public void RemoveFromSelection(Figure figure)
{
selection.Remove (figure);
figure.SetAttribute (FigureAttribute.Selected, false);
figure.Invalidate ();
}
public void AddToSelection(Figure figure)
{
if (!IsFigureSelected (figure) && Drawing.Includes (figure)) {
selection.Add (figure);
figure.SetAttribute (FigureAttribute.Selected, true);
figure.Invalidate ();
}
}