void Start()
        {
            hotkeysInputMode = HotkeysInputType.Default;

            Selection.productionUnitSelected += OnProductionSelected;
            Selection.selectionCleared       += OnClearSelection;
        }
 void OnClearSelection()
 {
     hotkeysInputMode = HotkeysInputType.Default;
 }
 void OnProductionSelected(Production production)
 {
     hotkeysInputMode = HotkeysInputType.Building;
 }