⭐️ Impl: UIViewController+ModalHelpers

ios/Temp/UIViewController+ModalHelpers.swift

@@ -0,0 +1,106 @@
+//
+//  UIViewController+ModalHelpers.swift
+//  react-native-ios-modal
+//
+//  Created by Dominic Go on 9/27/24.
+//
+
+import Foundation
+import DGSwiftUtilities
+
+
+extension UIViewController {
+
+  // MARK: - Embedded Types
+  // ----------------------
+
+  fileprivate enum PrivateSymbolString: String, HashedStringDecodable {
+
+    /// `UIDropShadowView`
+    case classNameForDropShadowView;
+
+    var encodedString: String {
+      switch self {
+        case .classNameForDropShadowView:
+          return "VUlEcm9wU2hhZG93Vmlldw==";
+      };
+    };
+  };
+
+  // MARK: - Computed Properties
+  // ---------------------------
+
+  public var modalPanGestureViaPresentationController: UIPanGestureRecognizer? {
+    guard let presentationController = self.presentationController,
+          let presentedView = presentationController.presentedView,
+          let gestureRecognizers = presentedView.gestureRecognizers
+    else {
+      return nil;
+    };
+
+    let match = gestureRecognizers.first {
+      $0 is UIPanGestureRecognizer;
+    };
+
+    guard let match = match as? UIPanGestureRecognizer else {
+      return nil;
+    };
+
+    return match;
+  };
+
+  public var modalPanGestureViaClimbingParentViews: UIPanGestureRecognizer? {
+    guard let targetClassName = PrivateSymbolString.classNameForDropShadowView.decodedString else {
+      return nil;
+    };
+
+    let matchingAncestorView = self.view.recursivelyFindParentView {
+         $0.className == targetClassName
+      && $0.gestureRecognizers?.count ?? 0 > 0;
+    };
+
+    guard let matchingAncestorView = matchingAncestorView,
+          let gestureRecognizers = matchingAncestorView.gestureRecognizers
+    else {
+      return nil;
+    };
+
+    let matchingGestureRecognizer = gestureRecognizers.first {
+      $0 is UIPanGestureRecognizer;
+    };
+
+    guard let matchingGestureRecognizer = matchingGestureRecognizer as? UIPanGestureRecognizer else {
+      return nil;
+    };
+
+    return matchingGestureRecognizer;
+  };
+
+  public var modalPanGesture: UIPanGestureRecognizer? {
+       self.modalPanGestureViaPresentationController
+    ?? self.modalPanGestureViaClimbingParentViews;
+  };
+
+  public var modalRootScrollViewGestureRecognizer: UIPanGestureRecognizer? {
+    guard let scrollView = self.view.recursivelyFindSubview(whereType: UIScrollView.self),
+          let scrollViewGestures = scrollView.gestureRecognizers
+    else {
+      return nil;
+    };
+
+    return scrollViewGestures.first(
+      whereType: UIPanGestureRecognizer.self
+    );
+  };
+
+  public var modalPositionAnimator: CAAnimation? {
+    guard self.isPresentedAsModal,
+          let presentationController = self.presentationController,
+          let presentedView = presentationController.presentedView
+    else {
+      return nil;
+    };
+
+    return presentedView.layer.animation(forKey: "position");
+  };
+};