Auto Layout and "Hide bottom bar when pushed"

ios objective-c storyboard uitabbarcontroller autolayout
Eyal picture Eyal · Feb 25, 2015 · Viewed 22k times · Source

My app's (simplified) structure is this:

UITabBarController with one UINavigationController holding a UITableViewController as root view controller.

when tapping one of the table view controller cells, I push a regular UIViewController (lets call it VC) end hiding the bottom tab bar. (using the "Hide bottom bar when pushed" flag)

In storyboard I added a regular UIView subclass to VC that look like a bottom bar, and I use Auto Layout to pin it to the bottom of the VC view.

The problem
when I push VC it takes a second for this view to pin to the bottom, it looks like auto layout pin it to the bottom as if the tab bar is not hidden and after a sec it recognise that the tab bar is hidden and moves it to the real bottom of the view.

I know its not the best explanation, so I added a very simple project to demonstrate the issue.

Answer

Earl Grey picture Earl Grey · Mar 6, 2015

The problem is with this specific constraint which is between the view and the top of the bottom layout guide.

enter image description here

Select the constraint and edit its "Second Item" property

enter image description here

Here you need to choose bottom

enter image description here

Once you have that, the pink view is not influenced by layout guide anymore. The layout guide seem to acknowledge that the tab bar is hidden only after the root view of the pushed view controller is in the bounds of main screen and this happens only when the animation is finished.

And that is the reason the view hierarchy needs to be laid out again which causes the unwanted animation.

Related questions

Storyboard doesn't contain a view controller with identifier

I keep getting the following error: Storyboard (<UIStoryboard: 0x7ebdd20>) doesn't contain a view controller with identifier 'drivingDetails' This is the code: - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { UIViewController *controller = [self.storyboard instantiateViewControllerWithIdentifier:@"drivingDetails"]; controller.title = [[…

Read More
How can I load storyboard programmatically from class?

My problem is that I was looking for way to use both storyboard and xib. But I can't find proper way to load and show storyboard programmatically. Project was started developing with xib, and now it's very hard to nest …

Read More
Storyboard - refer to ViewController in AppDelegate

consider the following scenario: I have a storyboard-based app. I add a ViewController object to the storyboard, add the class files for this ViewController into the project and specify the name of the new class in the IB identity inspector. …

Read More