Software
Customisation Guide
Gadget Set : List Gadgets
A list gadget allows the user to make single or multiple selections from many alternatives. The list of choices is scrollable if the list is too long to be displayed all at once.
A LIST gadget is thus appropriate if the user has a long list of choices, or if the user is constructing the list dynamically (at run time), especially if the user cannot predict how many choices there will be.
Typically the user enters text values into the list using an array of strings and assigning to its Dtext member.
As with the option gadget, the list gadget actually contains two parallel lists, of the same length, one containing display values (Dtext) and the other containing replacement values (Rtext).
If the user does not supply the Rtext values they will default to the Dtext values. The Rtext values are often used to assign callback strings to each field of the list.
Resetting a list gadget's display-texts automatically deletes the existing display and replacement-texts and clears any current selections. For example, the contents of gadget List of Figure 21:2.: The tabbed pages of a complex form could be replaced by:
The user can replace the list’s Rtext with a new array of the same length without disturbing the current Dtexts:
The user can use the new Add methods to add a single new entry to be appended to LIST and SELECTOR gadgets:
Where Dtext is the text to be displayed in the option list, and Rtext is the replacement text for the new field.
