Improve/image stack

Source/BottomView/StackView.swift

@@ -21,6 +21,7 @@ class StackView: UIView {
       view.layer.borderWidth = 1
       view.contentMode = .ScaleAspectFill
       view.clipsToBounds = true
+      view.alpha = 0
       array.append(view)
     }
     return array
@@ -33,11 +34,10 @@ class StackView: UIView {
     return gesture
     }()
 
-  lazy var viewSize: CGSize = CGSize(width: self.frame.width * 0.6, height: self.frame.height * 0.6)
-
   override init(frame: CGRect) {
     super.init(frame: frame)
     views.map{ self.addSubview($0) }
+    views[0].alpha = 1
     self.addGestureRecognizer(tapGestureRecognizer)
     layoutSubviews()
     ImageStack.sharedStack.delegate = self
@@ -46,6 +46,8 @@ class StackView: UIView {
 
   override func layoutSubviews() {
     let step = -4
+    let viewSize = CGSize(width: self.frame.width * 0.6, height: self.frame.height * 0.6)
+
     for (i, view) in enumerate(views) {
       var side = i * step
       var frame = CGRect(origin: CGPoint(x: side, y: side), size: viewSize)
@@ -64,26 +66,59 @@ class StackView: UIView {
 
 extension StackView: ImageStackDelegate {
   func imageDidPush(image: UIImage) {
+
+    //TODO indexOf in swift 2
+    let emptyView = views.filter( {$0.image == nil} ).first
+
+    if let emptyView = emptyView {
+      println("Animating")
+      animateImageView(emptyView)
+    }
     renderViews()
   }
 
   func imageStackDidDrop(image: UIImage) {
+    // Uncomment if you want fancy animations
+//    let viewToEmpty = views.filter( {$0.image == image} ).first
+//
+//    if let viewToEmpty = viewToEmpty {
+//      animateImageView(viewToEmpty)
+//    }
+
     renderViews()
   }
 
   func renderViews() {
-    let photos = ImageStack.sharedStack.images
-    //TODO: Find better way to limit value to bounds
-    var size = min(photos.count - 1, 3)
+    //because Swift is not functional language
+    if ImageStack.sharedStack.images.count < 1 {
+      views.map { $0.image = nil}
+      return
+    }
 
-    for (index, view) in enumerate(views.reverse()) {
-      if index <= size {
-        view.image = photos.reverse()[index]
+    let photos = suffix(ImageStack.sharedStack.images, 4)
+
+    //TODO: This can be done in functional-style
+    for (index, view) in enumerate(views) {
+      if index <= photos.count - 1 {
+        view.image = photos[index]
         view.alpha = 1
       } else {
         view.image = nil
         view.alpha = 0
       }
     }
   }
+
+  private func animateImageView(imageView: UIImageView) {
+    imageView.transform = CGAffineTransformMakeScale(0, 0)
+
+    UIView.animateWithDuration(0.3, animations: { [unowned self] in
+      imageView.transform = CGAffineTransformMakeScale(1.05, 1.05)
+      }, completion: { _ in
+        UIView.animateWithDuration(0.2, animations: { _ in
+          imageView.transform = CGAffineTransformIdentity
+        })
+    })
+  }
 }
+