Paginator

using System;
using cAlgo.API;

namespace devman
{
    [Indicator(AccessRights = AccessRights.None, IsOverlay = true)]
    public class Paginator : Indicator
    {
        [Parameter(DefaultValue = VerticalAlignment.Bottom)]
        public VerticalAlignment VerticalAlignment { get; set; }

        [Parameter(DefaultValue = HorizontalAlignment.Center)]
        public HorizontalAlignment HorizontalAlignment { get; set; }
        
        [Parameter(DefaultValue = 11)]
        public int FontSize { get; set; }

        private DateTime ActualOpenTime => Bars[Chart.FirstVisibleBarIndex].OpenTime;

        protected override void Initialize()
        {
            Chart.AddControl(CreateNavigationPanel());
        }

        public override void Calculate(int index)
        {
            // DO NOTHING
        }

        private StackPanel CreateNavigationPanel()
        {
            var panel = new StackPanel
            {
                VerticalAlignment = VerticalAlignment,
                HorizontalAlignment = HorizontalAlignment,
                Orientation = Orientation.Horizontal,
                Margin = 10,
            };

            var navBtnStyle = new Style(DefaultStyles.ButtonStyle);
            navBtnStyle.Set(ControlProperty.Margin, new Thickness(1, 0, 1, 0));
            navBtnStyle.Set(ControlProperty.FontSize, FontSize);

            var b0 = new Button { Text = "◀◀", Style = navBtnStyle };
            b0.Click += _ => Chart.ScrollXTo(0);

            var bY = new Button { Text = "◀◀ Y", Style = navBtnStyle };
            bY.Click += _ => NavigateTo(ActualOpenTime.AddYears(-1));

            var bM = new Button { Text = "◀◀ M", Style = navBtnStyle };
            bM.Click += _ => NavigateTo(ActualOpenTime.AddMonths(-1));

            var bD = new Button { Text = "◀ D", Style = navBtnStyle };
            bD.Click += _ => NavigateTo(ActualOpenTime.AddDays(-1));

            var fD = new Button { Text = "D ▶", Style = navBtnStyle };
            fD.Click += _ => NavigateTo(ActualOpenTime.AddDays(1));

            var fM = new Button { Text = "M ▶▶", Style = navBtnStyle };
            fM.Click += _ => NavigateTo(ActualOpenTime.AddMonths(1));

            var fY = new Button { Text = "Y ▶▶", Style = navBtnStyle };
            fY.Click += _ => NavigateTo(ActualOpenTime.AddYears(1));

            var f0 = new Button { Text = "▶▶", Style = navBtnStyle };
            f0.Click += _ => Chart.ScrollXTo(Bars.Count);

            panel.AddChild(b0);
            panel.AddChild(bY);
            panel.AddChild(bM);
            panel.AddChild(bD);
            panel.AddChild(fD);
            panel.AddChild(fM);
            panel.AddChild(fY);
            panel.AddChild(f0);

            return panel;
        }

        private void NavigateTo(DateTime time)
        {
            var indexByTime = Bars.OpenTimes.GetIndexByTime(time);

            if (indexByTime < 0)
                indexByTime = 0;

            Chart.ScrollXTo(indexByTime);
        }
    }
}