Display_D_HP/TeamAAS-VM/Behaviors/SliderUserInteractionBehavior.cs

using Microsoft.Xaml.Behaviors;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;

namespace TeamAAS_VP.Behaviors
{
    public class SliderUserInteractionBehavior : Behavior<Slider>
    {
        public static readonly DependencyProperty UserInteractionCommandProperty =
            DependencyProperty.Register(
                nameof(UserInteractionCommand),
                typeof(ICommand),
                typeof(SliderUserInteractionBehavior));

        public ICommand UserInteractionCommand
        {
            get => (ICommand)GetValue(UserInteractionCommandProperty);
            set => SetValue(UserInteractionCommandProperty, value);
        }

        public static readonly DependencyProperty CommandParameterProperty =
            DependencyProperty.Register(
                nameof(CommandParameter),
                typeof(object),
                typeof(SliderUserInteractionBehavior));

        public object CommandParameter
        {
            get => GetValue(CommandParameterProperty);
            set => SetValue(CommandParameterProperty, value);
        }

        private bool _isUserDragging = false;
        private double _previousValue;

        protected override void OnAttached()
        {
            base.OnAttached();
            AssociatedObject.PreviewMouseDown += OnPreviewMouseDown;
            AssociatedObject.PreviewMouseUp += OnPreviewMouseUp;
            AssociatedObject.ValueChanged += OnValueChanged;
        }

        protected override void OnDetaching()
        {
            base.OnDetaching();
            AssociatedObject.PreviewMouseDown -= OnPreviewMouseDown;
            AssociatedObject.PreviewMouseUp -= OnPreviewMouseUp;
            AssociatedObject.ValueChanged -= OnValueChanged;
        }

        private void OnPreviewMouseDown(object sender, MouseButtonEventArgs e)
        {
            _isUserDragging = true;
            _previousValue = AssociatedObject.Value;
        }

        private void OnPreviewMouseUp(object sender, MouseButtonEventArgs e)
        {
            if (_isUserDragging)
            {
                _isUserDragging = false;
            }
        }

        private void OnValueChanged(object sender, RoutedPropertyChangedEventArgs<double> e)
        {
            if (_isUserDragging && UserInteractionCommand?.CanExecute(CommandParameter) == true)
            {
                var parameter = new Tuple<object, double, double>(
                    CommandParameter,
                    _previousValue,
                    AssociatedObject.Value);

                UserInteractionCommand.Execute(parameter);
                _previousValue = AssociatedObject.Value;
            }
        }
    }
}