To run the example project, clone the repo, and run pod install from the Example directory first.
- Preview mutiple images
- Can load more imgae when scroll in preview image
- Can save photo
- Support Rotation
- iOS 9.0+
- Swift 4 & 5
- Nuke
BJImagePreview is available through CocoaPods. To install it, simply add the following line to your Podfile:
pod 'BJImagePreview'import UIKit
import BJCollection
import BJImagePreview
class PhotoView: UIView {
var imageArr: [String]? {
didSet {
vCollection.reloadData()
}
}
/** Check loadIndex when scroll image view to load more image */
var loadIndex: Int {
return (imageArr?.count ?? 0) - 10
}
/** Store old index for showing image cell */
var oldIndex: Int = 0
/** Check is get more image is reach limit */
var isReachLimit: Bool = false
override init(frame: CGRect) {
super.init(frame: frame)
backgroundColor = .clear
setupView()
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
func setupView() {
addSubview(vCollection)
vCollection.topAnchor.constraint(equalTo: self.topAnchor).isActive = true
vCollection.leftAnchor.constraint(equalTo: self.leftAnchor).isActive = true
vCollection.rightAnchor.constraint(equalTo: self.rightAnchor).isActive = true
vCollection.bottomAnchor.constraint(equalTo: self.bottomAnchor).isActive = true
}
lazy var vCollection: BJCollectionView = {
let view = BJCollectionView(numberOfItems: 3, spacingBetweenItems: 1.5)
view.translatesAutoresizingMaskIntoConstraints = false
view.showScrollIndicator = false
view.alwaysBounceVertical = true
view.register(cell: ImageCell.self)
view.delegate = self
view.dataSource = self
return view
}()
/// Store UIImageView from cell
var vImage: UIImageView = {
let view = UIImageView()
return view
}()
/// Store ImageViewerView after init ImageViewerView
var vImageViewer: ImageViewerView!
}
extension PhotoView: UICollectionViewDelegate, UICollectionViewDataSource {
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return imageArr?.count ?? 0
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell: ImageCell = collectionView.dequeue(for: indexPath)
cell.imageString = imageArr?[indexPath.row]
return cell
}
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
initImageViewer(indexPath: indexPath)
}
}
extension PhotoView: ImageViewerDelegate{
func imageViewer(imageViewerView: ImageViewerView) {
vImageViewer = imageViewerView
}
public func imageViewer(imageViewerView: ImageViewerView, getCurrentIndex index: Int) {
appendImage(imageViewerView: imageViewerView, index: index)
vCollection.scrollToItem(at: IndexPath(row: index, section: 0), at: .centeredVertically, animated: false)
if oldIndex != index {
updateImageView(imageViewerView: imageViewerView, index: oldIndex, alpha: 1)
}
updateImageView(imageViewerView: imageViewerView, index: index, alpha: 0)
oldIndex = index
}
public func imageViewer(imageViewerView: ImageViewerView, graggingView state: ImageViewerView.DraggingState) {
switch state {
case .ended:
let statusImageView = vImage
statusImageView.alpha = 1
vImageViewer = nil
default:
break
}
}
}
extension PhotoView {
///Mark: - Init ImageViewer view
func initImageViewer(indexPath: IndexPath) {
let cell = vCollection.cellForItem(at: indexPath) as! ImageCell
vImage = cell.vImage
oldIndex = indexPath.row
let statusImageView = vImage
statusImageView.alpha = 0
if let startingFrame = statusImageView.superview?.convert(statusImageView.frame, to: nil) {
let viewController = UIApplication.shared.keyWindow!.rootViewController!
viewController.popImageViewer(
photos: imageArr ?? [],
outsideFrame: startingFrame,
statusImageView: statusImageView,
currentIndex: indexPath.row,
imageViewerDelegate: self
)
}
}
///Mark: -- Update imageViewer view
func updateImageView(imageViewerView: ImageViewerView, index: Int, alpha: CGFloat) {
let indexPath = IndexPath(item: index, section: 0)
DispatchQueue.main.asyncAfter(deadline: .now() + 0.15) {[self] in
guard let cell = vCollection.cellForItem(at: indexPath) as? ImageCell else { return }
vImage = cell.vImage
oldIndex = index
let statusImageView = vImage
statusImageView.alpha = alpha
if let startingFrame = statusImageView.superview?.convert(statusImageView.frame, to: nil) {
let viewController = UIApplication.shared.keyWindow!.rootViewController!
viewController.updateImageViewer(
imageViewerView: imageViewerView,
outsideFrame: startingFrame,
statusImageView: statusImageView
)
}
}
}
///Mark: -- Append more image to imageArr & imageViewerView
func appendImage(imageViewerView: ImageViewerView, index: Int) {
let not = (!)
if not(isReachLimit) && index >= loadIndex {
isReachLimit = true
imageArr?.append(contentsOf: LocalData.moreImage)
let viewController = UIApplication.shared.keyWindow!.rootViewController!
viewController.loadMoreImageViewer(imageViewerView: imageViewerView, photo: LocalData.moreImage, currentIndex: index)
}
}
///Mark: -- Update imageView outsize & inside frame when orientation changed
func rotateChanged() {
DispatchQueue.main.async {[self] in
if let imageViewerView = vImageViewer {
vCollection.scrollToItem(at: IndexPath(item: oldIndex, section: 0), at: .centeredVertically, animated: false)
updateImageView(imageViewerView: imageViewerView, index: oldIndex, alpha: 0)
}
}
}
///Mark: -- Update collection view flow layout when orientation changed
func updateFlowLayout() {
guard let flowLayout = vCollection.collectionViewLayout as? BaseCollectionViewFlowLayout else {
return
}
flowLayout.heightItems = 0
if UIDevice.current.orientation.isLandscape {
//here you can do the logic for the cell size if phone is in landscape
flowLayout.numberOfItemsInRow = 5
} else {
//logic if not landscape
flowLayout.numberOfItemsInRow = 3
}
flowLayout.invalidateLayout()
}
}Sovannra, sovannrakong@gmail.com
BJImagePreview is available under the MIT license. See the LICENSE file for more info.