Tetris/TetrisUI/GridView.swift

//
//  GridView.swift
//  Tetris
//
//  Created by Shadowfacts on 10/14/19.
//  Copyright © 2019 Shadowfacts. All rights reserved.
//

import SwiftUI

struct GridView<Cell>: View where Cell: View {
    
    let rows: Int
    let columns: Int
    let cellProvider: (Int, Int, CGFloat) -> Cell
    
    init(rows: Int, columns: Int, @ViewBuilder cellProvider: @escaping (Int, Int, CGFloat) -> Cell) {
        self.rows = rows
        self.columns = columns
        self.cellProvider = cellProvider
    }
    
    var body: some View {
        GeometryReader { (geometry) in
            VStack(spacing: 0) {
                ForEach(0..<self.rows, id: \.self) { (row) in
                    HStack(spacing: 0) {
                        ForEach(0..<self.columns, id: \.self) { (col) in
                            self.cellProvider(col, row, self.cellSize(for: geometry))
                        }
                    }
                }
            }
        }
    }
    
    func cellSize(for geometry: GeometryProxy) -> CGFloat {
        min(geometry.size.width / CGFloat(columns), geometry.size.height / CGFloat(rows))
    }
}

struct GridView_Previews: PreviewProvider {
    static var previews: some View {
        GridView(rows: 3, columns: 3) { (col, row, size) in
            Rectangle().frame(width: size, height: size).foregroundColor(Color.red)
        }
    }
}