如何在自定义UICollectionViewCell和CollectionViewLayout中使用rbcollectionviewinfofolderlayout

Question

What I want to do is display a UICollectionView inside a UICollectionViewCell when this cell is selected. I want to use rbcollectionviewinfofolderlayout to fold out my collection view and show a new collection view inside of this. However I'm not sure how I can implement this into my existing code. I have three collection views inside one view. I hide and unhide my views accordingly to what selection the user makes. I use a custom cell xib for the cells inside my collection views and I have a custom collectionviewflowlayout that makes sure there are always 3 cells showing in the width of the device.

This is what my view controller looks like.

in my viewDidLoad I have to set the RBCollectionViewInfoFolderLayout to my collectionview. As you can see the layout variable holds my CustomCollectionViewFlow which I set as the collection view layout before I implemented the RBCollectionviewinfofolderlayout.

    override func viewDidLoad() {
    super.viewDidLoad()

    musicLib.loadLibrary()

    PlaylistCollectionView.indicatorStyle = UIScrollViewIndicatorStyle.White
    AlbumCollectionView.indicatorStyle = UIScrollViewIndicatorStyle.White
    ArtistCollectionView.indicatorStyle = UIScrollViewIndicatorStyle.White

    layout = CustomCollectionViewFlow()

    cview = ArtistCollectionView

    let lay: RBCollectionViewInfoFolderLayout = ArtistCollectionView.collectionViewLayout as! RBCollectionViewInfoFolderLayout
    lay.cellSize = CGSizeMake(80, 80)
    lay.interItemSpacingY = 10
    lay.interItemSpacingX = 0

    let nib = UINib(nibName: "CollectionViewCell", bundle: nil)

    cview.registerClass(UICollectionReusableView.self, forSupplementaryViewOfKind: RBCollectionViewInfoFolderHeaderKind, withReuseIdentifier: "header")
    cview.registerClass(UICollectionReusableView.self, forSupplementaryViewOfKind: RBCollectionViewInfoFolderFooterKind, withReuseIdentifier: "footer")
    cview.registerClass(collectionViewFolder.self, forSupplementaryViewOfKind: RBCollectionViewInfoFolderFolderKind, withReuseIdentifier: "folder")
    cview.registerClass(RBCollectionViewInfoFolderDimple.self, forSupplementaryViewOfKind: RBCollectionViewInfoFolderDimpleKind, withReuseIdentifier: "dimple")


    ArtistCollectionView.collectionViewLayout = lay
    ArtistCollectionView.registerNib(nib, forCellWithReuseIdentifier: "item")
    ArtistCollectionView.dataSource = self
    ArtistCollectionView.delegate = self

    PlaylistCollectionView.collectionViewLayout = layout
    PlaylistCollectionView.registerNib(nib, forCellWithReuseIdentifier: "item")
    PlaylistCollectionView.dataSource = self

    AlbumCollectionView.collectionViewLayout = layout
    AlbumCollectionView.registerNib(nib, forCellWithReuseIdentifier: "item")
    AlbumCollectionView.dataSource = self
}

My CustomCollectionViewFlow looks like this

class CustomCollectionViewFlow: UICollectionViewFlowLayout{
override init(){
    super.init()
    setupLayout()
}

required init?(coder aDecoder: NSCoder){
    super.init(coder: aDecoder)
    setupLayout()
}

override var itemSize: CGSize {
    set {

    }
    get {
        let numberOfColumns: CGFloat = 3

        let itemWidth = (CGRectGetWidth(self.collectionView!.frame) - (numberOfColumns - 1)) / numberOfColumns
        return CGSizeMake(itemWidth, itemWidth)
    }
}

func setupLayout() {
    minimumInteritemSpacing = 0
    minimumLineSpacing = 0
    scrollDirection = .Vertical
}

}

I will hold of on putting all my coding here as it will be become to big of a post and the other methodes are kind of irrelevant at this point. However what I did do is put the example application that I made for this on git here for anyone who wants to check it out.

This image shows what the state of my collectionview was before I implemented the rbcollectionview. The second image shows what I'm trying to achieve

This is how the view should look when an item is being tapped

EDIT

I have been able to get it working kind of. I was able to show the layout like I desired. Just like I had it before I implemented the rbcollectionviewinfofolderlayout. However it seems that when the folder is bigger then the screen size it won't actually fold out. It will fold out for a second and collapse again. It might be caused by the layout i've implemented. Below is the code that is responsible for this.

the class that is responsible for my layout

class RBCollectionLayout: RBCollectionViewInfoFolderLayout
{
    var view: UIView!
    init(view: UIView){
        super.init()
        self.view = view
        setupLayout()
    }

override init(){
    super.init()
    setupLayout()
}

required init?(coder aDecoder: NSCoder) {
    super.init(coder: aDecoder)
    setupLayout()
}

func setupLayout(){
    let numberofItems: CGFloat = 3

    let itemWidth = (CGRectGetWidth(view.frame)) / numberofItems
    cellSize = CGSizeMake(itemWidth, itemWidth)

    interItemSpacingX = 0
    interItemSpacingY = 0
}
}

The method that will calculate the desired with when the screen is changed from portrait to landscape

override func viewWillLayoutSubviews() {
    super.viewWillLayoutSubviews()

    if(view_artist.hidden == false){
        guard let ArtistFlowLayout = ArtistCollectionView.collectionViewLayout as? RBCollectionViewInfoFolderLayout else {
            return
        }
        lay = RBCollectionLayout(view: self.view)
        ArtistCollectionView.collectionViewLayout = lay
        ArtistFlowLayout.invalidateLayout()
    }
}

this is how the layout is being set in my viewdidload

lay = RBCollectionLayout(view: self.view)
ArtistCollectionView.collectionViewLayout = lay

again all my code is available on my git here

Answer 1

Well, I'm probably the only person who can answer your question, since I wrote this control and I doubt anyone else is actually using it.

You seem to be missing a key component which is the delegate method collectionView:viewForSupplementaryElementOfKind:atIndexPath: where you tell the CollectionView what views to use for the various elements. If you go to the GitHub Repo and look at the example you will see that in that method I return 4 different views depending on the viewKind that was asked for. In your code I believe what you want to do is return your custom flow layout based collection view for the RBCollectionViewInfoFolderFolderKind . This would place your 3 cell flow layout view into the expanded folder of the selected cell.

I cloned your repo but it doesn't appear to be up to date with the code you are showing here.