refactor: move UI constants to UIConstants enum

Mail/Components/CheckboxView.swift

@@ -27,7 +27,7 @@ struct CheckboxView: View {
 
     init(isSelected: Bool, density: ThreadDensity) {
         self.isSelected = isSelected
-        size = density == .large ? Constants.checkboxLargeSize : Constants.checkboxSize
+        size = density == .large ? UIConstants.checkboxLargeSize : UIConstants.checkboxSize
     }
 
     var body: some View {
@@ -38,7 +38,7 @@ struct CheckboxView: View {
                 .frame(width: size, height: size)
             MailResourcesAsset.check.swiftUIImage
                 .foregroundColor(accentColor.onAccent.swiftUIColor)
-                .frame(height: Constants.checkmarkSize)
+                .frame(height: UIConstants.checkmarkSize)
                 .opacity(isSelected ? 1 : 0)
         }
     }

Mail/Components/IKDivider.swift

@@ -27,7 +27,7 @@ struct IKDivider: View {
         Divider()
             .frame(height: 1)
             .overlay(MailResourcesAsset.elementsColor.swiftUIColor)
-            .padding(.horizontal, withPadding ? Constants.menuDrawerHorizontalPadding : 0)
+            .padding(.horizontal, withPadding ? UIConstants.menuDrawerHorizontalPadding : 0)
             .padding(.bottom, withPadding ? 8 : 0)
     }
 }

Mail/Components/MailButton.swift

@@ -31,7 +31,7 @@ struct MailButtonFullWidthKey: EnvironmentKey {
 }
 
 struct MailButtonIconSizeKey: EnvironmentKey {
-    static var defaultValue: CGFloat = Constants.buttonsIconSize
+    static var defaultValue: CGFloat = UIConstants.buttonsIconSize
 }
 
 struct MailButtonLoadingKey: EnvironmentKey {

Mail/Components/MailButtonStyle.swift

@@ -41,7 +41,7 @@ struct MailButtonStyle: ButtonStyle {
             .padding(.vertical, 18)
             .padding(.horizontal, 20)
             .background(largeBackground(configuration: configuration))
-            .clipShape(RoundedRectangle(cornerRadius: Constants.buttonsRadius))
+            .clipShape(RoundedRectangle(cornerRadius: UIConstants.buttonsRadius))
             .brightness(largeBrightness(configuration: configuration))
     }
 

Mail/Components/ThreadCell.swift

@@ -90,7 +90,7 @@ struct ThreadCell: View {
     let isSelected: Bool
 
     private var checkboxSize: CGFloat {
-        density == .large ? Constants.checkboxLargeSize : Constants.checkboxSize
+        density == .large ? UIConstants.checkboxLargeSize : UIConstants.checkboxSize
     }
 
     init(

Mail/Components/UnreadIndicatorView.swift

@@ -23,7 +23,7 @@ struct UnreadIndicatorView: View {
     let hidden: Bool
     var body: some View {
         Circle()
-            .frame(width: Constants.unreadIconSize, height: Constants.unreadIconSize)
+            .frame(width: UIConstants.unreadIconSize, height: UIConstants.unreadIconSize)
             .foregroundColor(hidden ? .clear : .accentColor)
     }
 }

Mail/LockedAppView.swift

@@ -40,14 +40,14 @@ struct LockedAppView: View {
                 MailResourcesAsset.logoText.swiftUIImage
                     .resizable()
                     .scaledToFit()
-                    .frame(height: Constants.onboardingLogoHeight)
+                    .frame(height: UIConstants.onboardingLogoHeight)
 
                 Spacer()
 
                 MailButton(label: MailResourcesStrings.Localizable.buttonUnlock, action: unlockApp)
                     .mailButtonFullWidth(true)
             }
-            .padding(.top, Constants.onboardingLogoPaddingTop)
+            .padding(.top, UIConstants.onboardingLogoPaddingTop)
             .padding(.bottom, 40)
         }
         .padding(.horizontal, 24)

Mail/Utils/FloatingActionButtonModifier.swift

@@ -33,7 +33,7 @@ struct FloatingActionButtonModifier: ViewModifier {
             if isEnabled {
                 MailButton(icon: icon, label: title, action: action)
                     .padding(.trailing, 24)
-                    .padding(.bottom, Constants.floatingButtonBottomPadding)
+                    .padding(.bottom, UIConstants.floatingButtonBottomPadding)
             }
         }
         .ignoresSafeArea(.keyboard)

Mail/Views/Bottom sheets/MoreStorageView.swift

@@ -48,7 +48,7 @@ struct MoreStorageView: View {
                              primaryButtonEnabled: false,
                              primaryButtonAction: getMoreStorage)
         }
-        .padding(.horizontal, Constants.bottomSheetHorizontalPadding)
+        .padding(.horizontal, UIConstants.bottomSheetHorizontalPadding)
         .matomoView(view: [MatomoUtils.View.bottomSheet.displayName, "MoreStorageView"])
     }
 

Mail/Views/Bottom sheets/ReportDisplayProblemView.swift

@@ -39,7 +39,7 @@ struct ReportDisplayProblemView: View {
                              primaryButtonAction: report)
             .padding(.top, 8)
         }
-        .padding(.horizontal, Constants.bottomSheetHorizontalPadding)
+        .padding(.horizontal, UIConstants.bottomSheetHorizontalPadding)
         .matomoView(view: [MatomoUtils.View.bottomSheet.displayName, "ReportDisplayProblemView"])
     }
 

Mail/Views/Bottom sheets/RestoreEmailsView.swift

@@ -57,7 +57,7 @@ struct RestoreEmailsView: View {
                              primaryButtonEnabled: !availableDates.isEmpty,
                              primaryButtonAction: restoreEmails)
         }
-        .padding(.horizontal, Constants.bottomSheetHorizontalPadding)
+        .padding(.horizontal, UIConstants.bottomSheetHorizontalPadding)
         .task {
             await tryOrDisplayError {
                 let backupsList = try await mailboxManager.apiFetcher.listBackups(mailbox: mailboxManager.mailbox).backups

Mail/Views/EmptyStateView.swift

@@ -44,7 +44,7 @@ struct EmptyStateView: View {
                 .multilineTextAlignment(.center)
         }
         .padding(.horizontal, 48)
-        .padding(.bottom, withFABPadding ? Constants.floatingButtonBottomPadding + 56 : 0)
+        .padding(.bottom, withFABPadding ? UIConstants.floatingButtonBottomPadding + 56 : 0)
         .frame(maxWidth: .infinity, maxHeight: .infinity)
         .matomoView(view: [MatomoUtils.View.threadListView.displayName, "Empty\(matomoName)View"])
     }

Mail/Views/Menu Drawer/Folders/FolderCell.swift

@@ -127,7 +127,7 @@ struct FolderCellContent: View {
 
     init(folder: Folder, level: Int, isCurrentFolder: Bool) {
         self.folder = folder
-        self.level = min(level, Constants.menuDrawerMaximumSubfolderLevel)
+        self.level = min(level, UIConstants.menuDrawerMaximumSubfolderLevel)
         self.isCurrentFolder = isCurrentFolder
     }
 
@@ -139,7 +139,7 @@ struct FolderCellContent: View {
     }
 
     var body: some View {
-        HStack(spacing: Constants.menuDrawerHorizontalItemSpacing) {
+        HStack(spacing: UIConstants.menuDrawerHorizontalItemSpacing) {
             folder.icon
                 .resizable()
                 .scaledToFit()
@@ -155,8 +155,8 @@ struct FolderCellContent: View {
             accessory
         }
         .padding(.vertical, 14)
-        .padding(.horizontal, Constants.menuDrawerHorizontalPadding)
-        .padding(.leading, Constants.menuDrawerSubFolderPadding * CGFloat(level))
+        .padding(.horizontal, UIConstants.menuDrawerHorizontalPadding)
+        .padding(.leading, UIConstants.menuDrawerSubFolderPadding * CGFloat(level))
         .background(background)
     }
 

Mail/Views/Menu Drawer/Folders/UserFoldersListView.swift

@@ -60,11 +60,11 @@ struct UserFoldersListView: View {
                     }
                 }
             }
-            .padding(.leading, Constants.menuDrawerHorizontalPadding)
+            .padding(.leading, UIConstants.menuDrawerHorizontalPadding)
             .padding(.trailing, 18)
 
             if isExpanded {
-                Spacer(minLength: Constants.menuDrawerVerticalPadding)
+                Spacer(minLength: UIConstants.menuDrawerVerticalPadding)
 
                 if folders.isEmpty {
                     Text(MailResourcesStrings.Localizable.noFolderTitle)

Mail/Views/Menu Drawer/Items/MenuDrawerItemCell.swift

@@ -32,7 +32,7 @@ struct MenuDrawerItemCell: View {
             matomo.track(eventWithCategory: .menuDrawer, name: content.matomoName)
             content.action()
         } label: {
-            HStack(spacing: Constants.menuDrawerHorizontalItemSpacing) {
+            HStack(spacing: UIConstants.menuDrawerHorizontalItemSpacing) {
                 content.icon.swiftUIImage
                     .resizable()
                     .scaledToFit()

Mail/Views/Menu Drawer/Items/MenuDrawerItemsListView.swift

@@ -74,7 +74,7 @@ struct MenuDrawerItemsListView: View {
             }
         }
         .padding(.bottom, 16)
-        .padding(.horizontal, Constants.menuDrawerHorizontalPadding)
+        .padding(.horizontal, UIConstants.menuDrawerHorizontalPadding)
     }
 }
 

Mail/Views/Menu Drawer/MailboxManagement/MailboxesManagementButtonView.swift

@@ -53,7 +53,7 @@ struct MailboxesManagementButtonView: View {
             }
         }
         .padding(.vertical, 10)
-        .padding(.horizontal, Constants.menuDrawerHorizontalPadding)
+        .padding(.horizontal, UIConstants.menuDrawerHorizontalPadding)
     }
 }
 

Mail/Views/Menu Drawer/MailboxManagement/MailboxesManagementView.swift

@@ -62,8 +62,8 @@ struct MailboxesManagementView: View {
                     }
                 }
                 .environment(\.isEnabled, true)
-                .padding(.vertical, Constants.menuDrawerVerticalPadding)
-                .padding(.horizontal, Constants.menuDrawerHorizontalPadding)
+                .padding(.vertical, UIConstants.menuDrawerVerticalPadding)
+                .padding(.horizontal, UIConstants.menuDrawerHorizontalPadding)
             }
             .disabled(otherMailboxes.isEmpty)
 

Mail/Views/Menu Drawer/MailboxQuotaView.swift

@@ -46,7 +46,7 @@ struct MailboxQuotaView: View {
             Spacer()
         }
         .padding(.vertical, 19)
-        .padding(.horizontal, Constants.menuDrawerHorizontalPadding)
+        .padding(.horizontal, UIConstants.menuDrawerHorizontalPadding)
     }
 }
 

Mail/Views/NoMailboxView.swift

@@ -38,8 +38,8 @@ struct NoMailboxView: View {
                     MailResourcesAsset.logoText.swiftUIImage
                         .resizable()
                         .scaledToFit()
-                        .frame(height: Constants.onboardingLogoHeight)
-                        .padding(.top, Constants.onboardingLogoPaddingTop)
+                        .frame(height: UIConstants.onboardingLogoHeight)
+                        .padding(.top, UIConstants.onboardingLogoPaddingTop)
                 }
 
             VStack(spacing: 24) {
@@ -53,7 +53,7 @@ struct NoMailboxView: View {
                 }
                 .mailButtonStyle(.link)
             }
-            .frame(height: Constants.onboardingButtonHeight + Constants.onboardingBottomButtonPadding, alignment: .top)
+            .frame(height: UIConstants.onboardingButtonHeight + UIConstants.onboardingBottomButtonPadding, alignment: .top)
             .padding(.horizontal, 24)
         }
         .matomoView(view: ["NoMailboxView"])

Mail/Views/Onboarding/OnboardingView.swift

@@ -187,8 +187,8 @@ struct OnboardingView: View {
                 MailResourcesAsset.logoText.swiftUIImage
                     .resizable()
                     .scaledToFit()
-                    .frame(height: Constants.onboardingLogoHeight)
-                    .padding(.top, Constants.onboardingLogoPaddingTop)
+                    .frame(height: UIConstants.onboardingLogoHeight)
+                    .padding(.top, UIConstants.onboardingLogoPaddingTop)
             }
 
             VStack(spacing: 24) {
@@ -211,10 +211,10 @@ struct OnboardingView: View {
                             selection += 1
                         }
                     }
-                    .mailButtonIconSize(Constants.onboardingArrowIconSize)
+                    .mailButtonIconSize(UIConstants.onboardingArrowIconSize)
                 }
             }
-            .frame(height: Constants.onboardingButtonHeight + Constants.onboardingBottomButtonPadding, alignment: .top)
+            .frame(height: UIConstants.onboardingButtonHeight + UIConstants.onboardingBottomButtonPadding, alignment: .top)
             .padding(.horizontal, 24)
         }
         .overlay(alignment: .topLeading) {

Mail/Views/Onboarding/SlideView.swift

@@ -51,7 +51,7 @@ struct SlideView: View {
                     .ignoresSafeArea(edges: .top)
 
                 VStack(spacing: 0) {
-                    Spacer(minLength: Constants.onboardingLogoHeight + Constants.onboardingVerticalTopPadding)
+                    Spacer(minLength: UIConstants.onboardingLogoHeight + UIConstants.onboardingVerticalTopPadding)
 
                     Group {
                         if let asset = slide.asset {

Mail/Views/Thread List/ThreadListView.swift

@@ -317,7 +317,7 @@ private struct ThreadListToolbar: ViewModifier {
                                     MailResourcesAsset.burger.swiftUIImage
                                         .resizable()
                                         .scaledToFit()
-                                        .frame(width: Constants.navbarIconSize, height: Constants.navbarIconSize)
+                                        .frame(width: UIConstants.navbarIconSize, height: UIConstants.navbarIconSize)
                                 }
                             }
                         }
@@ -346,7 +346,7 @@ private struct ThreadListToolbar: ViewModifier {
                                 MailResourcesAsset.search.swiftUIImage
                                     .resizable()
                                     .scaledToFit()
-                                    .frame(width: Constants.navbarIconSize, height: Constants.navbarIconSize)
+                                    .frame(width: UIConstants.navbarIconSize, height: UIConstants.navbarIconSize)
                             }
 
                             Button {

MailCore/UI/UIConstants.swift

@@ -20,6 +20,41 @@ import Foundation
 import MailResources
 import UIKit
 
+public enum BarAppearanceConstants {
+    public static let threadViewNavigationBarAppearance: UINavigationBarAppearance = {
+        let navigationBarAppearance = UINavigationBarAppearance()
+        navigationBarAppearance.configureWithTransparentBackground()
+        navigationBarAppearance.backgroundColor = MailResourcesAsset.backgroundColor.color
+        navigationBarAppearance.shadowColor = MailResourcesAsset.backgroundColor.color
+        return navigationBarAppearance
+    }()
+
+    public static let threadViewNavigationBarScrolledAppearance: UINavigationBarAppearance = {
+        let navigationBarAppearance = UINavigationBarAppearance()
+        navigationBarAppearance.configureWithDefaultBackground()
+        navigationBarAppearance.backgroundColor = MailResourcesAsset.backgroundTabBarColor.color
+        return navigationBarAppearance
+    }()
+
+    public static let threadListNavigationBarAppearance: UINavigationBarAppearance = {
+        let navigationBarAppearance = UINavigationBarAppearance()
+        navigationBarAppearance.configureWithTransparentBackground()
+        navigationBarAppearance.backgroundColor = UserDefaults.shared.accentColor.navBarBackground.color
+        navigationBarAppearance.largeTitleTextAttributes = [
+            .foregroundColor: MailResourcesAsset.textPrimaryColor.color,
+            .font: UIFont.systemFont(ofSize: 22, weight: .semibold)
+        ]
+        return navigationBarAppearance
+    }()
+
+    public static let threadViewToolbarAppearance: UIToolbarAppearance = {
+        let toolbarAppearance = UIToolbarAppearance()
+        toolbarAppearance.configureWithOpaqueBackground()
+        toolbarAppearance.backgroundColor = MailResourcesAsset.backgroundTabBarColor.color
+        return toolbarAppearance
+    }()
+}
+
 public enum UIConstants {
     public static let avatarColors = [
         MailResourcesAsset.yellowColor,
@@ -33,5 +68,30 @@ public enum UIConstants {
         MailResourcesAsset.princeColor
     ].map(\.color)
 
-    // TODO: Move the UI constants to this file
+    public static let navbarIconSize: CGFloat = 23
+
+    public static let onboardingLogoPaddingTop: CGFloat = 28
+    public static let onboardingLogoHeight: CGFloat = 54
+    public static let onboardingButtonHeight: CGFloat = 100
+    public static let onboardingVerticalTopPadding: CGFloat = 48
+    public static let onboardingBottomButtonPadding: CGFloat = 32
+    public static let onboardingArrowIconSize: CGFloat = 24
+
+    public static let menuDrawerHorizontalPadding: CGFloat = 20
+    public static let menuDrawerVerticalPadding: CGFloat = 12
+    public static let menuDrawerSubFolderPadding: CGFloat = 15
+    public static let menuDrawerHorizontalItemSpacing: CGFloat = 16
+    public static let menuDrawerMaximumSubfolderLevel = 2
+
+    public static let floatingButtonBottomPadding: CGFloat = 24
+
+    public static let unreadIconSize: CGFloat = 8
+    public static let checkboxSize: CGFloat = 32
+    public static let checkmarkSize: CGFloat = 14
+    public static let checkboxLargeSize: CGFloat = 40
+
+    public static let buttonsRadius: CGFloat = 16
+    public static let buttonsIconSize: CGFloat = 16
+
+    public static let bottomSheetHorizontalPadding: CGFloat = 24
 }