SwiftUI_TabBar_CustomModal

gistfile1.txt

import SwiftUI

class ViewRouter: ObservableObject {
    @Published var currentView = "clock.fill"
    @Published var flg = false
}

struct ContentView: View {

    @ObservedObject var viewRouter = ViewRouter()
    @State private var selection: Int = 1

    var body: some View {
        GeometryReader { geometry in
            VStack {
                Spacer()
                if self.selection == 2 {
                    Text("Hello, World!").onTapGesture {
                        self.viewRouter.flg.toggle()
                    }
                } else {
                    
                }
                Spacer()
                HStack {
                    self.modifier(TabModifier(text: "arrow.up.right.video.fill", selection:  self.$selection, viewRouter: self.viewRouter, tag: 1))
                    self.modifier(TabModifier(text: "icloud.and.arrow.up.fill", selection:  self.$selection,viewRouter: self.viewRouter, tag: 2))
                    self.modifier(TabModifier(text: "lock.icloud.fill", selection:  self.$selection, viewRouter: self.viewRouter, tag: 3))
                    self.modifier(TabModifier(text: "message.fill", selection:  self.$selection,viewRouter: self.viewRouter, tag: 4))
                }
                .frame(width: geometry.size.width, height: geometry.size.height/10)
            }
            AlertView()
        }
    }
}

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

struct AlertView: View {
    
    @State private var offSet: CGFloat = 1000
    @ObservedObject var viewRouter = ViewRouter()

    var body: some View {
        GeometryReader { geometry in
            Text("CustomDialog").frame(minWidth: 0, maxWidth: .infinity, minHeight: 0, maxHeight: .infinity)
                .onTapGesture {
                    withAnimation {
                        self.viewRouter.flg.toggle()
                    }
            }
            ZStack {
                if self.viewRouter.flg {
                    Color.gray
                        .frame(minWidth: 0, maxWidth: self.viewRouter.flg ? .infinity : 0 , minHeight: 0, maxHeight: self.viewRouter.flg ? .infinity : 0)
                        .opacity(0.6)
                        .edgesIgnoringSafeArea(.all)
                    Color.white
                        .frame(width: geometry.size.width, height: geometry.size.height/1.2, alignment: .center)
                        .cornerRadius(10, corners: [.topLeft, .topRight])
                        .padding(.top, geometry.size.height/5)
                        .offset(y: self.offSet)
                        .onTapGesture {
                            withAnimation(.linear(duration: 0.4)) {
                                self.offSet += CGFloat(1000)
                                DispatchQueue.main.asyncAfter(deadline: .now() + 0.2) {
                                    self.viewRouter.flg.toggle()
                                }
                            }
                    }
                    .onAppear {
                        withAnimation(.linear(duration: 0.4)) {
                            // select offSet
                            self.offSet = CGFloat(400)
                        }
                    }
                }
            }
        }
    }
}

struct TabModifier: ViewModifier {
    
    var text: String?  = ""
    let selection: Binding<Int>
    var viewRouter: ViewRouter
    var tag: Int
    var width = UIScreen.main.bounds.width
    
    func body(content: Content) -> some View {
        
        return GeometryReader { geometry in
            VStack {
                if self.tag == 1 {
                    Divider()
                        .frame(width: self.width, alignment: .bottom).offset(y: -8)
                }
            }
            HStack {
                Image(systemName: self.text ?? "")
                    .resizable()
                    .aspectRatio(contentMode: .fit)
                    .padding(20)
                    .frame(width: geometry.size.width, height: self.width/4 - 20)
                    .foregroundColor(self.fgColor())
                    .onTapGesture {
                        self.selection.wrappedValue = self.tag
                        self.viewRouter.currentView = self.text ?? ""
                }
            }
        }
    }

    private func fgColor() -> Color {
        return selection.wrappedValue == self.tag ? Color(UIColor.systemBlue) : Color(UIColor.systemGray)
    }
}

struct HiddenModifier: ViewModifier {

    fileprivate let isHidden: Bool

    fileprivate func body(content: Content) -> some View {
        Group {
            if isHidden {
                content.hidden()
            } else {
                content
            }
        }
    }
}

extension View {

    func cornerRadius(_ radius: CGFloat, corners: UIRectCorner) -> some View {
        clipShape( RoundedCorner(radius: radius, corners: corners) )
    }
    
}

struct RoundedCorner: Shape {

    var radius: CGFloat = .infinity
    var corners: UIRectCorner = .allCorners

    func path(in rect: CGRect) -> Path {
        let path = UIBezierPath(roundedRect: rect, byRoundingCorners: corners, cornerRadii: CGSize(width: radius, height: radius))
        return Path(path.cgPath)
    }
}

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