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I have a problem with making a self sizing UICollectionView with a cell that contains UITableView with a header that has a label with dynamic height.
Can someone point me out to what I need to change in the attached sample project?
You can see on the screenshot that the table does not fit the view as the cell's height is currently manually set.
import UIKit
class ViewController: UIViewController {
static let section1 = "section1"
static let section2 = "section2"
private weak var collectionView: UICollectionView!
override func viewDidLoad() {
self.navigationItem.title = "Collection View"
super.viewDidLoad()
self.setupCollectionView()
}
private func setupCollectionView() {
let flowLayout = UICollectionViewFlowLayout()
flowLayout.scrollDirection = .vertical
flowLayout.minimumInteritemSpacing = 0.0
flowLayout.minimumLineSpacing = 0.0
let collectionView = UICollectionView(frame: self.view.frame, collectionViewLayout: flowLayout)
collectionView.alwaysBounceVertical = true
collectionView.register(
SectionHeaderView.self,
forSupplementaryViewOfKind: UICollectionView.elementKindSectionHeader,
withReuseIdentifier: SectionHeaderView.sectionHeaderId
)
collectionView.register(Section1.self, forCellWithReuseIdentifier: ViewController.section1)
collectionView.register(Section2.self, forCellWithReuseIdentifier: ViewController.section2)
self.view.addSubview(collectionView)
self.collectionView = collectionView
self.collectionView.translatesAutoresizingMaskIntoConstraints = false
self.collectionView.topAnchor.constraint(equalTo: self.view.topAnchor).isActive = true
self.collectionView.bottomAnchor.constraint(equalTo: self.view.bottomAnchor).isActive = true
self.collectionView.leftAnchor.constraint(equalTo: self.view.leftAnchor).isActive = true
self.collectionView.rightAnchor.constraint(equalTo: self.view.rightAnchor).isActive = true
self.collectionView.dataSource = self
self.collectionView.delegate = self
}
}
// MARK: - UICollectionViewDelegateFlowLayout
extension ViewController: UICollectionViewDelegateFlowLayout {
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
switch indexPath.section {
case 0:
return CGSize(width: self.view.frame.width, height: 210.0)
case 1:
return CGSize(width: self.view.frame.width, height: 5 * 51.0 + 130.0) // How to enable self-sizing cells for table view inside
default:
fatalError("Unsupported section index.")
}
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForHeaderInSection section: Int) -> CGSize {
return CGSize(width: self.view.frame.width, height: 61)
}
}
// MARK: - UICollectionViewDataSource
extension ViewController: UICollectionViewDataSource {
func numberOfSections(in collectionView: UICollectionView) -> Int {
return 2
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 1
}
func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {
let header = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: SectionHeaderView.sectionHeaderId, for: indexPath) as! SectionHeaderView
switch indexPath.section {
case 0:
header.uiLabel.text = "Section 1"
case 1:
header.uiLabel.text = "Section 2"
default:
fatalError("Unsupported section index.")
}
return header
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
switch indexPath.section {
case 0:
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: ViewController.section1, for: indexPath) as! Section1
return cell
case 1:
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: ViewController.section2, for: indexPath) as! Section2
return cell
default:
fatalError("OverviewController: Unsupported section index.")
}
}
}
To implement auto-sizing collectionView cells, you really only need a few changes.
Couple key points:
Cells must satisfy their own constraints. So, instead of calculating sizing in sizeForItemAt, make sure the cells have width and height constraints. These can be dynamic, based on content.
Add elements to the collection view cell's contentView, not to the cell itself.
For the embedded non-scrolling table view, use a subclass that sets the intrinsic content size height based on the table's contentSize. Example:
final class ContentSizedTableView: UITableView {
override var contentSize:CGSize {
didSet {
invalidateIntrinsicContentSize()
}
}
override var intrinsicContentSize: CGSize {
layoutIfNeeded()
return CGSize(width: UIView.noIntrinsicMetric, height: contentSize.height)
}
}
There is a pretty good tutorial here (not mine): https://medium.com/#andrea.toso/uicollectionviewcell-dynamic-height-swift-b099b28ddd23 that has more detailed explanations.
I implement those concepts in the project you made available, and put it up on a GitHub repo (to make it easy to see the changes): https://github.com/DonMag/ThunderCollectionView
Results:
I have a collection view with sticky headers
flowLayout.sectionHeadersPinToVisibleBounds = true
My issue is that the top half of my header is translucent and when I scroll my cell up I can see the cell scrolling behind the header.
I would like to hide the part of the cell view behind the header. In my image attached I do not want to see the green when it is behind the red. The rest of the behavior I want to keep as is.
The reason I need this is I have a wallpaper image at the very back which I need to be shown
#IBOutlet weak var collectionView: UICollectionView!
override func viewDidLoad() {
super.viewDidLoad()
self.collectionView.alwaysBounceVertical = true
collectionView.register(UINib.init(nibName: EXAMPLE_CELL_REUSE_ID, bundle: nil), forCellWithReuseIdentifier: EXAMPLE_CELL_REUSE_ID)
collectionView.register(UINib.init(nibName: EXAMPLE_HEADER_REUSE_ID, bundle: nil), forSupplementaryViewOfKind: UICollectionElementKindSectionHeader, withReuseIdentifier: EXAMPLE_HEADER_REUSE_ID)
if let flowLayout = collectionView.collectionViewLayout as? UICollectionViewFlowLayout {
flowLayout.headerReferenceSize = CGSize(width: 400, height: 100)
flowLayout.sectionHeadersPinToVisibleBounds = true
}
}
func numberOfSections(in collectionView: UICollectionView) -> Int {
return sections.count;
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 1 //self.sections[section].1;
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let exampleCell = collectionView.dequeueReusableCell(withReuseIdentifier: EXAMPLE_CELL_REUSE_ID, for: indexPath) as! MyCellCollectionViewCell;
exampleCell.headerLabel.text = "Cell"
exampleCell.backgroundColor = UIColor.green
return exampleCell;
}
func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {
if kind == UICollectionElementKindSectionHeader {
if let header = collectionView.dequeueReusableSupplementaryView(ofKind: UICollectionElementKindSectionHeader, withReuseIdentifier: EXAMPLE_HEADER_REUSE_ID, for: indexPath) as? ExampleHeader {
// header.backgroundColor = UIColor(red: 1.0, green: 0, blue: 0, alpha: 0.5)
return header
} else {
return UICollectionReusableView()
}
}
return UICollectionReusableView()
}
I think the question here may be similar but there are no responses and it is not quite clear if it is the same issue.
Transparent sticky header ui collectionview don't show cells underneath
This worked for me:
let layout = collectionView.collectionViewLayout as! UICollectionViewFlowLayout
layout.sectionHeadersPinToVisibleBounds = true
layout.sectionInsetReference = .fromSafeArea
view.backgroundColor = .white
collectionView.anchor(top: view.safeAreaLayoutGuide.topAnchor, leading:
view.leadingAnchor, bottom: view.bottomAnchor, trailing: view.trailingAnchor)
You need to apply mask for all cells that located under header view. Use on scrollViewDidScroll
Tutorial: https://medium.com/#peteliev/layer-masking-for-beginners-c18a0a10743
I have created a very simple setup like yours and it is working fine.
class ViewController: UIViewController, UICollectionViewDataSource
{
#IBOutlet weak var collectionView: UICollectionView!
override func viewDidLoad()
{
super.viewDidLoad()
self.collectionView.alwaysBounceVertical = true
if let flowLayout = collectionView.collectionViewLayout as? UICollectionViewFlowLayout
{
flowLayout.headerReferenceSize = CGSize(width: 400, height: 100)
flowLayout.sectionHeadersPinToVisibleBounds = true
}
}
func numberOfSections(in collectionView: UICollectionView) -> Int
{
return 10
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int
{
return 1
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell
{
return collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath)
}
func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView
{
if kind == UICollectionElementKindSectionHeader
{
return collectionView.dequeueReusableSupplementaryView(ofKind: UICollectionElementKindSectionHeader, withReuseIdentifier: "rview", for: indexPath)
}
return UICollectionReusableView()
}
}
I am trying to add a header to my UICollectionViewController. I have done this all through storyboard. When I run the app it doesn't show up.
This is what I am trying to display in my header:
override func collectionView(collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, atIndexPath indexPath: NSIndexPath) -> UICollectionReusableView {
let header = collectionView.dequeueReusableSupplementaryViewOfKind(UICollectionElementKindSectionHeader, withReuseIdentifier: "Header", forIndexPath: indexPath) as! ProfileCollectionReusableView
header.editProfileButton.layer.cornerRadius = 5
header.nameLabel.adjustsFontSizeToFitWidth = true
header.nameLabel.text = PFUser.currentUser()!["name"] as? String
header.profilePictureImageView.layer.cornerRadius = header.profilePictureImageView.frame.size.height/2
header.profilePictureImageView.layer.masksToBounds = true
header.profilePictureImageView.layer.borderColor = UIColor.whiteColor().CGColor
return header
}
I am not seeing any errors on the console nor does the app crash. There is just a white screen with the navigation bars title updated to the users username.
if use .xib
let nib1:UINib = UINib(nibName: "ScheduleHeaderView", bundle: nil)
self.myCollection.register(nib1, forSupplementaryViewOfKind: UICollectionElementKindSectionHeader, withReuseIdentifier: "ScheduleHeaderView")
set size for header
let layout = self.myCollection.collectionViewLayout as! UICollectionViewFlowLayout
layout.headerReferenceSize = CGSize(width: 50, height: 180)
UICollectionViewDataSource
func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {
let header:ScheduleHeaderView = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: "ScheduleHeaderView", for: indexPath) as! ScheduleHeaderView
return header
}
Here are some tips you need to pay attention to what you have to do:
1.Implement UICollectionViewDelegateFlowLayout like:
class MyCollectionViewController: UICollectionViewController, UICollectionViewDelegateFlowLayout {}
2.register header class before you use :
self.collectionView!.registerClass(HeaderClass.self, forSupplementaryViewOfKind: UICollectionElementKindSectionHeader, withReuseIdentifier: "header")
in the method ViewDidLoad();
3.set the size in the UICollectionViewDelegateFlowLayout like UITableViewDelegate
func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForHeaderInSection section: Int) -> CGSize {
return CGSizeMake(Config.PHONE_WIDTH, 55)
}
4.return your own header like what you already done:
override func collectionView(collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, atIndexPath indexPath: NSIndexPath) -> UICollectionReusableView {
}
The issue could very well be with the height of the header section. I encountered the similar issue where I was registering the header but then the height was not set.
let layout = UICollectionViewFlowLayout()
layout.itemSize = CGSize(width: 20, height: 20)
layout.minimumInteritemSpacing = 10
layout.minimumLineSpacing = 10
let collectionView = UICollectionView(frame: CGRect.zero, collectionViewLayout: layout)
collectionView.backgroundColor = UIColor.white //default background color is black
collectionView.dataSource = self
collectionView.delegate = self
collectionView.register(CollectionViewCell.self, forCellWithReuseIdentifier: "Cell")
collectionView.register(Header.self, forSupplementaryViewOfKind: UICollectionElementKindSectionHeader, withReuseIdentifier: "HeaderCell")
//setting the height helped it in displaying on the page
layout.headerReferenceSize = CGSize(width: 50, height: 180)
To show header just make sure you have this code in your code with number "1", like this:
override func numberOfSections(in collectionView: UICollectionView) -> Int {
return 1
}
I am struggling trying to do multiple sections in my collection view with a header for each section. I don't know Obj-C and I've found a good amount of tutorials for it, but haven't been able to figure out how to convert it into Swift.
All my data is static so all I need is some sort of array or dictionary that I can use to create the multiple sections. I already have a collection view with 1 section working, so if you have any insight or code for multiple sections that'd be helpful.
I know how to set multiple sections using
func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int {
return sectionData.count
}
I think the main thing I need help with is implementing this func
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell { }
and setting up the data!
UICollectionView and UITableView are almost exactly the same, so if you know how to do multiple sections in a UITableView in Swift, your help is also appreciated
The cellForItemAtIndexPath function handles populating each section with cells, it does not handle sections or supplementaryViews, and therefore is not the main thing you need help with when it comes to creating section headers.
the method you need to implement is viewForSupplementaryElementOfKind. Its signature is:
func collectionView(collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, atIndexPath indexPath: NSIndexPath) -> UICollectionReusableView {}
Assuming that your collectionView is working correctly for 1 section (you have properly filled out the body of your cellForItemAtIndexPath and your sectionData array properly reflects the number of sections you want to display), you should be able to implement section headers using the following pointers:
Along with cells, UICollectionView also supports "supplementary" view objects, typically used for headers or footers. These Supplementary Views act very similarly to UICollectionViewCell objects. In the same way that cellForItemAtIndexPath handles cells, The viewForSupplementaryElementOfKind function handles supplementary views.
To implement it, you will need to first prepare your ViewController to do so. First edit your layout object to reflect an appropriate header size, that each header will adhere to:
let layout: UICollectionViewFlowLayout = UICollectionViewFlowLayout()
layout.headerReferenceSize = CGSize(width: self.view.frame.size.width, height: 30)
NOTE: I am using a UICollectionViewFlowLayout
Next, if you haven't already done so, create a SectionHeader class that defines each section header object, so you can then register that class with your collectionView object like so:
collectionView!.registerClass(SectionHeaderView.self, forSupplementaryViewOfKind:UICollectionElementKindSectionHeader, withReuseIdentifier: "SectionHeaderView");
Here, the first and third argument passed in are the same as a UICollectionViewCell Class registration, the first argument in this method is the reference to the section header class you created. The third is the reuse identifier for the Supplementary View.
The second argument is specific to Supplementary Views, this sets the kind of the SupplementaryView, which in this case is a header, the constant string provided by the UICollectionViewFlowLayout class UICollectionElementKindSectionHeader is used for it. If you noticed the parameters on the viewForSupplementaryElementOfKind, this kind is later passed in as the kind: String parameter.
Fill in the body of your viewForSupplementaryElementOfKind the same way you would for a cellForItemAtIndexPath function-- Using the dequeueReusableSupplementaryViewOfKind method to create a SectionHeader object, then set any attributes as necessary (labels, colors, etc.) and finally return the header object.
Hope this helps!!
Reference points:
https://developer.apple.com/library/prerelease/ios/documentation/UIKit/Reference/UICollectionViewDataSource_protocol/index.html#//apple_ref/occ/intfm/UICollectionViewDataSource/
https://developer.apple.com/library/ios/documentation/UIKit/Reference/UICollectionViewFlowLayout_class/index.html#//apple_ref/c/data/UICollectionElementKindSectionHeade
Define your UICollectionViewCell which will be your Header view of kind UICollectionElementKindSectionHeader - In my case I have two headers - OfferHeaderCell and APRHeaderCell defined as below:
verticalCollectionView.register(UINib(nibName: "OfferHeaderCell", bundle: nil), forSupplementaryViewOfKind:UICollectionElementKindSectionHeader, withReuseIdentifier: "OfferHeaderCell")
verticalCollectionView.register(UINib(nibName: "APRHeaderCell", bundle: nil), forSupplementaryViewOfKind:UICollectionElementKindSectionHeader, withReuseIdentifier: "APRHeaderCell")
Go ahead and return a header for each section and then set the size of the section header to have a size of zero in this UICollectionViewDelegateFlowLayout function
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForHeaderInSection section: Int) -> CGSize {
if(section==0) {
return CGSize.zero
} else if (section==1) {
return CGSize(width:collectionView.frame.size.width, height:133)
} else {
return CGSize(width:collectionView.frame.size.width, height:100)
}
}
Important to define the viewForSupplementaryElementOfKind for two different sections as below:
func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {
var reusableview = UICollectionReusableView()
if (kind == UICollectionElementKindSectionHeader) {
let section = indexPath.section
switch (section) {
case 1:
let firstheader: OfferHeaderCell = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: "OfferHeaderCell", for: indexPath) as! OfferHeaderCell
reusableview = firstheader
case 2:
let secondHeader: APRHeaderCell = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: "APRHeaderCell", for: indexPath) as! APRHeaderCell
reusableview = secondHeader
default:
return reusableview
}
}
return reusableview
}
And lastly the Datasource,
func numberOfSections(in collectionView: UICollectionView) -> Int {
return 3
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
if (section==2) {
return 2
}
return 0
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = verticalCollectionView.dequeueReusableCell(withReuseIdentifier: "ReviseOfferCell", for: indexPath)
cell.backgroundColor = UIColor.white
return cell
}
Note: Don't forgot to add UICollectionFlowLayout as below:
// MARK: UICollectionViewDelegateFlowLayout
extension MakeAnOfferController: UICollectionViewDelegateFlowLayout {
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
if indexPath.item == 0 {
return CGSize(width: self.view.frame.size.width, height: 626.0)
}
return CGSize()
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForHeaderInSection section: Int) -> CGSize {
if(section==0) {
return CGSize.zero
} else if (section==1) {
return CGSize(width:collectionView.frame.size.width, height:133)
} else {
return CGSize(width:collectionView.frame.size.width, height:100)
}
}
}
Here is the code that worked for me
create the header cell. To do which i created a custom cell class and a nib to do the customization of the cell in the graphic editor
In viewDidLoad add the following
self.collectionView?.registerNib(UINib(nibName: "KlosetCollectionHeaderViewCell", bundle: nil), forSupplementaryViewOfKind:UICollectionElementKindSectionHeader, withReuseIdentifier: "HeaderCell")
Then you add the delegate function
override func collectionView(collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, atIndexPath indexPath: NSIndexPath) -> KlosetCollectionHeaderViewCell {
let headerCell = collectionView.dequeueReusableSupplementaryViewOfKind(kind, withReuseIdentifier: "HeaderCell", forIndexPath: indexPath) as? KlosetCollectionHeaderViewCell
return headerCell!
}
This will put the HeaderCell in the SectionView of the PFCollectionView
The controls that show in the cell you add them to the xib file as well as the outlets and actions
Here is the code to achieve UICollection multiple sections made programmatically using SnapKit
ViewController
import SnapKit
import UIKit
class SelectIconViewController: GenericViewController<SelectIconView>, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout {
weak var delegate: SpaceAddViewController?
struct Section {
var sectionName : String
var rowData : [String]
}
var sections : [Section]!
init(delegate: SpaceAddViewController) {
self.delegate = delegate
super.init()
}
public required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func viewDidLoad() {
super.viewDidLoad()
contentView.closeButton.addTarget(self, action: #selector(self.back), for: .touchUpInside)
self.sections = [
Section(sectionName: "SPACES", rowData: ["Air Conditioner", "Apple HomePod"]),
Section(sectionName: "HOME APPLIANCES", rowData: ["Ceiling Fan", "Fan", "Desk Lamp", "Iron", "PC on Desk", "Plug", "Power Strip", "Lorem", "Lorem", "Lorem", "Lorem"]),
]
self.contentView.collectionView.dataSource = self
self.contentView.collectionView.delegate = self
self.contentView.collectionView.register(SelectIconHeaderViewCell.self, forSupplementaryViewOfKind: UICollectionView.elementKindSectionHeader, withReuseIdentifier: SelectIconHeaderViewCell.reuseId)
self.contentView.collectionView.register(SelectIconViewCell.self, forCellWithReuseIdentifier: SelectIconViewCell.reuseId)
}
#objc func back() {
self.dismiss(animated: true, completion: nil)
}
#objc func dismissKeyboard() {
view.endEditing(true)
}
func numberOfSections(in collectionView: UICollectionView) -> Int {
return self.sections.count
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return self.sections[section].rowData.count
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
return UIEdgeInsets(top: 0, left: 20, bottom: 0, right: 20)
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: getTotalSpacing(), height: getTotalSpacing())
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForHeaderInSection section: Int) -> CGSize {
let screenSize = UIScreen.main.bounds
let screenWidth = screenSize.width-40
return CGSize(width: screenWidth-80, height: 50)
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
return 0
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat {
return 0
}
// MARK: Cells
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = self.contentView.collectionView.dequeueReusableCell(withReuseIdentifier: SelectIconViewCell.reuseId, for: indexPath as IndexPath) as! SelectIconViewCell
cell.initializeUI()
cell.createConstraints()
cell.setValues(iconName: "", label: self.sections[indexPath.section].rowData[indexPath.row])
return cell
}
// MARK: Header
func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {
switch kind {
case UICollectionView.elementKindSectionHeader:
let cell = self.contentView.collectionView.dequeueReusableSupplementaryView(ofKind: UICollectionView.elementKindSectionHeader, withReuseIdentifier: SelectIconHeaderViewCell.reuseId, for: indexPath) as! SelectIconHeaderViewCell
cell.initializeUI()
cell.createConstraints()
cell.setTitle(title: self.sections[indexPath.section].sectionName)
return cell
default: fatalError("Unexpected element kind")
}
}
func getTotalSpacing() -> CGFloat {
let screenSize = UIScreen.main.bounds
let screenWidth = screenSize.width
let numberOfItemsPerRow:CGFloat = 3
let spacingBetweenCells:CGFloat = 0
let sideSpacing:CGFloat = 20
return (screenWidth-(2 * sideSpacing) - ((numberOfItemsPerRow - 1) * spacingBetweenCells))/numberOfItemsPerRow
}
}
The View:
import UIKit
import SnapKit
class SelectIconView: GenericView {
private let contentView = UIView(frame: .zero)
private (set) var closeButton = UIButton(type: .system)
internal var collectionView: UICollectionView!
internal override func initializeUI() {
self.backgroundColor = Theme.Color.white
self.addSubview(contentView)
contentView.addSubview(closeButton)
if let image = UIImage(named: "icon_close") {
image.withRenderingMode(.alwaysTemplate)
closeButton.setImage(image, for: .normal)
closeButton.tintColor = Theme.Color.text
}
let layout: UICollectionViewFlowLayout = UICollectionViewFlowLayout()
layout.sectionInset = UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 0)
layout.minimumInteritemSpacing = 0
collectionView = UICollectionView(frame: CGRect.zero, collectionViewLayout: layout)
contentView.addSubview(collectionView)
collectionView.backgroundColor = Theme.Color.background
}
internal override func createConstraints() {
contentView.snp.makeConstraints { (make) in
make.top.equalTo(safeAreaLayoutGuide.snp.top).priority(750)
make.left.right.equalTo(self).priority(1000)
make.bottom.equalTo(safeAreaLayoutGuide.snp.bottom)
}
closeButton.snp.makeConstraints { make in
make.right.equalTo(safeAreaLayoutGuide.snp.right).offset(-10)
make.top.equalTo(contentView.snp.top).offset(10)
make.height.equalTo(40)
make.width.equalTo(40)
}
collectionView.snp.makeConstraints { make in
make.top.equalTo(closeButton.snp.bottom).offset(20)
make.left.equalTo(safeAreaLayoutGuide.snp.left)
make.right.equalTo(safeAreaLayoutGuide.snp.right)
make.bottom.equalTo(contentView.snp.bottom)
}
}
}
The customized section Header
import UIKit
class SelectIconHeaderViewCell: UICollectionViewCell {
internal let mainView = UIView()
internal var title = UILabel()
override init(frame: CGRect) {
super.init(frame: frame)
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
func initializeUI() {
self.backgroundColor = UIColor.clear
self.addSubview(mainView)
mainView.backgroundColor = UIColor.clear
mainView.addSubview(title)
title.text = "Pick nameA"
title.font = Theme.Font.body()
title.textAlignment = .left
title.textColor = Theme.Color.text
title.numberOfLines = 1
}
internal func createConstraints() {
mainView.snp.makeConstraints { (make) in
make.edges.equalTo(self)
}
title.snp.makeConstraints { (make) in
make.centerY.equalTo(mainView.snp.centerY)
make.leading.equalTo(mainView).offset(20)
make.trailing.equalTo(mainView).offset(-20)
}
}
func setTitle(title: String) {
self.title.text = title
}
static var reuseId: String {
return NSStringFromClass(self)
}
}
And the cell:
import UIKit
class SelectIconViewCell: UICollectionViewCell {
internal let mainView = UIView()
internal var iconImage = UIImageView()
internal var label = UILabel()
override init(frame: CGRect) {
super.init(frame: frame)
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
func initializeUI() {
self.backgroundColor = UIColor.clear
self.addSubview(mainView)
mainView.backgroundColor = UIColor.clear
mainView.layer.masksToBounds = true
mainView.layer.borderColor = Theme.Color.backgroundCell.cgColor
mainView.layer.borderWidth = 1.0
mainView.addSubview(iconImage)
iconImage.image = UIImage(named: "icons8-air-conditioner-100")
mainView.addSubview(label)
label.font = Theme.Font.footnote()
label.textAlignment = .center
label.textColor = Theme.Color.textInfo
label.numberOfLines = 1
}
internal func createConstraints() {
mainView.snp.makeConstraints { (make) in
make.edges.equalTo(self)
}
iconImage.snp.makeConstraints { (make) in
make.center.equalTo(mainView.snp.center)
make.width.height.equalTo(20)
}
label.snp.makeConstraints { (make) in
make.top.equalTo(iconImage.snp.bottom).offset(6)
make.leading.equalTo(mainView).offset(5)
make.trailing.equalTo(mainView).offset(-5)
}
}
func setValues(iconName: String, label: String) {
//self.iconImage.image = UIImage(named: iconName)
self.label.text = label
}
static var reuseId: String {
return NSStringFromClass(self)
}
}
After creating and registering custom header (and/or footers), you can easily specify different header (or footers for that matter) for different section. Here's an example:
override func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {
switch kind {
case UICollectionElementKindSectionHeader:
let section = indexPath.section
switch section {
case 0:
let userHeader = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: userHeaderReuseIdentifier, for: indexPath) as! UserHeader
return userHeader
default:
let postHeader = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: postHeaderReuseIdentifier, for: indexPath) as! PostHeader
return postHeader
}
case UICollectionElementKindSectionFooter:
let userFooter = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: userFooterReuseIdentifier, for: indexPath) as! UserFooter
return userFooter
default:
return UICollectionReusableView()
}
}
Make sure to specify correct number of sections, too:
override func numberOfSections(in collectionView: UICollectionView) -> Int {
return 2
}
Worked solution for Swift-3
i)Create Custom Cell && corresponding xib
class SectionHeaderView: UICollectionViewCell {
static let kReuseIdentifier = "SectionHeaderView"
#IBOutlet weak var invitationsSectionHeader: UILabel!
#IBOutlet weak var numberOfPerson: UILabel!
}
ii)Register Custom Collection View Cell for HeaderView
self.collectionView.register(UINib(nibName: SectionHeaderView.kReuseIdentifier, bundle: nil), forSupplementaryViewOfKind:UICollectionElementKindSectionHeader, withReuseIdentifier: SectionHeaderView.kReuseIdentifier)
iii)Call delegate function to render Custom Header View.
func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {
switch kind {
case UICollectionElementKindSectionHeader:
let headerView: SectionHeaderView = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: SectionHeaderView.kReuseIdentifier, for: indexPath) as! SectionHeaderView
return headerView
default:
return UICollectionReusableView()
}
}
iv)Mention Height of the Custom Header View
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForHeaderInSection section: Int) -> CGSize {
return CGSize(width:collectionView.frame.size.width, height:30)
}
#Tarun's answer worked a treat for me; I was missing collectionView(_:layout:referenceSizeForHeaderInSection:), which I needed since sometimes the data to be shown would be sorted and sometimes not.
In addition, pinning the section header to the top of the screen (as in the table view Apple's Address Book app) was accomplished by adding the following to viewDidLoad() in the UICollectionViewController:
if let flowLayout = collectionViewLayout as? UICollectionViewFlowLayout {
flowLayout.sectionHeadersPinToVisibleBounds = true
}
I am interested in having a collectionview as a part of a collection view cell but for some reason cannot figure out how this would be done. Where would I implement the necessary methods for the cells collectionview?
There's an article that Ash Furrow wrote that explains how to put an UICollectionView inside an UITableViewCell. It's basically the same idea when using it inside an UICollectionViewCell.
Everything is done programatically. No storyboards.
I added a UICollectionView inside my UICollectionViewCell. I also show how to add again a UICollectionViewCell inside the created UICollectionView to have this result
import UIKit
class CategoryCell: UICollectionViewCell, UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout {
private let cellId = "cell"
override init(frame: CGRect) {
super.init(frame: frame)
setupViews()
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
let appsCollectionView: UICollectionView = {
let layout = UICollectionViewFlowLayout()
let collectionView = UICollectionView(frame: .zero, collectionViewLayout: layout)
return collectionView
}()
func setupViews() {
backgroundColor = .blue
addSubview(appsCollectionView)
appsCollectionView.delegate = self
appsCollectionView.dataSource = self
appsCollectionView.register(AppCell.self, forCellWithReuseIdentifier: cellId)
addConstrainstWithFormat("H:|-8-[v0]-8-|", views: appsCollectionView)
addConstrainstWithFormat("V:|[v0]|", views: appsCollectionView)
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 5
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: cellId, for: indexPath)
return cell
}
}
class AppCell: UICollectionViewCell {
override init(frame: CGRect) {
super.init(frame: frame)
setupViews()
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
func setupViews(){
backgroundColor = .red
}
}
My UICollectionViewController
import UIKit
class FeaturedAppsController: UICollectionViewController, UICollectionViewDelegateFlowLayout {
let cellId = "cell"
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
collectionView?.backgroundColor = .white
collectionView?.register(CategoryCell.self, forCellWithReuseIdentifier: cellId)
}
override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 3
}
override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: cellId, for: indexPath)
return cell
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(view.frame.width, 150)
}
}
The whole explanation can be found and was developed by "Let´s build that app": https://www.youtube.com/watch?v=Ko9oNhlTwH0&list=PL0dzCUj1L5JEXct3-OV6itP7Kz3tRDmma
This is too late for this answer but it might help others. This is an example of UICollectionView inside a UICollectionViewCell.
Lets start by having a mainCollectionView. Then on each cell of this collection create and initialize a new UICollectionView and right place to do that is in this following delegate of UICollectionView
func collectionView(collectionView: UICollectionView, willDisplayCell cell: UICollectionViewCell, forItemAtIndexPath indexPath: NSIndexPath)
e.g I initialize the MainCollectionViewCell here and then MainCollectionViewCell handles the logic to create a new UICollectionView
guard let collectionViewCell = cell as? MainCollectionViewCell else { return }
collectionViewCell.delegate = self
let dataProvider = ChildCollectionViewDataSource()
dataProvider.data = data[indexPath.row] as NSArray
let delegate = ChildCollectionViewDelegate()
collectionViewCell.initializeCollectionViewWithDataSource(dataProvider, delegate: delegate, forRow: indexPath.row)
collectionViewCell.collectionViewOffset = storedOffsets[indexPath.row] ?? 0
Here is the initializer on MainCollectionViewCell that creates a new UICollectionView
func initializeCollectionViewWithDataSource<D: protocol<UICollectionViewDataSource>,E: protocol<UICollectionViewDelegate>>(dataSource: D, delegate :E, forRow row: Int) {
self.collectionViewDataSource = dataSource
self.collectionViewDelegate = delegate
let flowLayout = UICollectionViewFlowLayout()
flowLayout.scrollDirection = .Horizontal
let collectionView = UICollectionView(frame: self.bounds, collectionViewLayout: flowLayout)
collectionView.registerClass(UICollectionViewCell.self, forCellWithReuseIdentifier: reuseChildCollectionViewCellIdentifier)
collectionView.backgroundColor = UIColor.whiteColor()
collectionView.dataSource = self.collectionViewDataSource
collectionView.delegate = self.collectionViewDelegate
collectionView.tag = row
self.addSubview(collectionView)
self.collectionView = collectionView
collectionView.reloadData()
}
Hope that helps !!
I did an example for this and put in on github. It demonstrates the use UICollectionView inside a UICollectionViewCell.
https://github.com/irfanlone/Collection-View-in-a-collection-view-cell
Easiest solution for collectionview inside collectionview using storyboard and Swift 5
Please refer this link for nested collectionview example
import UIKit
class ParentViewController:UIViewController,UICollectionViewDataSource,UICollectionViewDelegate {
//MARK: Declare variable
//MARK: Decalare outlet
#IBOutlet weak var outerCollectionView: UICollectionView!
#IBOutlet weak var pageControl: UIPageControl!
let outerCount = 4
//MARK: Decalare life cycle methods
override func viewDidLoad() {
super.viewDidLoad()
pageControl.numberOfPages = outerCount
}
//MARK: Collection View delegate methods
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return outerCount
}
//MARK: Collection View datasource methods
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "OuterCell", for: indexPath) as! OuterCollectionViewCell
cell.contentView.backgroundColor = .none
return cell
}
//MARK:- For Display the page number in page controll of collection view Cell
func scrollViewDidScroll(_ scrollView: UIScrollView) {
let visibleRect = CGRect(origin: self.outerCollectionView.contentOffset, size: self.outerCollectionView.bounds.size)
let visiblePoint = CGPoint(x: visibleRect.midX, y: visibleRect.midY)
if let visibleIndexPath = self.outerCollectionView.indexPathForItem(at: visiblePoint) {
self.pageControl.currentPage = visibleIndexPath.row
}
}
}
class OuterCollectionViewCell: UICollectionViewCell ,UICollectionViewDataSource,UICollectionViewDelegate {
#IBOutlet weak var InnerCollectionView: UICollectionView!
override func awakeFromNib() {
super.awakeFromNib()
InnerCollectionView.delegate = self
InnerCollectionView.dataSource = self
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
6
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "InnerCell", for: indexPath) as! InnerCollectionViewCell
cell.contentView.backgroundColor = .green
return cell
}
}
class InnerCollectionViewCell: UICollectionViewCell{
}