public static void DrawLines(this IShapeElement shape)
{
if (shape is Canvas)
{
System.Diagnostics.Debug.WriteLine(
$"{shape.Name}-EXTENSION: Drawing lines...");
foreach (var child in shape)
{
if (child is LineElement)
{
child.Draw();
}
}
}
}
public void Add(IShapeElement child)
{
_items.Add(child);
}
public void Remove(IShapeElement child)
{
_items.Remove(child);
}
public void Remove(IShapeElement child)
{
throw new InvalidOperationException("A line doesn't have any children.");
}