invalidateLayout in layoutSubviews
[Fix] layoutSubviews
[Add] Some manipulating rows/columns methods.
[Fix] AutoresizingMask of UICollectionViewCell in Demo.
[Add] Almost of UICollectionVIew compatible methods.
[Update] podspec
[Update] podspec
[Update] method signature
[Add] Support insert, move, delete rows/columns in HeaderSheet.
[Remove] Insets in Layout.
[Add] Support backgroundColor/View
[Add] Support for BackgroundColor/View in HeaderSheet
[Fix] Change collectionView’s superView from contentView to SpreadSheet itself
0.2.0
0.2.0
[Update] Demo project.