internal void EnsureRenderedGeometry()
{
if (_renderedGeometry == null)
{
_renderedGeometry = DefiningGeometry;
Debug.Assert(_renderedGeometry != null);
if (Stretch != Stretch.None)
{
Geometry currentValue = _renderedGeometry.CloneCurrentValue();
if (Object.ReferenceEquals(_renderedGeometry, currentValue))
{
_renderedGeometry = currentValue.Clone();
}
else
{
_renderedGeometry = currentValue;
}
Transform renderedTransform = _renderedGeometry.Transform;
BoxedMatrix boxedStretchMatrix = StretchMatrixField.GetValue(this);
Matrix stretchMatrix = (boxedStretchMatrix == null) ? Matrix.Identity : boxedStretchMatrix.Value;
if (renderedTransform == null || renderedTransform.IsIdentity)
{
_renderedGeometry.Transform = new MatrixTransform(stretchMatrix);
}
else
{
_renderedGeometry.Transform = new MatrixTransform(renderedTransform.Value * stretchMatrix);
}
}
}
}
/// <summary>
/// Compute the rendered geometry and the stretching transform.
/// </summary>
protected override Size ArrangeOverride(Size finalSize)
{
Size newSize;
Stretch mode = Stretch;
if (mode == Stretch.None)
{
StretchMatrixField.ClearValue(this);
ResetRenderedGeometry();
newSize = finalSize;
}
else
{
newSize = GetStretchedRenderSizeAndSetStretchMatrix(
mode, GetStrokeThickness(), finalSize, GetDefiningGeometryBounds());
}
if (SizeIsInvalidOrEmpty(newSize))
{
// We've encountered a numerical error. Don't draw anything.
newSize = new Size(0, 0);
_renderedGeometry = Geometry.Empty;
}
return(newSize);
}
internal Size GetStretchedRenderSizeAndSetStretchMatrix(Stretch mode, double strokeThickness, Size availableSize, Rect geometryBounds)
{
double xScale, yScale, dX, dY;
Size renderSize;
GetStretchMetrics(mode, strokeThickness, availableSize, geometryBounds,
out xScale, out yScale, out dX, out dY, out renderSize);
// Construct the matrix
Matrix stretchMatrix = Matrix.Identity;
stretchMatrix.ScaleAt(xScale, yScale, geometryBounds.Location.X, geometryBounds.Location.Y);
stretchMatrix.Translate(dX, dY);
StretchMatrixField.SetValue(this, new BoxedMatrix(stretchMatrix));
ResetRenderedGeometry();
return(renderSize);
}
