RenderDataDrawingContext.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / DotNET / DotNET / 8.0 / untmp / WIN_WINDOWS / lh_tools_devdiv_wpf / Windows / wcp / Core / System / Windows / Media / RenderDataDrawingContext.cs / 1 / RenderDataDrawingContext.cs
                        

                        
                            //------------------------------------------------------------------------------ 
//  Microsoft Avalon
//  Copyright (c) Microsoft Corporation, 2003
//
//  File:       RenderDataDrawingContext.cs 
//
//  History: 
//      [....]: 04/19/2003 
//          Created it based on the RenderDataDrawingContext used in the AvPhat branch.
//      [....]: 07/02/2003 
//          Renamed to RenderDataDrawingContext, which derives from DrawingContext
//      [....]: 07/02/2003
//          Renamed to RenderDataDrawingContext, which derives from DrawingContext
//          This class no longer understand Visuals, and simply produces RenderData. 
//
//----------------------------------------------------------------------------- 
 
using System;
using System.Collections.Generic; 
using System.Security.Permissions;
using System.Windows;
using System.Windows.Threading;
using System.Windows.Media.Animation; 
using System.Windows.Media;
using System.Windows.Media.Composition; 
using System.Diagnostics; 
using MS.Internal;
using System.Security; 

//-----------------------------------------------------------------------------
// This section lists various things that we could improve on the DrawingContxt
// class. 
//
// - Remove the isAnimated flag from being propagated everywhere. Rather mark 
//   the pail when we add an animated argument. 
//-----------------------------------------------------------------------------
 
namespace System.Windows.Media
{
    /// 
    /// Drawing context. 
    /// 
    internal partial class RenderDataDrawingContext : DrawingContext, IDisposable 
    { 
        #region Constructors
 
        /// 
        /// Creates a drawing context which is associated with a given Dispatcher
        /// 
        internal RenderDataDrawingContext() 
        {
        } 
 
        #endregion Constructors
 
        #region Public Methods

        internal RenderData GetRenderData()
        { 
            return _renderData;
        } 
 
        /// 
        /// Closes the DrawingContext and flushes the content. 
        /// Afterwards the DrawingContext can not be used anymore.
        /// This call does not require all Push calls to have been Popped.
        /// 
        ///  
        /// This call is illegal if this object has already been closed or disposed.
        ///  
        public override void Close() 
        {
            VerifyApiNonstructuralChange(); 

            ((IDisposable)this).Dispose();
        }
        ///  
        /// This is the same as the Close call:
        /// Closes the DrawingContext and flushes the content. 
        /// Afterwards the DrawingContext can not be used anymore. 
        /// This call does not require all Push calls to have been Popped.
        ///  
        /// 
        /// This call is illegal if this object has already been closed or disposed.
        /// 
        protected override void DisposeCore() 
        {
            if (!_disposed) 
            { 
                EnsureCorrectNesting();
                CloseCore(_renderData); 
                _disposed = true;
            }
        }
 

        #endregion Public Methods 
 
        #region Protected Methods
 
        /// 
        /// CloseCore - Implemented be derivees to Close the context.
        /// This will only be called once (if ever) per instance.
        ///  
        ///  The render data produced by this RenderDataDrawingContext.  
        protected virtual void CloseCore(RenderData renderData) {} 
 
        #endregion Protected Methods
 
        #region Private Methods

        /// 
        /// EnsureRenderData - this method ensures that the _renderData variable is initialized. 
        /// The render data's _buffer will be lazily instantiated via the Draw* methods which all
        /// call WriteDataRecord. 
        ///  
        private void EnsureRenderData()
        { 
            if (_renderData == null)
            {
                _renderData = new RenderData();
            } 
        }
 
        ///  
        /// This verifies that the API can be called for access which doesn't affect structure.
        ///  
        protected override void VerifyApiNonstructuralChange()
        {
            base.VerifyApiNonstructuralChange();
 
            if (_disposed)
            { 
                throw new ObjectDisposedException("RenderDataDrawingContext"); 
            }
        } 

        /// 
        /// This method checks if there were any Push calls that were not matched by
        /// the corresponding Pop. If this is the case, this method adds corresponding 
        /// number of Pop instructions to the render data.
        ///  
        private void EnsureCorrectNesting() 
        {
            if (_renderData != null && _stackDepth > 0) 
            {
                int stackDepth = _stackDepth;
                for (int i = 0; i < stackDepth; i++)
                { 
                    Pop();
                } 
            } 

            _stackDepth = 0; 
        }

        #endregion Private Methods
 
        #region Fields
 
        private RenderData _renderData; 
        private bool _disposed;
        private int _stackDepth; 

        #endregion Fields
    }
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.

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