The PaletteField class displays a list of values, represented as images, from which the user selects a single value. Because all choices are always displayed, the list should contain few choices.

The valid choices are contained in the ValueList attribute (see ValueList Attribute) from the ChoiceField class. This attribute refers to a ChoiceList object that contains the valid set of values allowed for entry into the field. Each value has text, an associated numeric value, and an image.

You can map PaletteFields to variables of either varchar or integer data type. Regardless of the variable mapping, the palette field always displays the list of choices as images. If you map the field to a varchar variable, the value of the variable is the text of the current choice. If you map the field to an integer variable, the value of the variable is the integer value of the current choice.

Palette fields can be nullable. (You can set nullability in the property sheet using the IsNullable toggle.) If the variable is not nullable, one of the valid settings for the field is always selected. If it is nullable, then the field can be unselected if the user clicks the currently selected value or if you assign null to the variable in the 4GL code.

You can set the choices displayed to the user dynamically. For more information about palette fields, see the Programming Guide.