⭐️ Impl: `ModalSheetViewControllerEventsNotifiable.notifyOnSheetBeing…

…DraggedByPanGesture`
dominicstop · Sep 29, 2024 · 1161634 · 1161634
1 parent 8db6026
commit 1161634
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diff --git a/ios/Temp/ModalSheetViewControllerEventsNotifiable.swift b/ios/Temp/ModalSheetViewControllerEventsNotifiable.swift
@@ -36,6 +36,11 @@ public protocol ModalSheetViewControllerEventsNotifiable: AnyObject {
     panGesture: UIPanGestureRecognizer,
     scrollView: UIScrollView
   );
+
+  func notifyOnSheetBeingDraggedByPanGesture(
+    sender: UIViewController,
+    panGesture: UIPanGestureRecognizer
+  );
 };
 
 // MARK: - SheetViewControllerEventsNotifiable
@@ -79,4 +84,11 @@ public extension ModalSheetViewControllerEventsNotifiable {
   ) {
     // no-op
   };
+
+  func notifyOnSheetBeingDraggedByPanGesture(
+    sender: UIViewController,
+    panGesture: UIPanGestureRecognizer
+  ) {
+    // no-op
+  };
 };
diff --git a/ios/Temp/ModalSheetViewControllerLifecycleNotifier.swift b/ios/Temp/ModalSheetViewControllerLifecycleNotifier.swift
@@ -177,6 +177,22 @@ open class ModalSheetViewControllerLifecycleNotifier: ViewControllerLifecycleNot
         gesturePoint: gesturePoint
       );
     };
+
+    let shouldInvokeCombinedGestureHandler: Bool = {
+      if let scrollViewPanGesture = self.modalRootScrollViewGestureRecognizer {
+        let isScrollGestureActive = scrollViewPanGesture.state.isActive;
+        let didSystemPanGestureFail = panGesture.state == .failed;
+
+        return !isScrollGestureActive || !didSystemPanGestureFail;
+      };
+
+      return true;
+    }();
+
+    if shouldInvokeCombinedGestureHandler {
+      self._handleCombinedSheetGesture(panGesture);
+    };
+  };
 
   @objc
   private func _handleSheetScrollViewGesture(
@@ -211,7 +227,34 @@ open class ModalSheetViewControllerLifecycleNotifier: ViewControllerLifecycleNot
         scrollView: scrollView
       );
     };
+
+    let shouldInvokeCombinedGestureHandler = {
+      if let sheetGesture = self.sheetGesture {
+        return sheetGesture.state == .failed;
+      };
+
+      let currentOffsetY = scrollView.contentOffset.y;
+      let initialOffsetY = self.sheetRootScrollViewInitialContentOffset.y;
+
+      return currentOffsetY <= initialOffsetY;
+    }();
+
+    if shouldInvokeCombinedGestureHandler {
+      self._handleCombinedSheetGesture(panGesture);
+    };
   };
+
+  @objc
+  private func _handleCombinedSheetGesture(
+    _ panGesture: UIPanGestureRecognizer
+  ) {
+
+    self.sheetLifecycleEventDelegates.invoke {
+      $0.notifyOnSheetBeingDraggedByPanGesture(
+        sender: self,
+        panGesture: panGesture
+      );
+    };
   };
 
   // MARK: - Debug-Related