ios - How to use autolayout to prevent overlapping of arbitrary number of dynamically created UIViews -

this question exact duplicate of:

• uiview contraints such no 2 subviews can touch

how can prevent multiple uiviews overlapping when number of uiviews isn't defined before hand? don't care placed on screen long padding definition met.

using autolayout seems way can't right.

i need have loop

uiview *prevview = nil; (uiview *aview in [self subviews]) {   // need check foreach subview if view isn't overlapping   // lets assume 2 views simplicity   if (cgrectintersectsrect(aview.frame,prevview.frame))   {     // update view frame     // or update autolayout constraints   } } // might need call function recursively if first pass wasn't successful 

depending on specific wants , needs could:

1. position new subview correctly when creating it. if subviews don't move write logic make correct layout of subviews.

2. loop through subviews suggests , relocate each overlapping subview until it's no longer overlapping:

   while(cgrectintersectsrect(aview.frame, prevview.frame)){     // re-locate aview     [aview setcenter: cgpointmake(arc4random_uniform(self.view.frame.size.width), arc4random_uniform(self.view.frame.size.height))]; } 

   downside of course performance: lot of subviews take while (and many randomly generated numbers) find free space. if use should @ least make sure app won't stuck in infinite loop.

3. divide screen fixed size blocks , use these blocks position views. if subviews never bigger 50 * 50, example, divide screen x blocks of 50 * 50. keep track of these spaces array.