Class: list_mixin

Description This procedure defines the accelerator keys and properties required to support the standard list-selection options. Assumptions/Preconditions This procedure should only be invoked from within the Construct_Object procedure of a class. Exceptions None. Notes Enumeration_Counter is used to scan selected items. Export_Item_State determines if the value of the selected item in a single-select or auto-select list should be placed into the current item of the object which 'invoked' the list (i.e. the object which had the focus when this object was activated - see Invoking_Object_ID). Invoking_Object_ID is the object id of the object which had the focus when this object was activated. Original_Selection is the item# (if batch) or record number (if virtual) of the item which was selected when the list was activated. Radio_State determines if the items in this list are radio-buttons. Target_Field identifies the field (in the Target_File), if any, which should receive the value of the currently selected item during a save operation (i.e. when the Entry_Update message is received during a save operation). This only applies to single-select or auto-select lists, not multi-select or no-select lists. Target_File identifies the file, if any, which has a field that should receive the value of the currently selected item during a save operation (see Target_Field).

**jjt** public message to init the selected item counter. Enumeration_Counter is too cryptic

See above

Description This procedure accepts the selected item(s) in the list, and surrenders the focus. The incremental-search index is reset. The value of the current item may be exported to the current item of the invoking object, and this object deactivated, if this object is move_value_out_state true, or the focus may be given to the next object in the rotation order. Assumptions/Preconditions This object (or one or its ancestor classes) must understand the Move_Value_Out message as a method of exporting a value, the Request_Cancel message as a method of deactivating this object, and the Next message as a method of rotating to the next focusable object. Exceptions None. Notes Sent by kENTER.

Augment Popup_state to set other (side effect) properties (JJT) This makes more sense than changing deactivating and popup - I still don't like it!!! Better to use Modal_state

Setting popup_state in lists (sel-list, pick-lists) etc must set other prorperties as well. We assume that a list popup is modal, scoped and will export it selection. Note that this does not get called when a popup client is used to contain a list. Usually in that case the block_mouse_state and scope_state should be set at the client while move_value_out_state still must be set in this object.

**JJT** Modified to also set auto_fill_State I don't like this, but it is the best I can come up with. Popup lists that are designed to selection items need to have auto-fill- state set to true. This can not be tied to popup. It is most closely tied to this property. If for some reason you don't want these set together you will need to set auto_fill_state AFTER you set move_value_out_state.

Description This is a stub because for the proper operation of request_cancel. Assumptions/Preconditions None. Exceptions None. Notes None.

Description This function returns the message id to be used to verify an operation which may cause the user to lose changes to the data in items. It is overridden here to return 0 because (popup) lists do not support the verification protocol. Assumptions/Preconditions This object must understand Component_State. Exceptions If this object's Verify_Data_Loss_Msg is 0, the value of this object's parent's Verify_Data_Loss_Msg is returned, if any. Notes None.