[C#] HC Glow Button - Printable Version

Code:
// HCGlowButton - (c)Arkphaze
// Released: May 11/2013
// http://hackcommunity.net

using System;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Windows.Forms;

sealed class HCGlowButton : Button
{
	private readonly SolidBrush _flatBgBrush = new SolidBrush(Color.FromArgb(20, 20, 20));
	private readonly Pen _penTopLine = new Pen(Color.FromArgb(77, 77, 77));
	private readonly Pen _penOuterBorder = new Pen(Color.FromArgb(40, 40, 40));

	private readonly SolidBrush _textBrush = new SolidBrush(Color.White);

	private readonly Color _gradient1 = Color.FromArgb(30, 30, 30);
	private readonly Color _gradient2 = Color.FromArgb(5, 5, 5);

	private MouseState _mouseState = MouseState.Normal;
	enum MouseState
	{
		Normal, Hover, Pressed
	}

	private const int MaxGlowAlpha = 100;
	private const int GlowSpeed = 5;
	private int _glowAlpha;
	private bool _glowBrighter;
	private bool _showGlow;
	private readonly Timer _timer = new Timer();
	
	public HCGlowButton()
	{
		DoubleBuffered = true;
		_timer.Interval = 1;
		_timer.Tick += _timer_Tick;
		_showGlow = true;
	}

	protected override void OnPaint(PaintEventArgs e)
	{
		base.OnPaint(e);
		e.Graphics.Clear(Color.Black);
		e.Graphics.SmoothingMode = SmoothingMode.HighQuality;

		switch (_mouseState)
		{
			case MouseState.Hover:
				using (
					LinearGradientBrush lgb = new LinearGradientBrush(Point.Empty, new Point(0, Height),
																	  _gradient2, _gradient1))
				{
					e.Graphics.FillRectangle(lgb, DisplayRectangle);
				}
				_textBrush.Color = Color.White;
				break;
			case MouseState.Pressed:
				e.Graphics.FillRectangle(_flatBgBrush, DisplayRectangle);
				_textBrush.Color = Color.FromArgb(145, 145, 145);
				break;
			default: // Normal
				using (
					LinearGradientBrush lgb = new LinearGradientBrush(Point.Empty, new Point(0, Height),
																	  _gradient1, _gradient2))
				{
					e.Graphics.FillRectangle(lgb, DisplayRectangle);
				}
				_textBrush.Color = Color.White;
				break;
		}

		// Draw top line
		e.Graphics.DrawLine(_penTopLine, 0f, 0f, Width, 0f);

		// Draw other border lines
		e.Graphics.DrawLine(_penOuterBorder, 0f, 0f, 0f, Height - 1); // Left
		e.Graphics.DrawLine(_penOuterBorder, 0f, Height - 1, Width - 1, Height - 1); // Bottom
		e.Graphics.DrawLine(_penOuterBorder, Width - 1, 0f, Width - 1, Height - 1); // Right

		// Draw text
		DrawText(e.Graphics);
	}

	#region Overrided Mouse Event Methods
	protected override void OnMouseDown(MouseEventArgs e)
	{
		base.OnMouseDown(e);
		_mouseState = MouseState.Pressed;
		_showGlow = false;
	}

	protected override void OnMouseUp(MouseEventArgs e)
	{
		base.OnMouseUp(e);
		_mouseState = MouseState.Hover;
		_showGlow = true;
		Invalidate();
	}

	protected override void OnMouseMove(MouseEventArgs mevent)
	{
		base.OnMouseMove(mevent);
		_mouseState = MouseState.Hover;
		_showGlow = true;
		_glowBrighter = true;
		if (_glowAlpha < MaxGlowAlpha)
		{
			_timer.Start();
		}
	}

	protected override void OnMouseLeave(EventArgs e)
	{
		base.OnMouseLeave(e);
		_mouseState = MouseState.Normal;
		_showGlow = true;
		_glowBrighter = false;
		if (_glowAlpha > 0)
		{
			_timer.Start();
		}
	}
	#endregion

	private void DrawText(Graphics graphics)
	{
		string text = Text.ToUpper();
		SizeF textSize = graphics.MeasureString(text, Font);
		float x = (Width / 2) - (textSize.Width / 2);
		float y = (Height / 2) - (textSize.Height / 2);
		graphics.DrawString(text, Font, _textBrush, x, y);

		if (_showGlow)
		{
			// Draw text glow
			DrawGlow(graphics, new Rectangle((int)x, (int)y, (int) textSize.Width, (int) textSize.Height));
		}
	}

	private void DrawGlow(Graphics graphics, Rectangle textRect)
	{
		Rectangle glowRect = ExpandRectangle(textRect, 2);
		Point[] pts = new[]
			{
				new Point(glowRect.X, glowRect.Y),
				new Point(glowRect.X + glowRect.Width, glowRect.Y),
				new Point(glowRect.X + glowRect.Width, glowRect.Y + glowRect.Height),
				new Point(glowRect.X, glowRect.Y + glowRect.Height)
			};
		using (PathGradientBrush pgb = new PathGradientBrush(pts))
		{
			pgb.CenterPoint = new PointF(Width / 2, Height / 2);
			pgb.CenterColor = Color.FromArgb(_glowAlpha, Color.White);
			pgb.SurroundColors = new[] { Color.Transparent };
			pgb.FocusScales = new PointF(0.25f, 0.25f);
			graphics.FillRectangle(pgb, glowRect);
		}
	}

	private void _timer_Tick(object sender, EventArgs e)
	{
		if (_glowBrighter)
		{
			if ((_glowAlpha += GlowSpeed) >= MaxGlowAlpha)
			{
				_timer.Stop();
				_glowAlpha = MaxGlowAlpha;
			}
		}
		else
		{
			if ((_glowAlpha -= GlowSpeed) <= 0)
			{
				_timer.Stop();
				_glowAlpha = 0;
			}
		}
		Invalidate();
	}

	private Rectangle ExpandRectangle(Rectangle rect, int expansion)
	{
		const int extraWidth = 4;
		return new Rectangle(rect.X - expansion - extraWidth, rect.Y - expansion,
							 rect.Width + (expansion * 2) + (extraWidth * 2), rect.Height + (expansion * 2));
	}
}