Updated to swift 4

ScrollPager.xcodeproj/project.pbxproj

@@ -169,17 +169,17 @@
 			attributes = {
 				LastSwiftMigration = 0700;
 				LastSwiftUpdateCheck = 0700;
-				LastUpgradeCheck = 0800;
+				LastUpgradeCheck = 0920;
 				ORGANIZATIONNAME = "Aryan Ghassemi";
 				TargetAttributes = {
 					15F9717A1A9A86E400169B7E = {
 						CreatedOnToolsVersion = 6.1.1;
 						DevelopmentTeam = 24FGDP9KJW;
-						LastSwiftMigration = 0800;
+						LastSwiftMigration = 0920;
 					};
 					15F9718F1A9A86E400169B7E = {
 						CreatedOnToolsVersion = 6.1.1;
-						LastSwiftMigration = 0800;
+						LastSwiftMigration = 0920;
 						TestTargetID = 15F9717A1A9A86E400169B7E;
 					};
 				};
@@ -280,14 +280,20 @@
 				CLANG_CXX_LIBRARY = "libc++";
 				CLANG_ENABLE_MODULES = YES;
 				CLANG_ENABLE_OBJC_ARC = YES;
+				CLANG_WARN_BLOCK_CAPTURE_AUTORELEASING = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
+				CLANG_WARN_COMMA = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
 				CLANG_WARN_DIRECT_OBJC_ISA_USAGE = YES_ERROR;
 				CLANG_WARN_EMPTY_BODY = YES;
 				CLANG_WARN_ENUM_CONVERSION = YES;
 				CLANG_WARN_INFINITE_RECURSION = YES;
 				CLANG_WARN_INT_CONVERSION = YES;
+				CLANG_WARN_NON_LITERAL_NULL_CONVERSION = YES;
+				CLANG_WARN_OBJC_LITERAL_CONVERSION = YES;
 				CLANG_WARN_OBJC_ROOT_CLASS = YES_ERROR;
+				CLANG_WARN_RANGE_LOOP_ANALYSIS = YES;
+				CLANG_WARN_STRICT_PROTOTYPES = YES;
 				CLANG_WARN_SUSPICIOUS_MOVE = YES;
 				CLANG_WARN_UNREACHABLE_CODE = YES;
 				CLANG_WARN__DUPLICATE_METHOD_MATCH = YES;
@@ -327,14 +333,20 @@
 				CLANG_CXX_LIBRARY = "libc++";
 				CLANG_ENABLE_MODULES = YES;
 				CLANG_ENABLE_OBJC_ARC = YES;
+				CLANG_WARN_BLOCK_CAPTURE_AUTORELEASING = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
+				CLANG_WARN_COMMA = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
 				CLANG_WARN_DIRECT_OBJC_ISA_USAGE = YES_ERROR;
 				CLANG_WARN_EMPTY_BODY = YES;
 				CLANG_WARN_ENUM_CONVERSION = YES;
 				CLANG_WARN_INFINITE_RECURSION = YES;
 				CLANG_WARN_INT_CONVERSION = YES;
+				CLANG_WARN_NON_LITERAL_NULL_CONVERSION = YES;
+				CLANG_WARN_OBJC_LITERAL_CONVERSION = YES;
 				CLANG_WARN_OBJC_ROOT_CLASS = YES_ERROR;
+				CLANG_WARN_RANGE_LOOP_ANALYSIS = YES;
+				CLANG_WARN_STRICT_PROTOTYPES = YES;
 				CLANG_WARN_SUSPICIOUS_MOVE = YES;
 				CLANG_WARN_UNREACHABLE_CODE = YES;
 				CLANG_WARN__DUPLICATE_METHOD_MATCH = YES;
@@ -368,7 +380,8 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = "com.aryaxt.$(PRODUCT_NAME:rfc1034identifier)";
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 3.0;
+				SWIFT_SWIFT3_OBJC_INFERENCE = On;
+				SWIFT_VERSION = 4.0;
 			};
 			name = Debug;
 		};
@@ -381,7 +394,8 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = "com.aryaxt.$(PRODUCT_NAME:rfc1034identifier)";
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 3.0;
+				SWIFT_SWIFT3_OBJC_INFERENCE = On;
+				SWIFT_VERSION = 4.0;
 			};
 			name = Release;
 		};
@@ -401,7 +415,8 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = "com.aryaxt.$(PRODUCT_NAME:rfc1034identifier)";
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 3.0;
+				SWIFT_SWIFT3_OBJC_INFERENCE = On;
+				SWIFT_VERSION = 4.0;
 				TEST_HOST = "$(BUILT_PRODUCTS_DIR)/ScrollPager.app/ScrollPager";
 			};
 			name = Debug;
@@ -418,7 +433,8 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = "com.aryaxt.$(PRODUCT_NAME:rfc1034identifier)";
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 3.0;
+				SWIFT_SWIFT3_OBJC_INFERENCE = On;
+				SWIFT_VERSION = 4.0;
 				TEST_HOST = "$(BUILT_PRODUCTS_DIR)/ScrollPager.app/ScrollPager";
 			};
 			name = Release;

ScrollPager.xcodeproj/xcshareddata/xcschemes/ScrollPager.xcscheme

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "0800"
+   LastUpgradeVersion = "0920"
    version = "1.3">
    <BuildAction
       parallelizeBuildables = "YES"
@@ -40,6 +40,7 @@
       buildConfiguration = "Debug"
       selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
       selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      language = ""
       shouldUseLaunchSchemeArgsEnv = "YES">
       <Testables>
          <TestableReference
@@ -69,6 +70,7 @@
       buildConfiguration = "Debug"
       selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
       selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      language = ""
       launchStyle = "0"
       useCustomWorkingDirectory = "NO"
       ignoresPersistentStateOnLaunch = "NO"

ScrollPager.xcodeproj/xcshareddata/xcschemes/ScrollPagerTests.xcscheme

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "0800"
+   LastUpgradeVersion = "0920"
    version = "1.3">
    <BuildAction
       parallelizeBuildables = "YES"
@@ -10,6 +10,7 @@
       buildConfiguration = "Debug"
       selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
       selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      language = ""
       shouldUseLaunchSchemeArgsEnv = "YES">
       <Testables>
          <TestableReference
@@ -30,6 +31,7 @@
       buildConfiguration = "Debug"
       selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
       selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      language = ""
       launchStyle = "0"
       useCustomWorkingDirectory = "NO"
       ignoresPersistentStateOnLaunch = "NO"

ScrollPager/Source/ScrollPager.swift

@@ -29,12 +29,12 @@
 import UIKit
 
 @objc public protocol ScrollPagerDelegate: NSObjectProtocol {
-	@objc optional func scrollPager(scrollPager: ScrollPager, changedIndex: Int)
+	@objc optional func scrollPager(_ scrollPager: ScrollPager, changedIndex: Int)
 }
 
 @IBDesignable public class ScrollPager: UIView, UIScrollViewDelegate{
 
-	private var selectedIndex = 0
+	public private(set) var selectedIndex = 0
 	private let indicatorView = UIView()
 	private var buttons = [UIButton]()
 	private var views = [UIView]()
@@ -105,7 +105,7 @@ import UIKit
 
 	private func initialize() {
 		#if TARGET_INTERFACE_BUILDER
-			addSegmentsWithTitles(["One", "Two", "Three", "Four"])
+			addSegments(with: ["One", "Two", "Three", "Four"])
 		#endif
 	}
 
@@ -120,45 +120,52 @@ import UIKit
 
 	// MARK: - Public Methods -
 
-	public func addSegmentsWithTitlesAndViews(segments: [(title: String, view: UIView)]) {
+	public func addSegments(with segments: [(title: String, view: UIView)]) {
 
-		addButtons(titleOrImages: segments.map { $0.title as AnyObject })
-		addViews(segmentViews: segments.map { $0.view })
+		addButtons(segments.map { $0.title as AnyObject })
+		addViews(segments.map { $0.view })
 
 		redrawComponents()
 	}
 
-	public func addSegmentsWithImagesAndViews(segments: [(image: UIImage, view: UIView)]) {
+	public func addSegments(with segments: [(image: UIImage, view: UIView)]) {
 
-		addButtons(titleOrImages: segments.map { $0.image })
-		addViews(segmentViews: segments.map { $0.view })
+		addButtons(segments.map { $0.image })
+		addViews(segments.map { $0.view })
 
 		redrawComponents()
 	}
-
-	public func addSegmentsWithTitles(segmentTitles: [String]) {
-		addButtons(titleOrImages: segmentTitles as [AnyObject])
+	@objc(addSegmentsWithTitles:)
+	public func addSegments(with segmentTitles: [String]) {
+		addButtons(segmentTitles as [AnyObject])
 		redrawComponents()
 	}
-	
-	public func addSegmentsWithImages(segmentImages: [UIImage]) {
-		addButtons(titleOrImages: segmentImages)
+    @objc(addSegmentsWithImages:)
+	public func addSegments(with segmentImages: [UIImage]) {
+		addButtons(segmentImages)
 		redrawComponents()
 	}
 
-	public func setSelectedIndex(index: Int, animated: Bool) {
-		setSelectedIndex(index: index, animated: animated, moveScrollView: true)
+	public func setSelectedIndex(_ index: Int, animated: Bool) {
+		setSelectedIndex(index, animated: animated, moveScrollView: true)
 	}
+
+    public func viewForItem(at index: Int) -> UIView? {
+        guard index < views.count else {
+            return nil
+        }
+        return views[index]
+    }
 
 	// MARK: - Private -
 
-	private func setSelectedIndex(index: Int, animated: Bool, moveScrollView: Bool) {
+	private func setSelectedIndex(_ index: Int, animated: Bool, moveScrollView: Bool) {
 		selectedIndex = index
 
-		moveToIndex(index: index, animated: animated, moveScrollView: moveScrollView)
+        move(to: index, animated: animated, moveScrollView: moveScrollView)
 	}
 
-	private func addViews(segmentViews: [UIView]) {
+	private func addViews(_ segmentViews: [UIView]) {
 		guard let scrollView = scrollView else { fatalError("trying to add views but the scrollView is nil") }
 
 		for view in scrollView.subviews {
@@ -172,7 +179,7 @@ import UIKit
 		}
 	}
 
-	private func addButtons(titleOrImages: [AnyObject]) {
+	private func addButtons(_ titleOrImages: [AnyObject]) {
 		for button in buttons {
 			button.removeFromSuperview()
 		}
@@ -182,7 +189,7 @@ import UIKit
 		for i in 0..<titleOrImages.count {
 			let button = UIButton(type: .custom)
 			button.tag = i
-			button.addTarget(self, action: #selector(ScrollPager.buttonSelected(sender:)), for: .touchUpInside)
+			button.addTarget(self, action: #selector(buttonSelected(_:)), for: .touchUpInside)
 			buttons.append(button)
 
 			if let title = titleOrImages[i] as? String {
@@ -197,7 +204,7 @@ import UIKit
 		}
 	}
 
-	private func moveToIndex(index: Int, animated: Bool, moveScrollView: Bool) {
+	private func move(to index: Int, animated: Bool, moveScrollView: Bool) {
 		animationInProgress = true
 
         UIView.animate(withDuration: animated ? TimeInterval(animationDuration) : 0.0, delay: 0.0, options: .curveEaseOut, animations: { [weak self] in
@@ -213,7 +220,7 @@ import UIKit
 			if strongSelf.indicatorSizeMatchesTitle {
 				guard let string = button.titleLabel?.text else { fatalError("missing title on button, title is required for width calculation") }
 				guard let font = button.titleLabel?.font else { fatalError("missing dont on button, title is required for width calculation")  }
-				let size = string.size(attributes: [NSFontAttributeName: font])
+				let size = string.size(withAttributes: [NSAttributedStringKey.font: font])
 				let x = width * CGFloat(index) + ((width - size.width) / CGFloat(2))
 				strongSelf.indicatorView.frame = CGRect(x: x, y: indicatorY, width: size.width, height: strongSelf.indicatorHeight)
 			}
@@ -237,7 +244,7 @@ import UIKit
 		redrawButtons()
 
 		if buttons.count > 0 {
-			moveToIndex(index: selectedIndex, animated: false, moveScrollView: false)
+            move(to: selectedIndex, animated: false, moveScrollView: false)
 		}
 
 		if let scrollView = scrollView {
@@ -266,14 +273,15 @@ import UIKit
 		}
 	}
 
-	internal func buttonSelected(sender: UIButton) {
+	@objc internal func buttonSelected(_ sender: UIButton) {
 		if sender.tag == selectedIndex {
 			return
 		}
+        // change the selected index
+        setSelectedIndex(sender.tag, animated: true, moveScrollView: true)
+        // notify the delegate that index has changed
+		delegate?.scrollPager?(self, changedIndex: sender.tag)
 
-		delegate?.scrollPager?(scrollPager: self, changedIndex: sender.tag)
-
-		setSelectedIndex(index: sender.tag, animated: true, moveScrollView: true)
 	}
 
 	// MARK: - UIScrollView Delegate -
@@ -287,8 +295,8 @@ import UIKit
 			}
 
 			if Int(page) != selectedIndex {
-				setSelectedIndex(index: Int(page), animated: true, moveScrollView: false)
-				delegate?.scrollPager?(scrollPager: self, changedIndex: Int(page))
+				setSelectedIndex(Int(page), animated: true, moveScrollView: false)
+				delegate?.scrollPager?(self, changedIndex: Int(page))
 			}
 		}
 	}

ScrollPager/ViewController.swift

@@ -37,14 +37,14 @@ class ViewController: UIViewController, ScrollPagerDelegate {
 		fourthView.textAlignment = .center
 
 		scrollPager.delegate = self
-		scrollPager.addSegmentsWithTitlesAndViews(segments: [
+        scrollPager.addSegments(with: [
 			("Home", firstView),
 			("Public Feed", secondView),
 			("Profile", thirdView),
 			("One More", fourthView)
 			])
 
-		secondScrollPager.addSegmentsWithImages(segmentImages: [
+		secondScrollPager.addSegments(with: [
 			UIImage(named: "envelope")!,
 			UIImage(named: "home")!,
 			UIImage(named: "like")!,