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| 1 | +import UIKit |
| 2 | + |
| 3 | +public protocol ImageDataSource:class { |
| 4 | + func numberOfImages() -> Int |
| 5 | + func imageItem(at index:Int) -> ImageItem |
| 6 | +} |
| 7 | + |
| 8 | +class ImageCarouselViewController:UIPageViewController { |
| 9 | + |
| 10 | + weak var imageDatasource:ImageDataSource? |
| 11 | + var initialIndex = 0 |
| 12 | + var sourceView:UIImageView! |
| 13 | + var theme:ImageViewerTheme = .light { |
| 14 | + didSet { |
| 15 | + navItem.leftBarButtonItem?.tintColor = theme.tintColor |
| 16 | + backgroundView.backgroundColor = theme.color |
| 17 | + } |
| 18 | + } |
| 19 | + |
| 20 | + var options:[ImageViewerOption] = [] |
| 21 | + |
| 22 | + private(set) lazy var navBar:UINavigationBar = { |
| 23 | + let _navBar = UINavigationBar(frame: .zero) |
| 24 | + _navBar.isTranslucent = true |
| 25 | + _navBar.setBackgroundImage(UIImage(), for: .default) |
| 26 | + _navBar.shadowImage = UIImage() |
| 27 | + return _navBar |
| 28 | + }() |
| 29 | + |
| 30 | + private(set) lazy var backgroundView:UIView = { |
| 31 | + let _v = UIView() |
| 32 | + _v.backgroundColor = theme.color |
| 33 | + _v.alpha = 0.0 |
| 34 | + return _v |
| 35 | + }() |
| 36 | + |
| 37 | + private(set) lazy var navItem = UINavigationItem() |
| 38 | + |
| 39 | + private func addNavBar() { |
| 40 | + // Add Navigation Bar |
| 41 | + let closeBarButton = UIBarButtonItem( |
| 42 | + title: NSLocalizedString("Close", comment: "Close button title"), |
| 43 | + style: .plain, |
| 44 | + target: self, |
| 45 | + action: #selector(dismiss(_:))) |
| 46 | + |
| 47 | + navItem.leftBarButtonItem = closeBarButton |
| 48 | + navItem.leftBarButtonItem?.tintColor = theme.tintColor |
| 49 | + |
| 50 | + navBar.items = [navItem] |
| 51 | + navBar.insert(to: view) |
| 52 | + } |
| 53 | + |
| 54 | + private func addBackgroundView() { |
| 55 | + view.addSubview(backgroundView) |
| 56 | + backgroundView.bindFrameToSuperview() |
| 57 | + view.sendSubviewToBack(backgroundView) |
| 58 | + } |
| 59 | + |
| 60 | + private func applyOptions() { |
| 61 | + |
| 62 | + options.forEach { |
| 63 | + switch $0 { |
| 64 | + case .theme(let theme): |
| 65 | + self.theme = theme |
| 66 | + case .closeIcon(let icon): |
| 67 | + navItem.leftBarButtonItem?.image = icon |
| 68 | + } |
| 69 | + } |
| 70 | + } |
| 71 | + |
| 72 | + override func viewDidLoad() { |
| 73 | + super.viewDidLoad() |
| 74 | + |
| 75 | + addBackgroundView() |
| 76 | + addNavBar() |
| 77 | + applyOptions() |
| 78 | + |
| 79 | + view.backgroundColor = .clear |
| 80 | + dataSource = self |
| 81 | + |
| 82 | + let initialVC = ImageViewerController(sourceView: sourceView) |
| 83 | + initialVC.index = initialIndex |
| 84 | + initialVC.backgroundView = backgroundView |
| 85 | + if let imageDatasource = imageDatasource { |
| 86 | + initialVC.imageItem = imageDatasource.imageItem(at: initialIndex) |
| 87 | + } else { |
| 88 | + // Use the image from source |
| 89 | + initialVC.imageItem = .image(sourceView.image) |
| 90 | + } |
| 91 | + initialVC.animateOnDidAppear = true |
| 92 | + initialVC.delegate = self |
| 93 | + setViewControllers([initialVC], direction: .forward, animated: true, completion: nil) |
| 94 | + } |
| 95 | + |
| 96 | + @objc |
| 97 | + func dismiss(_ sender:UIBarButtonItem?) { |
| 98 | + sourceView.alpha = 1.0 |
| 99 | + UIView.animate(withDuration: 0.235, animations: { |
| 100 | + self.view.alpha = 0.0 |
| 101 | + }) { _ in |
| 102 | + self.dismiss(animated: false, completion: nil) |
| 103 | + } |
| 104 | + } |
| 105 | + |
| 106 | + override var preferredStatusBarStyle: UIStatusBarStyle { |
| 107 | + if theme == .dark { |
| 108 | + return .lightContent |
| 109 | + } |
| 110 | + return .default |
| 111 | + } |
| 112 | +} |
| 113 | + |
| 114 | +extension ImageCarouselViewController:UIPageViewControllerDataSource { |
| 115 | + func pageViewController( |
| 116 | + _ pageViewController: UIPageViewController, |
| 117 | + viewControllerBefore viewController: UIViewController) -> UIViewController? { |
| 118 | + |
| 119 | + guard let vc = viewController as? ImageViewerController else { return nil } |
| 120 | + guard let imageDatasource = imageDatasource else { return nil } |
| 121 | + guard vc.index > 0 else { return nil } |
| 122 | + |
| 123 | + let newIndex = vc.index - 1 |
| 124 | + let sourceView = newIndex == initialIndex ? self.sourceView : nil |
| 125 | + return ImageViewerController.create( |
| 126 | + index: newIndex, |
| 127 | + imageItem: imageDatasource.imageItem(at: newIndex), |
| 128 | + sourceView: sourceView, |
| 129 | + backgroundView: backgroundView, |
| 130 | + delegate: self) |
| 131 | + } |
| 132 | + |
| 133 | + func pageViewController( |
| 134 | + _ pageViewController: UIPageViewController, |
| 135 | + viewControllerAfter viewController: UIViewController) -> UIViewController? { |
| 136 | + |
| 137 | + guard let vc = viewController as? ImageViewerController else { return nil } |
| 138 | + guard let imageDatasource = imageDatasource else { return nil } |
| 139 | + guard vc.index <= (imageDatasource.numberOfImages() - 2) else { return nil } |
| 140 | + |
| 141 | + let newIndex = vc.index + 1 |
| 142 | + let sourceView = newIndex == initialIndex ? self.sourceView : nil |
| 143 | + return ImageViewerController.create( |
| 144 | + index: newIndex, |
| 145 | + imageItem: imageDatasource.imageItem(at: newIndex), |
| 146 | + sourceView: sourceView, |
| 147 | + backgroundView: backgroundView, |
| 148 | + delegate: self) |
| 149 | + } |
| 150 | +} |
| 151 | + |
| 152 | +extension ImageCarouselViewController:ImageViewerControllerDelegate { |
| 153 | + func imageViewerDidClose(_ imageViewer: ImageViewerController) { |
| 154 | + sourceView.alpha = 1.0 |
| 155 | + } |
| 156 | +} |
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