Add pull to refresh for Subscriptions, Popular and Trending (fixes #31)

Vendor/RefreshControl/RefreshControl.swift

@@ -0,0 +1,56 @@
+//
+//  RefreshControl.swift
+//  SwiftUI_Pull_to_Refresh
+//
+//  Created by Geri Borbás on 18/09/2021.
+//
+
+import Combine
+import Foundation
+import SwiftUI
+import UIKit
+
+final class RefreshControl: ObservableObject {
+    static var navigationBarTitleDisplayMode: NavigationBarItem.TitleDisplayMode {
+        if #available(iOS 15.0, *) {
+            return .automatic
+        }
+
+        return .inline
+    }
+
+    let onValueChanged: (_ refreshControl: UIRefreshControl) -> Void
+
+    internal init(onValueChanged: @escaping ((UIRefreshControl) -> Void)) {
+        self.onValueChanged = onValueChanged
+    }
+
+    /// Adds a `UIRefreshControl` to the `UIScrollView` provided.
+    func add(to scrollView: UIScrollView) {
+        scrollView.refreshControl = UIRefreshControl().withTarget(
+            self,
+            action: #selector(onValueChangedAction),
+            for: .valueChanged
+        )
+        .testable(as: "RefreshControl")
+    }
+
+    @objc private func onValueChangedAction(sender: UIRefreshControl) {
+        onValueChanged(sender)
+    }
+}
+
+extension UIRefreshControl {
+    /// Convinience method to assign target action inline.
+    func withTarget(_ target: Any?, action: Selector, for controlEvents: UIControl.Event) -> UIRefreshControl {
+        addTarget(target, action: action, for: controlEvents)
+        return self
+    }
+
+    /// Convinience method to match refresh control for UI testing.
+    func testable(as id: String) -> UIRefreshControl {
+        isAccessibilityElement = true
+        accessibilityIdentifier = id
+        return self
+    }
+}