Cancellable Drag Gesture

CancellableDragGesture.swift

import SwiftUI

struct ContentView: View {
    
    @State private var isDragging: Bool = false
    @GestureState private var isDraggingActive: Bool = false
    
    var body: some View {
        ZStack {
            if isDragging {
                Color.green
            } else {
                Color.red
            }
        }
        .gesture(
            DragGesture()
                .updating($isDraggingActive) { _, isDraggingActive, _ in
                    isDraggingActive = true
                }
                .onChanged { value in
                    if !isDragging {
                        /// Started
                        isDragging = true
                    }
                    /// Update
                }
                .onEnded { _ in
                    /// Ended
                    isDragging = false
                }
        )
        .onChange(of: isDraggingActive) { _, isDraggingActive in
            if isDragging, !isDraggingActive {
                /// Cancelled
                isDragging = false
            }
        }
    }
}

#Preview {
    ContentView()
}