public UIActionState TryPromoteActiveVariation(bool perform)
{
// Find the first move in this variation.
Variation firstMoveInVariation = GetFirstMove(game.ActiveTree.ParentVariation);
if (firstMoveInVariation == null)
{
// Already the main line of the game.
return(UIActionVisibility.Disabled);
}
if (perform)
{
firstMoveInVariation.RepositionBefore(firstMoveInVariation.VariationIndex - 1);
GameUpdated();
}
return(UIActionVisibility.Enabled);
}
