ScaleToFill factor fixes & added childContainerView #4

Example/Athlee-ImagePicker/Athlee-ImagePicker/CropViewController.swift

@@ -25,6 +25,7 @@ final class CropViewController: UIViewController, FloatingViewLayout, Cropable {
   // MARK: Cropable properties
 
   var cropView = UIScrollView()
+  var childContainerView = UIView()
   var childView = UIImageView()
   var linesView = LinesView()
 

Source/CGAffineTransform.swift

@@ -0,0 +1,39 @@
+//
+//  CGAffineTransform.swift
+//  Pods
+//
+//  Created by mac on 27/11/2016.
+//
+//
+
+import UIKit 
+
+public extension CGAffineTransform {
+  public static func scalingFactor(toFill containerSize: CGSize, with contentSize: CGSize, atAngle angle: Double) -> Double {
+    var theta = fabs(angle - 2 * .pi * trunc(angle / .pi / 2) - .pi)
+
+    if theta > .pi / 2 {
+      theta = fabs(.pi - theta)
+    }
+
+    let h = Double(contentSize.height)
+    let H = Double(containerSize.height)
+    let w = Double(contentSize.width)
+    let W = Double(containerSize.width)
+
+    let scale1 = (H * cos(theta) + W * sin(theta)) / min(H, h)
+    let scale2 = (H * sin(theta) + W * cos(theta)) / min(W, w)
+
+    let scalingFactor = max(scale1, scale2)
+
+    return scalingFactor
+  }
+
+  func scaling(toFill containerSize: CGSize, with contentSize: CGSize, atAngle angle: Double) -> CGAffineTransform {
+    let factor = CGFloat(CGAffineTransform.scalingFactor(toFill: containerSize,
+                                                         with: contentSize,
+                                                         atAngle: angle))
+
+    return self.scaledBy(x: factor, y: factor)
+  }
+}

Source/Cropable.swift

@@ -18,6 +18,10 @@ public protocol Cropable {
   /// A cropable area containing the content.
   var cropView: UIScrollView { get set }
 
+  /// A view containing the child. It is required to simplify 
+  /// any transformations on the child.
+  var childContainerView: UIView { get set }
+
   /// A cropable content view.
   var childView: ChildView { get set }
 
@@ -125,7 +129,8 @@ public extension Cropable where ChildView == UIImageView {
     cropView.showsVerticalScrollIndicator = false
     cropView.contentSize = view.bounds.size
 
-    cropView.addSubview(childView)
+    childContainerView.addSubview(childView)
+    cropView.addSubview(childContainerView)
   }
 
   ///
@@ -150,10 +155,14 @@ public extension Cropable where ChildView == UIImageView {
     childView.image = image
 
     if adjustingContent {
-      childView.sizeToFit()
+      childView.bounds.size = image.size
+      childContainerView.bounds.size = image.size
+
+      childContainerView.frame.origin = .zero
       childView.frame.origin = .zero
+
       cropView.contentOffset = .zero
-      cropView.contentSize = childView.image!.size
+      cropView.contentSize = image.size
 
       updateContent()
       highlightArea(false, animated: false)
@@ -185,8 +194,9 @@ public extension Cropable {
   /// Updates the current cropable content area, zoom and scale.
   ///
   func updateContent() {
-    let childViewSize = childView.bounds.size
+    let childViewSize = childContainerView.bounds.size
     let scrollViewSize = cropView.bounds.size
+
     let widthScale = scrollViewSize.width / childViewSize.width
     let heightScale = scrollViewSize.height / childViewSize.height
 
@@ -215,16 +225,16 @@ public extension Cropable {
   func centerContent(forcing: Bool = false) {
     var (left, top): (CGFloat, CGFloat) = (0, 0)
 
-    if cropView.contentSize.width < cropView.bounds.width {
-      left = (cropView.bounds.width - cropView.contentSize.width) / 2
+    if cropView.contentSize.width < cropView.frame.width {
+      left = (cropView.frame.width - cropView.contentSize.width) / 2
     } else if forcing {
-      cropView.contentOffset.x = abs(cropView.bounds.width - cropView.contentSize.width) / 2
+      cropView.contentOffset.x = abs(cropView.frame.width - cropView.contentSize.width) / 2
     }
 
-    if cropView.contentSize.height < cropView.bounds.height {
-      top = (cropView.bounds.height - cropView.contentSize.height) / 2
+    if cropView.contentSize.height < cropView.frame.height {
+      top = (cropView.frame.height - cropView.contentSize.height) / 2
     } else if forcing {
-      cropView.contentOffset.y = abs(cropView.bounds.height - cropView.contentSize.height) / 2
+      cropView.contentOffset.y = abs(cropView.frame.height - cropView.contentSize.height) / 2
     }
 
     cropView.contentInset = UIEdgeInsets(top: top, left: left, bottom: top, right: left)
@@ -302,12 +312,12 @@ public extension Cropable {
     }
 
     linesView.frame.size = CGSize(
-      width: min(cropView.frame.width, childView.frame.width),
-      height: min(cropView.frame.height, childView.frame.height)
+      width: min(cropView.frame.width, childContainerView.frame.width),
+      height: min(cropView.frame.height, childContainerView.frame.height)
     )
 
     let visibleRect = CGRect(origin: cropView.contentOffset, size: cropView.bounds.size)
-    let intersection = visibleRect.intersection(childView.frame)
+    let intersection = visibleRect.intersection(childContainerView.frame)
     linesView.frame = intersection
   }
 }

Source/CropableScrollViewDelegate.swift

@@ -91,6 +91,6 @@ open class CropableScrollViewDelegate<T: Cropable>: NSObject, UIScrollViewDelega
   }
 
   open func viewForZooming(in scrollView: UIScrollView) -> UIView? {
-    return cropable.childView
+    return cropable.childContainerView
   }
 }

Source/Radians.swift

@@ -0,0 +1,21 @@
+//
+//  Radians.swift
+//  Pods
+//
+//  Created by mac on 27/11/2016.
+//
+//
+
+import Foundation
+
+public extension Double {
+  public func toRadians() -> Double {
+    return self * .pi / 180.0
+  }
+}
+
+public extension Float {
+  public func toRadians() -> Float {
+    return self * .pi / 180
+  }
+}