Problem combining a draggable NSView with SwiftUI components - swift

Question

I have a NSView-class written using Cocoa:
import Cocoa
import SwiftUI
final class EntityViewImpl: NSViewRepresentable {
func makeNSView(context: NSViewRepresentableContext<EntityViewImpl>) -> EntityView {
return EntityView(frame: NSRect(x: 0, y: 0, width: 100, height: 200))
}
func updateNSView(_ nsView: EntityView, context: NSViewRepresentableContext<EntityViewImpl>) {
// do nothing
}
}
class EntityView: NSView {
var oldMousePosition: NSPoint = .zero
var oldFrameOrigin: NSPoint = .zero
override func draw(_ dirtyRect: NSRect) {
super.draw(dirtyRect)
NSColor.white.setFill()
dirtyRect.fill()
}
override func mouseDown(with event: NSEvent) {
self.oldFrameOrigin = self.frame.origin
self.oldMousePosition = event.locationInWindow
}
override func mouseDragged(with event: NSEvent) {
let pointInSuperview = event.locationInWindow
self.frame.origin = NSPoint(x: oldFrameOrigin.x + (pointInSuperview.x - oldMousePosition.x),
y: oldFrameOrigin.y + (pointInSuperview.y - oldMousePosition.y))
}
}
and I want to use this class inside a SwiftUI View-body like:
struct ContentView: View {
var body: some View {
Group {
EntityViewImpl()
.frame(width: 100, height: 100)
}
.frame(maxWidth: .infinity, maxHeight: .infinity)
}
}
This works fine and I can also drag around the EntityView. However, I can only "grab" it inside of it's original frame. If I drag it outside of the bounds, the mouse event will no longer trigger on the parts of the view that are outside of the original frame. Do I have to somehow "tell" the ContentView that the NSView moved?

Answer 1

Actually if you are using SwiftUI, you need to move the superview of EntityView, like this:
override func mouseDown(with event: NSEvent) {
self.oldFrameOrigin = self.superview!.frame.origin
self.oldMousePosition = self.superview!.convert(event.locationInWindow, from: self)
}
override func mouseDragged(with event: NSEvent) {
let pointInSuperview = self.superview!.convert(event.locationInWindow, from: self)
self.superview!.frame.origin = NSPoint(x: oldFrameOrigin.x + (pointInSuperview.x - oldMousePosition.x),
y: oldFrameOrigin.y + (-pointInSuperview.y + oldMousePosition.y))
}