BizHawk/BizHawk.Util/HexTextBox.cs

using System;
using System.Globalization;
using System.Windows.Forms;

namespace BizHawk
{
	public class HexTextBox : TextBox
	{
		public HexTextBox()
		{
			CharacterCasing = CharacterCasing.Upper;
		}

		protected override void OnKeyPress(KeyPressEventArgs e)
		{
			if (e.KeyChar == '\b' || e.KeyChar == 22 || e.KeyChar == 1 || e.KeyChar == 3)
			{
				return;
			}
			else if (!InputValidate.IsValidHexNumber(e.KeyChar))
			{
				e.Handled = true;
			}
		}

        protected override void OnKeyDown(KeyEventArgs e)
        {
            if (e.KeyCode == Keys.Up)
            {
                if (InputValidate.IsValidHexNumber(Text))
                {
                    int val = ToInt();
                    val++;
                    string formatstr = "{0:X" + MaxLength.ToString() + "}";
                    Text = String.Format(formatstr, val);
                }
            }
            else if (e.KeyCode == Keys.Down)
            {
                if (InputValidate.IsValidHexNumber(Text))
                {
                    int val = ToInt();
                    val--;
                    string formatstr = "{0:X" + MaxLength.ToString() + "}";
                    Text = String.Format(formatstr, val);
                }
            }
            else
            {
                base.OnKeyDown(e);
            }
        }

		public int ToInt()
		{
			return int.Parse(Text, NumberStyles.HexNumber);
		}
	}
}