TabMenuController rework for view controller resource optimizations, and…

TabMenuController rework for view controller resource optimizations, and issue-552 fix, to remove @objc on UIKit subclasses TextView and PageTabBarController

Sources/iOS/PageTabBarController.swift

@@ -97,7 +97,6 @@ public protocol PageTabBarControllerDelegate {
     optional func pageTabBarController(pageTabBarController: PageTabBarController, didTransitionTo viewController: UIViewController)
 }
 
-@objc(PageTabBarController)
 open class PageTabBarController: RootController {
     /// Reference to the PageTabBar.
     @IBInspectable

Sources/iOS/TabMenuController.swift

@@ -44,6 +44,7 @@ open class TabMenuBarItem: FlatButton {
 public enum TabMenuAlignment: Int {
     case top
     case bottom
+    case hidden
 }
 
 extension UIViewController {
@@ -80,8 +81,37 @@ extension UIViewController {
 
 open class TabMenuController: UIViewController {
     @IBInspectable
-    open let tabBar = TabBar()
+    open var selectedIndex: Int {
+        didSet {
+            scrollView.setContentOffset(CGPoint(x: scrollView.width * CGFloat(selectedIndex), y: 0), animated: true)
+            
+            guard false == tabBar?.isAnimating else {
+                return
+            }
+            
+            tabBar?.select(at: selectedIndex)
+        }
+    }
+    
+    /// Enables and disables bouncing when swiping.
+    open var isBounceEnabled: Bool {
+        get {
+            return scrollView.bounces
+        }
+        set(value) {
+            scrollView.bounces = value
+        }
+    }
+    
+    /// The TabBar used to switch between view controllers.
+    @IBInspectable
+    open fileprivate(set) var tabBar: TabBar?
+    
+    /// The UIScrollView used to pan the application pages.
+    @IBInspectable
+    open let scrollView = UIScrollView()
     
+    /// An Array of UIViewControllers.
     open var viewControllers: [UIViewController] {
         didSet {
             oldValue.forEach {
@@ -95,16 +125,12 @@ open class TabMenuController: UIViewController {
         }
     }
     
-    @IBInspectable
-    open var selectedIndex: Int {
+    open var tabMenuAlignment = TabMenuAlignment.bottom {
         didSet {
-            scrollView.setContentOffset(CGPoint(x: scrollView.width * CGFloat(selectedIndex), y: 0), animated: true)
+            layoutSubviews()
         }
     }
     
-    @IBInspectable
-    open let scrollView = UIScrollView()
-    
     /**
      An initializer that initializes the object with a NSCoder object.
      - Parameter aDecoder: A NSCoder instance.
@@ -143,6 +169,29 @@ open class TabMenuController: UIViewController {
     open func layoutSubviews() {
         layoutScrollView()
         layoutViewControllers()
+    
+        let p = (tabBar?.intrinsicContentSize.height ?? 0) + (tabBar?.layoutEdgeInsets.top ?? 0) + (tabBar?.layoutEdgeInsets.bottom ?? 0)
+        let y = view.height - p
+        
+        tabBar?.height = p
+        tabBar?.width = view.width + (tabBar?.layoutEdgeInsets.left ?? 0) + (tabBar?.layoutEdgeInsets.right ?? 0)
+        
+        switch tabMenuAlignment {
+        case .top:
+            tabBar?.isHidden = false
+            tabBar?.y = 0
+            scrollView.y = p
+            scrollView.height = y
+        case .bottom:
+            tabBar?.isHidden = false
+            tabBar?.y = y
+            scrollView.y = 0
+            scrollView.height = y
+        case .hidden:
+            tabBar?.isHidden = true
+            scrollView.y = 0
+            scrollView.height = view.height
+        }
     }
     
     /**
@@ -153,18 +202,13 @@ open class TabMenuController: UIViewController {
      when subclassing.
      */
     open func prepare() {
-        prepareTabBar()
         prepareScrollView()
         prepareViewControllers()
     }
 }
 
 extension TabMenuController {
-    fileprivate func prepareTabBar() {
-        tabBar.isLineAnimated = false
-        tabBar.lineAlignment = .top
-    }
-    
+    /// Prepares the scrollView used to pan through view controllers.
     fileprivate func prepareScrollView() {
         scrollView.delegate = self
         scrollView.bounces = false
@@ -174,15 +218,102 @@ extension TabMenuController {
         view.addSubview(scrollView)
     }
     
+    /// Prepares the view controllers.
     fileprivate func prepareViewControllers() {
+        let count = 2 < viewControllers.count ? 3 : viewControllers.count
+        scrollView.contentSize = CGSize(width: scrollView.width * CGFloat(count), height: scrollView.height)
+        
+        if 0 == selectedIndex {
+            for i in 0..<count {
+                let vc = viewControllers[i]
+                addChildViewController(vc)
+                vc.didMove(toParentViewController: self)
+                vc.view.clipsToBounds = true
+                vc.view.contentScaleFactor = Screen.scale
+                scrollView.addSubview(vc.view)
+            }
+        } else if viewControllers.count - 1 == selectedIndex {
+            for i in 0..<count {
+                let vc = viewControllers[count - i - 1]
+                addChildViewController(vc)
+                vc.didMove(toParentViewController: self)
+                vc.view.clipsToBounds = true
+                vc.view.contentScaleFactor = Screen.scale
+                scrollView.addSubview(vc.view)
+            }
+        } else {
+            var vc = viewControllers[selectedIndex]
+            addChildViewController(vc)
+            vc.didMove(toParentViewController: self)
+            vc.view.clipsToBounds = true
+            vc.view.contentScaleFactor = Screen.scale
+            scrollView.addSubview(vc.view)
+            
+            vc = viewControllers[selectedIndex - 1]
+            addChildViewController(vc)
+            vc.didMove(toParentViewController: self)
+            vc.view.clipsToBounds = true
+            vc.view.contentScaleFactor = Screen.scale
+            scrollView.addSubview(vc.view)
+            
+            vc = viewControllers[selectedIndex + 1]
+            addChildViewController(vc)
+            vc.didMove(toParentViewController: self)
+            vc.view.clipsToBounds = true
+            vc.view.contentScaleFactor = Screen.scale
+            scrollView.addSubview(vc.view)
+        }
+        
+        prepareTabBar()
+    }
+    
+    /**
+     Prepares the tabBar buttons.
+     - Parameter _ buttons: An Array of UIButtons.
+     */
+    fileprivate func prepareTabBarButtons(_ buttons: [UIButton]) {
+        guard let tb = tabBar else {
+            return
+        }
+        
+        tb.buttons = buttons
+        
+        for v in tb.buttons {
+            v.removeTarget(self, action: #selector(tb.handleButton(button:)), for: .touchUpInside)
+            v.removeTarget(self, action: #selector(handleTabBarButton(button:)), for: .touchUpInside)
+            v.addTarget(self, action: #selector(handleTabBarButton(button:)), for: .touchUpInside)
+        }
+        
+        tb.select(at: selectedIndex)
+    }
+    
+    fileprivate func prepareTabBar() {
+        guard 0 < viewControllers.count else {
+            return
+        }
+        
+        var buttons = [UIButton]()
+        
         for v in viewControllers {
-            addChildViewController(v)
-            scrollView.addSubview(v.view)
-            v.didMove(toParentViewController: self)
-            v.view.clipsToBounds = true
-            v.view.autoresizingMask = [.flexibleWidth, .flexibleHeight]
-            v.view.contentScaleFactor = Screen.scale
+            let button = v.tabMenuBarItem as UIButton
+            buttons.append(button)
         }
+        
+        guard 0 < buttons.count else {
+            tabBar = nil
+            return
+        }
+        
+        guard nil == tabBar else {
+            prepareTabBarButtons(buttons)
+            return
+        }
+        
+        tabBar = TabBar()
+        tabBar?.isLineAnimated = false
+        tabBar?.lineAlignment = .top
+        view.addSubview(tabBar!)
+        prepareTabBarButtons(buttons)
     }
 }
 
@@ -190,20 +321,96 @@ extension TabMenuController {
     fileprivate func layoutScrollView() {
         scrollView.frame = view.bounds
         scrollView.contentSize = CGSize(width: scrollView.width * CGFloat(viewControllers.count), height: scrollView.height)
-        print(selectedIndex)
         scrollView.contentOffset = CGPoint(x: scrollView.width * CGFloat(selectedIndex), y: 0)
     }
     
     fileprivate func layoutViewControllers() {
-        for i in 0..<viewControllers.count {
-            let v = viewControllers[i]
-            v.view.frame = CGRect(x: CGFloat(i) * scrollView.width, y: 0, width: scrollView.width, height: scrollView.height)
+        let count = 2 < viewControllers.count ? 3 : viewControllers.count
+        scrollView.contentSize = CGSize(width: scrollView.width * CGFloat(count), height: scrollView.height)
+        
+        if 0 == selectedIndex {
+            for i in 0..<count {
+                let vc = viewControllers[i]
+                vc.view.frame = CGRect(x: CGFloat(i) * scrollView.width, y: 0, width: scrollView.width, height: scrollView.height)
+            }
+        } else if viewControllers.count - 1 == selectedIndex {
+            for i in 0..<count {
+                let j = count - i - 1
+                let vc = viewControllers[j]
+                vc.view.frame = CGRect(x: CGFloat(j) * scrollView.width, y: 0, width: scrollView.width, height: scrollView.height)
+            }
+        } else {
+            var vc = viewControllers[selectedIndex]
+            vc.view.frame = CGRect(x: scrollView.width, y: 0, width: scrollView.width, height: scrollView.height)
+            
+            vc = viewControllers[selectedIndex - 1]
+            vc.view.frame = CGRect(x: 0, y: 0, width: scrollView.width, height: scrollView.height)
+            
+            vc = viewControllers[selectedIndex + 1]
+            vc.view.frame = CGRect(x: 2 * scrollView.width, y: 0, width: scrollView.width, height: scrollView.height)
         }
+
+    }
+}
+
+extension TabMenuController {
+    /**
+     Handles the pageTabBarButton.
+     - Parameter button: A UIButton.
+     */
+    @objc
+    fileprivate func handleTabBarButton(button: UIButton) {
+        guard let tb = tabBar else {
+            return
+        }
+        
+        guard let index = tb.buttons.index(of: button) else {
+            return
+        }
+        
+        guard index != selectedIndex else {
+            return
+        }
+        
+        if 1 < abs(index - selectedIndex) {
+            let last = viewControllers.count - 1
+            var pos = 0
+            
+            if last == selectedIndex {
+                pos = last - 1
+            } else if 0 == selectedIndex {
+                pos = 1
+            } else {
+                pos = selectedIndex + (index > selectedIndex ? 1 : -1)
+            }
+            
+            scrollView.setContentOffset(CGPoint(x: scrollView.width * CGFloat(pos), y: 0), animated: false)
+        }
+        
+        selectedIndex = index
     }
 }
 
 extension TabMenuController: UIScrollViewDelegate {
     @objc
+    open func scrollViewDidScroll(_ scrollView: UIScrollView) {
+        guard let tb = tabBar else {
+            return
+        }
+        
+        guard tb.isAnimating else {
+            return
+        }
+        
+        guard let selected = tb.selected else {
+            return
+        }
+        
+        let x = (scrollView.contentOffset.x - scrollView.width) / scrollView.contentSize.width * scrollView.width
+        tb.line.center.x = selected.center.x + x
+    }
+    
+    @objc
     open func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {
         selectedIndex = lround(Double(scrollView.contentOffset.x / scrollView.width))
     }

Sources/iOS/TextView.swift

@@ -87,7 +87,6 @@ public protocol TextViewDelegate : UITextViewDelegate {
     optional func textView(textView: TextView, didProcessEditing textStorage: TextStorage, text: String, range: NSRange)
 }
 
-@objc(TextView)
 open class TextView: UITextView {
     /// A boolean indicating whether the text is empty.
     open var isEmpty: Bool {