Prepare Dark Theme

Observe user interface theme change.

https://github.com/vector-im/riot-meta/issues/22

Riot/ViewController/ContactDetailsViewController.m

@@ -74,6 +74,11 @@
      Current alert (if any).
      */
     UIAlertController *currentAlert;
+    
+    /**
+     Observe kRiotDesignValuesDidChangeThemeNotification to handle user interface theme change.
+     */
+    id kRiotDesignValuesDidChangeThemeNotificationObserver;
 }
 @end
 
@@ -100,7 +105,6 @@
     [super finalizeInit];
     
     // Setup `MXKViewControllerHandling` properties
-    self.defaultBarTintColor = kRiotNavBarTintColor;
     self.enableBarTintColorStatusChange = NO;
     self.rageShakeManager = [RageShakeManager sharedManager];
 }
@@ -202,6 +206,19 @@
         NSNumber *orientation = (NSNumber*)(notif.userInfo[UIApplicationStatusBarOrientationUserInfoKey]);
         self.bottomImageView.hidden = (orientation.integerValue == UIInterfaceOrientationLandscapeLeft || orientation.integerValue == UIInterfaceOrientationLandscapeRight);
     }];
+    
+    // Observe user interface theme change.
+    kRiotDesignValuesDidChangeThemeNotificationObserver = [[NSNotificationCenter defaultCenter] addObserverForName:kRiotDesignValuesDidChangeThemeNotification object:nil queue:[NSOperationQueue mainQueue] usingBlock:^(NSNotification *notif) {
+        
+        [self userInterfaceThemeDidChange];
+        
+    }];
+    [self userInterfaceThemeDidChange];
+}
+
+- (void)userInterfaceThemeDidChange
+{
+    self.defaultBarTintColor = kRiotSecondaryBgColor;
 }
 
 - (void)viewWillAppear:(BOOL)animated
@@ -271,6 +288,12 @@
 {
     [super destroy];
     
+    if (kRiotDesignValuesDidChangeThemeNotificationObserver)
+    {
+        [[NSNotificationCenter defaultCenter] removeObserver:kRiotDesignValuesDidChangeThemeNotificationObserver];
+        kRiotDesignValuesDidChangeThemeNotificationObserver = nil;
+    }
+    
     if (roomCreationRequest)
     {
         [roomCreationRequest cancel];