keyboardPadding SwiftUI

KeyboardPaddingModifier.swift

import SwiftUI
import Combine

struct KeyboardPaddingModifier: ViewModifier {
    @State private var keyboardMinY: CGFloat? = nil

    private var keyboardNotificationPublisher: AnyPublisher<Notification, Never> {
        Publishers.Merge(
            NotificationCenter.default
                .publisher(for: UIResponder.keyboardWillShowNotification),
            NotificationCenter.default
                .publisher(for: UIResponder.keyboardWillHideNotification)
       ).eraseToAnyPublisher()
    }
    
    func overlappingHeight(in geometry: GeometryProxy) -> CGFloat {
        guard let keyboardMinY = keyboardMinY else {
            return 0
        }
        return max(0, geometry.frame(in: .global).maxY - keyboardMinY)
    }

    func body(content: Content) -> some View {
        GeometryReader { geometry in
            content
                .padding(.bottom, self.overlappingHeight(in: geometry))
        }.onReceive(keyboardNotificationPublisher) { notification in
            let keyboardFrameEnd = notification.userInfo![UIResponder.keyboardFrameEndUserInfoKey]! as! CGRect
            let keyboardAnimationDuration = notification.userInfo![UIResponder.keyboardAnimationDurationUserInfoKey] as! Double
    
            withAnimation(.easeOut(duration: keyboardAnimationDuration)) {
                self.keyboardMinY = keyboardFrameEnd.minY
            }
        }
    }
}

extension View {
    func keyboardPadding() -> some View {
        modifier(KeyboardPaddingModifier())
    }
}