title: Detect page change in UICollectionView
body: <p>I tried finding this question for a while but could not find this problem's answer.
  My problem is that i have a <code>UICollectionView</code> and the Scroll Direction is <code>Horizontal</code> with <code>Paging Enabled</code>. My problem is that i want to keep the tack of the current page number on which the user is, so i created an <code>int</code> variable and now want to add or subtract it by 1 each time the user swipes right or left. I tried using <code>scrollView</code>'s delegate</p>
  
  <pre><code>- (void)scrollViewDidScroll:(UIScrollView *)scrollView
  </code></pre>
  
  <p>but when the user swipes right or left, it is called as many number of the times as the number of columns on a page in the <code>UICollectionView</code> plus it wont let me know that whether the user went to the next page or the previous one.</p>