namespace TACO.Widgets
{
	using System;
	using System.Drawing;

	public abstract class CanvasElement
	{
		public static Gdk.Drawable Drawable;

		private string mId;
		private Rectangle mBounds;
		private bool mSelected;
		private bool mVisible;

		public delegate void BoundsChangedEventHandler(object sender,
													   BoundsChangedArgs args);

		public event System.EventHandler VisibilityChanged;
		public event System.EventHandler SelectionChanged;
		public event BoundsChangedEventHandler BoundsChanged;

		protected CanvasElement(string id)
		{
			mId       = id;
			mBounds   = new Rectangle();
			mSelected = false;
			mVisible  = false;
		}

		public string Id
		{
			get { return mId; }
		}

		public abstract string Name
		{
			get;
		}

		public virtual bool Visible
		{
			get { return mVisible;  }
			set
			{
				if (mVisible != value)
				{
					mVisible = value;
					OnVisibilityChanged(new System.EventArgs());
				}
			}
		}

		public Rectangle Bounds
		{
			get { return mBounds; }
		}

		public bool Selected
		{
			get { return mSelected; }
			set
			{
				if (mSelected != value)
				{
					mSelected = value;
					OnSelectionChanged(new System.EventArgs());
				}
			}
		}

		public void SetBounds(int x, int y, int width, int height)
		{
			if (mBounds.X == x && mBounds.Y == y &&
				mBounds.Width == width && mBounds.Height == height)
			{
				return;
			}

			Rectangle oldBounds = Bounds;

			mBounds.X      = x;
			mBounds.Y      = y;
			mBounds.Width  = width;
			mBounds.Height = height;

			OnBoundsChanged(new BoundsChangedArgs(oldBounds));
		}

		public void SetBounds(Rectangle bounds)
		{
			SetBounds(bounds.X, bounds.Y, bounds.Width, bounds.Height);
		}

		public void MoveTo(int x, int y)
		{
			if (mBounds.X == x && mBounds.Y == y)
				return;

			SetBounds(x, y, Bounds.Width, Bounds.Height);
		}

		public void ResizeTo(int width, int height)
		{
			if (mBounds.Width == width && mBounds.Height == height)
				return;

			SetBounds(Bounds.X, Bounds.Y, width, height);
		}

		public virtual void Draw(System.Drawing.Graphics g)
		{
		}

		protected void OnVisibilityChanged(System.EventArgs e)
		{
			if (VisibilityChanged != null)
				VisibilityChanged(this, e);
		}

		protected void OnSelectionChanged(System.EventArgs e)
		{
			if (SelectionChanged != null)
				SelectionChanged(this, e);
		}

		protected void OnBoundsChanged(BoundsChangedArgs e)
		{
			if (BoundsChanged != null)
				BoundsChanged(this, e);
		}
	}
}