adjust nav bar height

apple/OmnivoreKit/Sources/Views/Article/WebAppViewCoordinator.swift

@@ -2,6 +2,7 @@ import SwiftUI
 import WebKit
 
 final class WebAppViewCoordinator: NSObject {
+  let navBarHeight = LinkItemDetailView.navBarHeight
   var webViewActionHandler: (WKScriptMessage) -> Void = { _ in }
   var linkHandler: (URL) -> Void = { _ in }
   var needsReload = true
@@ -54,9 +55,9 @@ extension WebAppViewCoordinator: UIScrollViewDelegate {
       return
     }
 
-    if yOffset < 30 {
+    if yOffset < navBarHeight {
       let isScrollingUp = yOffsetAtStartOfDrag ?? 0 > yOffset
-      updateNavBarVisibilityRatio(isScrollingUp ? 1 : 1 - (yOffset / 30))
+      updateNavBarVisibilityRatio(isScrollingUp ? 1 : 1 - (yOffset / navBarHeight))
       return
     }
 
@@ -64,7 +65,7 @@ extension WebAppViewCoordinator: UIScrollViewDelegate {
 
     if yOffset > yOffsetAtStartOfDrag, !isNavBarHidden {
       let translation = yOffset - yOffsetAtStartOfDrag
-      let ratio = translation < 30 ? translation / 30 : 0
+      let ratio = translation < navBarHeight ? 1 - (translation / navBarHeight) : 0
       isNavBarHidden = ratio == 0
       updateNavBarVisibilityRatio(ratio)
     }

apple/OmnivoreKit/Sources/Views/LinkedItemDetail/LinkItemDetailView.swift

@@ -27,6 +27,7 @@ public final class LinkItemDetailViewModel: ObservableObject {
 public struct LinkItemDetailView: View {
   @Environment(\.presentationMode) var presentationMode: Binding<PresentationMode>
 
+  static let navBarHeight = 50.0
   @ObservedObject private var viewModel: LinkItemDetailViewModel
   @State private var showFontSizePopover = false
   @State private var navBarVisibilityRatio = 1.0
@@ -73,20 +74,22 @@ public struct LinkItemDetailView: View {
             action: { self.presentationMode.wrappedValue.dismiss() },
             label: {
               Image(systemName: "chevron.backward")
-                .font(.appTitleThree)
+                .font(.appTitle)
                 .foregroundColor(.appGrayTextContrast)
                 .padding(.horizontal)
-                .padding(.bottom, 5)
             }
           )
+          .scaleEffect(navBarVisibilityRatio)
           Spacer()
           Button(
             action: { showFontSizePopover = true },
             label: {
               Image(systemName: "textformat.size")
+                .font(.appTitle)
             }
           )
           .padding(.horizontal)
+          .scaleEffect(navBarVisibilityRatio)
           #if os(iOS)
             .fittedPopover(isPresented: $showFontSizePopover) {
               FontSizeAdjustmentPopoverView(
@@ -96,15 +99,13 @@ public struct LinkItemDetailView: View {
             }
           #endif
         }
-        .frame(height: 30 * navBarVisibilityRatio)
+        .frame(height: LinkItemDetailView.navBarHeight * navBarVisibilityRatio)
         .opacity(navBarVisibilityRatio)
-        .offset(x: 0.0, y: -30 * (1 - navBarVisibilityRatio))
       }
       if let webAppWrapperViewModel = viewModel.webAppWrapperViewModel {
         WebAppWrapperView(
           viewModel: webAppWrapperViewModel,
           navBarVisibilityRatioUpdater: {
-            print($0)
             navBarVisibilityRatio = $0
           }
         )
@@ -164,3 +165,15 @@ public struct LinkItemDetailView: View {
     }
   }
 }
+
+// Enable swipe to go back behavior if nav bar is hidden
+extension UINavigationController: UIGestureRecognizerDelegate {
+  override open func viewDidLoad() {
+    super.viewDidLoad()
+    interactivePopGestureRecognizer?.delegate = self
+  }
+
+  public func gestureRecognizerShouldBegin(_: UIGestureRecognizer) -> Bool {
+    viewControllers.count > 1
+  }
+}