ImageBrush.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 / ImageBrush.cs / 1 / ImageBrush.cs
                        

                        
                            //---------------------------------------------------------------------------- 
//
// Copyright (c) Microsoft Corporation.  All rights reserved.
//
// Description: This file contains the implementation of ImageBrush. 
//              The ImageBrush is a TileBrush which defines its tile content
//              by use of an ImageSource. 
// 
// History:
// 
// 04/29/2003 : [....] - Created it.
// 01/19/2005 : [....] - Removed SizeViewboxToContent.  Moved UpdateResource
//              to the generated file.
//--------------------------------------------------------------------------- 

using MS.Internal; 
using MS.Internal.PresentationCore; 
using System;
using System.ComponentModel; 
using System.ComponentModel.Design.Serialization;
using System.Diagnostics;
using System.Reflection;
using System.Runtime.InteropServices; 
using System.Windows;
using System.Windows.Media; 
using System.Windows.Media.Animation; 
using System.Windows.Media.Composition;
using System.Windows.Media.Imaging; 

using SR=MS.Internal.PresentationCore.SR;
using SRID=MS.Internal.PresentationCore.SRID;
 
namespace System.Windows.Media
{ 
    ///  
    /// ImageBrush - This TileBrush defines its content as an Image
    ///  
    public sealed partial class ImageBrush : TileBrush
    {
        #region Constructors
 
        /// 
        /// Default constructor for ImageBrush.  The resulting Brush has no content. 
        ///  
        public ImageBrush()
        { 
            // We do this so that the property, when read, is consistent - not that
            // this will every actually affect drawing.
        }
 
        /// 
        /// ImageBrush Constructor where the image is set to the parameter's value 
        ///  
        ///  The image source. 
        public ImageBrush(ImageSource image) 
        {
            ImageSource = image;
        }
 
        #endregion Constructors
 
        #region Protected methods 

        ///  
        /// This node can introduce graphness
        /// 
        internal override bool CanIntroduceGraphness()
        { 
            if (ImageSource == null)
            { 
                // If we don't have an ImageSource, we can't introduce 
                // graphness right now, if we get an image source later
                // we'll precompute again. 
                return false;
            }
            else
            { 
                if (ImageSource.CanIntroduceGraphness())
                { 
                    return true; 
                }
                else 
                {
                    return false;
                }
            } 
        }
 
        ///  
        /// Obtains the current bounds of the brush's content
        ///  
        ///  Output bounds of content 
        protected override void GetContentBounds(out Rect contentBounds)
        {
            // Note, only implemented for DrawingImages. 

            contentBounds = Rect.Empty; 
            DrawingImage di = ImageSource as DrawingImage; 
            if (di != null)
            { 
                Drawing drawing = di.Drawing;
                if (drawing != null)
                {
                    contentBounds = drawing.Bounds; 
                }
            } 
        } 

        #endregion Protected methods 

        #region Realization Support
        /// 
        /// Precompute is called during the frame preparation phase. Derived classes 
        /// typically check if the brush requires realizations during this phase.
        ///  
        internal override void Precompute() 
        {
            ImageSource imageSource = ImageSource; 

            if (imageSource != null)
            {
                imageSource.Precompute(); 
                _requiresRealizationUpdates = imageSource.RequiresRealizationUpdates;
            } 
            else 
            {
                _requiresRealizationUpdates = false; 
            }
        }

        ///  
        /// Checks if realization updates are required for this resource.
        ///  
        internal override bool RequiresRealizationUpdates 
        {
            get { return _requiresRealizationUpdates; } 
        }

        /// 
        /// Derived classes must override this method and update realizations on dependent 
        /// resources if required.
        ///  
        internal override void UpdateRealizations(Rect fillShapeBounds, RealizationContext ctx) 
        {
            if (_requiresRealizationUpdates) 
            {
                Matrix m;
                ImageSource imageSource = ImageSource;
                Debug.Assert(imageSource != null); // Otherwise _requiresRealizationUpdates would be false. 

                GetTileBrushMapping(fillShapeBounds, out m); 
                ctx.TransformStack.Push(ref m, true); 
                imageSource.UpdateRealizations(ctx);
                ctx.TransformStack.Pop(); 
            }
        }
        #endregion
 

        private bool _requiresRealizationUpdates; 
    } 
}

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

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