development: fixed grid issue, where views were causing an out of bounds index error

Sources/iOS/ControlView.swift

@@ -91,29 +91,15 @@ open class ControlView: View {
 	open private(set) var contentView: View!
 	
 	/// Left side UIControls.
-	open var leftControls: [UIView] {
+	open var leftControls = [UIView]() {
 		didSet {
-            for v in oldValue {
-                v.removeFromSuperview()
-            }
-			
-            for v in leftControls {
-                addSubview(v)
-            }
             layoutSubviews()
 		}
 	}
 	
 	/// Right side UIControls.
-	open var rightControls: [UIView] {
+	open var rightControls = [UIView]() {
 		didSet {
-            for v in oldValue {
-                v.removeFromSuperview()
-            }
-            
-            for v in rightControls {
-                addSubview(v)
-            }
             layoutSubviews()
 		}
 	}
@@ -123,8 +109,6 @@ open class ControlView: View {
      - Parameter aDecoder: A NSCoder instance.
      */
 	public required init?(coder aDecoder: NSCoder) {
-        leftControls = []
-        rightControls = []
         super.init(coder: aDecoder)
 	}
 	
@@ -135,15 +119,11 @@ open class ControlView: View {
      - Parameter frame: A CGRect instance.
      */
 	public override init(frame: CGRect) {
-        leftControls = []
-        rightControls = []
         super.init(frame: frame)
 	}
 	
 	/// Basic initializer.
 	public init() {
-		leftControls = []
-        rightControls = []
 		super.init(frame: .zero)
         frame.size = intrinsicContentSize
 	}

Sources/iOS/Grid.swift

@@ -173,7 +173,7 @@ public class Grid {
     }
     
     /// An Array of UIButtons.
-    public var views: [UIView] {
+    public var views = [UIView]() {
         didSet {
             reload()
         }
@@ -190,7 +190,6 @@ public class Grid {
         self.rows = rows
         self.columns = columns
         self.interimSpace = interimSpace
-        views = [UIView]()
         offset = GridOffset(grid: self)
         axis = GridAxis(grid: self)
     }
@@ -198,11 +197,13 @@ public class Grid {
     /// Reload the button layout.
     public func reload() {
         var n: Int = 0
+        var i: Int = 0
         
-        for i in 0..<views.count {
-            let child = views[i]
+        for child in views {
+            guard let parent = context else {
+                return
+            }
             
-            if let parent = context {
             if parent != child.superview {
                 child.removeFromSuperview()
                 parent.addSubview(child)
@@ -248,7 +249,8 @@ public class Grid {
                 child.width = w * CGFloat(c) - interimSpace
                 child.height = h * CGFloat(r) - interimSpace
             }
-            }
+            
+            i += 1
         }
     }
 }

Sources/iOS/PageController.swift

@@ -55,6 +55,9 @@ public protocol PageControllerDelegate {
 
 @objc(PageController)
 open class PageController: RootController {
+    /// A boolean that indicates when a button animation is active.
+    internal var animating = false
+    
     /// The currently selected UIViewController.
     open internal(set) var selectedIndex: Int = 0
     
@@ -137,6 +140,12 @@ open class PageController: RootController {
         v.delegate = self
         v.dataSource = self
         v.isDoubleSided = false
+        
+        for view in v.view.subviews {
+            if view.isKind(of: UIScrollView.self) {
+                (view as? UIScrollView)?.delegate = self
+            }
+        }
     }
     
     /// Prepares the tabBar.
@@ -145,6 +154,7 @@ open class PageController: RootController {
             tabBar = TabBar()
             tabBar.zPosition = 1000
             view.addSubview(tabBar)
+            tabBar.select(at: selectedIndex)
         }
     }
 }
@@ -157,7 +167,25 @@ extension PageController {
 }
 
 extension PageController: UIPageViewControllerDelegate {
+    public func pageViewController(_ pageViewController: UIPageViewController, didFinishAnimating finished: Bool, previousViewControllers: [UIViewController], transitionCompleted completed: Bool) {
+        guard let vc = previousViewControllers.first else {
+            return
+        }
         
+        guard let index = viewControllers.index(of: vc) else {
+            return
+        }
+        
+        guard completed else {
+            tabBar.select(at: index) { [weak self] _ in
+                guard let s = self else {
+                    return
+                }
+                s.animating = false
+            }
+            return
+        }
+    }
 }
 
 extension PageController: UIPageViewControllerDataSource {
@@ -190,3 +218,28 @@ extension PageController: UIPageViewControllerDataSource {
         return viewControllers[next]
     }
 }
+
+extension PageController: UIScrollViewDelegate {
+    public func scrollViewDidScroll(_ scrollView: UIScrollView) {
+        guard !animating else {
+            return
+        }
+        
+        let x = scrollView.contentOffset.x / scrollView.contentSize.width * scrollView.width
+        
+        guard 0 < x else {
+            return
+        }
+        
+        tabBar.line.x = x
+        print("scrolling", x)
+    }
+    
+    public func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {
+//        animating = true
+    }
+    
+    public func scrollViewWillBeginDecelerating(_ scrollView: UIScrollView) {
+        animating = true
+    }
+}

Sources/iOS/TabBar.swift

@@ -185,6 +185,27 @@ open class TabBar: View {
 	/// Handles the button touch event.
     @objc
 	internal func handleButton(button: UIButton) {
+        animate(to: button)
+	}
+	
+    /**
+     Selects a given index from the buttons array.
+     - Parameter at index: An Int.
+     - Paramater completion: An optional completion block.
+     */
+    open func select(at index: Int, completion: (@escaping (UIButton) -> Void)? = nil) {
+        guard -1 < index, index < buttons.count else {
+            return
+        }
+        animate(to: buttons[index], completion: completion)
+    }
+    
+    /**
+     Animates to a given button.
+     - Parameter to button: A UIButton.
+     - Paramater completion: An optional completion block.
+     */
+    internal func animate(to button: UIButton, completion: (@escaping (UIButton) -> Void)? = nil) {
         delegate?.tabBarWillSelectButton?(tabBar: self, button: button)
         selected = button
         
@@ -194,11 +215,12 @@ open class TabBar: View {
             }
             s.line.x = button.x
             s.line.width = button.width
-        }) { [weak self, button = button] _ in
+        }) { [weak self, button = button, completion = completion] _ in
             guard let s = self else {
                 return
             }
             s.delegate?.tabBarDidSelectButton?(tabBar: s, button: button)
+            completion?(button)
         }
     }