Ooui-tws-port/Ooui.Forms/Cells/SwitchCellElement.cs

using System;
using System.ComponentModel;
using Ooui.Forms.Extensions;
using Ooui.Forms.Renderers;
using Xamarin.Forms;

namespace Ooui.Forms.Cells
{
    public class SwitchCellElement : CellElement
    {
        public Label TextLabel { get; } = new Label ();
        public SwitchRenderer.SwitchElement Switch { get; } = new SwitchRenderer.SwitchElement ();

        public SwitchCellElement ()
        {
            AppendChild (TextLabel);
            AppendChild (Switch);

            Switch.Style.Display = "inline-block";

            Switch.Change += Switch_Change;
        }

        protected override void BindCell ()
        {
            Cell.PropertyChanged += Cell_PropertyChanged;

            if (Cell is SwitchCell cell) {
                UpdateText (cell);
                UpdateOn (cell);
            }

            base.BindCell ();
        }

        protected override void UnbindCell ()
        {
            Cell.PropertyChanged -= Cell_PropertyChanged;

            base.UnbindCell ();
        }

        void Cell_PropertyChanged (object sender, PropertyChangedEventArgs e)
        {
            var cell = (SwitchCell)sender;

            if (e.PropertyName == SwitchCell.TextProperty.PropertyName)
                UpdateText (cell);
            else if (e.PropertyName == SwitchCell.OnProperty.PropertyName)
                UpdateOn (cell);
        }

        void UpdateText (SwitchCell cell)
        {
            TextLabel.Text = cell.Text ?? string.Empty;
        }

        void UpdateOn (SwitchCell cell)
        {
            Switch.IsChecked = cell.On;
        }

        void Switch_Change (object sender, EventArgs e)
        {
            if (Cell is SwitchCell cell)
                cell.On = Switch.IsChecked;
        }
    }
}