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//------------------------------------------------------------------------------
// Microsoft Avalon
// Copyright (c) Microsoft Corporation, 2001
//
// File: DrawingVisual.cs
//------------------------------------------------------------------------------
using System;
using System.Windows.Threading;
using System.Windows.Media;
using System.Windows.Media.Composition;
using System.Diagnostics;
using System.Collections.Generic;
using MS.Internal;
using MS.Win32;
using System.Resources;
using System.Runtime.InteropServices;
namespace System.Windows.Media
{
/// <summary>
/// A DrawingVisual is a Visual that can be used to render Vector graphics on the screen.
/// The content is persistet by the System.
/// </summary>
public class DrawingVisual : ContainerVisual
{
// bbox in inner coordinate space. Note that this bbox does not
// contain the childrens extent.
IDrawingContent _content;
/// <summary>
/// HitTestCore implements precise hit testing against render contents
/// </summary>
protected override HitTestResult HitTestCore(PointHitTestParameters hitTestParameters)
{
if (hitTestParameters == null)
{
throw new ArgumentNullException("hitTestParameters");
}
if (_content != null)
{
if (_content.HitTestPoint(hitTestParameters.HitPoint))
{
return new PointHitTestResult(this, hitTestParameters.HitPoint);
}
}
return null;
}
/// <summary>
/// HitTestCore implements precise hit testing against render contents
/// </summary>
protected override GeometryHitTestResult HitTestCore(GeometryHitTestParameters hitTestParameters)
{
if (hitTestParameters == null)
{
throw new ArgumentNullException("hitTestParameters");
}
if ((_content != null) && GetHitTestBounds().IntersectsWith(hitTestParameters.Bounds))
{
IntersectionDetail intersectionDetail;
intersectionDetail = _content.HitTestGeometry(hitTestParameters.InternalHitGeometry);
Debug.Assert(intersectionDetail != IntersectionDetail.NotCalculated);
if (intersectionDetail != IntersectionDetail.Empty)
{
return new GeometryHitTestResult(this, intersectionDetail);
}
}
return null;
}
/// <summary>
/// Opens the DrawingVisual for rendering. The returned DrawingContext can be used to
/// render into the DrawingVisual.
/// </summary>
public DrawingContext RenderOpen()
{
VerifyAPIReadWrite();
return new VisualDrawingContext(this);
}
/// <summary>
/// Called from the DrawingContext when the DrawingContext is closed.
/// </summary>
internal override void RenderClose(IDrawingContent newContent)
{
IDrawingContent oldContent;
//
// First cleanup the old content and the state associate with this node
// related to it's content.
//
oldContent = _content;
_content = null;
if (oldContent != null)
{
//
// Remove the notification handlers.
//
oldContent.PropagateChangedHandler(ContentsChangedHandler, false /* remove */);
//
// Disconnect the old content from this visual.
//
DisconnectAttachedResource(
VisualProxyFlags.IsContentConnected,
((DUCE.IResource)oldContent));
}
//
// Prepare the new content.
//
if (newContent != null)
{
// Propagate notification handlers.
newContent.PropagateChangedHandler(ContentsChangedHandler, true /* adding */);
}
_content = newContent;
//
// Mark the visual dirty on all channels and propagate
// the flags up the parent chain.
//
SetFlagsOnAllChannels(true, VisualProxyFlags.IsContentDirty);
PropagateFlags(
this,
VisualFlags.IsSubtreeDirtyForPrecompute,
VisualProxyFlags.IsSubtreeDirtyForRender);
}
/// <summary>
/// Overriding this function to release DUCE resources during Dispose and during removal of a subtree.
/// </summary>
internal override void FreeContent(DUCE.Channel channel)
{
Debug.Assert(_proxy.IsOnChannel(channel));
if (_content != null)
{
if (CheckFlagsAnd(channel, VisualProxyFlags.IsContentConnected))
{
DUCE.CompositionNode.SetContent(
_proxy.GetHandle(channel),
DUCE.ResourceHandle.Null,
channel);
SetFlags(
channel,
false,
VisualProxyFlags.IsContentConnected);
((DUCE.IResource)_content).ReleaseOnChannel(channel);
}
}
// Call the base method too
base.FreeContent(channel);
}
/// <summary>
/// Returns the bounding box of the content.
/// </summary>
internal override Rect GetContentBounds()
{
if (_content != null)
{
Rect resultRect = Rect.Empty;
MediaContext mediaContext = MediaContext.From(Dispatcher);
BoundsDrawingContextWalker ctx = mediaContext.AcquireBoundsDrawingContextWalker();
resultRect = _content.GetContentBounds(ctx);
mediaContext.ReleaseBoundsDrawingContextWalker(ctx);
return resultRect;
}
else
{
return Rect.Empty;
}
}
/// <summary>
/// WalkContent - method which walks the content (if present) and calls out to the
/// supplied DrawingContextWalker.
/// </summary>
/// <param name="walker">
/// DrawingContextWalker - the target of the calls which occur during
/// the content walk.
/// </param>
internal void WalkContent(DrawingContextWalker walker)
{
VerifyAPIReadOnly();
if (_content != null)
{
_content.WalkContent(walker);
}
}
/// <summary>
/// RenderContent is implemented by derived classes to hook up their
/// content. The implementer of this function can assert that the _hCompNode
/// is valid on a channel when the function is executed.
/// </summary>
internal override void RenderContent(RenderContext ctx, bool isOnChannel)
{
DUCE.Channel channel = ctx.Channel;
Debug.Assert(!CheckFlagsAnd(channel, VisualProxyFlags.IsContentConnected));
Debug.Assert(_proxy.IsOnChannel(channel));
//
// Create the content on the channel.
//
if (_content != null)
{
DUCE.CompositionNode.SetContent(
_proxy.GetHandle(channel),
((DUCE.IResource)_content).AddRefOnChannel(channel),
channel);
SetFlags(
channel,
true,
VisualProxyFlags.IsContentConnected);
}
else if (isOnChannel) /*_content == null*/
{
DUCE.CompositionNode.SetContent(
_proxy.GetHandle(channel),
DUCE.ResourceHandle.Null,
channel);
}
}
/// <summary>
/// GetDrawing - Returns the drawing content of this Visual.
/// </summary>
/// <remarks>
/// Changes to this DrawingGroup will not be propagated to the Visual's content.
/// This method is called by both the Drawing property, and VisualTreeHelper.GetDrawing()
/// </remarks>
internal override DrawingGroup GetDrawing()
{
//
VerifyAPIReadOnly();
DrawingGroup drawingGroupContent = null;
// Convert our content to a DrawingGroup, if content exists
if (_content != null)
{
drawingGroupContent = DrawingServices.DrawingGroupFromRenderData((RenderData) _content);
}
return drawingGroupContent;
}
/// <summary>
/// Drawing - Returns the drawing content of this Visual.
/// </summary>
/// <remarks>
/// Changes to this DrawingGroup will not propagated to the Visual's content.
/// </remarks>
public DrawingGroup Drawing
{
get
{
return GetDrawing();
}
}
}
}
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