Auto Layout and "Hide bottom bar when pushed"

Question

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.

Solution 1

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

Select the constraint and edit its "Second Item" property

Here you need to choose bottom

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.

Solution 2

The accepted answer did not work for me (the option was not available). However I have found another solution. (based on Hide Bottom Bar When Pushed through Autolayout)

Select booth the view and the object to align (in my case btnShare) and add a new alignment constraint (Bottom Edges).

Solution 3

Hi In storyboard select Tab bar (Is Tab Bar Controller Scene > Tab Bar Controller > Tab Bar ), in the attribute inspector, uncheck Translucent box. This action fix your problem. (But there are many things, "Hide bottom bar when pushed" is to toolbar).

Solution 4

IF you can't select bottomlayoutguide bottom in your Xcode 7+

just do the following: open your storyboard in source code editor

search your controller's identifier

find <layoutGuides>, type <bottom>, copy it id

search by id change attribute from top to bottom

enjoy.

Solution 5

Select your "Navigation Controller" and in "Attribute Inspector" remove the checkmark from "Under Bottom Bars".

View more solutions

Comments

[Eyal]

but now the tab bar is visible when I push VC, I need it to be hidden.

[Onik IV]

At least, in the example project you have shared (AutoLayoutTest), if you only uncheck translucent property in the tab bar, the tab bar disappear when you push and the violet view appear in its place. (Test you own project)

[Eyal]

the problem with this solution is that you see the disappearing / appearing of the tab bar. especially when using the swipe back gesture.

[rdelmar]

@Eyal, I edited my answer to show ways to improve the animation.

[Eyal]

im not comfortable with this kind of solution, hiding/showing the tab bar on viewWillAppear/viewWillDisapear is a bit risky i think. it seems that "hide bottom bar" works great without auto layout, so I wonder if there is something to do with the auto layout configuration.

[rdelmar]

@Eyal, what's wrong with Onik IV's solution? I don't see the tab bar either when I uncheck the translucent property for the tab bar (and hide's bottom bar on push is still checked).

[DogCoffee]

When autolayout will not work stackoverflow.com/questions/29334285/…

[Greg]

@AnthonyM I ran into that problem as well. I ended up editing the storyboard's source by hand so that I could change the constraint's item to use bottom layout guide.bottom.

[aaddesso]

@AnthonyM it's a bit hidden in Xcode 7 but it's there: stackoverflow.com/a/33432500/125407

[alionthego]

just wondering how you managed to edit storyboard source by hand so that you could change the constraint's item to use bottom layout guide.bottom? I've been stuck on this for sometime now and don't understand why I can't just select bottom in storyboard anymore?

[Ashkan Ghodrat]

worked for me, but i m looking for any future bug it may cause.

[Peterdk]

This did not work for me, I still get 1s of white space displayed when pushing ViewController.

[Sudhakar Tharigoppula]

Super...Very useful

[thetrutz]

Yes, this is the correct answer. Set "Hide bottom bar on push" on the view controller, that should not show the tab bar. Don't set it on the tab bar controller, the navigation controller or on the parent view controller of your controller.