【SwiftUI】View を ドラッグ して移動 する 👉 https://android.benigumo.com/20240514/drag-view/

TestDragGesture.swift

import SwiftUI

struct TestDragGesture: View {
  @State private var location = CGPoint(x: 150, y: 150)
  @State private var startLocation: CGPoint?

  var body: some View {
    Circle()
      .fill(.orange)
      .frame(width: 200)
      .position(location)
      .gesture(
        DragGesture()
          .onChanged { drag in
            startLocation = startLocation ?? location
            location = CGPoint(
              x: startLocation!.x + drag.translation.width,
              y: startLocation!.y + drag.translation.height
            )
          }
          .onEnded { _ in
            startLocation = nil
          }
      )
  }
}

#Preview {
  TestDragGesture()
}

TestDragGesture2.swift

import SwiftUI

struct TestDragGesture: View {
  @State private var location = CGPoint(x: 150, y: 150)
  @State private var diff: CGPoint?

  var body: some View {
    Circle()
      .fill(.orange)
      .frame(width: 200)
      .position(location)
      .gesture(
        DragGesture()
          .onChanged { drag in
            diff = diff ?? CGPoint(
              x: location.x - drag.location.x,
              y: location.y - drag.location.y
            )
            location.x = drag.location.x + diff!.x
            location.y = drag.location.y + diff!.y
          }
          .onEnded { _ in
            diff = nil
          }
      )
  }
}

#Preview {
  TestDragGesture()
}