How to use Auto Layout to move other views when a view is hidden?

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It is possible, but you’ll have to do a little extra work. There are a couple conceptual things to get out of the way first:

  • Hidden views, even though they don’t draw, still participate in Auto Layout and usually retain their frames, leaving other related views in their places.
  • When removing a view from its superview, all related constraints are also removed from that view hierarchy.

In your case, this likely means:

  • If you set your left view to be hidden, the labels stay in place, since that left view is still taking up space (even though it’s not visible).
  • If you remove your left view, your labels will probably be left ambiguously constrained, since you no longer have constraints for your labels’ left edges.

What you need to do is judiciously over-constrain your labels. Leave your existing constraints (10pts space to the other view) alone, but add another constraint: make your labels’ left edges 10pts away from their superview’s left edge with a non-required priority (the default high priority will probably work well).

Then, when you want them to move left, remove the left view altogether. The mandatory 10pt constraint to the left view will disappear along with the view it relates to, and you’ll be left with just a high-priority constraint that the labels be 10pts away from their superview. On the next layout pass, this should cause them to expand left until they fill the width of the superview but for your spacing around the edges.

One important caveat: if you ever want your left view back in the picture, not only do you have to add it back into the view hierarchy, but you also have to reestablish all its constraints at the same time. This means you need a way to put your 10pt spacing constraint between the view and its labels back whenever that view is shown again.

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