Swipe to Dismiss Images

Closes: #343

damus/Components/ImageCarousel.swift

@@ -179,6 +179,9 @@ struct ImageView: View {
                                 .offset(x: offset.width + offsetState.width, y: offset.height + offsetState.height)
                                 .gesture(SimultaneousGesture(zoomGesture, dragGesture))
                                 .gesture(doubleTapGesture)
+                                .modifier(SwipeToDismissModifier(onDismiss: {
+                                    presentationMode.wrappedValue.dismiss()
+                                }))
                             
                         }.padding(.bottom, 50) // Ensure carousel appears beneath
                     }

damus/Modifiers/SwipeToDismiss.swift

@@ -0,0 +1,34 @@
+//
+//  SwipeToDismiss.swift
+//  damus
+//
+//  Created by Joel Klabo on 1/18/23.
+//
+
+import SwiftUI
+
+struct SwipeToDismissModifier: ViewModifier {
+    var onDismiss: () -> Void
+    @State private var offset: CGSize = .zero
+
+    func body(content: Content) -> some View {
+        content
+            .offset(y: offset.height)
+            .animation(.interactiveSpring(), value: offset)
+            .simultaneousGesture(
+                DragGesture()
+                    .onChanged { gesture in
+                        if gesture.translation.width < 50 {
+                            offset = gesture.translation
+                        }
+                    }
+                    .onEnded { _ in
+                        if abs(offset.height) > 100 {
+                            onDismiss()
+                        } else {
+                            offset = .zero
+                        }
+                    }
+            )
+    }
+}

damus/Views/ProfileZoomView.swift

@@ -78,6 +78,9 @@ struct ProfileZoomView: View {
                     .offset(x: offset.width + offsetState.width, y: offset.height + offsetState.height)
                     .gesture(SimultaneousGesture(zoomGesture, dragGesture))
                     .gesture(doubleTapGesture)
+                    .modifier(SwipeToDismissModifier(onDismiss: {
+                        presentationMode.wrappedValue.dismiss()
+                    }))
 
             }
         }