hide NavigationBar when scrolling at down CollectionView - ios

Question

i made NavigationBar and TabBar programmatically, but hide navigationBar when i scroll at down collectionView. here is code
import Foundation
import Foundation
import UIKit
class HomeMyBazar: UICollectionViewController, UICollectionViewDelegateFlowLayout {
let cellId = "cellId"
let productCellId = "productCellId"
let dealsCellId = "dealsCellId"
let titles = ["Hello world", "Product", "Deals", "Store world"]
override func viewDidLoad() {
super.viewDidLoad()
navigationController?.navigationBar.isTranslucent = false
setupNavBarButtons()
setupMenuBar()
setupCollectionView()
}
func setupNavBarButtons() {
lazy var settingsLauncher: SettingsLauncher = {
let launcher = SettingsLauncher()
launcher.homeController = self
return launcher
}()
func targetMyBazar() {
let secondViewController = ViewController1()
self.navigationController?.pushViewController(secondViewController, animated: true)
}
func targetSearch() {
let viewController = ViewController4()
self.navigationController?.pushViewController(viewController, animated: true)
}
func targetUser() {
let viewController = ViewController3()
self.navigationController?.pushViewController(viewController, animated: true)
}
func targetCart() {
let viewController = ViewController5()
self.navigationController?.pushViewController(viewController, animated: true)
}
func handleMore() {
settingsLauncher.showSettings()
}
func showControllerForSetting(_ setting: Setting) {
let dummySettingsViewController = UIViewController()
dummySettingsViewController.view.backgroundColor = UIColor.white
dummySettingsViewController.navigationItem.title = setting.name.rawValue
navigationController?.navigationBar.tintColor = UIColor.white
navigationController?.navigationBar.titleTextAttributes = [NSForegroundColorAttributeName: UIColor.white]
navigationController?.pushViewController(dummySettingsViewController, animated: true)
}
func scrollToMenuIndex(_ menuIndex: Int) {
let indexPath = IndexPath(item: menuIndex, section: 0)
collectionView?.scrollToItem(at: indexPath, at: UICollectionViewScrollPosition(), animated: true)
}
fileprivate func setTitleForIndex(_ index: Int) {
if let titleLabel = navigationItem.titleView as? UILabel {
titleLabel.text = " \(titles[index])"
}
}
lazy var menuBar: MenuBar = {
let mb = MenuBar()
mb.homeController = self
return mb
}()
fileprivate func setupMenuBar() {
navigationController?.hidesBarsOnSwipe = true
let blackView = UIView()
blackView.backgroundColor = .lightGray
view.addSubview(blackView)
view.addConstraintsWithFormat("H:|[v0]|", views: blackView)
view.addConstraintsWithFormat("V:[v0(50)]", views: blackView)
view.addSubview(menuBar)
view.addConstraintsWithFormat("H:|[v0]|", views: menuBar)
view.addConstraintsWithFormat("V:[v0(80)]", views: menuBar)
menuBar.topAnchor.constraint(equalTo: topLayoutGuide.bottomAnchor).isActive = true
}
override func scrollViewDidScroll(_ scrollView: UIScrollView) {
menuBar.horizontalBarLeftAnchorConstraint?.constant = scrollView.contentOffset.x / 4
}
override func scrollViewWillEndDragging(_ scrollView: UIScrollView, withVelocity velocity: CGPoint, targetContentOffset: UnsafeMutablePointer<CGPoint>) {
let index = targetContentOffset.pointee.x / view.frame.width
let indexPath = IndexPath(item: Int(index), section: 0)
menuBar.collectionView.selectItem(at: indexPath, animated: true, scrollPosition: UICollectionViewScrollPosition())
setTitleForIndex(Int(index))
}
func setupCollectionView() {
if let flowLayout = collectionView?.collectionViewLayout as? UICollectionViewFlowLayout {
flowLayout.scrollDirection = .horizontal
flowLayout.minimumLineSpacing = 0
}
collectionView?.backgroundColor = UIColor.blue
collectionView?.register(MyBazarCell.self, forCellWithReuseIdentifier: cellId)
collectionView?.register(ProductCell.self, forCellWithReuseIdentifier: productCellId)
collectionView?.register(DealsCell.self, forCellWithReuseIdentifier: dealsCellId)
collectionView?.contentInset = UIEdgeInsetsMake(110, 0, 0, 0)
collectionView?.isPagingEnabled = true
}
override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 4
}
override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let identifier: String
if indexPath.item == 1 {
identifier = productCellId
} else if indexPath.item == 2 {
identifier = dealsCellId
} else {
identifier = cellId
}
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: identifier, for: indexPath)
return cell
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: view.frame.width, height: view.frame.height - 50)
}
}
import Foundation
import UIKit
struct Item {
var imageName: String
var text: String
}
class MenuBar: UIView, UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout {
lazy var collectionView: UICollectionView = {
let layout = UICollectionViewFlowLayout()
let cv = UICollectionView(frame: .zero, collectionViewLayout: layout)
cv.backgroundColor = UIColor.black
cv.dataSource = self
cv.delegate = self
return cv
}()
let data: [Item] = [
Item(imageName: "service", text: "Service"),
Item(imageName: "product", text: "Product "),
Item(imageName: "deals", text: " Deals"),
Item(imageName: "store", text: "Store")
]
let cellId = "cellId"
let imageNames = ["service", "product", "deals", "store"]
let imageTitle = ["Servic", "Product", "Deals", "Store"]
var homeController: HomeMyBazar?
override init(frame: CGRect) {
super.init(frame: frame)
collectionView.register(MenuCell.self, forCellWithReuseIdentifier: cellId)
addSubview(collectionView)
addConstraintsWithFormat("H:|[v0]|", views: collectionView)
addConstraintsWithFormat("V:|[v0]|", views: collectionView)
let selectedIndexPath = IndexPath(item: 0, section: 0)
collectionView.selectItem(at: selectedIndexPath, animated: false, scrollPosition: UICollectionViewScrollPosition())
setupHorizontalBar()
}
var horizontalBarLeftAnchorConstraint: NSLayoutConstraint?
func setupHorizontalBar() {
let horizontalBarView = UIView()
horizontalBarView.backgroundColor = UIColor.red
horizontalBarView.translatesAutoresizingMaskIntoConstraints = false
addSubview(horizontalBarView)
horizontalBarLeftAnchorConstraint = horizontalBarView.leftAnchor.constraint(equalTo: self.leftAnchor)
horizontalBarLeftAnchorConstraint?.isActive = true
horizontalBarView.bottomAnchor.constraint(equalTo: self.bottomAnchor).isActive = true
horizontalBarView.widthAnchor.constraint(equalTo: self.widthAnchor, multiplier: 1/4).isActive = true
horizontalBarView.heightAnchor.constraint(equalToConstant: 4).isActive = true
}
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
homeController?.scrollToMenuIndex(indexPath.item)
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return data.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: cellId, for: indexPath) as! MenuCell
let item = data[indexPath.item]
cell.imageView.image = UIImage(named: item.imageName)
cell.imageTitle.text = item.text
cell.tintColor = UIColor.white
return cell
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: frame.width / 4, height: frame.height)
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat {
return 0
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
class MenuCell: BaseCell {
let imageTitle: UILabel = {
let label = UILabel()
label.text = "hellow world label"
label.textColor = .white
return label
}()
let imageView: UIImageView = {
let iv = UIImageView()
iv.image = UIImage(named: "service")?.withRenderingMode(.alwaysTemplate)
iv.tintColor = .white
return iv
}()
override var isHighlighted: Bool {
didSet {
imageView.tintColor = isHighlighted ? UIColor.white : UIColor.white
}
}
override var isSelected: Bool {
didSet {
imageView.tintColor = isSelected ? UIColor.white : UIColor.white
}
}
override func setupViews() {
super.setupViews()
addSubview(imageTitle)
addSubview(imageView)
addConstraintsWithFormat("H:|-25-[v0(80)]|", views: imageTitle)
addConstraintsWithFormat("V:|-45-[v0(20)]|", views: imageTitle)
addConstraintsWithFormat("H:[v0(28)]", views: imageView)
addConstraintsWithFormat("V:|-15-[v0(28)]|", views: imageView)
addConstraint(NSLayoutConstraint(item: imageTitle, attribute: .centerX, relatedBy: .equal, toItem: self, attribute: .centerX, multiplier: 1, constant: 0))
addConstraint(NSLayoutConstraint(item: imageTitle, attribute: .centerY, relatedBy: .equal, toItem: self, attribute: .centerY, multiplier: 1, constant: 0))
addConstraint(NSLayoutConstraint(item: imageView, attribute: .centerX, relatedBy: .equal, toItem: self, attribute: .centerX, multiplier: 1, constant: 0))
addConstraint(NSLayoutConstraint(item: imageView, attribute: .centerY, relatedBy: .equal, toItem: self, attribute: .centerY, multiplier: 1, constant: 0))
}
}
after scrolling

Answer 1

You can try this
self.navigationController.hidesBarsOnSwipe = true