| Developing a User Interface > Custom Editing and Lookup > Modal Editing |
It may be necessary to implement editing of some constants with a special menu, dialog or modal form. In this case, the user cannot leave the constant being edited until the editing is done, the dialog or menu closed. This is called modal editing.
Modal editing can be implemented in the BeforeEdit and EndEdit event procedures. There is no need in other events, because in this case the editing process as such does not take place. Upon return from the user code (dialog, menu, and so on), the constant’s value and text are immediately changed and the editing process ends.
To implement modal editing, write your code in the BeforeEdit event, open a dialog, menu, and so on. Before leaving the BeforeEdit code, you set the ModalEditing argument to True. In the EndEdit event, set the Value and ValueText arguments to, respectively, the value entered by the user and its display (string) representation.