title: UICollectionView not adapting to iPad screen during rotation
body: <pre><code>#pragma mark Rotation handling methods
  
  -(void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:
  (NSTimeInterval)duration {
  NSLog(@"IS ROTATING");
  // Fade the collectionView out
  [self.collectionView setAlpha:0.0f];
  
  // Suppress the layout errors by invalidating the layout
  [self.collectionView.collectionViewLayout invalidateLayout];
  
  // Calculate the index of the item that the collectionView is currently displaying
  CGPoint currentOffset = [self.collectionView contentOffset];
  self.currentIndex = currentOffset.x / self.collectionView.frame.size.width;
  }
  
  - (void)viewWillLayoutSubviews;
  {
  [super viewWillLayoutSubviews];
  UICollectionViewFlowLayout *flowLayout = (id)self.collectionView.collectionViewLayout;
  
  if (UIDeviceOrientationIsLandscape([[UIApplication sharedApplication] statusBarOrientation])) {
      flowLayout.itemSize = CGSizeMake(self.view.bounds.size.width, self.view.bounds.size.height);
  } else {
      flowLayout.itemSize = CGSizeMake(self.view.bounds.size.width, self.view.bounds.size.height);
  }
  
  [flowLayout invalidateLayout]; //force the elements to get laid out again with the new size
  }
  
  
  -(void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation {
  
  // Force realignment of cell being displayed
  CGSize currentSize = self.view.bounds.size;
  float offset = self.currentIndex * currentSize.width;
  [self.collectionView setContentOffset:CGPointMake(offset, 0)];
  
  
  NSLog(@"CURRENT bounds: %f",self.view.bounds.size.width);
  NSIndexPath *indexPath = [NSIndexPath indexPathForItem:self.currentIndex inSection:0];
  [self.collectionView scrollToItemAtIndexPath:indexPath atScrollPosition:UICollectionViewScrollPositionLeft animated:NO];
  
  
  // Fade the collectionView back in
  [UIView animateWithDuration:0.125f animations:^{
      [self.collectionView setAlpha:1.0f];
  }];
  
  
  }
  </code></pre>
  
  <p>This is the code. I just want the image to maintain full screen and the collection view is conforming to portrait. I can see that the cells are trying to adjust, but the collection view itself is not resizing. Any suggestions/fixes?</p>