⭐️ Impl: ModalSheetPresentationStateMachine.eventDelegates

ios/Temp/ModalSheetPresentationStateEventsNotifiable.swift

@@ -0,0 +1,47 @@
+//
+//  ModalSheetPresentationStateEventsNotifiable.swift
+//  react-native-ios-modal
+//
+//  Created by Dominic Go on 9/27/24.
+//
+
+import Foundation
+
+public protocol ModalSheetPresentationStateEventsNotifiable: AnyObject {
+
+  func onModalSheetStateWillChange(
+    sender: ModalSheetPresentationStateMachine,
+    prevState: ModalSheetState?,
+    currentState: ModalSheetState,
+    nextState: ModalSheetState
+  );
+
+  func onModalSheetStateDidChange(
+    sender: ModalSheetPresentationStateMachine,
+    prevState: ModalSheetState?,
+    currentState: ModalSheetState
+  );
+};
+
+// MARK: - ModalSheetPresentationStateEventsNotifiable+Default
+// -----------------------------------------------------------
+
+public extension ModalSheetPresentationStateEventsNotifiable {
+
+  func onModalSheetStateWillChange(
+    sender: ModalSheetPresentationStateMachine,
+    prevState: ModalSheetState?,
+    currentState: ModalSheetState,
+    nextState: ModalSheetState
+  ) {
+    // no-op
+  };
+
+  func onModalSheetStateDidChange(
+    sender: ModalSheetPresentationStateMachine,
+    prevState: ModalSheetState?,
+    currentState: ModalSheetState
+  ) {
+    // no-op
+  };
+};

ios/Temp/ModalSheetPresentationStateMachine.swift

@@ -17,6 +17,8 @@ public class ModalSheetPresentationStateMachine {
   public var didPresent = false;
   public var didDismissAfterPresented = false;
 
+  public var eventDelegates:
+    MulticastDelegate<ModalSheetPresentationStateEventsNotifiable> = .init();
 
   // MARK: - Methods
   // ---------------
@@ -39,6 +41,15 @@ public class ModalSheetPresentationStateMachine {
       );
     };
     #endif
+
+    self.eventDelegates.invoke {
+      $0.onModalSheetStateWillChange(
+        sender: self,
+        prevState: prevState,
+        currentState: currentState,
+        nextState: nextState
+      );
+    };
 
     self.prevState = self.currentState;
     self.currentState = nextState;
@@ -71,6 +82,14 @@ public class ModalSheetPresentationStateMachine {
       );
     };
     #endif
+
+    self.eventDelegates.invoke {
+      $0.onModalSheetStateDidChange(
+        sender: self,
+        prevState: self.prevState,
+        currentState: self.currentState
+      );
+    };
   };
 
   public func setState(nextState: ModalSheetState) {