Dashboard/Dashboard/Controls/Container.cs

using System;
using System.Collections;
using System.Collections.Generic;
using Dashboard.Drawing;
using Dashboard.Events;
using Dashboard.Layout;
using Dashboard.Pal;

namespace Dashboard.Controls
{
    public class Container : Control, IList<Control>, ILayoutContainer
    {
        private readonly List<Control> _controls = new List<Control>();

        public int Count => _controls.Count;

        public bool IsReadOnly => false;

        public ContainerLayoutInfo ContainerLayout { get; } = new ContainerLayoutInfo();

        public event EventHandler<ContainerChildAddedEventArgs>? ChildAdded;
        public event EventHandler<ContainerChildRemovedEventArgs>? ChildRemoved;


        public Control this[int index]
        {
            get => _controls[index];
            set => _controls[index] = value;
        }

        protected override void ValidateLayout()
        {
            if (!IsLayoutEnabled || IsLayoutValid)
                return;

            // LayoutSolution solution = LayoutSolution.CalculateLayout(this, ClientArea.Size);

            base.ValidateLayout();
        }

        public override void OnPaint(DeviceContext dc)
        {
            base.OnPaint(dc);

            var dcb = dc.ExtensionRequire<IDeviceContextBase>();
            dcb.PushClip(ClientArea);
            ValidateLayout();

            foreach (Control child in _controls)
            {
                if (child.Layout.DisplayMode == DisplayMode.None)
                    continue;

                child.SendEvent(this, new PaintEventArgs(dc));
            }

            dcb.PopClip();
        }

        IEnumerator<ILayoutItem> IEnumerable<ILayoutItem>.GetEnumerator()
        {
            return GetEnumerator();
        }

        public IEnumerator<Control> GetEnumerator()
        {
            return _controls.GetEnumerator();
        }

        IEnumerator IEnumerable.GetEnumerator()
        {
            return ((IEnumerable)_controls).GetEnumerator();
        }

        public void Add(Control item)
        {
            SetParent(this, item);

            _controls.Add(item);
            ChildAdded?.Invoke(this, new ContainerChildAddedEventArgs(this, item));
        }

        public void Clear()
        {
            foreach (Control control in this)
            {
                ChildRemoved?.Invoke(this, new ContainerChildRemovedEventArgs(this, control));
            }
            _controls.Clear();
        }

        public bool Contains(Control item)
        {
            return _controls.Contains(item);
        }

        public void CopyTo(Control[] array, int arrayIndex)
        {
            _controls.CopyTo(array, arrayIndex);
        }

        public bool Remove(Control item)
        {
            if (!_controls.Remove(item))
                return false;

            ChildRemoved?.Invoke(this, new ContainerChildRemovedEventArgs(this, item));
            return true;
        }

        public int IndexOf(Control item)
        {
            return _controls.IndexOf(item);
        }

        public void Insert(int index, Control item)
        {
            SetParent(this, item);

            _controls.Insert(index, item);
            ChildAdded?.Invoke(this, new ContainerChildAddedEventArgs(this, item));
        }

        public void RemoveAt(int index)
        {
            Control child = _controls[index];
            _controls.RemoveAt(index);
            ChildRemoved?.Invoke(this, new ContainerChildRemovedEventArgs(this, child));
        }


    }

    public class ContainerChildAddedEventArgs(Container parent, Control child) : EventArgs
    {
        public Container Parent { get; } = parent;
        public Control Child { get; } = child;
    }

    public class ContainerChildRemovedEventArgs(Container parent, Control child) : EventArgs
    {
        public Container Parent { get; } = parent;
        public Control Child { get; } = child;
    }
}