🟢 Release v0.1.0

Sources/StylableScrollView/BackButton.swift

@@ -14,20 +14,25 @@ public struct BackButton: View {
 
     @Environment(\.presentationMode)
     public var presentationMode: Binding<PresentationMode>
-    
+
     @State private var hasBeenShownAtLeastOnce: Bool = false
 
     public var body: some View {
         (presentationMode.wrappedValue.isPresented || hasBeenShownAtLeastOnce) ?
-            Button(action: { self.presentationMode.wrappedValue.dismiss() }) {
-               Image(systemName: "chevron.left")
-                   .resizable()
-                   .aspectRatio(contentMode: .fit)
-                   .frame(height: 20, alignment: .leading)
-                   .foregroundColor(color)
-                   .padding(.horizontal, 16)
-                   .font(Font.body.bold())
-            }
+            Button(
+                action: {
+                    self.presentationMode.wrappedValue.dismiss()
+                },
+                label: {
+                   Image(systemName: "chevron.left")
+                       .resizable()
+                       .aspectRatio(contentMode: .fit)
+                       .frame(height: 20, alignment: .leading)
+                       .foregroundColor(color)
+                       .padding(.horizontal, 16)
+                       .font(Font.body.bold())
+                }
+            )
             .onAppear {
                 self.hasBeenShownAtLeastOnce = true
             }

Sources/StylableScrollView/Extensions/Color.swift

@@ -28,6 +28,14 @@ public extension Color {
         return scheme == .light ? Color(red: 0.95, green: 0.95, blue: 0.97) : Color(red: 0.11, green: 0.11, blue: 0.12)
     }
 
+    /// `Color.systemGray6` multi-platform equivalent.
+    ///
+    /// - Parameters:
+    ///    - scheme: The current color scheme.
+    static func label(for scheme: ColorScheme) -> Color {
+        return scheme == .light ? Color.black : Color.white
+    }
+
     /// A multi-platform solution for obtaining the window's background color.
     static var backgroundColor: Color {
 

Sources/StylableScrollView/Extensions/Modifiers.swift

@@ -18,7 +18,7 @@
 import Foundation
 import SwiftUI
 
-//  MARK: - SCROLLVIEW STYLE
+// MARK: - SCROLLVIEW STYLE
 @available(iOS 13.0, macOS 10.15, tvOS 13.0, watchOS 6.0, *)
 public extension View {
 
@@ -53,17 +53,18 @@ public extension View {
     ///         )
     ///     }
     ///
-    /// ![A stretchable scroll view with a big text talking about French footballer Kylian Mbappé. On top, a stretchable header can be seen.](StretchableHeader-kmbappe.png)
+    /// ![A stretchable scroll view with a big text talking about French footballer
+    /// Kylian Mbappé. On top, a stretchable header can be seen.](StretchableHeader-kmbappe.png)
     ///
-    @inlinable @ViewBuilder func scrollViewStyle<S>(_ style: S) -> some View where S : ScrollViewStyle {
+    @inlinable @ViewBuilder func scrollViewStyle<S>(_ style: S) -> some View where S: ScrollViewStyle {
 
         self.environment(\.scrollViewStyle, AnyScrollViewStyle(style))
 
     }
 
 }
 
-//  MARK: - STRETCHABLE HEADER
+// MARK: - STRETCHABLE HEADER
 @available(iOS 15.0, macOS 12, *)
 @available(tvOS, unavailable)
 @available(watchOS, unavailable)
@@ -84,19 +85,24 @@ public extension ScrollView {
     ///   - header: The header image that will be used for the sticky header.
     ///   - title: The title that appears on top of the header.
     ///   - navBar: The contents of the navigationBar that appears when scrolling.
+    ///   - leadingElements: The navigation bar elements that will appear on the leading side.
+    ///   - trailingElements: The navigation bar elements that will appear on the trailing side.
     ///
-    @ViewBuilder @inlinable func stretchableHeader<Title, NavBar>(
+    @ViewBuilder @inlinable func stretchableHeader<Title, NavBar, TrailingElements, LeadingElements>(
         header: Image,
         title: () -> Title,
-        navBar: () -> NavBar
-    ) -> some View where Title: View, NavBar: View {
+        navBar: () -> NavBar,
+        leadingElements: @escaping (NavigationBarProxy) -> LeadingElements,
+        trailingElements: @escaping (NavigationBarProxy) -> TrailingElements
+    ) -> some View where Title: View, NavBar: View, LeadingElements: View, TrailingElements: View {
 
         StylableScrollView(
             .vertical,
             showIndicators: false,
             content: {
                 self
-            })
+            }
+        )
             .scrollViewStyle(
                 StretchableScrollViewStyle(
                     header: {
@@ -105,7 +111,12 @@ public extension ScrollView {
                             .aspectRatio(contentMode: .fill)
                     },
                     title: title,
-                    navBarContent: navBar
+                    navBarContent: navBar,
+                    leadingElements: {
+                        leadingElements($0)
+                    }, trailingElements: {
+                        trailingElements($0)
+                    }
                 )
             )
 
@@ -126,32 +137,42 @@ public extension ScrollView {
     ///   - header: The view that will be used for the sticky header.
     ///   - title: The title that appears on top of the header.
     ///   - navBar: The contents of the navigationBar that appears when scrolling.
+    ///   - leadingElements: The navigation bar elements that will appear on the leading side.
+    ///   - trailingElements: The navigation bar elements that will appear on the trailing side.
     ///
-    @ViewBuilder @inlinable func stretchableHeader<Header, Title, NavBar>(
+    @ViewBuilder @inlinable func stretchableHeader<Header, Title, NavBar, TrailingElements, LeadingElements>(
         header: () -> Header,
         title: () -> Title,
-        navBar: () -> NavBar
-    ) -> some View where Header: View, Title: View, NavBar: View {
+        navBar: () -> NavBar,
+        leadingElements: @escaping (NavigationBarProxy) -> LeadingElements,
+        trailingElements: @escaping (NavigationBarProxy) -> TrailingElements
+    ) -> some View where Header: View, Title: View, NavBar: View, LeadingElements: View, TrailingElements: View {
 
         StylableScrollView(
             .vertical,
             showIndicators: false,
             content: {
                 self
-            })
+            }
+        )
             .scrollViewStyle(
                 StretchableScrollViewStyle(
                     header: header,
                     title: title,
-                    navBarContent: navBar
+                    navBarContent: navBar,
+                    leadingElements: {
+                        leadingElements($0)
+                    }, trailingElements: {
+                        trailingElements($0)
+                    }
                 )
             )
 
     }
 
 }
 
-//  MARK: - SIZE MODIFIERS
+// MARK: - SIZE MODIFIERS
 @available(iOS 13.0, macOS 10.15, tvOS 13.0, watchOS 6.0, *)
 public extension View {
 
@@ -175,7 +196,7 @@ public extension View {
 
 }
 
-//  MARK: - NAVIGATION BAR ELEMENTS
+// MARK: - NAVIGATION BAR ELEMENTS
 extension View {
 
     /// Creates a fake navigation bar item for ``StretchableScrollViewStyle``'s fake navigation bar using
@@ -184,7 +205,8 @@ extension View {
     ///    - Parameters:
     ///        - axis: The horizontal edge the element will appear at.
     ///        - content: The element view
-    ///        - affectedByColorChanges: Whether the element is affected by the changes in color when shown in a navigation Bar. Defaults to `true`.
+    ///        - affectedByColorChanges: Whether the element is affected by
+    ///        the changes in color when shown in a navigation Bar. Defaults to `true`.
     ///
     /// Use this modifier to set a specific navigation bar element for
     /// ``StretchableScrollViewStyle`` instances within a view:
@@ -202,9 +224,22 @@ extension View {
     @available(iOS 15.0, macOS 12.0, *)
     @available(tvOS, unavailable)
     @available(watchOS, unavailable)
-    @ViewBuilder public func navigationBarElement<Content: View>(axis: HorizontalEdge, _ content: () -> Content) -> some View {
-
-        self.preference(
+    @available(*, deprecated, message: "Please pass your elements as arguments to the ScrollViewStyle.")
+    public func navigationBarElement<Content: View>(axis: HorizontalEdge, _ content: () -> Content) -> some View {
+
+        guard Constants.MAJOR < 1 else {
+            fatalError(".navigationBarElement(axis:,_:) is obsolete and is not working anymore.")
+        }
+
+        /*
+         *  This function passes the navigation bar elements as preference items to the scroll view style,
+         *  but they do not update, even if a state variable is changed.
+         *
+         *  For this reason, this function is deprecated and should be deleted before the stable release,
+         *  unless we find a way to make it work as desired.
+         */
+        #warning("TODO: We should remove this function before the stable release (X.y.z | X > 0).")
+        return self.preference(
             key: Preferences.NavigationBar.Elements.Key.self,
             value: [
                 Preferences.NavigationBar.Elements.Data(
@@ -215,4 +250,5 @@ extension View {
         )
 
     }
+
 }

Sources/StylableScrollView/Namespaces/Constants.swift

@@ -0,0 +1,14 @@
+//
+//  File.swift
+//  
+//
+//  Created by Alex Modroño Vara on 26/12/21.
+//
+
+import Foundation
+
+struct Constants {
+    static let MAJOR = 0
+    static let MINOR = 1
+    static let PATCH = 0
+}

Sources/StylableScrollView/Namespaces/NavigationBarProxy.swift

@@ -0,0 +1,38 @@
+/*
+*   THE WORK (AS DEFINED BELOW) IS PROVIDED UNDER THE TERMS OF THIS
+*   NON-VIOLENT PUBLIC LICENSE v4 ("LICENSE"). THE WORK IS PROTECTED BY
+*   COPYRIGHT AND ALL OTHER APPLICABLE LAWS. ANY USE OF THE WORK OTHER THAN
+*   AS AUTHORIZED UNDER THIS LICENSE OR COPYRIGHT LAW IS PROHIBITED. BY
+*   EXERCISING ANY RIGHTS TO THE WORK PROVIDED IN THIS LICENSE, YOU AGREE
+*   TO BE BOUND BY THE TERMS OF THIS LICENSE. TO THE EXTENT THIS LICENSE
+*   MAY BE CONSIDERED TO BE A CONTRACT, THE LICENSOR GRANTS YOU THE RIGHTS
+*   CONTAINED HERE IN AS CONSIDERATION FOR ACCEPTING THE TERMS AND
+*   CONDITIONS OF THIS LICENSE AND FOR AGREEING TO BE BOUND BY THE TERMS
+*   AND CONDITIONS OF THIS LICENSE.
+*
+*   StylableScrollView.swift
+*
+*   Created by Alex Modroño Vara on 26/12/21.
+*
+*/
+import Foundation
+import SwiftUI
+
+// MARK: - NAVIGATION BAR
+//
+/// A proxy for access to several aspects of a Navigation Bar Element,
+/// such as whether the navigation bar has changed display mode, the
+/// preferred color for navigation bar elements, and more.
+@available(iOS 13.0, macOS 10.15, tvOS 13.0, watchOS 6.0, *)
+public struct NavigationBarProxy {
+
+    public enum Mode {
+        case large
+        case inline
+    }
+
+    public var mode: Mode
+
+    public var elementsColor: Color
+
+}

Sources/StylableScrollView/Configuration/Preferences.swift → Sources/StylableScrollView/Namespaces/Preferences.swift

@@ -18,6 +18,9 @@
 import Foundation
 import SwiftUI
 
+// MARK: – SWIFTLINT
+//  swiftlint:disable nesting
+
 @available(iOS 13.0, macOS 10.15, tvOS 13.0, watchOS 6.0, *)
 public struct Preferences {
 
@@ -26,11 +29,11 @@ public struct Preferences {
 
         /// Allows us to read the minY of the header from ancestor views.
         public struct Key: PreferenceKey {
-            
+
             public typealias Value = Data
 
             public static var defaultValue: Data = Data.init(minY: 0)
-           
+
             public static func reduce(value: inout Data, nextValue: () -> Data) {
                 value = nextValue()
             }
@@ -74,7 +77,7 @@ public struct Preferences {
                 public typealias Value = [Data]
 
                 public static var defaultValue: [Data] = []
-                
+
                 public static func reduce(value: inout [Data], nextValue: () -> [Data]) {
                     value.append(contentsOf: nextValue())
                 }

Sources/StylableScrollView/ScrollViewStyle.swift

@@ -29,7 +29,7 @@ import SwiftUI
 public protocol ScrollViewStyle {
 
     /// A view that represents the body of a ScrollView.
-    associatedtype Body : View
+    associatedtype Body: View
 
     /// Creates a view that represents the body of a ScrollView.
     ///

Sources/StylableScrollView/StylableScrollView.swift

@@ -70,14 +70,18 @@ import SwiftUI
 ///         )
 ///     }
 ///
-/// ![A stretchable scroll view with a big text talking about French footballer Kylian Mbappé. On top, a stretchable header can be seen.](StretchableHeader-kmbappe.png)
+/// ![A stretchable scroll view with a big text talking about
+/// French footballer Kylian Mbappé. On top, a stretchable header can be seen.](StretchableHeader-kmbappe.png)
 ///
 @available(iOS 13.0, macOS 10.15, tvOS 13.0, watchOS 6.0, *)
 public struct StylableScrollView<Content>: View {
 
+    /// The actual version of StylableScrollView that is being used.
+    public let version: String = "\(Constants.MAJOR).\(Constants.MINOR).\(Constants.PATCH)"
+
     /// The style that is being used.
     @Environment(\.scrollViewStyle) private var style
-    
+
     /// The configuration for the ScrollView
     private var configuration: ScrollViewStyleConfiguration
 
@@ -93,7 +97,7 @@ public struct StylableScrollView<Content>: View {
 
 }
 
-public extension StylableScrollView where Content : View {
+public extension StylableScrollView where Content: View {
 
     /// Creates an instance of an ``StylableScrollView`` that is scrollable in a specific
     /// axis, and can show indicators while scrolling, using the body that you define.
@@ -104,7 +108,11 @@ public extension StylableScrollView where Content : View {
     ///      component of the content offset, in a way that's suitable for the platform.
     ///    - content: The scroll view's content.
     ///
-    init(_ axes: Axis.Set = .vertical, showIndicators: Bool = true, content: () -> Content) {
+    init(
+        _ axes: Axis.Set = .vertical,
+        showIndicators: Bool = true,
+        content: () -> Content
+    ) {
 
         self.init(
             ScrollViewStyleConfiguration(

Sources/StylableScrollView/Styles/AnyScrollViewStyle.swift

@@ -21,11 +21,11 @@ import SwiftUI
 /// A type-erased ``ScrollViewStyle``.
 public struct AnyScrollViewStyle: ScrollViewStyle {
     private let styleMakeBody: (ScrollViewStyle.Configuration) -> AnyView
-    
+
     public init<S: ScrollViewStyle>(_ style: S) {
         self.styleMakeBody = style.makeTypeErasedBody
     }
-    
+
     public func makeBody(configuration: ScrollViewStyle.Configuration) -> AnyView {
         self.styleMakeBody(configuration)
     }