I can't get the column widths in this UICollectionView to resize upon a rotation change as the invalidateLayout from the custom UICollectionViewFlowLayout is NOT triggering the sizeForItemAtIndexPath method in the collectionView? Any ideas? I really just want the column resizing to occur via the sizeForItemAtIndexPath upon rotation.
**Output Code on Rotation**
Note: "sizeForItemAtIndexPath" is not triggered even though "invalidateLayout" is...
> ViewController:viewWillLayoutSubviews
> GCCalendarLayout:shouldInvalidateLayoutForBoundsChange
> GCCalendarLayout:invalidateLayout**Custom Collection View**
import UIKit
class GCCalendar : UICollectionView, UICollectionViewDataSource, UICollectionViewDelegate {
// Init ---------------
func commonInit(coder aDecoder: NSCoder) {
print("GCCalendar - commonInit")
self.registerClass(GCCalendarCell.self, forCellWithReuseIdentifier: "GCCalendarCell")
self.dataSource = self
self.delegate = self
let layout : GCCalendarLayout = GCCalendarLayout(coder: aDecoder)!
self.setCollectionViewLayout(layout, animated: false)
self.backgroundColor = UIColor.whiteColor()
}
required init?(coder aDecoder: NSCoder) {
print("GCCalendar - init coder")
super.init(coder: aDecoder)
commonInit(coder: aDecoder)
}
// UICollectionViewDelegateFlowLayout ------------
func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
print("sizeForItemAtIndexPath")
let w : CGFloat = floor(self.frame.size.width/7)
return CGSize(width: w, height: w)
}
func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAtIndex section: Int) ->
CGFloat {
print("minimumInteritemSpacingForSectionAtIndex")
return 0.0
}
func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAtIndex section: Int) -> CGFloat {
print("minimumLineSpacingForSectionAtIndex")
return 0.0
}
// UICollectionViewDataSource -------------------
func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 21
}
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCellWithReuseIdentifier("GCCalendarCell", forIndexPath: indexPath) as? GCCalendarCell
return cell!
}
}**Custom Layout**
import UIKit
class GCCalendarLayout : UICollectionViewFlowLayout {
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
override func shouldInvalidateLayoutForBoundsChange(newBounds: CGRect) -> Bool {
print("GCCalendarLayout:shouldInvalidateLayoutForBoundsChange")
return true
}
override func invalidateLayout() {
print("GCCalendarLayout:invalidateLayout")
super.invalidateLayout()
}
override func prepareForCollectionViewUpdates(updateItems: [UICollectionViewUpdateItem]) {
print("GCCalendarLayout:prepareForCollectionViewUpdates")
super.prepareForCollectionViewUpdates(updateItems)
}
override func finalizeCollectionViewUpdates() {
print("GCCalendarLayout:finalizeCollectionViewUpdates")
super.finalizeCollectionViewUpdates()
}
}