Allow tapping diff header title to visit associated page

Wikipedia/Code/DiffContainerViewController.swift

@@ -874,7 +874,7 @@ private extension DiffContainerViewController {
         default:
             break
         }
-        diffHeaderView?.configure(with: headerViewModel)
+        diffHeaderView?.configure(with: headerViewModel, titleViewTapDelegate: self)
         headerExtendedView?.update(headerViewModel)
         navigationBar.isExtendedViewHidingEnabled = headerViewModel.isExtendedViewHidingEnabled
     }
@@ -1507,3 +1507,15 @@ extension DiffContainerViewController: WatchlistControllerDelegate {
         diffToolbarView?.updateMoreButton(needsWatchButton: true, needsUnwatchHalfButton: false, needsUnwatchFullButton: false, needsArticleEditHistoryButton: true)
     }
 }
+
+extension DiffContainerViewController: DiffHeaderTitleViewTapDelegate {
+
+    func userDidTapTitleLabel() {
+        guard let navigationURL = fetchPageURL() else {
+            return
+        }
+
+        navigate(to: navigationURL)
+    }
+
+}

Wikipedia/Code/DiffHeaderTitleView.swift

@@ -1,12 +1,18 @@
 import UIKit
 
+protocol DiffHeaderTitleViewTapDelegate: AnyObject {
+    func userDidTapTitleLabel()
+}
+
 class DiffHeaderTitleView: UIView {
 
     @IBOutlet var contentView: UIView!
     @IBOutlet var headingLabel: UILabel!
     @IBOutlet var titleLabel: UILabel!
     @IBOutlet var subtitleLabel: UILabel!
-
+
+    weak var titleViewTapDelegate: DiffHeaderTitleViewTapDelegate?
+
     private(set) var viewModel: DiffHeaderTitleViewModel?
 
     override init(frame: CGRect) {
@@ -27,10 +33,11 @@ class DiffHeaderTitleView: UIView {
         }
     }
 
-    func update(_ viewModel: DiffHeaderTitleViewModel) {
-        
+    func update(_ viewModel: DiffHeaderTitleViewModel, titleViewTapDelegate: DiffHeaderTitleViewTapDelegate? = nil) {
+
         self.viewModel = viewModel
-
+        self.titleViewTapDelegate = titleViewTapDelegate
+
         headingLabel.text = viewModel.heading
         titleLabel.text = viewModel.title
 
@@ -54,6 +61,12 @@ class DiffHeaderTitleView: UIView {
         guard !UIAccessibility.isVoiceOverRunning else {
             return super.point(inside: point, with: event)
         }
+
+        let titleConverted = convert(point, to: titleLabel)
+        if titleLabel.point(inside: titleConverted, with: event) {
+            return true
+        }
+
         return false
     }
 }
@@ -66,6 +79,10 @@ private extension DiffHeaderTitleView {
         contentView.autoresizingMask = [.flexibleHeight, .flexibleWidth]
         updateFonts(with: traitCollection)
         contentView.isAccessibilityElement = true
+
+        let tapGesture = UITapGestureRecognizer(target: self, action: #selector(userDidTapTitleLabel))
+        titleLabel.isUserInteractionEnabled = true
+        titleLabel.addGestureRecognizer(tapGesture)
     }
 
     func updateFonts(with traitCollection: UITraitCollection) {
@@ -77,6 +94,10 @@ private extension DiffHeaderTitleView {
             subtitleLabel.font = UIFont.wmf_font(DynamicTextStyle.footnote, compatibleWithTraitCollection: traitCollection)
         }
     }
+
+    @objc func userDidTapTitleLabel() {
+        titleViewTapDelegate?.userDidTapTitleLabel()
+    }
 }
 
 extension DiffHeaderTitleView: Themeable {
@@ -85,8 +106,8 @@ extension DiffHeaderTitleView: Themeable {
         backgroundColor = theme.colors.paperBackground
         contentView.backgroundColor = theme.colors.paperBackground
         headingLabel.textColor = theme.colors.secondaryText
-        titleLabel.textColor = theme.colors.primaryText
-        
+        titleLabel.textColor = theme.colors.link
+
         if let subtitleColor = viewModel?.subtitleColor {
             subtitleLabel.textColor = subtitleColor
         } else {

Wikipedia/Code/DiffHeaderView.swift

@@ -55,10 +55,10 @@ final class DiffHeaderView: SetupView {
 
     }
 
-    func configure(with vm: DiffHeaderViewModel) {
+    func configure(with vm: DiffHeaderViewModel, titleViewTapDelegate: DiffHeaderTitleViewTapDelegate? = nil) {
         self.viewModel = vm
         if let viewModel {
-            updateTitleView(with: viewModel.title)
+            updateTitleView(with: viewModel.title, titleViewTapDelegate: titleViewTapDelegate)
             updateImageView(with: viewModel)
         }
     }
@@ -77,14 +77,20 @@ final class DiffHeaderView: SetupView {
         }
     }
 
-    func updateTitleView(with viewModel: DiffHeaderTitleViewModel) {
-        headerTitleView.update(viewModel)
+    func updateTitleView(with viewModel: DiffHeaderTitleViewModel, titleViewTapDelegate: DiffHeaderTitleViewTapDelegate? = nil) {
+        headerTitleView.update(viewModel, titleViewTapDelegate: titleViewTapDelegate)
     }
 
     override func point(inside point: CGPoint, with event: UIEvent?) -> Bool {
         guard !UIAccessibility.isVoiceOverRunning else {
             return super.point(inside: point, with: event)
         }
+
+        let headerTitleViewConvertedPoint = convert(point, to: headerTitleView)
+        if headerTitleView.point(inside: headerTitleViewConvertedPoint, with: event) {
+            return true
+        }
+
         return false
     }