public object?Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
{
if (values?.Length != 4)
{
return(Binding.DoNothing);
}
if (values[0] is not double ||
values[1] is not double ||
values[2] is not ShadowDepth ||
values[3] is not ShadowEdges)
{
return(Binding.DoNothing);
}
double width = (double)values[0];
double height = (double)values[1];
if (double.IsNaN(width) || double.IsInfinity(width) || double.IsNaN(height) || double.IsInfinity(height))
{
return(Binding.DoNothing);
}
DropShadowEffect?dropShadow = ShadowInfo.GetDropShadow((ShadowDepth)values[2]);
if (dropShadow is null)
{
return(null);
}
ShadowEdges edges = (ShadowEdges)values[3];
double blurRadius = dropShadow.BlurRadius;
var rect = new Rect(0, 0, width, height);
if (edges.HasFlag(ShadowEdges.Left))
{
rect = new Rect(rect.X - blurRadius, rect.Y, rect.Width + blurRadius, rect.Height);
}
if (edges.HasFlag(ShadowEdges.Top))
{
rect = new Rect(rect.X, rect.Y - blurRadius, rect.Width, rect.Height + blurRadius);
}
if (edges.HasFlag(ShadowEdges.Right))
{
rect = new Rect(rect.X, rect.Y, rect.Width + blurRadius, rect.Height);
}
if (edges.HasFlag(ShadowEdges.Bottom))
{
rect = new Rect(rect.X, rect.Y, rect.Width, rect.Height + blurRadius);
}
var size = new GeometryDrawing(new SolidColorBrush(Colors.White), new Pen(), new RectangleGeometry(rect));
return(new DrawingBrush(size)
{
Stretch = Stretch.None,
TileMode = TileMode.None,
Viewport = rect,
ViewportUnits = BrushMappingMode.Absolute,
Viewbox = rect,
ViewboxUnits = BrushMappingMode.Absolute
});
}
public override DropShadowEffect?ConvertValue(ShadowDepth value, Type targetType, object parameter, CultureInfo culture)
{
return(Clone(ShadowInfo.GetDropShadow(value)));
}
