circles.swift

//
//  ContentView.swift
//
//  Created by Dominic Williams on 12/07/2020.
//

import SwiftUI

struct ContentView: View {
    
    @State private var previousCircle: Int = 1
    @State private var selectedCircle: Int = 7
    @State private var circleScale: CGFloat = 1.0
    
    @State private var delay =  1.0
        
    var body: some View {
        
        
        HStack {
            ForEach(1..<8) { i in
                Circle()
                    .frame(height: 30)
                    .scaleEffect(selectedCircle == i ? 1.3 : circleScale)
                    .animation(
                            Animation.easeIn(duration: 0.2)
                            .repeatCount(1, autoreverses: true)
                            .delay(Double(i) * 0.15)
                    )

                    .onTapGesture {
                       circleTapped(circleIndex: i)
                    }
            }
        }
    }
    

    func inBetweenCircle(circleIndex: Int) -> Bool {
    
        let lower = min(previousCircle, selectedCircle)
        let upper = max(previousCircle, selectedCircle)
        let range = lower...upper
        
        if range.contains(circleIndex) {
            return true
        } else {
            return false
        }
        
    }
    
    
    func delayForCircle(circleIndex: Int) -> Double {
        
        // This circle is inbetween the previous and selected circles
        if inBetweenCircle(circleIndex: circleIndex) {
            // how far away from the previous circle am I?
            let circleDistance = abs(circleIndex - previousCircle)
            print("Circle \(circleIndex) is between \(previousCircle) and \(selectedCircle) and is \(circleDistance) circles away from the newly selected circle in terms of distance")
            
            // Each circle takes a second delay so its very easy to see what is happening for now
            return Double(circleDistance) * 1.0
        }
        return 1.0
    }
    
    func circleTapped(circleIndex: Int) {
        previousCircle = selectedCircle
        selectedCircle = circleIndex
    }
 
    
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}