Billing/Billing.Shared/UI/Definition.cs

using System;
using Xamarin.Forms;

namespace Billing.UI
{
    public static partial class Definition
    {
        public static partial string GetCascadiaRegularFontFamily();
        public static partial string GetCascadiaBoldFontFamily();
        public static partial string GetRobotoCondensedRegularFontFamily();
        public static partial string GetRobotoCondensedBoldFontFamily();
        public static partial string GetBrandsFontFamily();
    }

    public static class ExtensionHelper
    {
        public static T Binding<T>(this T obj, BindableProperty property, string path, BindingMode mode = BindingMode.Default, IValueConverter converter = null) where T : BindableObject
        {
            obj.SetBinding(property, path, mode, converter);
            return obj;
        }

        public static T HorizontalOptions<T>(this T view, LayoutOptions options) where T : View
        {
            if (view != null)
            {
                view.HorizontalOptions = options;
            }
            return view;
        }

        public static T VerticalOptions<T>(this T view, LayoutOptions options) where T : View
        {
            if (view != null)
            {
                view.VerticalOptions = options;
            }
            return view;
        }

        public static T Margin<T>(this T view, Thickness margin) where T : View
        {
            view.Margin = margin;
            return view;
        }

        public static T DynamicResource<T>(this T view, BindableProperty property, string key) where T : Element
        {
            view.SetDynamicResource(property, key);
            return view;
        }

        public static T GridColumn<T>(this T view, int column) where T : BindableObject
        {
            Grid.SetColumn(view, column);
            return view;
        }

        public static T GridRow<T>(this T view, int row) where T : BindableObject
        {
            Grid.SetRow(view, row);
            return view;
        }

        public static T GridColumnSpan<T>(this T view, int columnSpan) where T : BindableObject
        {
            Grid.SetColumnSpan(view, columnSpan);
            return view;
        }

        public static T GridRowSpan<T>(this T view, int rowSpan) where T : BindableObject
        {
            Grid.SetRowSpan(view, rowSpan);
            return view;
        }
    }

    public class Tap : IDisposable
    {
        private readonly static object sync = new();
        private static Tap instance;

        private bool busy = false;

        private Tap() { }

        public static bool IsBusy => instance?.busy ?? false;

        public static Tap Start()
        {
            lock (sync)
            {
                (instance ??= new Tap()).busy = true;
            }
            return instance;
        }

        public void Dispose()
        {
            lock (sync)
            {
                busy = false;
            }
        }
    }
}