iOS6 UICollecionViewFlowLayout - Horizontal layout - Alignment of cells - ios6

Question

I have a UICollectionViewFlowLayout that basically does what I want, except for one thing - the correct alignment of UICollectionViewCells, when it is scrolling horizontally and with paging enabled.
What i basically want is this - scrolling pagewise over multiple pages:
See 1 here:
UICollectionView Pictures
My problem is, that i have multiple sections, always with this same layout, but when i scroll to the right, it gets empty (just background color), and when i scroll back to the first page (like the one above) i get a weird result:
See 2. in the link above
Apparently the index paths get somehow mixed up - and i really don't know why.
My collectionView:numberOfItemsInSection: method returns always "5", and my numberOfSectionsInCollectionView: returns "2" in this example. I have subclassed UICollectionViewFlowLayout with this:
static CGRect elementLayout[] = {
{20, 20, 649.333333, 294},
{20, 334, 314.666666, 294},
{688, 20.0, 314.666666, 294},
{354.666666, 334, 314.666666, 294},
{688, 334, 314.666666, 294},
};
-(NSArray*)layoutAttributesForElementsInRect:(CGRect)rect {
NSArray *attributes = [super layoutAttributesForElementsInRect:rect];
NSMutableArray *newAttributes = [NSMutableArray array];
for(int i = 0; i < [attributes count]; i++)
{
UICollectionViewLayoutAttributes* attrs = attributes[i];
attrs.frame = elementLayout[i];
[newAttributes addObject:attrs];
}
return newAttributes;
}
But if i don't subclass and try to make it with the standard delegate calls from UICollectionViewFlowLayout, then i get this:
See 3. in the link above
This scrolls correctly to the right, but with the wrong layout. What I expected, is that the cell with NSIndexPath [0, 1] will be on the right side of the "big" cell, and not under it. But even so, i would need the cell with NSIndexPath [0, 1] be aligned like in picture one.
Am I missing something here?

Answer 1

After a lot of trouble i eventually figured out, why the layout behaved strangely.
When having multiple sections, you will need to change the x-origin of every item rect by a multiple of the views width.
Even more interesting: If the UICollectionViewFlowLayout produces less cells than you anticipate, you one can override the indexPath of the UICollectionViewLayoutAttributes, to match the anticipated layout.
So the working configuration would be:
for(int i = 0; i < (countOfCellsAnticipated); i++)
{
UICollectionViewLayoutAttributes* attrs = attributes[i];
NSIndexPath* anticipatedIndexPath = [NSIndexPath indexPathForItem:i
inSection:sectionIndex];
attrs.indexPath = anticipatedIndexPath;
attrs.frame = recalculatedFrameInAbsoluteViewCoordinates;
[newAttributes addObject:attrs];
}
return newAttributes;