using System;
using System.Collections.Generic;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;
namespace GeminiCricket
{
    class DoubleBufferedPanel : Panel
    {
        public DoubleBufferedPanel()
        {
            this.DoubleBuffered = true;
            this.SetStyle(ControlStyles.AllPaintingInWmPaint | ControlStyles.UserPaint | ControlStyles.OptimizedDoubleBuffer | ControlStyles.Opaque, true);
            this.UpdateStyles();
        }
        protected override void OnScroll(ScrollEventArgs se)
        {
            if (se.Type == ScrollEventType.First) LockWindowUpdate(this.Handle);
            else if (se.Type == ScrollEventType.ThumbTrack || se.Type == ScrollEventType.ThumbPosition)
            {
                LockWindowUpdate(IntPtr.Zero);
                this.Refresh();
                LockWindowUpdate(this.Handle);
            }
            else
            {
                LockWindowUpdate(IntPtr.Zero);
                this.Invalidate();
            }
            base.OnScroll(se);
        }
        // P/Invoke declarations
        [DllImport("user32.dll")]
        private static extern bool LockWindowUpdate(IntPtr hWnd);
    }
}