Add AnalyticsScreenTimer and track more screens.

Update Analytics with new methods in MXAnalyticsDelegate.

Riot/Modules/GlobalSearch/Rooms/DirectoryViewController.m

@@ -35,6 +35,8 @@
     id kThemeServiceDidChangeThemeNotificationObserver;
 }
 
+@property (nonatomic) AnalyticsScreenTimer *screenTimer;
+
 @end
 
 @implementation DirectoryViewController
@@ -46,6 +48,8 @@
     // Setup `MXKViewControllerHandling` properties
     self.enableBarTintColorStatusChange = NO;
     self.rageShakeManager = [RageShakeManager sharedManager];
+    
+    self.screenTimer = [[AnalyticsScreenTimer alloc] initWithScreen:AnalyticsScreenRoomDirectory];
 }
 
 - (void)viewDidLoad
@@ -106,9 +110,6 @@
 - (void)viewWillAppear:(BOOL)animated
 {
     [super viewWillAppear:animated];
-
-    // Screen tracking
-    [Analytics.shared trackScreen:AnalyticsScreenRoomDirectory];
     
     // Observe kAppDelegateDidTapStatusBarNotificationObserver.
     kAppDelegateDidTapStatusBarNotificationObserver = [[NSNotificationCenter defaultCenter] addObserverForName:kAppDelegateDidTapStatusBarNotification object:nil queue:[NSOperationQueue mainQueue] usingBlock:^(NSNotification *notif) {
@@ -135,6 +136,8 @@
         // the selected room (if any) is highlighted.
         [self refreshCurrentSelectedCell:YES];
     }
+    
+    [self.screenTimer start];
 }
 
 - (void)viewWillDisappear:(BOOL)animated
@@ -148,6 +151,12 @@
     [super viewWillDisappear:animated];
 }
 
+- (void)viewDidDisappear:(BOOL)animated
+{
+    [super viewDidDisappear:animated];
+    [self.screenTimer stop];
+}
+
 - (void)displayWitDataSource:(PublicRoomsDirectoryDataSource *)dataSource2
 {
     // Let the data source provide cells