/// <summary>
/// Hides the polygons
/// </summary>
private void OnHideAll(object sender, CommandEventArgs e)
{
_polygonDrawer.ToggleVisibility(false);
}
/// <summary>
/// Hides/Shows one polygon
/// </summary>
private void ToggleVisibility(object sender, CommandEventArgs e)
{
_polygonDrawer.ToggleVisibility();
}