CODEWITHSUNDEEP
ioscocoa-touchautolayout
Snowman
Snowman

Reputation: 32061

Autolayout height equal to MAX(multiple view heights)

Say I have a view called container. container contains 5 UIButtons. I want to add a height NSLayoutConstraint on container, and this height should be equal to the NSLayoutHeightAttribute of the tallest button in its subviews.

I don't see a straightforward way to do this. Anyone have any ideas?

Upvotes: 28

Views: 4817

Answers (1)

rob mayoff
rob mayoff

Reputation: 385580

You need one constraint for each subview (button), specifying that the container's height should be greater than or equal to the subview's height. Give that constraint a high priority, like UILayoutPriorityRequired (which is the default anyway).

Then add one more constraint on the container's height, specifying that it should have a height equal to zero. Give that constraint a low priority, like UILayoutPriorityLow. Since auto layout tries to minimize the error of unsatisfied constraints, it will make the container as short as possible while still satisfying all higher-priority constraints.

I have put an example in this gist. It produces this result:

example screen shot

The blue views have fixed heights. The tan view is the superview of the blue views and its height is constrained as I described above. I pinned each subview's bottom to the container's bottom, but you could pin the tops or the Y centers instead.

Upvotes: 40

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