development: added TabsController for PageTabBarController rework

Material.xcodeproj/project.pbxproj

@@ -233,6 +233,7 @@
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 		96E09DBD1F2108000000B121 /* TransitionPreprocessor.swift in Headers */ = {isa = PBXBuildFile; fileRef = 96E09D721F2107DD0000B121 /* TransitionPreprocessor.swift */; settings = {ATTRIBUTES = (Public, ); }; };
 		96E09DBD1F2108000000B121 /* TransitionPreprocessor.swift in Headers */ = {isa = PBXBuildFile; fileRef = 96E09D721F2107DD0000B121 /* TransitionPreprocessor.swift */; settings = {ATTRIBUTES = (Public, ); }; };
+		96E09DC81F2287E50000B121 /* TabsController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 96E09DC71F2287E50000B121 /* TabsController.swift */; };
 		96E3C3951D3A1CC20086A024 /* IconButton.swift in Headers */ = {isa = PBXBuildFile; fileRef = 9658F2161CD6FA4700B902C1 /* IconButton.swift */; settings = {ATTRIBUTES = (Public, ); }; };
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 		96E3C3971D3A1CC20086A024 /* Material+UIView.swift in Headers */ = {isa = PBXBuildFile; fileRef = 96E3C3931D397AE90086A024 /* Material+UIView.swift */; settings = {ATTRIBUTES = (Public, ); }; };
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@@ -367,6 +368,7 @@
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 		96E09D721F2107DD0000B121 /* TransitionPreprocessor.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = TransitionPreprocessor.swift; sourceTree = "<group>"; };
+		96E09DC71F2287E50000B121 /* TabsController.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = TabsController.swift; sourceTree = "<group>"; };
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@@ -505,6 +507,7 @@
 			isa = PBXGroup;
 			isa = PBXGroup;
 			children = (
 			children = (
 				96BCB79A1CB40DC500C806FE /* TabBar.swift */,
 				96BCB79A1CB40DC500C806FE /* TabBar.swift */,
+				96E09DC71F2287E50000B121 /* TabsController.swift */,
 			);
 			);
 			name = Tab;
 			name = Tab;
 			sourceTree = "<group>";
 			sourceTree = "<group>";
@@ -1144,6 +1147,7 @@
 				96328B991E05C0CE009A4C90 /* TableViewController.swift in Sources */,
 				96328B991E05C0CE009A4C90 /* TableViewController.swift in Sources */,
 				965E80F91DD4D59500D61E4B /* PresenterCard.swift in Sources */,
 				965E80F91DD4D59500D61E4B /* PresenterCard.swift in Sources */,
 				96E09D8B1F2107DD0000B121 /* MotionContext.swift in Sources */,
 				96E09D8B1F2107DD0000B121 /* MotionContext.swift in Sources */,
+				96E09DC81F2287E50000B121 /* TabsController.swift in Sources */,
 				965689611F002F4C001C656D /* CardCollectionViewController.swift in Sources */,
 				965689611F002F4C001C656D /* CardCollectionViewController.swift in Sources */,
 				965E80CC1DD4C50600D61E4B /* Bar.swift in Sources */,
 				965E80CC1DD4C50600D61E4B /* Bar.swift in Sources */,
 				96E09D871F2107DD0000B121 /* Motion.swift in Sources */,
 				96E09D871F2107DD0000B121 /* Motion.swift in Sources */,

Sources/iOS/TabBar.swift

@@ -60,7 +60,7 @@ public protocol TabBarDelegate {
 @objc(TabBarStyle)
 @objc(TabBarStyle)
 public enum TabBarStyle: Int {
 public enum TabBarStyle: Int {
     case normal
     case normal
-//    case scrollable
+    case scrollable
 }
 }
 
 
 open class TabBar: Bar {
 open class TabBar: Bar {
@@ -270,31 +270,31 @@ open class TabBar: Bar {
         
         
         layoutDivider()
         layoutDivider()
         
         
-//        let buttonsWidth = buttons.reduce(0) {
-//            $0 + $1.sizeThatFits(CGSize(width: .greatestFiniteMagnitude, height: contentView.height)).width + interimSpace
-//        }
-        
-//        if .scrollable == tabBarStyle && buttonsWidth > p {
-//            scrollView.frame = CGRect(x: l, y: 0, width: p, height: height)
-//            
-//            var w: CGFloat = 0
-//            
-//            for b in buttons {
-//                let width = b.sizeThatFits(CGSize(width: CGFloat.greatestFiniteMagnitude, height: contentView.height)).width + interimSpace
-//                scrollView.addSubview(b)
-//                b.height = scrollView.height
-//                b.width = width
-//                b.x = w
-//                w += width
-//            }
-//            
-//            scrollView.contentSize = CGSize(width: buttonsWidth, height: height)
-//            scrollView.addSubview(line)
-//        } else {
+        let buttonsWidth = buttons.reduce(0) {
+            $0 + $1.sizeThatFits(CGSize(width: .greatestFiniteMagnitude, height: contentView.height)).width + interimSpace
+        }
+        
+        if .scrollable == tabBarStyle && buttonsWidth > p {
+            scrollView.frame = CGRect(x: l, y: 0, width: p, height: height)
+            
+            var w: CGFloat = 0
+            
+            for b in buttons {
+                let width = b.sizeThatFits(CGSize(width: CGFloat.greatestFiniteMagnitude, height: contentView.height)).width + interimSpace
+                scrollView.addSubview(b)
+                b.height = scrollView.height
+                b.width = width
+                b.x = w
+                w += width
+            }
+            
+            scrollView.contentSize = CGSize(width: buttonsWidth, height: height)
+            scrollView.addSubview(line)
+        } else {
             contentView.grid.axis.columns = buttons.count
             contentView.grid.axis.columns = buttons.count
             centerViews = buttons
             centerViews = buttons
             addSubview(line)
             addSubview(line)
-//        }
+        }
         
         
         updateSelectionLine()
         updateSelectionLine()
 	}
 	}

Sources/iOS/TabsController.swift

+/*
+ * Copyright (C) 2015 - 2017, Daniel Dahan and CosmicMind, Inc. <http://cosmicmind.com>.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *	*	Redistributions of source code must retain the above copyright notice, this
+ *		list of conditions and the following disclaimer.
+ *
+ *	*	Redistributions in binary form must reproduce the above copyright notice,
+ *		this list of conditions and the following disclaimer in the documentation
+ *		and/or other materials provided with the distribution.
+ *
+ *	*	Neither the name of CosmicMind nor the names of its
+ *		contributors may be used to endorse or promote products derived from
+ *		this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+import UIKit
+
+/// A memory reference to the TabsBarItem instance for UIViewController extensions.
+fileprivate var TabsBarItemKey: UInt8 = 0
+
+open class TabsBarItem: FlatButton {
+    open override func prepare() {
+        super.prepare()
+        pulseAnimation = .none
+    }
+}
+
+@objc(TabBarAlignment)
+public enum TabBarAlignment: Int {
+    case top
+    case bottom
+    case hidden
+}
+
+extension UIViewController {
+    /// pageMenuBarItem reference.
+    public private(set) var pageMenuBarItem: TabsBarItem {
+        get {
+            return AssociatedObject.get(base: self, key: &TabsBarItemKey) {
+                return TabsBarItem()
+            }
+        }
+        set(value) {
+            AssociatedObject.set(base: self, key: &TabsBarItemKey, value: value)
+        }
+    }
+}
+
+extension UIViewController {
+    /**
+     A convenience property that provides access to the TabsController.
+     This is the recommended method of accessing the TabsController
+     through child UIViewControllers.
+     */
+    public var tabsController: TabsController? {
+        var viewController: UIViewController? = self
+        while nil != viewController {
+            if viewController is TabsController {
+                return viewController as? TabsController
+            }
+            viewController = viewController?.parent
+        }
+        return nil
+    }
+}
+
+open class TabsController: UIViewController {
+    /// A reference to the currently selected view controller index value.
+    @IBInspectable
+    open var selectedIndex = 0
+    
+    /// 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 { [weak self] in
+                self?.removeViewController(viewController: $0)
+            }
+            
+            prepareViewControllers()
+            prepareTabBar()
+            layoutSubviews()
+        }
+    }
+    
+    open var tabBarAlignment = TabBarAlignment.bottom {
+        didSet {
+            layoutSubviews()
+        }
+    }
+    
+    /**
+     An initializer that initializes the object with a NSCoder object.
+     - Parameter aDecoder: A NSCoder instance.
+     */
+    public required init?(coder aDecoder: NSCoder) {
+        viewControllers = []
+        super.init(coder: aDecoder)
+    }
+    
+    /// Previous scroll view content offset.
+    fileprivate var previousContentOffset: CGFloat = 0
+    
+    /// The number of views used in the scrollViewPool.
+    open var viewPoolCount = 3 {
+        didSet {
+            layoutSubviews()
+        }
+    }
+    
+    /**
+     An initializer that accepts an Array of UIViewControllers.
+     - Parameter viewControllers: An Array of UIViewControllers.
+     */
+    public init(viewControllers: [UIViewController], selectedIndex: Int = 0) {
+        self.viewControllers = viewControllers
+        self.selectedIndex = selectedIndex
+        super.init(nibName: nil, bundle: nil)
+    }
+    
+    open override func viewDidLoad() {
+        super.viewDidLoad()
+        prepare()
+    }
+    
+    open override func viewWillLayoutSubviews() {
+        super.viewWillLayoutSubviews()
+        layoutSubviews()
+    }
+    
+    /**
+     To execute in the order of the layout chain, override this
+     method. `layoutSubviews` should be called immediately, unless you
+     have a certain need.
+     */
+    open func layoutSubviews() {
+        layoutTabBar()
+        layoutScrollView()
+        layoutViewControllers()
+    }
+    
+    /**
+     Prepares the view instance when intialized. When subclassing,
+     it is recommended to override the prepare method
+     to initialize property values and other setup operations.
+     The super.prepare method should always be called immediately
+     when subclassing.
+     */
+    open func prepare() {
+        view.contentScaleFactor = Screen.scale
+        prepareScrollView()
+        prepareViewControllers()
+        prepareTabBar()
+    }
+}
+
+extension TabsController {
+    /// Prepares the scrollView used to pan through view controllers.
+    fileprivate func prepareScrollView() {
+        scrollView.delegate = self
+        scrollView.bounces = false
+        scrollView.isPagingEnabled = true
+        scrollView.showsVerticalScrollIndicator = false
+        scrollView.showsHorizontalScrollIndicator = false
+        scrollView.contentScaleFactor = Screen.scale
+        view.addSubview(scrollView)
+    }
+    
+    /// Prepares the view controllers.
+    fileprivate func prepareViewControllers() {
+        let n = viewControllers.count
+        
+        guard 1 < n else {
+            if 1 == n {
+                prepareViewController(at: 0)
+            }
+            return
+        }
+        
+        let m = viewPoolCount < n ? viewPoolCount : n
+        
+        if 0 == selectedIndex {
+            for i in 0..<m {
+                prepareViewController(at: i)
+            }
+        } else if n - 1 == selectedIndex {
+            for i in 0..<m {
+                prepareViewController(at: selectedIndex - i)
+            }
+        } else {
+            prepareViewController(at: selectedIndex)
+            prepareViewController(at: selectedIndex - 1)
+            prepareViewController(at: selectedIndex + 1)
+        }
+    }
+    
+    /**
+     Prepares the tabBar buttons.
+     - Parameter _ buttons: An Array of UIButtons.
+     */
+    fileprivate func prepareTabBarButtons(_ buttons: [UIButton]) {
+        guard let v = tabBar else {
+            return
+        }
+        
+        v.buttons = buttons
+        
+        for b in v.buttons {
+            b.removeTarget(self, action: #selector(handleTabBarButton(button:)), for: .touchUpInside)
+            b.addTarget(self, action: #selector(handleTabBarButton(button:)), for: .touchUpInside)
+        }
+    }
+    
+    fileprivate func prepareTabBar() {
+        var buttons = [UIButton]()
+        
+        for v in viewControllers {
+            let button = v.pageMenuBarItem as UIButton
+            v.isMotionEnabled = true
+            buttons.append(button)
+        }
+        
+        guard 0 < buttons.count else {
+            tabBar?.removeFromSuperview()
+            tabBar = nil
+            return
+        }
+        
+        guard nil == tabBar else {
+            prepareTabBarButtons(buttons)
+            return
+        }
+        
+        tabBar = TabBar()
+        tabBar?.isLineAnimated = false
+        tabBar?.lineAlignment = .top
+        view.addSubview(tabBar!)
+        
+        prepareTabBarButtons(buttons)
+    }
+    
+    /**
+     Loads a view controller based on its index in the viewControllers Array
+     and adds it as a child view controller.
+     - Parameter at index: An Int for the viewControllers index.
+     */
+    fileprivate func prepareViewController(at index: Int) {
+        let vc = viewControllers[index]
+        
+        guard !childViewControllers.contains(vc) else {
+            return
+        }
+        
+        addChildViewController(vc)
+        vc.didMove(toParentViewController: self)
+        vc.view.clipsToBounds = true
+        vc.view.contentScaleFactor = Screen.scale
+        scrollView.addSubview(vc.view)
+    }
+    
+    /**
+     Transitions from one view controller to another.
+     - Parameter from: The index of the view controller to transition from.
+     - Parameter to: The index of the view controller to transition to.
+     */
+    fileprivate func prepareViewControllersForTransition(from: Int, to: Int) {
+        let fromVC = viewControllers[from]
+        let toVC = viewControllers[to]
+        
+        fromVC.present(toVC, animated: true)
+    }
+}
+
+extension TabsController {
+    fileprivate func layoutScrollView() {
+        let w = view.bounds.width
+        scrollView.contentSize = CGSize(width: w * CGFloat(viewControllers.count), height: scrollView.height)
+        scrollView.contentOffset = CGPoint(x: w * CGFloat(selectedIndex), y: 0)
+        
+        guard let v = tabBar else {
+            scrollView.frame = view.bounds
+            return
+        }
+        
+        let p = v.height
+        let y = view.height - p
+        
+        switch tabBarAlignment {
+        case .top:
+            scrollView.y = p
+            scrollView.height = y
+        case .bottom:
+            scrollView.y = 0
+            scrollView.height = y
+        case .hidden:
+            scrollView.y = 0
+            scrollView.height = view.height
+        }
+        
+        scrollView.width = w
+    }
+    
+    fileprivate func layoutViewControllers() {
+        let n = viewControllers.count
+        
+        guard 1 < n else {
+            layoutViewController(at: 0, position: 0)
+            return
+        }
+        
+        let m = viewPoolCount < n ? viewPoolCount : n
+        
+        if 0 == selectedIndex {
+            for i in 0..<m {
+                layoutViewController(at: i, position: i)
+            }
+        } else if n - 1 == selectedIndex {
+            var q = 0
+            for i in 0..<m {
+                q = selectedIndex - i
+                layoutViewController(at: q, position: q)
+            }
+        } else {
+            layoutViewController(at: selectedIndex, position: selectedIndex)
+            layoutViewController(at: selectedIndex - 1, position: selectedIndex - 1)
+            layoutViewController(at: selectedIndex + 1, position: selectedIndex + 1)
+        }
+    }
+    
+    /**
+     Positions a view controller within the scrollView.
+     - Parameter position: An Int for the position of the view controller.
+     */
+    fileprivate func layoutViewController(at index: Int, position: Int) {
+        let w = scrollView.width
+        viewControllers[index].view.frame = CGRect(x: CGFloat(position) * w, y: 0, width: w, height: scrollView.height)
+    }
+    
+    /**
+     Layout the TabBar.
+     */
+    fileprivate func layoutTabBar() {
+        guard let v = tabBar else {
+            return
+        }
+        
+        let y = view.height - v.height
+        
+        v.width = view.width
+        
+        switch tabBarAlignment {
+        case .top:
+            v.isHidden = false
+            v.y = 0
+        case .bottom:
+            v.isHidden = false
+            v.y = y
+        case .hidden:
+            v.isHidden = true
+        }
+    }
+}
+
+extension TabsController {
+    /// Removes the view controllers not within the scrollView.
+    fileprivate func removeViewControllers() {
+        let n = viewControllers.count
+        
+        guard 1 < n else {
+            return
+        }
+        
+        if 0 == selectedIndex {
+            for i in 1..<n {
+                removeViewController(at: i)
+            }
+        } else if n - 1 == selectedIndex {
+            for i in 0..<n - 2 {
+                removeViewController(at: i)
+            }
+        } else {
+            for i in 0..<selectedIndex {
+                removeViewController(at: i)
+            }
+            
+            let x = selectedIndex + 1
+            
+            if x < n {
+                for i in x..<n {
+                    removeViewController(at: i)
+                }
+            }
+        }
+    }
+    
+    /**
+     Removes the view controller as a child view controller with
+     the given index.
+     - Parameter at index: An Int for the view controller position.
+     */
+    fileprivate func removeViewController(at index: Int) {
+        let v = viewControllers[index]
+        
+        guard childViewControllers.contains(v) else {
+            return
+        }
+        
+        removeViewController(viewController: v)
+    }
+    
+    /**
+     Removes a given view controller from the childViewControllers array.
+     - Parameter at index: An Int for the view controller position.
+     */
+    fileprivate func removeViewController(viewController: UIViewController) {
+        viewController.willMove(toParentViewController: nil)
+        viewController.view.removeFromSuperview()
+        viewController.removeFromParentViewController()
+    }
+}
+
+extension TabsController {
+    /**
+     Handles the pageTabBarButton.
+     - Parameter button: A UIButton.
+     */
+    @objc
+    fileprivate func handleTabBarButton(button: UIButton) {
+        guard let v = tabBar else {
+            return
+        }
+        
+        guard let i = v.buttons.index(of: button) else {
+            return
+        }
+        
+        guard i != selectedIndex else {
+            return
+        }
+        //        removeViewControllers()
+        
+        //        prepareViewControllersForTransition(from: selectedIndex, to: i)
+        
+        
+        
+        selectedIndex = i
+        v.select(at: i)
+        
+        removeViewControllers()
+        prepareViewControllers()
+        prepareTabBar()
+        layoutSubviews()
+    }
+}
+
+extension TabsController: UIScrollViewDelegate {
+    @objc
+    open func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {
+        let w = scrollView.width
+        let p = Int(floor((scrollView.contentOffset.x - w / 2) / w) + 1)
+        
+        selectedIndex = p
+        
+        removeViewControllers()
+        prepareViewControllers()
+        //        prepareTabBar()
+        layoutSubviews()
+    }
+}