SwiftUI Shape concurrency warnings

Question

RyanLintott OP

Created 6d

Replies 2

Boosts 0

Participants 3

How are SwiftUI Shapes supposed to work with Swift 6?

Shape conforms to View which uses @MainActor but the path function and animatableData are both nonisolated. How can they access animatable properties that have to be a var on the main actor?

Below is a simple Shape that will show these warnings:

struct SimpleShape: Shape {
    var width: Double
    
    var animatableData: Double {
        get { width }
        set { width = newValue }
    }
    
    func path(in rect: CGRect) -> Path {
        var path = Path()
        let width = self.width
        path.addRect(.init(origin: rect.origin, size: .init(width: width, height: rect.height)))
        return path
    }
}

Answered by DTS Engineer in 790883022

@RyanLintott Thanks for flagging that. Could you please file a bug report and post the FB number here once you do. Please be sure to test on future beta releases as well.

Boost

Answer 1

mattie OP

6d

I have a workaround, but I'm not 100% sure I understand why the Shape properties are nonisolated so I'm not sure if this actually safe or not.

struct SimpleShape: Shape {
    var width: Double

    nonisolated var animatableData: Double {
        get { MainActor.assumeIsolated { width } }
        set { MainActor.assumeIsolated { width = newValue } }
    }

    func path(in rect: CGRect) -> Path {
        return Path()
    }
}

0

Answer 2

DTS Engineer OP

Apple

4d

Recommended

@RyanLintott Thanks for flagging that. Could you please file a bug report and post the FB number here once you do. Please be sure to test on future beta releases as well.

0