DemoCustomTextField.swift

//
//  ContentView.swift
//  newUI
//
//  Created by prafull kumar on 3/4/20.
//  Copyright © 2020 prafull kumar. All rights reserved.
//

import SwiftUI

struct ContentView: View {
    @State private var name: String = ""
    @State private var appointmentDate: String = ""
    @State private var package: String = ""
    @State private var phone: String = ""
    let someFuturedate = Calendar.current.date(byAdding: .year, value: 20, to: Date()) ?? Date()
    var body: some View {
        NavigationView {
            VStack(alignment: .leading) {
                Group {
                    Text("Please Fill the form:").padding()
                    TextView(pickerType: .keyboard(type: .default), text: $name, placeholder: "Enter Name")
                            .frame(height: 40)
                    TextView(pickerType: .keyboard(type: .phonePad), text: $phone, placeholder: "Enter Phone Number")
                    .frame(height: 40)
                    TextView(pickerType: .datePicker(minDate: Date(), maxDate: someFuturedate), text: $appointmentDate, placeholder: "Select Date of Appointment")
                    .frame(height: 40)
                    TextView(pickerType: .customList(list: ["Premium","Economy","Free Demo"]), text: $package, placeholder: "Select Package")
                    .frame(height: 40)
                }
                Group {
                    Text("Your Input details:").padding()

                    Text("Name: \(name)").frame(height: 40)
                    Text("Appointment Date: \(appointmentDate)").frame(height: 40)
                    Text("Package: \(package)").frame(height: 40)
                    Text("Phone: \(phone)").frame(height: 40)
                    
                }
                Spacer()
            }
            .padding()
            .navigationBarTitle("Custom TextFields")
        }
    }
}

#if DEBUG
struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}
#endif

struct TextView: UIViewRepresentable {
    
    enum PickerType {
        case keyboard(type: UIKeyboardType)
        case datePicker(minDate: Date, maxDate: Date)
        case customList(list: [String])
    }
    var pickerType: TextView.PickerType
    @Binding var text: String
    let placeholder: String
    func makeUIView(context: Context) -> UITextField {
        let textField = UITextField()
        textField.delegate = context.coordinator
        textField.placeholder = placeholder
        textField.frame.size.height = 40
        textField.borderStyle = .roundedRect
        textField.setContentCompressionResistancePriority(.defaultLow, for: .horizontal)
        return textField
    }

    func updateUIView(_ uiView: UITextField, context: Context) {
        switch pickerType {
        case .datePicker:
            uiView.text = text
        case .customList:
            uiView.text = text
        default:
            break
        }
        
    }
    
    
    func makeCoordinator() -> Coordinator {
        return Coordinator(text: $text, pickerType: pickerType)
    }

    final class Coordinator: NSObject {
        
        
        var text: Binding<String>
        var pickerType: TextView.PickerType

        init(text: Binding<String>, pickerType: TextView.PickerType) {
            self.pickerType = pickerType
           self.text = text
        }
        
        private func setPickerType(textField: UITextField) {
               switch pickerType {
               case .keyboard(let type):
                   textField.keyboardType = type
                   textField.inputView = nil
               case .customList:
                   textField.inputView = getPicker()
               case .datePicker(let minDate, let maxDate):
                   textField.inputView = getDatePicker(minDate: minDate, maxDate: maxDate)
               }
               textField.inputAccessoryView = getToolBar()
        }
        
        //Mark: custom Picker
        private func getPicker() -> UIPickerView {
               let picker = UIPickerView()
               picker.backgroundColor = UIColor.systemBackground
               picker.delegate = self
               picker.dataSource = self
               return picker
           }
        //Mark: date Picker
        private func getDatePicker(minDate: Date, maxDate: Date) -> UIDatePicker {
           let picker = UIDatePicker()
           picker.datePickerMode = .date
           picker.backgroundColor = UIColor.systemBackground
           picker.maximumDate = maxDate
           picker.minimumDate = minDate
           picker.addTarget(self, action: #selector(handleDatePicker(sender:)), for: .valueChanged)
           return picker
        }
        
        @objc func handleDatePicker(sender: UIDatePicker) {
            let dateFormatter = DateFormatter()
            dateFormatter.dateFormat = "dd MMM yyyy"
            text.wrappedValue = dateFormatter.string(from: sender.date)
        }
        
        
        //Mark: Toolbar
        private func getToolBar() -> UIToolbar {
               let toolBar = UIToolbar()
               toolBar.barStyle = UIBarStyle.default
               toolBar.backgroundColor = UIColor.systemBackground
               toolBar.isTranslucent = true
               toolBar.sizeToFit()
               let spaceButton = UIBarButtonItem(barButtonSystemItem: UIBarButtonItem.SystemItem.flexibleSpace, target: nil, action: nil)
               let doneButton = UIBarButtonItem(title: "Done", style: UIBarButtonItem.Style.done, target: self, action: #selector(self.donePicker))
               toolBar.setItems([spaceButton, doneButton], animated: false)
               toolBar.isUserInteractionEnabled = true
               return toolBar
        }
        
        @objc func donePicker() {
            UIApplication.shared.sendAction(#selector(UIResponder.resignFirstResponder), to: nil, from: nil, for: nil)
        }

        
    }
    
               
}



extension TextView.Coordinator: UIPickerViewDataSource{
    func numberOfComponents(in pickerView: UIPickerView) -> Int {
        return 1
    }
    
    func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
        switch pickerType {
         case .customList(let list):
             return list.count
         default:
             return 0
        }
    }
}

extension TextView.Coordinator: UIPickerViewDelegate {
    func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
         switch pickerType {
         case .customList(let list):
           return list[row]
         default:
           return ""
        }
    }

    
    func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
         switch pickerType {
         case .customList(let list):
            text.wrappedValue = list[row]
         default:
              break
       }
    }
}


extension TextView.Coordinator: UITextFieldDelegate {
    func textFieldShouldBeginEditing(_ textField: UITextField) -> Bool {
        setPickerType(textField: textField)
        return true
    }

    func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
        
            defer {
                if let currentText = textField.text, let stringRange = Range(range, in: currentText) {
                    text.wrappedValue = currentText.replacingCharacters(in: stringRange, with: string)
                }
            }
        
        return true
    }
    
    func textFieldDidEndEditing(_ textField: UITextField) {
        donePicker()
    }
}