FlyoutHelper

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Windows.Devices.Input;
using Windows.Foundation;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;

namespace Telegram.Common
{
    public class FlyoutHelper
    {
        public static FlyoutBase GetAttachedFlyout(DependencyObject obj)
        {
            return (FlyoutBase)obj.GetValue(AttachedFlyoutProperty);
        }

        public static void SetAttachedFlyout(DependencyObject obj, FlyoutBase value)
        {
            obj.SetValue(AttachedFlyoutProperty, value);
        }

        public static readonly DependencyProperty AttachedFlyoutProperty =
            DependencyProperty.RegisterAttached("AttachedFlyout", typeof(FlyoutBase), typeof(FlyoutHelper), new PropertyMetadata(null, OnAttachedFlyoutChanged));

        private static void OnAttachedFlyoutChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            var sender = d as FrameworkElement;
            var newValue = e.NewValue as FlyoutBase;

            if (newValue == null)
            {
                FlyoutBase.SetAttachedFlyout(sender, null);
                sender.RightTapped -= OnRightTapped;
                sender.Holding -= OnHolding;
            }
            else
            {
                FlyoutBase.SetAttachedFlyout(sender, newValue);
                sender.RightTapped += OnRightTapped;
                sender.Holding += OnHolding;
            }
        }

        private static void OnHolding(object sender, Windows.UI.Xaml.Input.HoldingRoutedEventArgs e)
        {
            if (e.PointerDeviceType == PointerDeviceType.Touch)
            {
                FlyoutBase.ShowAttachedFlyout(sender as FrameworkElement);
            }
        }

        private static void OnRightTapped(object sender, Windows.UI.Xaml.Input.RightTappedRoutedEventArgs e)
        {
            if (e.PointerDeviceType != PointerDeviceType.Touch)
            {
                FlyoutBase.ShowAttachedFlyout(sender as FrameworkElement);
            }
        }
    }
}