Iphone: Is it possible to hide the TabBar? (Pre-iOS 8)

Question

I have an application that uses a UITabBarController to switch between modes. When in a certain mode, I'd like to hide the tab bar until the steps of that mode have been completed. Note that I'm not using a navigation controller so I can't use the setHidesBottomBarWhenPushed method on the navigation controller to hide the tab bar.

Prior to iOS 8, When I attempt to hide the tarbar using:

self.tabBarController.tabBar.hidden = YES

the tab bar goes away, but it leaves a 50 pixel blank area at the bottom of the screen where the tab bar used to be. I can't seem to figure out how to fill that area. Anything in the UI that is in that area is clipped and cannot be seen.

Any ideas if this is even possible? I'd really like to stay away from the navigation controller.

Answer 1

Here's my code for that:

This is, of course, mucking with the goings on in the controller's view hierarchy. It could change/break. This uses defined APIs, so Apple won't care, but they won't care about breaking your code, either.

- (void)hideTabBar {
  UITabBar *tabBar = self.tabBarController.tabBar;
  UIView *parent = tabBar.superview; // UILayoutContainerView
  UIView *content = [parent.subviews objectAtIndex:0];  // UITransitionView
  UIView *window = parent.superview;

  [UIView animateWithDuration:0.5
                   animations:^{
                     CGRect tabFrame = tabBar.frame;
                     tabFrame.origin.y = CGRectGetMaxY(window.bounds);
                     tabBar.frame = tabFrame;
                     content.frame = window.bounds;
                   }];

  // 1
}

- (void)showTabBar {
  UITabBar *tabBar = self.tabBarController.tabBar;
  UIView *parent = tabBar.superview; // UILayoutContainerView
  UIView *content = [parent.subviews objectAtIndex:0];  // UITransitionView
  UIView *window = parent.superview;

  [UIView animateWithDuration:0.5
                   animations:^{
                     CGRect tabFrame = tabBar.frame;
                     tabFrame.origin.y = CGRectGetMaxY(window.bounds) - CGRectGetHeight(tabBar.frame);
                     tabBar.frame = tabFrame;

                     CGRect contentFrame = content.frame;
                     contentFrame.size.height -= tabFrame.size.height;
                   }];

  // 2
}

Edit: An anonymous user has suggested the following addition for 7.0 (i have not tested this, and could not say whether it is a workaround or an ideal implementation):

// 1. To Hide the black line in IOS7 only, this extra bit is required
if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"7.0")) {
    [self.tabBarController.tabBar setTranslucent:YES];
}  

// 2. For IOS 7 only
if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"7.0")) {
    [self.tabBarController.tabBar setTranslucent:NO];
}

Edit: Entirely untested in 8.x and likely lacking in some layouts.