//
// System.Drawing.Rectangle.cs
//
// Author:
//   Mike Kestner (mkestner@speakeasy.net)
//
// Copyright (C) 2001 Mike Kestner
// Copyright (C) 2004 Novell, Inc.  http://www.novell.com 
//

//
// Copyright (C) 2004 Novell, Inc (http://www.novell.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
// 
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//

using System;
using System.Runtime.InteropServices;
using System.ComponentModel;

namespace System.Drawing
{
	[Serializable]
	[ComVisible (true)]
	[TypeConverter (typeof (RectangleConverter))]
	public struct Rectangle
	{
		private int x, y, width, height;

		/// <summary>
		///	Empty Shared Field
		/// </summary>
		///
		/// <remarks>
		///	An uninitialized Rectangle Structure.
		/// </remarks>
		
		public static readonly Rectangle Empty;


		/// <summary>
		///	Ceiling Shared Method
		/// </summary>
		///
		/// <remarks>
		///	Produces a Rectangle structure from a RectangleF 
		///	structure by taking the ceiling of the X, Y, Width,
		///	and Height properties.
		/// </remarks>
		
		public static Rectangle Ceiling (RectangleF value)
		{
			int x, y, w, h;
			checked {
				x = (int) Math.Ceiling (value.X);
				y = (int) Math.Ceiling (value.Y);
				w = (int) Math.Ceiling (value.Width);
				h = (int) Math.Ceiling (value.Height);
			}

			return new Rectangle (x, y, w, h);
		}

		/// <summary>
		///	FromLTRB Shared Method
		/// </summary>
		///
		/// <remarks>
		///	Produces a Rectangle structure from left, top, right,
		///	and bottom coordinates.
		/// </remarks>
		
		public static Rectangle FromLTRB (int left, int top,
						  int right, int bottom)
		{
			return new Rectangle (left, top, right - left,
					      bottom - top);
		}

		/// <summary>
		///	Inflate Shared Method
		/// </summary>
		///
		/// <remarks>
		///	Produces a new Rectangle by inflating an existing 
		///	Rectangle by the specified coordinate values.
		/// </remarks>
		
		public static Rectangle Inflate (Rectangle rect, int x, int y)
		{
			Rectangle r = new Rectangle (rect.Location, rect.Size);
			r.Inflate (x, y);
			return r;
		}

		/// <summary>
		///	Inflate Method
		/// </summary>
		///
		/// <remarks>
		///	Inflates the Rectangle by a specified width and height.
		/// </remarks>
		
		public void Inflate (int width, int height)
		{
			Inflate (new Size (width, height));
		}

		/// <summary>
		///	Inflate Method
		/// </summary>
		///
		/// <remarks>
		///	Inflates the Rectangle by a specified Size.
		/// </remarks>
		
		public void Inflate (Size size)
		{
			x -= size.Width;
			y -= size.Height;
			Width += size.Width * 2;
			Height += size.Height * 2;
		}

		/// <summary>
		///	Intersect Shared Method
		/// </summary>
		///
		/// <remarks>
		///	Produces a new Rectangle by intersecting 2 existing 
		///	Rectangles. Returns null if there is no	intersection.
		/// </remarks>
		
		public static Rectangle Intersect (Rectangle a, Rectangle b)
		{
			// MS.NET returns a non-empty rectangle if the two rectangles
			// touch each other
			if (!a.IntersectsWithInclusive (b))
				return Empty;

			return Rectangle.FromLTRB (
				Math.Max (a.Left, b.Left),
				Math.Max (a.Top, b.Top),
				Math.Min (a.Right, b.Right),
				Math.Min (a.Bottom, b.Bottom));
		}

		/// <summary>
		///	Intersect Method
		/// </summary>
		///
		/// <remarks>
		///	Replaces the Rectangle with the intersection of itself
		///	and another Rectangle.
		/// </remarks>
		
		public void Intersect (Rectangle rect)
		{
			this = Rectangle.Intersect (this, rect);
		}

		/// <summary>
		///	Round Shared Method
		/// </summary>
		///
		/// <remarks>
		///	Produces a Rectangle structure from a RectangleF by
		///	rounding the X, Y, Width, and Height properties.
		/// </remarks>
		
		public static Rectangle Round (RectangleF value)
		{
			int x, y, w, h;
			checked {
				x = (int) Math.Round (value.X);
				y = (int) Math.Round (value.Y);
				w = (int) Math.Round (value.Width);
				h = (int) Math.Round (value.Height);
			}

			return new Rectangle (x, y, w, h);
		}

		/// <summary>
		///	Truncate Shared Method
		/// </summary>
		///
		/// <remarks>
		///	Produces a Rectangle structure from a RectangleF by
		///	truncating the X, Y, Width, and Height properties.
		/// </remarks>
		
		// LAMESPEC: Should this be floor, or a pure cast to int?

		public static Rectangle Truncate (RectangleF value)
		{
			int x, y, w, h;
			checked {
				x = (int) value.X;
				y = (int) value.Y;
				w = (int) value.Width;
				h = (int) value.Height;
			}

			return new Rectangle (x, y, w, h);
		}

		/// <summary>
		///	Union Shared Method
		/// </summary>
		///
		/// <remarks>
		///	Produces a new Rectangle from the union of 2 existing 
		///	Rectangles.
		/// </remarks>
		
		public static Rectangle Union (Rectangle a, Rectangle b)
		{
			return FromLTRB (Math.Min (a.Left, b.Left),
					 Math.Min (a.Top, b.Top),
					 Math.Max (a.Right, b.Right),
					 Math.Max (a.Bottom, b.Bottom));
		}

		/// <summary>
		///	Equality Operator
		/// </summary>
		///
		/// <remarks>
		///	Compares two Rectangle objects. The return value is
		///	based on the equivalence of the Location and Size 
		///	properties of the two Rectangles.
		/// </remarks>

		public static bool operator == (Rectangle left, Rectangle right)
		{
			return ((left.Location == right.Location) && 
				(left.Size == right.Size));
		}
		
		/// <summary>
		///	Inequality Operator
		/// </summary>
		///
		/// <remarks>
		///	Compares two Rectangle objects. The return value is
		///	based on the equivalence of the Location and Size 
		///	properties of the two Rectangles.
		/// </remarks>

		public static bool operator != (Rectangle left, Rectangle right)
		{
			return ((left.Location != right.Location) || 
				(left.Size != right.Size));
		}
		

		// -----------------------
		// Public Constructors
		// -----------------------

		/// <summary>
		///	Rectangle Constructor
		/// </summary>
		///
		/// <remarks>
		///	Creates a Rectangle from Point and Size values.
		/// </remarks>
		
		public Rectangle (Point location, Size size)
		{
			x = location.X;
			y = location.Y;
			width = size.Width;
			height = size.Height;
		}

		/// <summary>
		///	Rectangle Constructor
		/// </summary>
		///
		/// <remarks>
		///	Creates a Rectangle from a specified x,y location and
		///	width and height values.
		/// </remarks>
		
		public Rectangle (int x, int y, int width, int height)
		{
			this.x = x;
			this.y = y;
			this.width = width;
			this.height = height;
		}



		/// <summary>
		///	Bottom Property
		/// </summary>
		///
		/// <remarks>
		///	The Y coordinate of the bottom edge of the Rectangle.
		///	Read only.
		/// </remarks>
		
		[Browsable (false)]
		public int Bottom {
			get {
				return y + height;
			}
		}

		/// <summary>
		///	Height Property
		/// </summary>
		///
		/// <remarks>
		///	The Height of the Rectangle.
		/// </remarks>
		
		public int Height {
			get {
				return height;
			}
			set {
				height = value;
			}
		}

		/// <summary>
		///	IsEmpty Property
		/// </summary>
		///
		/// <remarks>
		///	Indicates if the width or height are zero. Read only.
		/// </remarks>		
		[Browsable (false)]
		public bool IsEmpty {
			get {
				return ((x == 0) && (y == 0) && (width == 0) && (height == 0));
			}
		}

		/// <summary>
		///	Left Property
		/// </summary>
		///
		/// <remarks>
		///	The X coordinate of the left edge of the Rectangle.
		///	Read only.
		/// </remarks>
		
		[Browsable (false)]
		public int Left {
			get {
				return X;
			}
		}

		/// <summary>
		///	Location Property
		/// </summary>
		///
		/// <remarks>
		///	The Location of the top-left corner of the Rectangle.
		/// </remarks>
		
		[Browsable (false)]
		public Point Location {
			get {
				return new Point (x, y);
			}
			set {
				x = value.X;
				y = value.Y;
			}
		}

		/// <summary>
		///	Right Property
		/// </summary>
		///
		/// <remarks>
		///	The X coordinate of the right edge of the Rectangle.
		///	Read only.
		/// </remarks>
		
		[Browsable (false)]
		public int Right {
			get {
				return X + Width;
			}
		}

		/// <summary>
		///	Size Property
		/// </summary>
		///
		/// <remarks>
		///	The Size of the Rectangle.
		/// </remarks>
		
		[Browsable (false)]
		public Size Size {
			get {
				return new Size (Width, Height);
			}
			set {
				Width = value.Width;
				Height = value.Height;
			}
		}

		/// <summary>
		///	Top Property
		/// </summary>
		///
		/// <remarks>
		///	The Y coordinate of the top edge of the Rectangle.
		///	Read only.
		/// </remarks>
		
		[Browsable (false)]
		public int Top {
			get {
				return y;
			}
		}

		/// <summary>
		///	Width Property
		/// </summary>
		///
		/// <remarks>
		///	The Width of the Rectangle.
		/// </remarks>
		
		public int Width {
			get {
				return width;
			}
			set {
				width = value;
			}
		}

		/// <summary>
		///	X Property
		/// </summary>
		///
		/// <remarks>
		///	The X coordinate of the Rectangle.
		/// </remarks>
		
		public int X {
			get {
				return x;
			}
			set {
				x = value;
			}
		}

		/// <summary>
		///	Y Property
		/// </summary>
		///
		/// <remarks>
		///	The Y coordinate of the Rectangle.
		/// </remarks>
		
		public int Y {
			get {
				return y;
			}
			set {
				y = value;
			}
		}

		/// <summary>
		///	Contains Method
		/// </summary>
		///
		/// <remarks>
		///	Checks if an x,y coordinate lies within this Rectangle.
		/// </remarks>
		
		public bool Contains (int x, int y)
		{
			return ((x >= Left) && (x < Right) && 
				(y >= Top) && (y < Bottom));
		}

		/// <summary>
		///	Contains Method
		/// </summary>
		///
		/// <remarks>
		///	Checks if a Point lies within this Rectangle.
		/// </remarks>
		
		public bool Contains (Point pt)
		{
			return Contains (pt.X, pt.Y);
		}

		/// <summary>
		///	Contains Method
		/// </summary>
		///
		/// <remarks>
		///	Checks if a Rectangle lies entirely within this 
		///	Rectangle.
		/// </remarks>
		
		public bool Contains (Rectangle rect)
		{
			return (rect == Intersect (this, rect));
		}

		/// <summary>
		///	Equals Method
		/// </summary>
		///
		/// <remarks>
		///	Checks equivalence of this Rectangle and another object.
		/// </remarks>
		
		public override bool Equals (object obj)
		{
			if (!(obj is Rectangle))
				return false;

			return (this == (Rectangle) obj);
		}

		/// <summary>
		///	GetHashCode Method
		/// </summary>
		///
		/// <remarks>
		///	Calculates a hashing value.
		/// </remarks>
		
		public override int GetHashCode ()
		{
			return (height + width) ^ x + y;
		}

		/// <summary>
		///	IntersectsWith Method
		/// </summary>
		///
		/// <remarks>
		///	Checks if a Rectangle intersects with this one.
		/// </remarks>
		
		public bool IntersectsWith (Rectangle rect)
		{
			return !((Left >= rect.Right) || (Right <= rect.Left) ||
			    (Top >= rect.Bottom) || (Bottom <= rect.Top));
		}

		private bool IntersectsWithInclusive (Rectangle r)
		{
			return !((Left > r.Right) || (Right < r.Left) ||
			    (Top > r.Bottom) || (Bottom < r.Top));
		}

		/// <summary>
		///	Offset Method
		/// </summary>
		///
		/// <remarks>
		///	Moves the Rectangle a specified distance.
		/// </remarks>

		public void Offset (int x, int y)
		{
			this.x += x;
			this.y += y;
		}
		
		/// <summary>
		///	Offset Method
		/// </summary>
		///
		/// <remarks>
		///	Moves the Rectangle a specified distance.
		/// </remarks>

		public void Offset (Point pos)
		{
			x += pos.X;
			y += pos.Y;
		}
		
		/// <summary>
		///	ToString Method
		/// </summary>
		///
		/// <remarks>
		///	Formats the Rectangle as a string in (x,y,w,h) notation.
		/// </remarks>
		
		public override string ToString ()
		{
			return String.Format ("{{X={0},Y={1},Width={2},Height={3}}}",
						 x, y, width, height);
		}

	}
}