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// 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: The implementation of HitTestWithPointDrawingContextWalker,
// used to perform hit tests with a point on renderdata.
//
//
using System.Windows.Media.Effects;
namespace System.Windows.Media
{
/// <summary>
/// HitTestDrawingContextWalker - a DrawingContextWalker which performs a hit test with a point
/// </summary>
internal class HitTestWithPointDrawingContextWalker: HitTestDrawingContextWalker
{
/// <summary>
/// Constructor
/// </summary>
/// <param name="point"> Point - the point to hit test, in local coordinates. </param>
internal HitTestWithPointDrawingContextWalker(Point point)
{
_point = point;
}
/// <summary>
/// IsHit Property - Returns whether the point hit the drawing instructions.
/// </summary>
internal override bool IsHit
{
get
{
return _contains;
}
}
internal override IntersectionDetail IntersectionDetail
{
get
{
return _contains ? IntersectionDetail.FullyInside : IntersectionDetail.Empty;
}
}
#region Static Drawing Context Methods
/// <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 (IsCurrentLayerNoOp ||(geometry == null) || geometry.IsEmpty())
{
return;
}
if (brush != null)
{
_contains |= geometry.FillContains(_point);
}
// If we have a pen and we haven't yet hit, try the widened geometry.
if ((pen != null) && !_contains)
{
_contains |= geometry.StrokeContains(pen, _point);
}
// If we've hit, stop walking.
if (_contains)
{
StopWalking();
}
}
/// <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 (!IsCurrentLayerNoOp && (glyphRun != null))
{
// The InkBoundingBox + the Origin produce the true InkBoundingBox.
Rect rectangle = glyphRun.ComputeInkBoundingBox();
if (!rectangle.IsEmpty)
{
rectangle.Offset((Vector)glyphRun.BaselineOrigin);
_contains |= rectangle.Contains(_point);
// If we've hit, stop walking.
if (_contains)
{
StopWalking();
}
}
}
}
/// <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 (!IsPushNoOp())
{
PushPointStack(_point);
// If the clip being pushed doesn't contain the hit test point,
// then we don't need to consider any of the subsequent Drawing
// operations in this layer.
if ((clipGeometry != null) && !clipGeometry.FillContains(_point))
{
IsCurrentLayerNoOp = true;
}
}
}
/// <summary>
/// PushOpacityMask -
/// Push an opacity mask
/// </summary>
/// <param name="brush">
/// The opacity mask brush
/// </param>
public override void PushOpacityMask(Brush brush)
{
if (!IsPushNoOp())
{
// This Push doesn't affect the hit test, so just push the current point
PushPointStack(_point);
}
}
/// <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 (!IsPushNoOp())
{
// This Push doesn't affect the hit test, so just push the current point
PushPointStack(_point);
}
}
/// <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 (!IsPushNoOp())
{
if (transform == null || transform.IsIdentity)
{
PushPointStack(_point);
}
else
{
Matrix matrix = transform.Value;
if (matrix.HasInverse)
{
// Invert the transform. The inverse will be applied to the point
// so that hit testing is done in the original geometry's coordinates
matrix.Invert();
// Push the transformed point on the stack. This also updates _point.
PushPointStack(_point * matrix);
}
else
{
// If this transform doesn't have an inverse, then we don't need to consider any
// of the subsequent Drawing operations in this layer.
IsCurrentLayerNoOp = true;
}
}
}
}
/// <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 (!IsPushNoOp())
{
// This Push doesn't affect the hit test, so just push the current point
PushPointStack(_point);
}
}
/// <summary>
/// PushGuidelineY1 -
/// Explicitly push one horizontal guideline.
/// </summary>
/// <param name="coordinate"> The coordinate of leading guideline. </param>
internal override void PushGuidelineY1(
Double coordinate)
{
if (!IsPushNoOp())
{
// This Push doesn't affect the hit test, so just push the current point
PushPointStack(_point);
}
}
/// <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 (!IsPushNoOp())
{
// This Push doesn't affect the hit test, so just push the current point
PushPointStack(_point);
}
}
/// <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 (!IsPushNoOp())
{
// This API has been deprecated, so any BitmapEffect is ignored.
PushPointStack(_point);
}
}
/// <summary>
/// Pop
/// </summary>
public override void Pop(
)
{
if (!IsPopNoOp())
{
PopPointStack();
}
}
#endregion Static Drawing Context Methods
#region Private Methods
/// <summary>
/// PushPointStack - push a point onto the stack and update _point with it.
/// </summary>
/// <param name="point"> The new Point to push. </param>
private void PushPointStack(Point point)
{
if (_pointStack == null)
{
_pointStack = new Stack<Point>(2);
}
// Push the old point.
_pointStack.Push(_point);
// update current point
_point = point;
}
/// <summary>
/// PopPointStack - pop a point off of the point stack and update _point.
/// </summary>
private void PopPointStack()
{
// We must have a point stack and it must not be empty.
Debug.Assert(_pointStack != null);
Debug.Assert(_pointStack.Count > 0);
// Retrieve the previous point from the stack.
_point = _pointStack.Pop();
}
/// <summary>
/// Called by every Push operation, this method returns whether or not
/// the operation should be a no-op. If the current subgraph layer
/// is being no-op'd, it also increments the no-op depth.
/// </summary>
private bool IsPushNoOp()
{
if (IsCurrentLayerNoOp)
{
// Increment the depth so that the no-op status isn't reset
// when this layer's cooresponding Pop is called.
_noOpLayerDepth++;
return true;
}
else
{
return false;
}
}
/// <summary>
/// Called by Pop, this method returns whether or not Pop should be
/// a no-op'd. If the current subgraph layer is being no-op'd, it also
/// decrements the no-op depth, then reset's the no-op status if this
/// is the last Pop in the no-op layer.
/// </summary>
private bool IsPopNoOp()
{
if (IsCurrentLayerNoOp)
{
Debug.Assert(_noOpLayerDepth >= 1);
_noOpLayerDepth--;
// If this Pop cooresponds to the Push that created
// the no-op layer, then reset the no-op status.
if (_noOpLayerDepth == 0)
{
IsCurrentLayerNoOp = false;
}
return true;
}
else
{
return false;
}
}
/// <summary>
/// Set/resets and gets whether or not the current subgraph layer is a no-op.
/// Currently, all subsequent instructions are skipped (no-op'd) when a non-invertible
/// transform is pushed (because we have to invert the matrix to perform
/// a hit-test), or during a point hit-test when a clip is pushed that
/// doesn't contain the point.
/// </summary>
private bool IsCurrentLayerNoOp
{
set
{
if (value == true)
{
// Guard that we aren't already in a no-op layer
//
// Instructions that can cause the layer to be no-op'd should be
// no-op'd themselves, and thus can't call this method, if we
// are already in a no-op layer
Debug.Assert(!_currentLayerIsNoOp);
Debug.Assert(_noOpLayerDepth == 0);
// Set the no-op status & initial depth
_currentLayerIsNoOp = true;
_noOpLayerDepth++;
}
else
{
// Guard that we are in a no-op layer, and that the correct corresponding
// Pop has been called.
Debug.Assert(_currentLayerIsNoOp);
Debug.Assert(_noOpLayerDepth == 0);
// Reset the no-op status
_currentLayerIsNoOp = false;
}
}
get
{
return _currentLayerIsNoOp;
}
}
#endregion Private Methods
#region Private Fields
// If _isPointHitTest is true, this _point is the hit test point.
private Point _point;
// The hit test point transformed to target geometry's original coordinates
private Stack<Point> _pointStack;
// When true, all instructions should be perform no logic until the
// layer is exited via a Pop()
private bool _currentLayerIsNoOp;
// Number of Pop() calls until _currentLayerIsNoOp should be reset.
private int _noOpLayerDepth;
#endregion Private Fields
}
}
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