File: System\Windows\Media\DrawingDrawingContext.cs
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Project: src\src\Microsoft.DotNet.Wpf\src\PresentationCore\PresentationCore.csproj (PresentationCore)
// 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.
 
 
//
//
// Description: Creates a Drawing representation of the Draw calls made
//              to this DrawingContext.
//
 
using MS.Internal;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Windows;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Media.Composition;
using System.Windows.Media.Effects;
using System.Windows.Media.Imaging;
using System.Windows.Media.Media3D;
using System.Windows.Threading;
 
using SR=MS.Internal.PresentationCore.SR;
 
namespace System.Windows.Media
{
    /// <summary>
    /// Creates DrawingGroup content to represent the Draw calls made to this DrawingContext
    /// </summary>
    internal class DrawingDrawingContext : DrawingContext
    {
        #region Constructors
 
        /// <summary>
        /// Default DrawingDrawingContext constructor.
        /// </summary>
        internal DrawingDrawingContext()
        {
        }
 
        #endregion Constructors
 
        #region Public Methods
 
        /// <summary>
        ///     DrawLine -
        ///     Draws a line with the specified pen.
        ///     Note that this API does not accept a Brush, as there is no area to fill.
        /// </summary>
        /// <param name="pen"> The Pen with which to stroke the line. </param>
        /// <param name="point0"> The start Point for the line. </param>
        /// <param name="point1"> The end Point for the line. </param>
        public override void DrawLine(
            Pen pen,
            Point point0,
            Point point1)
        {
        #if DEBUG
            MediaTrace.DrawingContextOp.Trace("DrawLine(const)");
        #endif
 
            // Forward call to the animate version with null animations
            DrawLine(pen, point0, null, point1, null);
        }
 
        /// <summary>
        ///     DrawLine -
        ///     Draws a line with the specified pen.
        ///     Note that this API does not accept a Brush, as there is no area to fill.
        /// </summary>
        /// <param name="pen"> The Pen with which to stroke the line. </param>
        /// <param name="point0"> The start Point for the line. </param>
        /// <param name="point0Animations"> Optional AnimationClock for point0. </param>
        /// <param name="point1"> The end Point for the line. </param>
        /// <param name="point1Animations"> Optional AnimationClock for point1. </param>
        public override void DrawLine(
            Pen pen,
            Point point0,
            AnimationClock point0Animations,
            Point point1,
            AnimationClock point1Animations)
        {
        #if DEBUG
            MediaTrace.DrawingContextOp.Trace("DrawLine(animate)");
        #endif
 
            //
            // Verify that parameters & state are valid
            //
 
            VerifyApiNonstructuralChange();
 
            if (pen == null)
            {
                return;
            }
 
            //
            // Create a geometry & add animations if they exist
            //
 
            // Instantiate the geometry
            LineGeometry geometry = new LineGeometry(point0, point1);
 
            //
            // We may need to opt-out of inheritance through the new Freezable.
            // This is controlled by this.CanBeInheritanceContext.
            //
 
            geometry.CanBeInheritanceContext = CanBeInheritanceContext;
 
            // Setup the geometries freezable-related state
            SetupNewFreezable(
                geometry,
                (point0Animations == null) && // Freeze if animations are null
                (point1Animations == null)
                );
 
            // Add animations to the geometry
            if (point0Animations != null)
            {
                geometry.ApplyAnimationClock(LineGeometry.StartPointProperty, point0Animations);
            }
 
            if(point1Animations != null)
            {
                geometry.ApplyAnimationClock(LineGeometry.EndPointProperty, point1Animations);
            }
 
            //
            // Add Drawing to the Drawing graph
            //
 
            AddNewGeometryDrawing(null, pen, geometry);
        }
        /// <summary>
        ///     DrawRectangle -
        ///     Draw a rectangle with the provided Brush and/or Pen.
        ///     If both the Brush and Pen are null this call is a no-op.
        /// </summary>
        /// <param name="brush">
        ///     The Brush with which to fill the rectangle.
        ///     This is optional, and can be null, in which case no fill is performed.
        /// </param>
        /// <param name="pen">
        ///     The Pen with which to stroke the rectangle.
        ///     This is optional, and can be null, in which case no stroke is performed.
        /// </param>
        /// <param name="rectangle"> The Rect to fill and/or stroke. </param>
        public override void DrawRectangle(
            Brush brush,
            Pen pen,
            Rect rectangle)
        {
        #if DEBUG
            MediaTrace.DrawingContextOp.Trace("DrawRectangle(const)");
        #endif
 
            // Forward call to the animate version with null animations
            DrawRectangle(brush, pen, rectangle, null);
        }
 
        /// <summary>
        ///     DrawRectangle -
        ///     Draw a rectangle with the provided Brush and/or Pen.
        ///     If both the Brush and Pen are null this call is a no-op.
        /// </summary>
        /// <param name="brush">
        ///     The Brush with which to fill the rectangle.
        ///     This is optional, and can be null, in which case no fill is performed.
        /// </param>
        /// <param name="pen">
        ///     The Pen with which to stroke the rectangle.
        ///     This is optional, and can be null, in which case no stroke is performed.
        /// </param>
        /// <param name="rectangle"> The Rect to fill and/or stroke. </param>
        /// <param name="rectangleAnimations"> Optional AnimationClock for rectangle. </param>
        public override void DrawRectangle(
            Brush brush,
            Pen pen,
            Rect rectangle,
            AnimationClock rectangleAnimations)
        {
        #if DEBUG
            MediaTrace.DrawingContextOp.Trace("DrawRectangle(animate)");
        #endif
 
            //
            // Verify that parameters & state are valid
            //
 
            VerifyApiNonstructuralChange();
 
            if ((brush == null) && (pen == null))
            {
                return;
            }
 
            //
            // Create a geometry & add animations if they exist
            //
 
            // Instantiate the geometry
            RectangleGeometry geometry = new RectangleGeometry(rectangle);
 
            //
            // We may need to opt-out of inheritance through the new Freezable.
            // This is controlled by this.CanBeInheritanceContext.
            //
 
            geometry.CanBeInheritanceContext = CanBeInheritanceContext;
 
            // Setup the geometries freezable-related state
            SetupNewFreezable(
                geometry,
                (rectangleAnimations == null) // Freeze if there are no animations
                );
 
            // Add animations to the geometry
            if (rectangleAnimations != null)
            {
                geometry.ApplyAnimationClock(RectangleGeometry.RectProperty, rectangleAnimations);
            }
 
            //
            // Add Drawing to the Drawing graph
            //
 
            AddNewGeometryDrawing(brush, pen, geometry);
        }
 
        /// <summary>
        ///     DrawRoundedRectangle -
        ///     Draw a rounded rectangle with the provided Brush and/or Pen.
        ///     If both the Brush and Pen are null this call is a no-op.
        /// </summary>
        /// <param name="brush">
        ///     The Brush with which to fill the rectangle.
        ///     This is optional, and can be null, in which case no fill is performed.
        /// </param>
        /// <param name="pen">
        ///     The Pen with which to stroke the rectangle.
        ///     This is optional, and can be null, in which case no stroke is performed.
        /// </param>
        /// <param name="rectangle"> The Rect to fill and/or stroke. </param>
        /// <param name="radiusX">
        ///     The radius in the X dimension of the rounded corners of this
        ///     rounded Rect.  This value will be clamped to the range [0..rectangle.Width/2]
        /// </param>
        /// <param name="radiusY">
        ///     The radius in the Y dimension of the rounded corners of this
        ///     rounded Rect.  This value will be clamped to the range [0..rectangle.Height/2].
        /// </param>
        public override void DrawRoundedRectangle(
            Brush brush,
            Pen pen,
            Rect rectangle,
            Double radiusX,
            Double radiusY)
        {
        #if DEBUG
            MediaTrace.DrawingContextOp.Trace("DrawRoundedRectangle(const)");
        #endif
 
            // Forward call to the animate version with null animations
            DrawRoundedRectangle(brush, pen, rectangle, null, radiusX, null, radiusY, null);
        }
 
        /// <summary>
        ///     DrawRoundedRectangle -
        ///     Draw a rounded rectangle with the provided Brush and/or Pen.
        ///     If both the Brush and Pen are null this call is a no-op.
        /// </summary>
        /// <param name="brush">
        ///     The Brush with which to fill the rectangle.
        ///     This is optional, and can be null, in which case no fill is performed.
        /// </param>
        /// <param name="pen">
        ///     The Pen with which to stroke the rectangle.
        ///     This is optional, and can be null, in which case no stroke is performed.
        /// </param>
        /// <param name="rectangle"> The Rect to fill and/or stroke. </param>
        /// <param name="rectangleAnimations"> Optional AnimationClock for rectangle. </param>
        /// <param name="radiusX">
        ///     The radius in the X dimension of the rounded corners of this
        ///     rounded Rect.  This value will be clamped to the range [0..rectangle.Width/2]
        /// </param>
        /// <param name="radiusXAnimations"> Optional AnimationClock for radiusX. </param>
        /// <param name="radiusY">
        ///     The radius in the Y dimension of the rounded corners of this
        ///     rounded Rect.  This value will be clamped to the range [0..rectangle.Height/2].
        /// </param>
        /// <param name="radiusYAnimations"> Optional AnimationClock for radiusY. </param>
        public override void DrawRoundedRectangle(
            Brush brush,
            Pen pen,
            Rect rectangle,
            AnimationClock rectangleAnimations,
            Double radiusX,
            AnimationClock radiusXAnimations,
            Double radiusY,
            AnimationClock radiusYAnimations)
        {
        #if DEBUG
            MediaTrace.DrawingContextOp.Trace("DrawRoundedRectangle(animate)");
        #endif
 
            //
            // Verify that parameters & state are valid
            //
 
            VerifyApiNonstructuralChange();
 
            if ((brush == null) && (pen == null))
            {
                return;
            }
 
            //
            // Create a geometry & add animations if they exist
            //
 
            // Instantiate the geometry
            RectangleGeometry geometry = new RectangleGeometry(rectangle, radiusX, radiusY);
 
            //
            // We may need to opt-out of inheritance through the new Freezable.
            // This is controlled by this.CanBeInheritanceContext.
            //
 
            geometry.CanBeInheritanceContext = CanBeInheritanceContext;
 
            // Setup the geometries freezable-related state
            SetupNewFreezable(
                geometry,
                (rectangleAnimations == null) &&    // Freeze if animations are null
                (radiusXAnimations == null) &&
                (radiusYAnimations == null)
                );
 
            // Add animations to the geometry
            if (rectangleAnimations != null)
            {
                geometry.ApplyAnimationClock(RectangleGeometry.RectProperty, rectangleAnimations);
            }
 
            if (radiusXAnimations != null)
            {
                geometry.ApplyAnimationClock(RectangleGeometry.RadiusXProperty, radiusXAnimations);
            }
 
            if (radiusYAnimations != null)
            {
                geometry.ApplyAnimationClock(RectangleGeometry.RadiusYProperty, radiusYAnimations);
            }
 
            //
            // Add Drawing to the Drawing graph
            //
 
            AddNewGeometryDrawing(brush, pen, geometry);
        }
 
        /// <summary>
        ///     DrawEllipse -
        ///     Draw an ellipse with the provided Brush and/or Pen.
        ///     If both the Brush and Pen are null this call is a no-op.
        /// </summary>
        /// <param name="brush">
        ///     The Brush with which to fill the ellipse.
        ///     This is optional, and can be null, in which case no fill is performed.
        /// </param>
        /// <param name="pen">
        ///     The Pen with which to stroke the ellipse.
        ///     This is optional, and can be null, in which case no stroke is performed.
        /// </param>
        /// <param name="center">
        ///     The center of the ellipse to fill and/or stroke.
        /// </param>
        /// <param name="radiusX">
        ///     The radius in the X dimension of the ellipse.
        ///     The absolute value of the radius provided will be used.
        /// </param>
        /// <param name="radiusY">
        ///     The radius in the Y dimension of the ellipse.
        ///     The absolute value of the radius provided will be used.
        /// </param>
        public override void DrawEllipse(
            Brush brush,
            Pen pen,
            Point center,
            Double radiusX,
            Double radiusY)
        {
        #if DEBUG
            MediaTrace.DrawingContextOp.Trace("DrawEllipse(const)");
        #endif
 
            // Forward call to the animate version with null animations
            DrawEllipse(brush, pen, center, null, radiusX, null, radiusY, null);
        }
 
        /// <summary>
        ///     DrawEllipse -
        ///     Draw an ellipse with the provided Brush and/or Pen.
        ///     If both the Brush and Pen are null this call is a no-op.
        /// </summary>
        /// <param name="brush">
        ///     The Brush with which to fill the ellipse.
        ///     This is optional, and can be null, in which case no fill is performed.
        /// </param>
        /// <param name="pen">
        ///     The Pen with which to stroke the ellipse.
        ///     This is optional, and can be null, in which case no stroke is performed.
        /// </param>
        /// <param name="center">
        ///     The center of the ellipse to fill and/or stroke.
        /// </param>
        /// <param name="centerAnimations"> Optional AnimationClock for center. </param>
        /// <param name="radiusX">
        ///     The radius in the X dimension of the ellipse.
        ///     The absolute value of the radius provided will be used.
        /// </param>
        /// <param name="radiusXAnimations"> Optional AnimationClock for radiusX. </param>
        /// <param name="radiusY">
        ///     The radius in the Y dimension of the ellipse.
        ///     The absolute value of the radius provided will be used.
        /// </param>
        /// <param name="radiusYAnimations"> Optional AnimationClock for radiusY. </param>
        public override void DrawEllipse(
            Brush brush,
            Pen pen,
            Point center,
            AnimationClock centerAnimations,
            Double radiusX,
            AnimationClock radiusXAnimations,
            Double radiusY,
            AnimationClock radiusYAnimations)
        {
        #if DEBUG
            MediaTrace.DrawingContextOp.Trace("DrawEllipse(animate)");
        #endif
 
            //
            // Verify that parameters & state are valid
            //
 
            VerifyApiNonstructuralChange();
 
            if ((brush == null) && (pen == null))
            {
                return;
            }
 
            //
            // Create a geometry & add animations if they exist
            //
 
            // Instantiate the geometry
            EllipseGeometry geometry = new EllipseGeometry(center, radiusX, radiusY);
 
            //
            // We may need to opt-out of inheritance through the new Freezable.
            // This is controlled by this.CanBeInheritanceContext.
            //
 
            geometry.CanBeInheritanceContext = CanBeInheritanceContext;
 
            // Setup the geometries freezable-related state
            SetupNewFreezable(
                geometry,
                (centerAnimations == null) && // Freeze if there are no animations
                (radiusXAnimations == null) &&
                (radiusYAnimations == null)
                );
 
            // Add animations to the geometry
            if (centerAnimations != null)
            {
                geometry.ApplyAnimationClock(EllipseGeometry.CenterProperty, centerAnimations);
            }
 
            if (radiusXAnimations != null)
            {
                geometry.ApplyAnimationClock(EllipseGeometry.RadiusXProperty, radiusXAnimations);
            }
 
            if (radiusYAnimations != null)
            {
                geometry.ApplyAnimationClock(EllipseGeometry.RadiusYProperty, radiusYAnimations);
            }
 
            //
            // Add Drawing to the Drawing graph
            //
 
            AddNewGeometryDrawing(brush, pen, geometry);
        }
        /// <summary>
        ///     DrawGeometry -
        ///     Draw a Geometry with the provided Brush and/or Pen.
        ///     If both the Brush and Pen are null this call is a no-op.
        /// </summary>
        /// <param name="brush">
        ///     The Brush with which to fill the Geometry.
        ///     This is optional, and can be null, in which case no fill is performed.
        /// </param>
        /// <param name="pen">
        ///     The Pen with which to stroke the Geometry.
        ///     This is optional, and can be null, in which case no stroke is performed.
        /// </param>
        /// <param name="geometry"> The Geometry to fill and/or stroke. </param>
        public override void DrawGeometry(
            Brush brush,
            Pen pen,
            Geometry geometry)
        {
        #if DEBUG
            MediaTrace.DrawingContextOp.Trace("DrawGeometry(const)");
        #endif
 
            //
            // Create a drawing & add animations if they exist
            //
 
            VerifyApiNonstructuralChange();
 
            if (((brush == null) && (pen == null)) || (geometry == null))
            {
                return;
            }
 
            AddNewGeometryDrawing(brush, pen, geometry);
        }
 
        /// <summary>
        ///     DrawImage -
        ///     Draw an Image into the region specified by the Rect.
        ///     The Image will potentially be stretched and distorted to fit the Rect.
        ///     For more fine grained control, consider filling a Rect with an ImageBrush via
        ///     DrawRectangle.
        /// </summary>
        /// <param name="imageSource"> The ImageSource to draw. </param>
        /// <param name="rectangle">
        ///     The Rect into which the ImageSource will be fit.
        /// </param>
        public override void DrawImage(
            ImageSource imageSource,
            Rect rectangle)
        {
        #if DEBUG
            MediaTrace.DrawingContextOp.Trace("DrawImage(const)");
        #endif
 
            // Forward call to the animate version with null animations
            DrawImage(imageSource, rectangle, null);
        }
 
        /// <summary>
        ///     DrawImage -
        ///     Draw an Image into the region specified by the Rect.
        ///     The Image will potentially be stretched and distorted to fit the Rect.
        ///     For more fine grained control, consider filling a Rect with an ImageBrush via
        ///     DrawRectangle.
        /// </summary>
        /// <param name="imageSource"> The ImageSource to draw. </param>
        /// <param name="rectangle">
        ///     The Rect into which the ImageSource will be fit.
        /// </param>
        /// <param name="rectangleAnimations"> Optional AnimationClock for rectangle. </param>
        public override void DrawImage(
            ImageSource imageSource,
            Rect rectangle,
            AnimationClock rectangleAnimations)
        {
        #if DEBUG
            MediaTrace.DrawingContextOp.Trace("DrawImage(animate)");
        #endif
 
            //
            // Verify that parameters & state are valid
            //
 
            VerifyApiNonstructuralChange();
 
            if (imageSource == null)
            {
                return;
            }
 
            //
            // Create a drawing & add animations if they exist
            //
 
            ImageDrawing imageDrawing = new ImageDrawing();
 
            //
            // We may need to opt-out of inheritance through the new Freezable.
            // This is controlled by this.CanBeInheritanceContext.
            //
 
            imageDrawing.CanBeInheritanceContext = CanBeInheritanceContext;
 
            imageDrawing.ImageSource = imageSource;
            imageDrawing.Rect = rectangle;
 
            SetupNewFreezable(
                imageDrawing,
                (null == rectangleAnimations) && // Freeze if there are no animations
                imageSource.IsFrozen            // and the bitmap source is frozen
                );
 
            if (rectangleAnimations != null)
            {
                imageDrawing.ApplyAnimationClock(ImageDrawing.RectProperty, rectangleAnimations);
            }
 
            AddDrawing(imageDrawing);
        }
        /// <summary>
        ///     DrawDrawing -
        ///     Draw a Drawing.
        ///     For more fine grained control, consider filling a Rect with an DrawingBrush via
        ///     DrawRect.
        /// </summary>
        /// <param name="drawing"> The Drawing to draw. </param>
        public override void DrawDrawing(
            Drawing drawing)
        {
        #if DEBUG
            MediaTrace.DrawingContextOp.Trace("DrawDrawing(const)");
        #endif
 
            //
            // Verify that parameters & state are valid
            //
 
            VerifyApiNonstructuralChange();
 
            if (drawing == null)
            {
                return;
            }
 
            //
            // Add the Drawing to the children collection
            //
 
            AddDrawing(drawing);
        }
 
        /// <summary>
        ///     DrawVideo -
        ///     Draw a Video into the region specified by the Rect.
        ///     The Video will potentially be stretched and distorted to fit the Rect.
        ///     For more fine grained control, consider filling a Rect with an VideoBrush via
        ///     DrawRectangle.
        /// </summary>
        /// <param name="player"> The MediaPlayer to draw. </param>
        /// <param name="rectangle">
        ///     The Rect into which the MediaPlayer will be fit.
        /// </param>
        public override void DrawVideo(
            MediaPlayer player,
            Rect rectangle)
        {
        #if DEBUG
            MediaTrace.DrawingContextOp.Trace("DrawVideo(const)");
        #endif
 
            // Forward to non-animate version with null animations
            DrawVideo(player, rectangle, null);
        }
 
        /// <summary>
        ///     DrawVideo -
        ///     Draw a Video into the region specified by the Rect.
        ///     The Video will potentially be stretched and distorted to fit the Rect.
        ///     For more fine grained control, consider filling a Rect with an VideoBrush via
        ///     DrawRectangle.
        /// </summary>
        /// <param name="player"> The MediaPlayer to draw. </param>
        /// <param name="rectangle">
        ///     The Rect into which the MediaPlayer will be fit.
        /// </param>
        /// <param name="rectangleAnimations"> Optional AnimationClock for rectangle. </param>
        public override void DrawVideo(
            MediaPlayer player,
            Rect rectangle,
            AnimationClock rectangleAnimations)
        {
        #if DEBUG
            MediaTrace.DrawingContextOp.Trace("DrawVideo(animate)");
        #endif
 
            //
            // Verify that parameters & state are valid
            //
 
            VerifyApiNonstructuralChange();
 
            if (player == null)
            {
                return;
            }
 
            //
            // Create a drawing & add animations if they exist
            //
 
            VideoDrawing videoDrawing = new VideoDrawing();
 
            //
            // We may need to opt-out of inheritance through the new Freezable.
            // This is controlled by this.CanBeInheritanceContext.
            //
 
            videoDrawing.CanBeInheritanceContext = CanBeInheritanceContext;
 
            videoDrawing.Player = player;
            videoDrawing.Rect = rectangle;
 
            SetupNewFreezable(
                videoDrawing,
                false   // Don't ever freeze a VideoDrawing because it would
                        // lose it's MediaPlayer
                );
 
            if (rectangleAnimations != null)
            {
                videoDrawing.ApplyAnimationClock(VideoDrawing.RectProperty, rectangleAnimations);
            }
 
            AddDrawing(videoDrawing);
        }
 
        /// <summary>
        ///     PushClip -
        ///     Push a clip region, which will apply to all drawing primitives until the
        ///     corresponding Pop call.
        /// </summary>
        /// <param name="clipGeometry"> The Geometry to which we will clip. </param>
        public override void PushClip(
            Geometry clipGeometry)
        {
        #if DEBUG
            MediaTrace.DrawingContextOp.Trace("PushClip(const)");
        #endif
 
            //
            // Verify that parameters & state are valid
            //
 
            VerifyApiNonstructuralChange();
 
            //
            // Instantiate a new drawing group and set it as the _currentDrawingGroup
            //
 
            PushNewDrawingGroup();
 
            //
            // Set the clip on the new DrawingGroup
            //
 
            _currentDrawingGroup.ClipGeometry = clipGeometry;
        }
 
        public override void PushOpacityMask(Brush brush)
        {
        #if DEBUG
            MediaTrace.DrawingContextOp.Trace("PushOpacityMask(const)");
        #endif
 
            //
            // Verify this object's state
            //
            VerifyApiNonstructuralChange();
 
            //
            // Instantiate a new drawing group and set it as the _currentDrawingGroup
            //
            PushNewDrawingGroup();
 
            //
            // Set the opacity mask
            //
            _currentDrawingGroup.OpacityMask = brush;
        }
 
        /// <summary>
        ///     PushOpacity -
        ///     Push an opacity which will blend the composite of all drawing primitives added
        ///     until the corresponding Pop call.
        /// </summary>
        /// <param name="opacity">
        ///     The opacity with which to blend - 0 is transparent, 1 is opaque.
        /// </param>
        public override void PushOpacity(
            Double opacity
            )
        {
        #if DEBUG
            MediaTrace.DrawingContextOp.Trace("PushOpacity(const)");
        #endif
 
            // Forward to the animate version with null animations
            PushOpacity(opacity, null);
        }
 
        /// <summary>
        ///     PushOpacity -
        ///     Push an opacity which will blend the composite of all drawing primitives added
        ///     until the corresponding Pop call.
        /// </summary>
        /// <param name="opacity">
        ///     The opacity with which to blend - 0 is transparent, 1 is opaque.
        /// </param>
        /// <param name="opacityAnimations"> Optional AnimationClock for opacity. </param>
        public override void PushOpacity(
            Double opacity,
            AnimationClock opacityAnimations)
        {
        #if DEBUG
            MediaTrace.DrawingContextOp.Trace("PushOpacity(animate)");
        #endif
 
            //
            // Verify this object's state
            //
 
            VerifyApiNonstructuralChange();
 
            //
            // Instantiate a new drawing group and set it as the _currentDrawingGroup
            //
 
            PushNewDrawingGroup();
 
            //
            // Set the opacity & opacity animations on the new DrawingGroup
            //
 
            _currentDrawingGroup.Opacity = opacity;
 
            if (null != opacityAnimations)
            {
                _currentDrawingGroup.ApplyAnimationClock(DrawingGroup.OpacityProperty, opacityAnimations);
            }
        }
        /// <summary>
        ///     PushTransform -
        ///     Push a Transform which will apply to all drawing operations until the corresponding
        ///     Pop.
        /// </summary>
        /// <param name="transform"> The Transform to push. </param>
        public override void PushTransform(
            Transform transform)
        {
        #if DEBUG
            MediaTrace.DrawingContextOp.Trace("PushTransform(const)");
        #endif
 
            //
            // Verify that parameters & state are valid
            //
 
            VerifyApiNonstructuralChange();
 
            //
            // Instantiate a new drawing group and set it as the _currentDrawingGroup
            //
 
            PushNewDrawingGroup();
 
            //
            // Set the transform on the new DrawingGroup
            //
 
            _currentDrawingGroup.Transform = transform;
        }
 
        /// <summary>
        ///     PushGuidelineSet -
        ///     Push a set of guidelines which should be applied
        ///     to all drawing operations until the
        ///     corresponding Pop.
        /// </summary>
        /// <param name="guidelines"> The GuidelineSet to push. </param>
        public override void PushGuidelineSet(
            GuidelineSet guidelines)
        {
#if DEBUG
            MediaTrace.DrawingContextOp.Trace("PushGuidelineSet");
#endif
 
            //
            // Verify that parameters & state are valid
            //
 
            VerifyApiNonstructuralChange();
 
            //
            // Instantiate a new drawing group and set it as the _currentDrawingGroup
            //
 
            PushNewDrawingGroup();
 
            //
            // Set the guideline collection on the new DrawingGroup
            //
 
            _currentDrawingGroup.GuidelineSet = guidelines;
        }
 
        /// <summary>
        ///     PushGuidelineY1 -
        ///     Explicitly push one horizontal guideline.
        /// </summary>
        /// <param name="coordinate"> The coordinate of leading guideline. </param>
        internal override void PushGuidelineY1(
            Double coordinate)
        {
#if DEBUG
            MediaTrace.DrawingContextOp.Trace("PushGuidelineY1");
#endif
 
            //
            // Verify that parameters & state are valid
            //
 
            VerifyApiNonstructuralChange();
 
            //
            // Instantiate a new drawing group and set it as the _currentDrawingGroup
            //
 
            PushNewDrawingGroup();
 
            //
            // Convert compact record to generic GuidelineSet.
            //
 
            GuidelineSet guidelineCollection = new GuidelineSet(
                null,                           // x guidelines
                new double[] { coordinate, 0 }, // y guidelines
                true                            // dynamic flag
                );
            guidelineCollection.Freeze();
 
            //
            // Set the guideline collection on the new DrawingGroup
            //
 
            _currentDrawingGroup.GuidelineSet = guidelineCollection;
        }
 
        /// <summary>
        ///     PushGuidelineY2 -
        ///     Explicitly push a pair of horizontal guidelines.
        /// </summary>
        /// <param name="leadingCoordinate"> The coordinate of leading guideline. </param>
        /// <param name="offsetToDrivenCoordinate">
        ///     The offset from leading guideline to driven guideline.
        /// </param>
        internal override void PushGuidelineY2(
            Double leadingCoordinate,
            Double offsetToDrivenCoordinate)
        {
#if DEBUG
            MediaTrace.DrawingContextOp.Trace("PushGuidelineY2");
#endif
 
            //
            // Verify that parameters & state are valid
            //
 
            VerifyApiNonstructuralChange();
 
            //
            // Instantiate a new drawing group and set it as the _currentDrawingGroup
            //
 
            PushNewDrawingGroup();
 
            //
            // Convert compact record to generic GuidelineSet.
            //
 
            GuidelineSet guidelineCollection = new GuidelineSet(
                null,                                   // x guidelines
                new double[]
                    {
                        leadingCoordinate,
                        offsetToDrivenCoordinate
                    }, // y guidelines
                true                                    // dynamic flag
                );
            guidelineCollection.Freeze();
 
            //
            // Set the guideline collection on the new DrawingGroup
            //
 
            _currentDrawingGroup.GuidelineSet = guidelineCollection;
        }
 
        /// <summary>
        ///     PushEffect -
        ///     Push a BitmapEffect which will apply to all drawing operations until the
        ///     corresponding Pop.
        /// </summary>
        /// <param name="effect"> The BitmapEffect to push. </param>
        /// <param name="effectInput"> The BitmapEffectInput. </param>
        [Obsolete(MS.Internal.Media.VisualTreeUtils.BitmapEffectObsoleteMessage)]
        public override void PushEffect(
            BitmapEffect effect,
            BitmapEffectInput effectInput)
        {
#if DEBUG
            MediaTrace.DrawingContextOp.Trace("PushEffect(const)");
#endif
 
            //
            // Verify that parameters & state are valid
            //
 
 
 
            VerifyApiNonstructuralChange();
 
            //
            // Instantiate a new drawing group and set it as the _currentDrawingGroup
            //
 
            PushNewDrawingGroup();
 
            //
            // Set the transform on the new DrawingGroup
            //
            
            // NOTE:Disabling this API for now
            
            _currentDrawingGroup.BitmapEffect = effect;
            _currentDrawingGroup.BitmapEffectInput = (effectInput != null) ?
                                                        effectInput : new BitmapEffectInput();
}
 
        /// <summary>
        /// Pop
        /// </summary>
        public override void Pop()
        {
        #if DEBUG
            MediaTrace.DrawingContextOp.Trace("Pop");
        #endif
 
            VerifyApiNonstructuralChange();
 
            // Verify that Pop hasn't been called too many times
            if ( (_previousDrawingGroupStack == null) ||
                 (_previousDrawingGroupStack.Count == 0))
            {
                throw new InvalidOperationException(SR.DrawingContext_TooManyPops);
            }
 
            // Restore the previous value of the current drawing group
            _currentDrawingGroup = _previousDrawingGroupStack.Pop();
        }
 
        /// <summary>
        /// Draw a GlyphRun.
        /// </summary>
        /// <param name="foregroundBrush">Foreground brush to draw GlyphRun with. </param>
        /// <param name="glyphRun"> The GlyphRun to draw. </param>
        /// <exception cref="ObjectDisposedException">
        /// This call is illegal if this object has already been closed or disposed.
        /// </exception>
        public override void DrawGlyphRun(Brush foregroundBrush, GlyphRun glyphRun)
        {
#if DEBUG
            MediaTrace.DrawingContextOp.Trace("DrawGlyphRun(constant)");
#endif
 
            //
            // Verify that parameters & state are valid
            //
 
            VerifyApiNonstructuralChange();
 
            if (foregroundBrush == null || glyphRun == null)
            {
                return;
            }
 
            // Add a GlyphRunDrawing to the Drawing graph
 
            GlyphRunDrawing glyphRunDrawing = new GlyphRunDrawing();
 
            //
            // We may need to opt-out of inheritance through the new Freezable.
            // This is controlled by this.CanBeInheritanceContext.
            //
 
            glyphRunDrawing.CanBeInheritanceContext = CanBeInheritanceContext;
 
            glyphRunDrawing.ForegroundBrush = foregroundBrush;
            glyphRunDrawing.GlyphRun = glyphRun;
 
            SetupNewFreezable(
                glyphRunDrawing,
                foregroundBrush.IsFrozen
                );
 
            AddDrawing(glyphRunDrawing);
        }
 
        /// <summary>
        /// Dispose() closes this DrawingContext for any further additions, and
        /// returns it's content to the object that created it.
        /// </summary>
        /// <remarks>
        /// Further Draw/Push/Pop calls to this DrawingContext will result in an
        /// exception.  This method also matches any outstanding Push calls with
        /// a cooresponding Pop.  Calling Close after this object has been closed
        /// or Disposed will also result in an exception.
        /// </remarks>
        /// <exception cref="ObjectDisposedException">
        /// This call is illegal if this object has already been Closed.
        /// </exception>
        public override void Close()
        {
            // Throw an exception if this object has already been closed/disposed.
            ObjectDisposedException.ThrowIf(_disposed, typeof(DrawingDrawingContext));
 
            // Close this object
            ((IDisposable)this).Dispose();
        }
 
        /// <summary>
        /// Dispose() closes this DrawingContext for any further additions, and
        /// returns it's content to the object that created it.
        /// </summary>
        /// <remarks>
        /// Further Draw/Push/Pop calls to this DrawingContext will result in an
        /// exception.  This method also matches any outstanding Push calls with
        /// a cooresponding Pop.  Multiple calls to Dispose will not result in
        /// an exception.
        /// </remarks>
        protected override void DisposeCore()
        {
            // Dispose may be called multiple times without throwing
            // an exception.
            if (!_disposed)
            {
                //
                // Match any outstanding Push calls with a Pop
                //
 
                if (_previousDrawingGroupStack != null)
                {
                    int stackCount = _previousDrawingGroupStack.Count;
                    for (int i = 0; i < stackCount; i++)
                    {
                        Pop();
                    }
                }
 
                //
                // Call CloseCore with the root DrawingGroup's children
                //
 
                DrawingCollection rootChildren;
 
                if (_currentDrawingGroup != null)
                 {
                    // If we created a root DrawingGroup because multiple elements
                    // exist at the root level, provide it's Children collection
                    // directly.
                    rootChildren = _currentDrawingGroup.Children;
                }
                else
                {
                    // Create a new DrawingCollection if we didn't create a
                    // root DrawingGroup because the root level only contained
                    // a single child.
                    //
                    // This collection is needed by DrawingGroup.Open because
                    // Open always replaces it's Children collection.  It isn't
                    // strictly needed for Append, but always using a collection
                    // simplifies the TransactionalAppend implementation (i.e.,
                    // a seperate implemention isn't needed for a single element)
                    rootChildren = new DrawingCollection();
 
                    //
                    // We may need to opt-out of inheritance through the new Freezable.
                    // This is controlled by this.CanBeInheritanceContext.
                    //
 
                    rootChildren.CanBeInheritanceContext = CanBeInheritanceContext;
 
                    if (_rootDrawing != null)
                    {
                        rootChildren.Add(_rootDrawing);
                    }
                }
 
                // Inform our derived classes that Close was called
                CloseCore(rootChildren);
 
                _disposed = true;
            }
        }
 
        #endregion Public Methods
 
        #region Protected Methods
 
        /// <summary>
        /// Called during Close/Dispose when the content created this DrawingContext
        /// needs to be committed.
        /// </summary>
        /// <param name="rootDrawingGroupChildren">
        ///     Collection containing the Drawing elements created with this
        ///     DrawingContext.
        /// </param>
        /// <remarks>
        ///     This will only be called once (at most) per instance.
        /// </remarks>
        protected virtual void CloseCore(DrawingCollection rootDrawingGroupChildren)
        {
            // Default implementation is a no-op
        }
 
        /// <summary>
        /// Verifies that the DrawingContext is being referenced from the
        /// appropriate UIContext, and that the object hasn't been disposed
        /// </summary>
        protected override void VerifyApiNonstructuralChange()
        {
            base.VerifyApiNonstructuralChange();
 
            ObjectDisposedException.ThrowIf(_disposed, typeof(DrawingDrawingContext));
        }
 
        #endregion Protected Methods
 
        #region Internal Properties
 
        /// <summary>
        /// Determines whether this DrawingContext should connect inheritance contexts
        /// to DependencyObjects which are passed to its methods.
        /// This property is modeled after DependencyObject.CanBeInheritanceContext.
        /// Defaults to true.
        /// NOTE: This is currently only respected by DrawingDrawingContext and sub-classes.
        /// </summary>
        internal bool CanBeInheritanceContext
        {
            get
            {
                return _canBeInheritanceContext;
            }
 
            set
            {
                _canBeInheritanceContext = value;
            }
        }
 
        #endregion Internal Properties
 
        #region Private Methods
 
        /// <summary>
        /// Freezes the given freezable if the fFreeze flag is true.  Used by
        /// the various drawing methods to freeze resources if there is no
        /// chance the user might attempt to mutate it.
        /// (i.e., there are no animations and the dependant properties are
        /// null or themselves frozen.)
        /// </summary>
        private Freezable SetupNewFreezable(Freezable newFreezable, bool fFreeze)
        {
            if (fFreeze)
            {
                newFreezable.Freeze();
            }
 
            return newFreezable;
        }
 
        /// <summary>
        /// Contains the functionality common to GeometryDrawing operations of
        /// instantiating the GeometryDrawing, setting it's Freezable state,
        /// and Adding it to the Drawing Graph.
        /// </summary>
        private void AddNewGeometryDrawing(Brush brush, Pen pen, Geometry geometry)
        {
            Debug.Assert(geometry != null);
 
            // Instantiate the GeometryDrawing
            GeometryDrawing geometryDrawing = new GeometryDrawing();
 
            //
            // We may need to opt-out of inheritance through the new Freezable.
            // This is controlled by this.CanBeInheritanceContext.
            //
 
            geometryDrawing.CanBeInheritanceContext = CanBeInheritanceContext;
 
            geometryDrawing.Brush = brush;
            geometryDrawing.Pen = pen;
            geometryDrawing.Geometry = geometry;
 
            // Setup it's Freezeable-related state
            SetupNewFreezable(
                geometryDrawing,
                ((brush == null) || (brush.IsFrozen)) &&    // Freeze if the brush is frozen
                ((pen == null) || (pen.IsFrozen)) &&        // and the pen is frozen
                (geometry.IsFrozen)                         // and the geometry is frozen
                );
 
            // Add it to the drawing graph
            AddDrawing(geometryDrawing);
        }
 
        /// <summary>
        /// Creates a new DrawingGroup for a Push* call by setting the
        /// _currentDrawingGroup to a newly instantiated DrawingGroup,
        /// and saving the previous _currentDrawingGroup value on the
        /// _previousDrawingGroupStack.
        /// </summary>
        private void PushNewDrawingGroup()
        {
            // Instantiate a new drawing group
            DrawingGroup drawingGroup = new DrawingGroup();
 
            //
            // We may need to opt-out of inheritance through the new Freezable.
            // This is controlled by this.CanBeInheritanceContext.
            //
 
            drawingGroup.CanBeInheritanceContext = CanBeInheritanceContext;
 
            // Setup it's freezable state
            SetupNewFreezable(
                    drawingGroup,
                    false // Don't freeze, DrawingGroup's may contain unfrozen children/properties
                    );
 
            // Add it to the drawing graph, like any other Drawing
            AddDrawing(drawingGroup);
 
            // Lazily allocate the stack when it is needed because many uses
            // of DrawingDrawingContext will have a depth of one.
            if (null == _previousDrawingGroupStack)
            {
                _previousDrawingGroupStack = new Stack<DrawingGroup>(2);
            }
 
            // Save the previous _currentDrawingGroup value.
            //
            // If this is the first call, the value of _currentDrawingGroup
            // will be null because AddDrawing doesn't create a _currentDrawingGroup
            // for the first drawing.  Having null on the stack is valid, and simply
            // denotes that this new DrawingGroup is the first child in the root
            // DrawingGroup.  It is also possible for the first value on the stack
            // to be non-null, which means that the root DrawingGroup has other
            // children.
            _previousDrawingGroupStack.Push(_currentDrawingGroup);
 
            // Set this drawing group as the current one so that subsequent drawing's
            // are added as it's children until Pop is called.
            _currentDrawingGroup = drawingGroup;
        }
 
        /// <summary>
        /// Adds a new Drawing to the DrawingGraph.
        ///
        /// This method avoids creating a DrawingGroup for the common case
        /// where only a single child exists in the root DrawingGroup.
        /// </summary>
        private void AddDrawing(Drawing newDrawing)
        {
            Debug.Assert(newDrawing != null);
 
            if (_rootDrawing == null)
            {
                // When a DrawingGroup is set, it should be made the root if
                // a root drawing didnt exist.
                Debug.Assert(_currentDrawingGroup == null);
 
                // If this is the first Drawing being added, avoid creating a DrawingGroup
                // and set this drawing as the root drawing.  This optimizes the common
                // case where only a single child exists in the root DrawingGroup.
                _rootDrawing = newDrawing;
            }
            else if (_currentDrawingGroup == null)
            {
                // When the second drawing is added at the root level, set a
                // DrawingGroup as the root and add both drawings to it.
 
                // Instantiate the DrawingGroup
                _currentDrawingGroup = new DrawingGroup();
 
                //
                // We may need to opt-out of inheritance through the new Freezable.
                // This is controlled by this.CanBeInheritanceContext.
                //
 
                _currentDrawingGroup.CanBeInheritanceContext = CanBeInheritanceContext;
 
                SetupNewFreezable(
                    _currentDrawingGroup,
                    false // Don't freeze DrawingGroups, subsequent Draw calls may modify them
                    );
 
                // Add both Children
                _currentDrawingGroup.Children.Add(_rootDrawing);
                _currentDrawingGroup.Children.Add(newDrawing);
 
                // Set the new DrawingGroup as the current
                _rootDrawing = _currentDrawingGroup;
            }
            else
            {
                // If there already is a current drawing group, then simply add
                // the new drawing too it.
                _currentDrawingGroup.Children.Add(newDrawing);
            }
        }
 
        #endregion Private Methods
 
        #region Fields
 
        // Root drawing created by this DrawingContext.
        //
        // If there is only a single child of the root DrawingGroup, _rootDrawing
        // will reference the single child, and the root _currentDrawingGroup
        // value will be null.  Otherwise, _rootDrawing will reference the
        // root DrawingGroup, and be the same value as the root _currentDrawingGroup.
        //
        // Either way, _rootDrawing always references the root drawing.
        protected Drawing _rootDrawing;
 
        // Current DrawingGroup that new children are added to
        protected DrawingGroup _currentDrawingGroup;
 
        // Previous values of _currentDrawingGroup
        private Stack<DrawingGroup> _previousDrawingGroupStack;
 
        // Has Dispose() or Close() been called?
        private bool _disposed;
 
        // Determines whether this DrawingContext should connect inheritance contexts
        // to DependencyObjects which are passed to its methods.
        private bool _canBeInheritanceContext = true;
        #endregion Fields
    }
}