chore: handle header view in video block

Source/VideoBlockViewController.swift

@@ -10,7 +10,7 @@ import Foundation
 import MediaPlayer
 import UIKit
 
-class VideoBlockViewController : OfflineSupportViewController, CourseBlockViewController, StatusBarOverriding, InterfaceOrientationOverriding, VideoTranscriptDelegate, RatingViewControllerDelegate, VideoPlayerDelegate {
+class VideoBlockViewController : OfflineSupportViewController, CourseBlockViewController, StatusBarOverriding, InterfaceOrientationOverriding, VideoTranscriptDelegate, RatingViewControllerDelegate, VideoPlayerDelegate, ScrollableDelegateProvider {
 
     typealias Environment = DataManagerProvider & OEXInterfaceProvider & ReachabilityProvider & OEXConfigProvider & OEXRouterProvider & OEXAnalyticsProvider & OEXStylesProvider & OEXSessionProvider & NetworkManagerProvider
 
@@ -32,6 +32,12 @@ class VideoBlockViewController : OfflineSupportViewController, CourseBlockViewCo
     private var overlayLabel: UILabel?
     var shouldCelebrationAppear: Bool
 
+    weak var scrollableDelegate: ScrollableDelegate? {
+        didSet {
+            videoTranscriptView?.scrollableDelegate = scrollableDelegate
+        }
+    }
+
     init(environment : Environment, blockID : CourseBlockID?, courseID: String, shouldCelebrationAppear: Bool = false) {
         self.blockID = blockID
         self.environment = environment

Source/VideoTranscript.swift

@@ -12,10 +12,13 @@ protocol VideoTranscriptDelegate: AnyObject {
     func didSelectSubtitleAtInterval(time: TimeInterval)
 }
 
-class VideoTranscript: NSObject, UITableViewDelegate, UITableViewDataSource{
+class VideoTranscript: NSObject, UITableViewDelegate, UITableViewDataSource, ScrollableDelegateProvider {
 
     typealias Environment = DataManagerProvider & OEXInterfaceProvider & ReachabilityProvider
 
+    weak var scrollableDelegate: ScrollableDelegate?
+    private var scrollByDragging = false
+
     let transcriptTableView = UITableView(frame: CGRect.zero, style: .plain)
     var transcripts = [TranscriptObject]()
 
@@ -68,7 +71,18 @@ class VideoTranscript: NSObject, UITableViewDelegate, UITableViewDataSource{
         delegate?.didSelectSubtitleAtInterval(time: transcripts[indexPath.row].start)
     }
 
+    func scrollViewDidScroll(_ scrollView: UIScrollView) {
+        if scrollByDragging {
+            scrollableDelegate?.scrollViewDidScroll(scrollView: scrollView)
+        }
+    }
+
+    func scrollViewDidEndDragging(_ scrollView: UIScrollView, willDecelerate decelerate: Bool) {
+        scrollByDragging = false
+    }
+
     func scrollViewWillBeginDragging(_ scrollView: UIScrollView) {
+        scrollByDragging = true
         isTableDragged = true
         draggingTimer.invalidate()
         draggingTimer = Timer.scheduledTimer(timeInterval: dragDelay, target: self, selector: #selector(invalidateDragging), userInfo: nil, repeats: false)