任意のViewをFlashさせる

code:View+Flashing.swift

import SwiftUI

// definition

struct FlashingModifier: ViewModifier {

let trigger: PassthroughSubject<Void, Never>

@State private var isVisible = false

func body(content: Content) -> some View {

content

.opacity(isVisible ? 1 : 0)

.onReceive(trigger) { _ in

isVisible = true

withAnimation(.easeOut(duration: 0.3)) {

isVisible = false

}

}

}

}

extension View {

func flashing(trigger: PassthroughSubject<Void, Never>) -> some View {

modifier(FlashingModifier(trigger: trigger))

}

}

code:Usage.swift

struct ContentView: View {

let flashTrigger = PassthroughSubject<Void, Never>()

var body: some View {

VStack {

Text("フラッシュするテキスト")

.flashing(trigger: flashTrigger)

Button("フラッシュ開始") {

flashTrigger.send() // イベントを送信するだけ！

}

}

}

}