fix(macos): remove monitor after use

Sources/CropImage/UnderlyingImageView.swift

@@ -27,7 +27,8 @@ struct UnderlyingImageView: View {
     @State private var tempRotation: Angle = .zero
     @State private var scrolling: Bool = false
 #if os(macOS)
-    @State private var isHovering: Bool = false
+    @State private var hovering: Bool = false
+    @State private var scrollMonitor: Any?
 #endif
 
     // When rotated odd multiples of 90 degrees, we need to switch width and height of the image in calculations.
@@ -91,18 +92,24 @@ struct UnderlyingImageView: View {
         scale = min(widthScale, heightScale)
     }
 
-    private func setupScrollMonitor() {
 #if os(macOS)
-        NSEvent.addLocalMonitorForEvents(matching: .scrollWheel) {event in
+    private func setupScrollMonitor() {
-            if isHovering {
+      scrollMonitor = NSEvent.addLocalMonitorForEvents(matching: .scrollWheel) { event in
+            if hovering {
                 scrolling = true
                 scale = scale + event.scrollingDeltaY / 1000
             }
             return event
         }
-        #endif
     }
   
+    private func removeScrollMonitor() {
+        if let scrollMonitor {
+            NSEvent.removeMonitor(scrollMonitor)
+        }
+    }
+#endif
+
     var imageView: Image {
 #if os(macOS)
         Image(nsImage: image)
@@ -116,9 +123,14 @@ struct UnderlyingImageView: View {
             .gesture(dragGesture)
             .gesture(magnificationgesture)
             .gesture(rotationGesture)
+#if os(macOS)
             .onAppear {
                 setupScrollMonitor()
             }
+            .onDisappear {
+                removeScrollMonitor()
+            }
+#endif
     }
 
     var dragGesture: some Gesture {
@@ -174,9 +186,7 @@ struct UnderlyingImageView: View {
                 adjustToFulfillTargetFrame()
             }
 #if os(macOS)
-            .onHover { hovering in
+            .onHover { hovering = $0 }
-                isHovering = hovering
-            }
 #endif
     }
 }