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

Vendor/RefreshControl/RefreshControlModifier.swift

@@ -0,0 +1,42 @@
+//
+//  RefreshControlModifier.swift
+//  SwiftUI_Pull_to_Refresh
+//
+//  Created by Geri Borbás on 18/09/2021.
+//
+
+import Foundation
+import SwiftUI
+
+struct RefreshControlModifier: ViewModifier {
+    @State private var geometryReaderFrame: CGRect = .zero
+    let refreshControl: RefreshControl
+
+    internal init(onValueChanged: @escaping (UIRefreshControl) -> Void) {
+        refreshControl = RefreshControl(onValueChanged: onValueChanged)
+    }
+
+    func body(content: Content) -> some View {
+        content
+            .background(
+                GeometryReader { geometry in
+                    ScrollViewMatcher(
+                        onResolve: { scrollView in
+                            refreshControl.add(to: scrollView)
+                        },
+                        geometryReaderFrame: $geometryReaderFrame
+                    )
+                    .preference(key: FramePreferenceKey.self, value: geometry.frame(in: .global))
+                    .onPreferenceChange(FramePreferenceKey.self) { frame in
+                        self.geometryReaderFrame = frame
+                    }
+                }
+            )
+    }
+}
+
+extension View {
+    func refreshControl(onValueChanged: @escaping (_ refreshControl: UIRefreshControl) -> Void) -> some View {
+        modifier(RefreshControlModifier(onValueChanged: onValueChanged))
+    }
+}