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//---------------------------------------------------------------------------
//
// Copyright (c) Microsoft Corporation. All rights reserved.
//
// Description: Implements services for Drawings including walking, bounding,
// and hit-testing.
//
// History:
//
// 2004/11/19 : timothyc - Created it.
//
//---------------------------------------------------------------------------
using System.Diagnostics;
using System.Windows.Media.Animation;
namespace System.Windows.Media
{
/// <summary>
/// Implements services for Drawings including walking, bounding, and
/// hit-testing.
/// </summary>
internal static class DrawingServices
{
/// <summary>
/// Determines whether or not a point exists in a Drawing
/// </summary>
/// <param name="drawing"> Drawing to hit-test</param>
/// <param name="point"> Point to hit-test for </param>
/// <returns>
/// 'true' if the point exists within the drawing, 'false' otherwise
/// </returns>
internal static bool HitTestPoint(Drawing drawing, Point point)
{
if (drawing != null)
{
HitTestDrawingContextWalker ctx = new HitTestWithPointDrawingContextWalker(point);
drawing.WalkCurrentValue(ctx);
return ctx.IsHit;
}
else
{
return false;
}
}
/// <summary>
/// Hit-tests a Drawing against a PathGeometry
/// </summary>
/// <param name="drawing"> The drawing to hit test against </param>
/// <param name="geometry"> The geometry (in local coordinate space) to hit test. </param>
/// <returns>
/// IntersectionDetail that describes the hit result
/// </returns>
internal static IntersectionDetail HitTestGeometry(Drawing drawing, PathGeometry geometry)
{
if (drawing != null)
{
HitTestDrawingContextWalker ctx =
new HitTestWithGeometryDrawingContextWalker(geometry);
drawing.WalkCurrentValue(ctx);
return ctx.IntersectionDetail;
}
else
{
return IntersectionDetail.Empty;
}
}
/// <summary>
/// Converts a RenderData content representation into a DrawingGroup
/// content representation.
/// </summary>
/// <param name="renderData"> The RenderData to convert </param>
/// <returns>
/// A new DrawingGroup representation that is functionally equivalent to the
/// passed-in RenderData.
/// </returns>
internal static DrawingGroup DrawingGroupFromRenderData(RenderData renderData)
{
//
// Create & open a new DrawingGroup
//
DrawingGroup drawingGroup = new DrawingGroup();
DrawingContext dc = drawingGroup.Open();
//
// Create a DrawingGroup from the RenderData by walking
// the RenderData & having it forward it's base value's
// and animations to DrawingGroup
//
//
// The Drawing tree we're about to produce should not be an inheritance context,
// since that would place all mutable Freezables in the render data into shared
// state, which would in turn case them to lose their inheritance context entirely.
// This is controlled by setting "CanBeInheritanceContext" to false on the
// DrawingContext which will then be applied to all new objects it creates.
//
DrawingDrawingContext ddc = dc as DrawingDrawingContext;
if (ddc != null)
{
ddc.CanBeInheritanceContext = false;
}
DrawingContextDrawingContextWalker walker =
new DrawingContextDrawingContextWalker(dc);
renderData.BaseValueDrawingContextWalk(walker);
//
// Close the DrawingContext & return the new DrawingGroup
//
dc.Close();
return drawingGroup;
}
}
}
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