('favicon');
-        if (oldLink) {
-            head.removeChild(oldLink);
-        }
-        head.appendChild(link);
 
         var directMessageMore = (
             <li key='more'>