//---------------------------------------------------------------------------
//
// Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// Description: ImageDrawing represents a drawing operation that renders 
//              an image into a destination rectangle.
//
// History:  
//
//  2004/11/17 : timothyc - Created it.
//
//---------------------------------------------------------------------------
 
using System.Diagnostics;
using System.Windows.Media.Imaging;
using MS.Internal;
 
namespace System.Windows.Media
{
    /// <summary>
    /// ImageDrawing represents a drawing operation that renders an image into 
    /// a destination rectangle
    /// </summary>
    public sealed partial class ImageDrawing : Drawing
    {
        #region Constructors
 
        /// <summary>
        /// Default ImageDrawing constructor.  
        /// Constructs an object with all properties set to their default values
        /// </summary>        
        public ImageDrawing()
        {
        }
 
        /// <summary>
        /// Two-argument ImageDrawing constructor.
        /// Constructs an object with the ImageSource and Rect properties
        /// set to the value of their respective arguments.
        /// </summary>        
        public ImageDrawing(ImageSource imageSource, Rect rect)
        {
            ImageSource = imageSource;
            Rect = rect;
        }               
 
        #endregion        
 
        #region Internal methods
 
        /// <summary>
        /// Calls methods on the DrawingContext that are equivalent to the
        /// Drawing with the Drawing's current value.
        /// </summary>        
        internal override void WalkCurrentValue(DrawingContextWalker ctx)
        {     
            // We avoid unneccessary ShouldStopWalking checks based on assumptions
            // about when ShouldStopWalking is set.  Guard that assumption with an
            // assertion.  See DrawingGroup.WalkCurrentValue comment for more details.
           
            ctx.DrawImage(
                ImageSource,
                Rect
                );                      
        }
 
        #endregion Internal methods 
    }
}