public AppLogic(IUserInterface ui, AppLogic oldLogic = null) { this.ui = ui; if (oldLogic == null) { this.formulaDatabase = ui.GetDatabase<Formula> (ui.DatabaseLocation + "formula_database.db3"); this.categoryDatabase = ui.GetDatabase<Category> (ui.DatabaseLocation + "category_database.db3"); } else { this.formulaDatabase = oldLogic.formulaDatabase; this.categoryDatabase = oldLogic.categoryDatabase; } }