Merge branch 'release/0.4.8'

Author: msaps

Artwork/artwork.sketch

@@ -4,7 +4,7 @@ Pod::Spec.new do |s|
   s.platform     = :ios, "9.0"
   s.requires_arc = true
 
-  s.version      = "0.4.7"
+  s.version      = "0.4.8"
   s.summary      = "A simple, highly informative page view controller."
   s.description  = <<-DESC
   					Pageboy is a page view controller that provides simplified data source management, enhanced delegation and other useful features.

Artwork/logo.png

@@ -15,7 +15,7 @@
 	<key>CFBundlePackageType</key>
 	<string>FMWK</string>
 	<key>CFBundleShortVersionString</key>
-	<string>0.4.7</string>
+	<string>0.4.8</string>
 	<key>CFBundleVersion</key>
 	<string>AUTO_GENERATED</string>
 	<key>NSPrincipalClass</key>

Pageboy.podspec

@@ -69,10 +69,18 @@ extension PageboyViewController: UIPageViewControllerDelegate, UIScrollViewDeleg
             contentOffset = scrollView.contentOffset.y
         }
 
-        let scrollIndexDiff = CGFloat(max(1, abs((self.expectedTransitionIndex ?? currentIndex + 1) - currentIndex)))
-        let scrollOffset = contentOffset - pageSize
-        let pageOffset = (CGFloat(currentIndex) * pageSize) + (scrollOffset * scrollIndexDiff)
-        var pagePosition = pageOffset / pageSize
+        guard let scrollIndexDiff = self.pageScrollIndexDiff(forCurrentIndex: currentIndex,
+                                                       expectedIndex: self.expectedTransitionIndex,
+                                                       currentContentOffset: contentOffset,
+                                                       pageSize: pageSize) else {
+                                                        return
+        }
+        
+        guard var pagePosition = self.pagePosition(forContentOffset: contentOffset,
+                                                   pageSize: pageSize,
+                                                   indexDiff: scrollIndexDiff) else {
+                                                        return
+        }
 
         // do not continue if a page change is detected
         guard !self.detectCurrentPageIndexIfNeeded(pagePosition: pagePosition,
@@ -117,13 +125,11 @@ extension PageboyViewController: UIPageViewControllerDelegate, UIScrollViewDeleg
     ///
     /// - Parameter pagePosition: the relative page position.
     private func detectInfiniteOverscrollIfNeeded(pagePosition: inout CGFloat) {
-        let maxPagePosition = CGFloat((self.viewControllers?.count ?? 1) - 1)
-        let overscrolling = pagePosition < 0.0 || pagePosition > maxPagePosition
-        
-        guard self.isInfiniteScrollEnabled && overscrolling else {
+        guard self.isInfinitelyScrolling(forPosition: pagePosition) else {
             return
         }
 
+        let maxPagePosition = CGFloat((self.viewControllers?.count ?? 1) - 1)
         var integral: Double = 0.0
         var progress = CGFloat(modf(fabs(Double(pagePosition)), &integral))
         var maxInfinitePosition: CGFloat!
@@ -142,6 +148,20 @@ extension PageboyViewController: UIPageViewControllerDelegate, UIScrollViewDeleg
         pagePosition = infinitePagePosition
     }
 
+    /// Whether a position is infinitely scrolling between end ranges
+    ///
+    /// - Parameter pagePosition: The position.
+    /// - Returns: Whether the position is infinitely scrolling.
+    private func isInfinitelyScrolling(forPosition pagePosition: CGFloat) -> Bool {
+        let maxPagePosition = CGFloat((self.viewControllers?.count ?? 1) - 1)
+        let overscrolling = pagePosition < 0.0 || pagePosition > maxPagePosition
+        
+        guard self.isInfiniteScrollEnabled && overscrolling else {
+            return false
+        }
+        return true
+    }
+    
     /// Detects whether a page boundary has been passed.
     /// As pageViewController:didFinishAnimating is not reliable.
     ///
@@ -184,6 +204,53 @@ extension PageboyViewController: UIPageViewControllerDelegate, UIScrollViewDeleg
         }
         self.currentIndex = index
     }
+    
+    /// Calculate the expected index diff for a page scroll.
+    ///
+    /// - Parameters:
+    ///   - index: The current index.
+    ///   - expectedIndex: The target page index.
+    ///   - currentContentOffset: The current content offset.
+    ///   - pageSize: The size of each page.
+    /// - Returns: The expected index diff.
+    private func pageScrollIndexDiff(forCurrentIndex index: Int?,
+                                     expectedIndex: Int?,
+                                     currentContentOffset: CGFloat,
+                                     pageSize: CGFloat) -> CGFloat? {
+        guard let index = index else {
+            return nil
+        }
+        
+        let expectedIndex = expectedIndex ?? index
+        let expectedDiff = CGFloat(max(1, abs(expectedIndex - index)))
+        let expectedPosition = self.pagePosition(forContentOffset: currentContentOffset,
+                                                 pageSize: pageSize,
+                                                 indexDiff: expectedDiff) ?? CGFloat(index)
+        
+        guard self.isInfinitelyScrolling(forPosition: expectedPosition) == false else {
+            return 1
+        }
+        return expectedDiff
+    }
+    
+    /// Calculate the relative page position.
+    ///
+    /// - Parameters:
+    ///   - contentOffset: The current contentOffset.
+    ///   - pageSize: The current page size.
+    ///   - indexDiff: The expected difference between current / target page indexes.
+    /// - Returns: The relative page position.
+    private func pagePosition(forContentOffset contentOffset: CGFloat,
+                                       pageSize: CGFloat,
+                                       indexDiff: CGFloat) -> CGFloat? {
+        guard let currentIndex = self.currentIndex else {
+            return nil
+        }
+        
+        let scrollOffset = contentOffset - pageSize
+        let pageOffset = (CGFloat(currentIndex) * pageSize) + (scrollOffset * indexDiff)
+        return pageOffset / pageSize
+    }
 }
 
 

Sources/Pageboy/Info.plist

@@ -167,7 +167,11 @@ open class PageboyViewController: UIViewController {
     /// Whether the page view controller should infinitely scroll at the end of page ranges.
     ///
     /// Default is FALSE.
-    public var isInfiniteScrollEnabled: Bool = false
+    public var isInfiniteScrollEnabled: Bool = false {
+        didSet {
+            self.reloadCurrentPageSoftly()
+        }
+    }
 
     /// The view controllers that are displayed in the page view controller.
     public internal(set) var viewControllers: [UIViewController]?
@@ -235,6 +239,15 @@ open class PageboyViewController: UIViewController {
         self.reloadPages(reloadViewControllers: true)
     }
 
+    /// Reload the currently active page into the page view controller if possible. 
+    /// Does not reload from dataSource.
+    private func reloadCurrentPageSoftly() {
+        guard let currentIndex = self.currentIndex else { return }
+        guard let currentViewController = self.viewControllers?[currentIndex] else { return }
+        
+        self.pageViewController.setViewControllers([currentViewController], direction: .forward, animated: false, completion: nil)
+    }
+    
     //
     // MARK: Transitioning
     //
@@ -361,3 +374,17 @@ internal extension PageboyViewController {
         }
     }
 }
+
+// MARK: - NavigationDirection: CustomStringConvertible
+extension PageboyViewController.NavigationDirection: CustomStringConvertible {
+    public var description: String {
+        switch self {
+        case .forward:
+            return "Forward"
+        case .reverse:
+            return "Reverse"
+        default:
+            return "Neutral"
+        }
+    }
+}

Sources/Pageboy/PageboyScrollDetection.swift

@@ -114,9 +114,7 @@ class PageboyTransitionTests: PageboyTests {
         self.pageboyViewController.dataSource = self.dataSource
 
         // simulate scroll
-        let boundsWidth = self.pageboyViewController.view.frame.size.width
-        self.pageboyViewController.pageViewController.scrollView?.setContentOffset(CGPoint(x: boundsWidth + (boundsWidth / 2.0), y: 0.0),
-                                                                                   animated: false)
+        self.simulateScroll(toPosition: 0.5)
 
         XCTAssert(String(format:"%.1f", self.delegate.lastRecordedPagePosition?.x ?? 0.0) == "0.5" &&
             self.pageboyViewController.currentIndex == 0,
@@ -145,9 +143,7 @@ class PageboyTransitionTests: PageboyTests {
         self.pageboyViewController.dataSource = self.dataSource
 
         // simulate scroll
-        let boundsWidth = self.pageboyViewController.view.frame.size.width
-        self.pageboyViewController.pageViewController.scrollView?.setContentOffset(CGPoint(x: boundsWidth + (boundsWidth / 2.0), y: 0.0),
-                                                                                   animated: false)
+        self.simulateScroll(toPosition: 0.5)
 
         XCTAssert(self.delegate.lastRecordedDirection == .forward && self.pageboyViewController.currentIndex == 0,
                   "Not reporting partial user interacted transition direction values correctly.")
@@ -197,5 +193,15 @@ class PageboyTransitionTests: PageboyTests {
                       "Animated flags for an non animated scrollToPage are incorrect.")
         }
     }
-
+    
+    // MARK: Utils
+    
+    func simulateScroll(toPosition position: CGFloat) {
+        let targetIndex = Int(position.rounded())
+        
+        let boundsWidth = self.pageboyViewController.view.frame.size.width
+        self.pageboyViewController.expectedTransitionIndex = targetIndex
+        self.pageboyViewController.pageViewController.scrollView?.setContentOffset(CGPoint(x: boundsWidth + (boundsWidth * position), y: 0.0),
+                                                                                   animated: false)
+    }
 }