WPF-Demo/Waaagh/CustomControl/NavigationBar.cs

using System.Windows;
using System.Windows.Controls;
using System.Windows.Media.Animation;
using Jamesnet.Wpf.Animation;
using Jamesnet.Wpf.Controls;

namespace Waaagh.CustomControl {
    public class NavigationBar: ListBox {
        private ValueItem _vi;
        private Storyboard _sb;

        static NavigationBar() {
            DefaultStyleKeyProperty.OverrideMetadata(typeof(NavigationBar), new FrameworkPropertyMetadata(typeof(NavigationBar)));
        }

        public override void OnApplyTemplate() {
            base.OnApplyTemplate();
            Grid grid = (Grid)GetTemplateChild("PART_Circle");

            InitStoryboard(grid);
        }

        private void InitStoryboard(Grid circle) {
            _vi = new();
            _sb = new();

            _vi.Mode = EasingFunctionBaseMode.QuinticEaseInOut;
            _vi.Property = new PropertyPath(Canvas.LeftProperty);
            _vi.Duration = new Duration(new TimeSpan(0, 0, 0, 0, 500));

            Storyboard.SetTarget(_vi, circle);
            Storyboard.SetTargetProperty(_vi, _vi.Property);

            _sb.Children.Add(_vi);
        }

        protected override void OnSelectionChanged(SelectionChangedEventArgs e) {
            base.OnSelectionChanged(e);

            _vi.To = SelectedIndex * 80;
            _sb.Begin();
        }
    }
}