// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
 
namespace System.Windows.Media
{
    /// <summary>
    /// VisualDrawingContext - the DrawingContext for Visuals that can create it.
    /// </summary>
    internal class VisualDrawingContext : RenderDataDrawingContext
    {
        #region Constructors
        
        /// <summary>
        /// Creates a drawing context for a DrawingVisual.
        /// The Visual must not be null.
        /// </summary>
        /// <param name="ownerVisual"> The Visual that created the DrawingContext, which must not be null. </param>
        internal VisualDrawingContext(
            Visual ownerVisual
            )
        {
            Debug.Assert(null != ownerVisual);
 
            _ownerVisual = ownerVisual;
        }
 
        #endregion Constructors
 
        #region Protected Methods
 
        /// <summary>
        /// CloseCore - Implemented be derivees to Close the context.
        /// This will only be called once (if ever) per instance.
        /// </summary>
        /// <param name="renderData"> The render data produced by this RenderDataDrawingContext.  </param>
        protected override void CloseCore(RenderData renderData)
        {
            Debug.Assert(null != _ownerVisual);
                
            _ownerVisual.RenderClose(renderData);
 
#if DEBUG
            _ownerVisual = null;
#endif
        }
 
        #endregion Protected Methods
 
        #region Private Fields
 
        private Visual _ownerVisual; 
 
        #endregion Private Fields
    }
}