Merge pull request #45 from hyperoslo/feature/loading-spinner

Feature/loading spinner

Author: vadymmarkov

Source/LightboxDataSource.swift

@@ -14,13 +14,18 @@ extension LightboxController: UICollectionViewDataSource {
     let config = LightboxConfig.sharedInstance.config
 
     cell.parentViewController = self
+    cell.loadingIndicator.alpha = 0
     cell.setupTransitionManager()
 
     if let imageString = image as? String {
       if let imageURL = NSURL(string: imageString) where config.remoteImages {
+        cell.loadingIndicator.alpha = 1
         config.loadImage(
           imageView: cell.lightboxView.imageView, URL: imageURL) { error in
-            if error == nil { cell.lightboxView.updateViewLayout() }
+            if error == nil {
+              cell.loadingIndicator.alpha = 0
+              cell.lightboxView.updateViewLayout()
+            }
         }
       } else {
         cell.lightboxView.imageView.image = UIImage(named: imageString)

Source/LightboxView.swift

@@ -10,8 +10,9 @@ public class LightboxView: UIView {
     let imageView = UIImageView(frame: CGRectZero)
     imageView.translatesAutoresizingMaskIntoConstraints = false
     imageView.userInteractionEnabled = true
+    
     return imageView
-  }()
+    }()
 
   lazy var scrollView: UIScrollView = { [unowned self] in
     let scrollView = UIScrollView(frame: CGRectZero)
@@ -24,7 +25,7 @@ public class LightboxView: UIView {
     scrollView.showsHorizontalScrollIndicator = false
 
     return scrollView
-  }()
+    }()
 
   var imageConstraintLeading: NSLayoutConstraint!
   var imageConstraintTrailing: NSLayoutConstraint!
@@ -45,7 +46,7 @@ public class LightboxView: UIView {
     minimumZoomScale = config.zoom.minimumScale
     maximumZoomScale = config.zoom.maximumScale
 
-    scrollView.addSubview(self.imageView)
+    scrollView.addSubview(imageView)
     addSubview(scrollView)
   }
 

Source/LightboxViewCell.swift

@@ -16,8 +16,20 @@ public class LightboxViewCell: UICollectionViewCell {
     return lightboxView
     }()
 
+  public lazy var loadingIndicator: UIActivityIndicatorView = {
+    let loadingIndicator = UIActivityIndicatorView(activityIndicatorStyle: .White)
+    loadingIndicator.startAnimating()
+    loadingIndicator.alpha = 0
+    loadingIndicator.translatesAutoresizingMaskIntoConstraints = false
+
+    return loadingIndicator
+    }()
+
   public override func layoutSubviews() {
     super.layoutSubviews()
+
+    if loadingIndicator.superview == nil { self.contentView.addSubview(loadingIndicator) }
+
     setupConstraints()
     lightboxView.updateViewLayout()
   }
@@ -37,6 +49,14 @@ public class LightboxViewCell: UICollectionViewCell {
           multiplier: 1, constant: 0))
       }
 
+      addConstraint(NSLayoutConstraint(item: loadingIndicator, attribute: .CenterX,
+        relatedBy: .Equal, toItem: self.contentView, attribute: .CenterX,
+        multiplier: 1, constant: 0))
+
+      addConstraint(NSLayoutConstraint(item: loadingIndicator, attribute: .CenterY,
+        relatedBy: .Equal, toItem: self.contentView, attribute: .CenterY,
+        multiplier: 1, constant: 0))
+
       constraintsAdded = true
     }
   }