UICollectionViewFlexLayout
UICollectionViewFlexLayout is a drop-in replacement for UICollectionViewFlowLayout.
Features
- Section Spacing
- Section Margin
- Section Padding
- Section Background
- Item Spacing
- Item Margin
- Item Padding
- Item Size
- Item Background
- Item Z-Index
Basic Concept
Don't let cells have margins and paddings. Cell metrics are now set outside of the cell. Just focus on contents.
Usage
UICollectionViewDelegateFlexLayout
protocol UICollectionViewDelegateFlexLayout {
// section vertical spacing
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewFlexLayout, verticalSpacingBetweenSectionAt section: Int, and nextSection: Int) -> CGFloat
// section margin
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewFlexLayout, marginForSectionAt section: Int) -> UIEdgeInsets
// section padding
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewFlexLayout, paddingForSectionAt section: Int) -> UIEdgeInsets
// item horizontal spacing
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewFlexLayout, horizontalSpacingBetweenItemAt indexPath: IndexPath, and nextIndexPath: IndexPath) -> CGFloat
// item vertical spacing
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewFlexLayout, verticalSpacingBetweenItemAt indexPath: IndexPath, and nextIndexPath: IndexPath) -> CGFloat
// item margin
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewFlexLayout, marginForItemAt indexPath: IndexPath) -> UIEdgeInsets
// item padding
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewFlexLayout, paddingForItemAt indexPath: IndexPath) -> UIEdgeInsets
// item size
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewFlexLayout, sizeForItemAt indexPath: IndexPath) -> CGSize
// item z-index
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewFlexLayout, zIndexForItemAt indexPath: IndexPath) -> Int
}Section and Item Background
// register
collectionView.register(MySectionBackgroundView.self, forSupplementaryViewOfKind: UICollectionElementKindSectionBackground, withReuseIdentifier: "mySectionBackgroundView")
collectionView.register(MyItemBackgroundView.self, forSupplementaryViewOfKind: UICollectionElementKindItemBackground, withReuseIdentifier: "myItemBackgroundView")
// configure
func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {
switch kind {
case UICollectionElementKindSectionBackground: // section background
return collectionView.dequeueReusableSupplementaryView(ofKind: UICollectionElementKindSectionBackground, withReuseIdentifier: "mySectionBackgroundView", for: indexPath)
case UICollectionElementKindItemBackground: // item background
return collectionView.dequeueReusableSupplementaryView(ofKind: UICollectionElementKindItemBackground, withReuseIdentifier: "myItemBackgroundView", for: indexPath)
case foo: // else
return bar
}
}Tips and Tricks
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Using with RxCocoa
If you're using UICollectionView with RxSwift and RxCocoa, you should create an extension of
_RXDelegateProxyclass to support delegate proxy.import RxCocoa import UICollectionViewFlexLayout extension _RXDelegateProxy: UICollectionViewDelegateFlexLayout { }
Contributing
$ swift package generate-xcodeprojLicense
UICollectionViewFlexLayout is under MIT license. See the LICENSE file for more info.