AutoLayout Modify constraints

Question

I have a problem where I want to modify NSLayoutconstraints on a UIView but it appears a lot of the properties are readonly. I initially have four UIViews as squares in a sort of quad view and they are all tied to each other with a gap of about 20 pixels.

I have a button that increases the frame of one of those squares into full screen encompassing all others. It is at this point I would like to change the constraints of that UIView to attach it to the superviews borders at 20 pixels, that way when I rotate it it doesn't go back to the quad view but maintains full screen. It looks like the property I would want to change is 'seconditem' but this won't work. Am I approaching this problem in the wrong way? I find Autolayout a bit difficult so any help would be much appreciated

Answer 1

Hi you can do 2 sets of constraints :

• 1 to manage your quad view with priority High
• 1 to manage your fullscreen with priority Low

In the method called when you tap your button, set priority high to your fullscreen constraints and priority low to your quad view constraints.