Paywalls: added support for custom fonts

RevenueCatUI/Data/TemplateViewConfiguration.swift

@@ -16,6 +16,7 @@ struct TemplateViewConfiguration {
     let packages: PackageConfiguration
     let configuration: PaywallData.Configuration
     let colors: PaywallData.Configuration.Colors
+    let fonts: PaywallFontProvider
     let assetBaseURL: URL
 
 }

RevenueCatUI/Helpers/PreviewHelpers.swift

@@ -59,6 +59,7 @@ struct PreviewableTemplate<T: TemplateViewType>: View {
         self.configuration = offering.paywall!.configuration(
             for: offering,
             mode: .fullScreen,
+            fonts: DefaultPaywallFontProvider(),
             locale: .current
         )
         self.presentInSheet = presentInSheet

RevenueCatUI/PaywallFontProvider.swift

@@ -0,0 +1,102 @@
+//
+//  PaywallFontProvider.swift
+//  
+//
+//  Created by Nacho Soto on 8/8/23.
+//
+
+import SwiftUI
+
+/// A type that returns a font for a given `Font.TextStyle`.
+///
+/// You can use one of the provided implementations, or make your own:
+/// - ``DefaultPaywallFontProvider``
+/// - ``CustomPaywallFontProvider``
+public protocol PaywallFontProvider {
+
+    /// - Returns: Desired `Font` for the given `Font.TextStyle`.
+    @available(iOS 15.0, macOS 12.0, tvOS 15.0, *)
+    func font(for textStyle: Font.TextStyle) -> Font
+
+}
+
+/// Default ``PaywallFontProvider`` which uses the system default font
+/// supporting dynamic type.
+open class DefaultPaywallFontProvider: PaywallFontProvider {
+
+    // swiftlint:disable:next missing_docs
+    public init() {}
+
+    @available(iOS 15.0, macOS 12.0, tvOS 15.0, *)
+    // swiftlint:disable:next cyclomatic_complexity missing_docs
+    open func font(for textStyle: Font.TextStyle) -> Font {
+        switch textStyle {
+        case .largeTitle: return .largeTitle
+        case .title: return .title
+        case .title2: return .title2
+        case .title3: return .title3
+        case .headline: return .headline
+        case .subheadline: return .subheadline
+        case .body: return .body
+        case .callout: return .callout
+        case .footnote: return .footnote
+        case .caption: return .caption
+        case .caption2: return .caption2
+        @unknown default: return .body
+        }
+    }
+
+}
+
+#if canImport(UIKit)
+
+/// A ``PaywallFontProvider`` implementation that allows you to provide a custom
+/// font name, and it will automatically scale up based on the size category.
+open class CustomPaywallFontProvider: PaywallFontProvider {
+
+    private let fontName: String
+
+    /// Creates a ``CustomPaywallFontProvider`` with a name.
+    public init(fontName: String) {
+        self.fontName = fontName
+    }
+
+    @available(iOS 15.0, macOS 12.0, tvOS 15.0, *)
+    // swiftlint:disable:next missing_docs
+    open func font(for textStyle: Font.TextStyle) -> Font {
+        return Font.custom(self.fontName,
+                           size: UIFont.preferredFont(forTextStyle: textStyle.style).pointSize,
+                           relativeTo: textStyle)
+    }
+
+}
+
+#endif
+
+// MARK: - Private
+
+#if canImport(UIKit)
+
+@available(iOS 15.0, macOS 12.0, tvOS 15.0, *)
+private extension Font.TextStyle {
+
+    var style: UIFont.TextStyle {
+        switch self {
+        case .largeTitle: return .largeTitle
+        case .title: return .title1
+        case .title2: return .title2
+        case .title3: return .title3
+        case .headline: return .headline
+        case .subheadline: return .subheadline
+        case .body: return .body
+        case .callout: return .callout
+        case .footnote: return .footnote
+        case .caption: return .caption1
+        case .caption2: return .caption2
+        @unknown default: return .body
+        }
+    }
+
+}
+
+#endif

RevenueCatUI/PaywallView.swift

@@ -13,6 +13,7 @@ import SwiftUI
 public struct PaywallView: View {
 
     private let mode: PaywallViewMode
+    private let fonts: PaywallFontProvider
     private let introEligibility: TrialOrIntroEligibilityChecker?
     private let purchaseHandler: PurchaseHandler?
 
@@ -26,10 +27,14 @@ public struct PaywallView: View {
     /// an error will be displayed.
     /// - Warning: `Purchases` must have been configured prior to displaying it.
     /// If you want to handle that, you can use ``init(offering:mode:)`` instead.
-    public init(mode: PaywallViewMode = .default) {
+    public init(
+        mode: PaywallViewMode = .default,
+        fonts: PaywallFontProvider = DefaultPaywallFontProvider()
+    ) {
         self.init(
             offering: nil,
             mode: mode,
+            fonts: fonts,
             introEligibility: .default(),
             purchaseHandler: .default()
         )
@@ -39,10 +44,15 @@ public struct PaywallView: View {
     /// - Note: if `offering` does not have a current paywall, or it fails to load due to invalid data,
     /// a default paywall will be displayed.
     /// - Warning: `Purchases` must have been configured prior to displaying it.
-    public init(offering: Offering?, mode: PaywallViewMode = .default) {
+    public init(
+        offering: Offering,
+        mode: PaywallViewMode = .default,
+        fonts: PaywallFontProvider = DefaultPaywallFontProvider()
+    ) {
         self.init(
             offering: offering,
             mode: mode,
+            fonts: fonts,
             introEligibility: .default(),
             purchaseHandler: .default()
         )
@@ -51,13 +61,15 @@ public struct PaywallView: View {
     init(
         offering: Offering?,
         mode: PaywallViewMode = .default,
+        fonts: PaywallFontProvider = DefaultPaywallFontProvider(),
         introEligibility: TrialOrIntroEligibilityChecker?,
         purchaseHandler: PurchaseHandler?
     ) {
         self._offering = .init(initialValue: offering)
         self.introEligibility = introEligibility
         self.purchaseHandler = purchaseHandler
         self.mode = mode
+        self.fonts = fonts
     }
 
     // swiftlint:disable:next missing_docs
@@ -73,6 +85,7 @@ public struct PaywallView: View {
             if let checker = self.introEligibility, let purchaseHandler = self.purchaseHandler {
                 if let offering = self.offering {
                     self.paywallView(for: offering,
+                                     fonts: self.fonts,
                                      checker: checker,
                                      purchaseHandler: purchaseHandler)
                     .transition(Self.transition)
@@ -104,6 +117,7 @@ public struct PaywallView: View {
     @ViewBuilder
     private func paywallView(
         for offering: Offering,
+        fonts: PaywallFontProvider,
         checker: TrialOrIntroEligibilityChecker,
         purchaseHandler: PurchaseHandler
     ) -> some View {
@@ -112,6 +126,7 @@ public struct PaywallView: View {
                 offering: offering,
                 paywall: paywall,
                 mode: self.mode,
+                fonts: fonts,
                 introEligibility: checker,
                 purchaseHandler: purchaseHandler
             )
@@ -127,6 +142,7 @@ public struct PaywallView: View {
                             offering: offering,
                             paywall: .createDefault(with: offering.availablePackages),
                             mode: self.mode,
+                            fonts: fonts,
                             introEligibility: checker,
                             purchaseHandler: purchaseHandler
                         )
@@ -147,6 +163,7 @@ struct LoadedOfferingPaywallView: View {
     private let offering: Offering
     private let paywall: PaywallData
     private let mode: PaywallViewMode
+    private let fonts: PaywallFontProvider
 
     @StateObject
     private var introEligibility: IntroEligibilityViewModel
@@ -160,12 +177,14 @@ struct LoadedOfferingPaywallView: View {
         offering: Offering,
         paywall: PaywallData,
         mode: PaywallViewMode,
+        fonts: PaywallFontProvider,
         introEligibility: TrialOrIntroEligibilityChecker,
         purchaseHandler: PurchaseHandler
     ) {
         self.offering = offering
         self.paywall = paywall
         self.mode = mode
+        self.fonts = fonts
         self._introEligibility = .init(
             wrappedValue: .init(introEligibilityChecker: introEligibility)
         )
@@ -176,6 +195,7 @@ struct LoadedOfferingPaywallView: View {
         let view = self.paywall
             .createView(for: self.offering,
                         mode: self.mode,
+                        fonts: self.fonts,
                         introEligibility: self.introEligibility,
                         locale: self.locale)
             .environmentObject(self.introEligibility)

RevenueCatUI/Templates/Template1View.swift

@@ -5,7 +5,7 @@ import SwiftUI
 @available(tvOS, unavailable)
 struct Template1View: TemplateViewType {
 
-    private let configuration: TemplateViewConfiguration
+    let configuration: TemplateViewConfiguration
     private var localization: ProcessedLocalizedConfiguration
 
     @EnvironmentObject
@@ -34,14 +34,14 @@ struct Template1View: TemplateViewType {
                 introEligibility: self.introEligibility,
                 foregroundColor: self.configuration.colors.text1Color
             )
-            .font(self.configuration.mode.offerDetailsFont)
+            .font(self.font(for: self.configuration.mode.offerDetailsFont))
             .multilineTextAlignment(.center)
 
             self.button
                 .padding(.horizontal)
 
             if case .fullScreen = self.configuration.mode {
-                FooterView(configuration: self.configuration.configuration,
+                FooterView(configuration: self.configuration,
                            color: self.configuration.colors.callToActionBackgroundColor,
                            purchaseHandler: self.purchaseHandler)
             }
@@ -55,7 +55,7 @@ struct Template1View: TemplateViewType {
 
             Group {
                 Text(.init(self.localization.title))
-                    .font(self.configuration.mode.titleFont)
+                    .font(self.font(for: self.configuration.mode.titleFont))
                     .fontWeight(.heavy)
                     .padding(
                         self.configuration.mode.displaySubtitle
@@ -65,7 +65,7 @@ struct Template1View: TemplateViewType {
 
                 if self.configuration.mode.displaySubtitle, let subtitle = self.localization.subtitle {
                     Text(.init(subtitle))
-                        .font(self.configuration.mode.subtitleFont)
+                        .font(self.font(for: self.configuration.mode.subtitleFont))
                 }
             }
             .padding(.horizontal, 20)
@@ -112,10 +112,9 @@ struct Template1View: TemplateViewType {
     private var button: some View {
         PurchaseButton(
             package: self.configuration.packages.single.content,
-            colors: self.configuration.colors,
             localization: self.localization,
+            configuration: self.configuration,
             introEligibility: self.introEligibility,
-            mode: self.configuration.mode,
             purchaseHandler: self.purchaseHandler
         )
     }
@@ -142,15 +141,15 @@ private extension PaywallViewMode {
         }
     }
 
-    var titleFont: Font {
+    var titleFont: Font.TextStyle {
         switch self {
         case .fullScreen: return .largeTitle
         case .card: return .title
         case .banner: return .headline
         }
     }
 
-    var subtitleFont: Font {
+    var subtitleFont: Font.TextStyle {
         switch self {
         case .fullScreen: return .subheadline
         case .card, .banner: return .callout
@@ -164,7 +163,7 @@ private extension PaywallViewMode {
         }
     }
 
-    var offerDetailsFont: Font {
+    var offerDetailsFont: Font.TextStyle {
         switch self {
         case .fullScreen: return .callout
         case .card, .banner: return .caption

RevenueCatUI/Templates/Template2View.swift

@@ -5,7 +5,7 @@ import SwiftUI
 @available(tvOS, unavailable)
 struct Template2View: TemplateViewType {
 
-    private let configuration: TemplateViewConfiguration
+    let configuration: TemplateViewConfiguration
     private var localization: [Package: ProcessedLocalizedConfiguration]
 
     @State
@@ -41,7 +41,7 @@ struct Template2View: TemplateViewType {
                 .padding(.horizontal)
 
             if case .fullScreen = self.configuration.mode {
-                FooterView(configuration: self.configuration.configuration,
+                FooterView(configuration: self.configuration,
                            color: self.configuration.colors.text1Color,
                            purchaseHandler: self.purchaseHandler)
             }
@@ -61,13 +61,13 @@ struct Template2View: TemplateViewType {
 
             Text(.init(self.selectedLocalization.title))
                 .foregroundColor(self.configuration.colors.text1Color)
-                .font(.largeTitle.bold())
+                .font(self.font(for: .largeTitle).bold())
 
             Spacer()
 
             Text(.init(self.selectedLocalization.subtitle ?? ""))
                 .foregroundColor(self.configuration.colors.text1Color)
-                .font(.title3)
+                .font(self.font(for: .title3))
 
             Spacer()
 
@@ -108,9 +108,9 @@ struct Template2View: TemplateViewType {
                 alignment: Self.packageButtonAlignment
             )
             .fixedSize(horizontal: false, vertical: true)
-            .font(.body)
+            .font(self.font(for: .body))
         }
-        .font(.body.weight(.medium))
+        .font(self.font(for: .body).weight(.medium))
         .padding()
         .multilineTextAlignment(.leading)
         .frame(maxWidth: .infinity, alignment: Self.packageButtonAlignment)
@@ -162,10 +162,9 @@ struct Template2View: TemplateViewType {
     private var subscribeButton: some View {
         PurchaseButton(
             package: self.selectedPackage,
-            colors: self.configuration.colors,
             localization: self.selectedLocalization,
+            configuration: self.configuration,
             introEligibility: self.introEligibility[self.selectedPackage],
-            mode: self.configuration.mode,
             purchaseHandler: self.purchaseHandler
         )
     }