SwiftUI DragGesture & MagnificationGesture

SwiftUIDragPinchView.swift

struct DragPinchView: View {
    @State var currentOffset = CGSize.zero
    @State var currentScale: CGFloat = 1.0
    @State var gestureOffset = CGSize.zero
    @State var gestureScale: CGFloat = 1.0

    var body: some View {
        let dragGesture = DragGesture()
            .onChanged { value in gestureOffset = value.translation }
            .onEnded { _ in
                withAnimation {
                    currentOffset = CGSize(width: gestureOffset.width + currentOffset.width, height: gestureOffset.height + currentOffset.height)
                    gestureOffset = .zero
                }
            }

        let magnificationGesture = MagnificationGesture()
            .onChanged { val in
                let delta = val / gestureScale
                gestureScale = gestureScale * delta
            }
            .onEnded { val in
                currentScale = gestureScale * currentScale
                gestureScale = 1.0
            }

        GeometryReader { geometry in
            VStack {
                Circle()
                    .fill(.red)
                    .frame(width: 64, height: 64)
                    .scaleEffect(gestureScale * currentScale)
                    .offset(CGSize(width: gestureOffset.width + currentOffset.width, height: gestureOffset.height + currentOffset.height))
            }
            .frame(width: geometry.size.width, height: geometry.size.height)
            .background(Color.purple.opacity(0.1))
            .gesture(dragGesture)
            .gesture(magnificationGesture)
        }
    }
}