fix button [+]

iOSClient/AppDelegate.m

@@ -831,10 +831,16 @@
 {
     UITabBarItem *item;
     NSLayoutConstraint *constraint;
+    CGFloat multiplier = 0;
+    CGFloat safeAreaBottom = 0;
     
     UISplitViewController *splitViewController = (UISplitViewController *)self.window.rootViewController;
     UITabBarController *tabBarController = [splitViewController.viewControllers firstObject];
     
+    if (@available(iOS 11, *)) {
+        safeAreaBottom = [UIApplication sharedApplication].delegate.window.safeAreaInsets.bottom/2;
+    }
+    
     [app aspectTabBar:tabBarController.tabBar hidden:NO];
     
     // File
@@ -880,14 +886,17 @@
     
     constraint =[NSLayoutConstraint constraintWithItem:buttonPlus attribute:NSLayoutAttributeCenterX relatedBy:NSLayoutRelationEqual toItem:tabBarController.tabBar attribute:NSLayoutAttributeCenterX multiplier:1.0 constant:0];
     [tabBarController.view addConstraint:constraint];
-        
-    constraint =[NSLayoutConstraint constraintWithItem:buttonPlus attribute:NSLayoutAttributeCenterY relatedBy:NSLayoutRelationEqual toItem:tabBarController.tabBar attribute:NSLayoutAttributeCenterY multiplier:1.0 constant:0];
+    
+    multiplier = 1 * (tabBarController.tabBar.frame.size.height - safeAreaBottom) / tabBarController.tabBar.frame.size.height;
+    constraint =[NSLayoutConstraint constraintWithItem:buttonPlus attribute:NSLayoutAttributeCenterY relatedBy:NSLayoutRelationEqual toItem:tabBarController.tabBar attribute:NSLayoutAttributeCenterY multiplier:multiplier constant:0];
     [tabBarController.view addConstraint:constraint];
     
-    constraint =[NSLayoutConstraint constraintWithItem:buttonPlus attribute:NSLayoutAttributeWidth relatedBy:NSLayoutRelationEqual toItem:tabBarController.tabBar attribute:NSLayoutAttributeHeight multiplier:0.8 constant:0];
+    multiplier = 0.8 * (tabBarController.tabBar.frame.size.height - safeAreaBottom) / tabBarController.tabBar.frame.size.height;
+    
+    constraint =[NSLayoutConstraint constraintWithItem:buttonPlus attribute:NSLayoutAttributeWidth relatedBy:NSLayoutRelationEqual toItem:tabBarController.tabBar attribute:NSLayoutAttributeHeight multiplier:multiplier constant:0];
     [tabBarController.view addConstraint:constraint];
     
-    constraint =[NSLayoutConstraint constraintWithItem:buttonPlus attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationEqual toItem:tabBarController.tabBar attribute:NSLayoutAttributeHeight multiplier:0.8 constant:0];
+    constraint =[NSLayoutConstraint constraintWithItem:buttonPlus attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationEqual toItem:tabBarController.tabBar attribute:NSLayoutAttributeHeight multiplier:multiplier constant:0];
     [tabBarController.view addConstraint:constraint];
 }