using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace TradeIdeas.TIProGUI
{
    public partial class CustomCheckedListBox : CheckedListBox
    {
        public CustomCheckedListBox()
        {
           this.DoubleBuffered = true;
        }
        //courtesy of http://stackoverflow.com/questions/3666682/which-checkedlistbox-event-triggers-after-a-item-is-checked
        //This class will trigger *after* the item has been checked (after CheckedItems is updated). It simplifies things greatly for certain purposes.
        //Normally, when one clicks the checkbox, the ItemCheck event fires *before* the CheckedItems is actually updated.
        protected override void OnItemCheck(ItemCheckEventArgs e)
        {
            base.OnItemCheck(e);
            EventHandler handler = AfterItemCheck;
            if (handler != null)
            {
                Delegate[] invocationList = AfterItemCheck.GetInvocationList();
                foreach (var receiver in invocationList)
                {
                    AfterItemCheck -= (EventHandler)receiver;
                }

                SetItemCheckState(e.Index, e.NewValue);

                foreach (var receiver in invocationList)
                {
                    AfterItemCheck += (EventHandler)receiver;
                }
            }
            OnAfterItemCheck(EventArgs.Empty);
        }
        public event EventHandler AfterItemCheck;

        public void OnAfterItemCheck(EventArgs e)
        {
            EventHandler handler = AfterItemCheck;
            if (handler != null)
                handler(this, e);
        }

        public override Font Font
        {
            get { return base.Font; }
            set
            {
                base.Font = value;
                CalculateItemHeight();
            }
        }

        private const int CHECKBOX_HEIGHT_ADJUSTMENT = 6;
        private void CalculateItemHeight()
        {
            Size measuredItemSize = TextRenderer.MeasureText("XXX", Font);
            ItemHeight = measuredItemSize.Height + CHECKBOX_HEIGHT_ADJUSTMENT;
        }

        private int _itemHeight = DefaultItemHeight;
        public override int ItemHeight
        {
            get { return _itemHeight; }
            set { _itemHeight = value; }
        }
    }
}