Statistical parsing of English sentences

using System;
using System.Drawing;
using System.ComponentModel;
namespace Netron.Lithium
{
	/// <summary>
	/// Abstract base class for every object part of the diagram
	/// </summary>
	public abstract class Entity
	{
		#region Fields
		/// <summary>
		/// tells whether the current entity is hovered by the mouse
		/// </summary>
		protected internal bool hovered = false;
		/// <summary>
		/// the control to which the eneity belongs
		/// </summary>
		protected internal LithiumControl site;
		/// <summary>
		/// tells whether the entity is selected
		/// </summary>
		protected bool isSelected = false;

		/// <summary>
		/// Default font for drawing text
		/// </summary>
		protected Font font = new Font("Verdana", 10F);

		/// <summary>
		/// Default black pen
		/// </summary>
		protected Pen blackPen = new Pen(Brushes.Black,1f);

		/// <summary>
		/// a red pen
		/// </summary>
		protected Pen  redPen = new Pen(Brushes.Red,2f);

		/// <summary>
		/// a thicker version of the black pen
		/// </summary>
		protected Pen thickPen = new Pen(Color.Black, 1.7f);
		/// <summary>
		/// the unique identifier
		/// </summary>
		protected Guid uid;

		/// <summary>
		/// whatever pen you use instead of the black one
		/// </summary>
		protected Pen pen;

		/// <summary>
		/// the visibility bit
		/// </summary>
		protected internal bool visible = false;
		#endregion

		#region Properties
		/// <summary>
		/// Gets or sets whether the entity is selected
		/// </summary>
		[Browsable(false)]
		public bool IsSelected
		{
			get{return isSelected;}
			set{isSelected = value;}
		}
		/// <summary>
		/// Gets or sets the site of the entity
		/// </summary>
		[Browsable(false)]
		public LithiumControl Site
		{
			get{return site;}
			set{site = value;}
		}

		/// <summary>
		/// The globally unique identifier of the entity.
		/// Mostly useful for serialization.
		/// </summary>
		[Browsable(false), GraphData]
		public Guid UID
		{
			get{return uid;}
			set{uid = value;}
		}
		

		/// <summary>
		/// The font used for drawing the text (if any)
		/// </summary>
		[Browsable(false)]
		public Font Font
		{
			get{return font;}
			set{font =value;}
		}
		#endregion

		#region Constructor
		/// <summary>
		/// Default ctor
		/// </summary>
		public Entity()
		{			
			this.uid = Guid.NewGuid();
		}

		/// <summary>
		/// Ctor with the site of the entity
		/// </summary>
		/// <param name="site"></param>
		public Entity(LithiumControl site):this()
		{
			this.site = site;
		}

		
		#endregion

		#region Methods
		/// <summary>
		/// Paints the entity on the control
		/// </summary>
		/// <param name="g">the graphics object to paint on</param>
		public abstract void Paint(Graphics g);
		/// <summary>
		/// Tests whether the shape is hit by the mouse
		/// </summary>
		/// <param name="p"></param>
		/// <returns></returns>
		public abstract bool Hit(Point p);
		/// <summary>
		/// Invalidates the entity
		/// </summary>
		public abstract void Invalidate();
		/// <summary>
		/// Moves the entity on the canvas
		/// </summary>
		/// <param name="p">the shifting vector, not an absolute position!</param>
		public abstract void Move(Point p);

		#endregion
	}
}