2 Visual Components Manuals

3.2.3.6 ListBox Output Field − Reference
Using this output field, a list of texts can be shown on the screen underneath one another. They can be used
either from a text group or a process variable. A text can be highlighted and selected using a process variable.
If more texts are defined in the text group or the process variable than there is space set in the ListBox output
field, then a corresponding excerpt is displayed. This ensures that the selected highlighted text is always visible.
The ListBox output field doesn't allow user interaction, either from panel keys or touch screen keypads. Thus,
any necessary operations need to be implemented in the application.
General
Summary of the basic properties of these types of output fields.
Function
Data Types
Displays vertically−ordered lists of texts from a text group or from an array of string
variables in a process variable. Highlighting is based on the number index from a
process variable.
The following data types can be displayed for this field:
STRING[][] − optional as the source of the text to be displayed
UINT − Chooses which text should be highlighted.
Availability This field can be used by all systems supported by Visual Components.
Special Features
Appearance
Individual Colors
Special functions:
• Almost any number of texts can be defined during creation in the Visual
Components editor and displayed during runtime (limited by the memory
capacity of the target system).
• Texts can be translated either conveniently in the editor or using external
tools
• Texts can also be provided using a process variable during runtime; in this
case, language−switching must be prepared in the application.
• Any desired operation can be implemented in the application using additional
function keys or touch−operated fields.
• Text groups can be used several times
Texts are output as a vertical list and are either extended to the set length with blank
spaces or shortened if necessary. Because of this, the entire field always appears as
a rectangle.
Special functions:
• Automatic display of the correct text section so that the highlighted text is
always visible in the picture.
• Visible/Invisible switching using the Status process variable
• Selectable foreground and background colors as well as a separate color for
highlighted text.
• Display of incorrect/missing variables (field filled in with hyphens '−')
• Display of invalid values in the index variable (Field filled in with asterisks '*')
• Fully selectable fonts
The following can be individually set for each output field of this type:
• Foreground color (text color)
• Background color
• Foreground color (text color) for highlighted text
• Background color for highlighted text
All colors can either be set in the editor or during runtime using a process variable.
Properties
Introduction to Visual Components 2.3
Output field properties are set under the various tabs of the Properties dialog box. Field properties can be
displayed by double−clicking on the output field in the editor and are automatically shown after a new field is
100 3.2.3.6 ListBox Output Field − Reference