IGListKit/Example/IGListKitExamples/SectionControllers/WorkingRangeSectionController.swift
Bofei Zhu 59242c5b7e Add final to each class in Example
Summary: Closes https://github.com/Instagram/IGListKit/pull/173

Differential Revision: D4143811

Pulled By: rnystrom

fbshipit-source-id: 879ba9fa858648677fd2e3750bcf1815ac37ef18
2016-11-07 15:59:04 -08:00

95 lines
3.3 KiB
Swift

/**
Copyright (c) 2016-present, Facebook, Inc. All rights reserved.
The examples provided by Facebook are for non-commercial testing and evaluation
purposes only. Facebook reserves all rights not expressly granted.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
FACEBOOK BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
import UIKit
import IGListKit
final class WorkingRangeSectionController: IGListSectionController, IGListSectionType, IGListWorkingRangeDelegate {
var height: Int?
var downloadedImage: UIImage?
var task: URLSessionDataTask?
var urlString: String? {
guard let height = height,
let width = collectionContext?.containerSize.width
else { return nil }
return "https://unsplash.it/" + width.description + "/" + height.description
}
deinit {
task?.cancel()
}
override init() {
super.init()
workingRangeDelegate = self
}
func numberOfItems() -> Int {
return 2
}
func sizeForItem(at index: Int) -> CGSize {
let width: CGFloat = collectionContext?.containerSize.width ?? 0
let height: CGFloat = CGFloat(index == 0 ? 55 : (self.height ?? 0))
return CGSize(width: width, height: height)
}
func cellForItem(at index: Int) -> UICollectionViewCell {
let cellClass: AnyClass = index == 0 ? LabelCell.self : ImageCell.self
let cell = collectionContext!.dequeueReusableCell(of: cellClass, for: self, at: index)
if let cell = cell as? LabelCell {
cell.label.text = urlString
} else if let cell = cell as? ImageCell {
cell.setImage(image: downloadedImage)
}
return cell
}
func didUpdate(to object: Any) {
self.height = object as? Int
}
func didSelectItem(at index: Int) {}
//MARK: IGListWorkingRangeDelegate
func listAdapter(_ listAdapter: IGListAdapter, sectionControllerWillEnterWorkingRange sectionController: IGListSectionController) {
guard downloadedImage == nil,
task == nil,
let urlString = urlString,
let url = URL(string: urlString)
else { return }
let section = collectionContext?.section(for: self) ?? 0
print("Downloading image \(urlString) for section \(section)")
task = URLSession.shared.dataTask(with: url) { data, response, err in
guard let data = data, let image = UIImage(data: data) else {
return print("Error downloading \(urlString): \(err)")
}
DispatchQueue.main.async {
self.downloadedImage = image
if let cell = self.collectionContext?.cellForItem(at: 1, sectionController: self) as? ImageCell {
cell.setImage(image: image)
}
}
}
task?.resume()
}
func listAdapter(_ listAdapter: IGListAdapter, sectionControllerDidExitWorkingRange sectionController: IGListSectionController) {}
}