User Guide

Chapter 10290
Controlling scrolling text with Lingo
Lingo can scroll text and determine the location of specific text within the text box for text and
field cast members. For example, this statement sets the scrollTop value for the text cast
member called Discussion to 0, which makes its first line appear at the top of its scrolling field:
(member "Discussion").scrollTop = 0
This procedure can be useful for making a scrolling field automatically scroll back to the top. For
more information on the following properties, see individual entries in the Lingo Dictionary.
• To scroll up or down by a specific number of pages in a text or field cast member, use the
scrollByPage command.
• To scroll up or down by a specific number of lines in a text or field cast member, use the
scrollByLine command.
• To determine the number of lines that appear in a field cast member on the Stage, set the
lineCount cast member property. (This property doesn’t apply to text cast members.)
• To determine a line’s distance from the top edge of a text or field cast member, use the
linePosToLocV() function.
• To determine the number of the line that appears at a specific vertical position in a text or field
cast member, use the
locVToLinePos() function. (This measures the distance from the top of
the cast member, not what appears on the Stage.)
• To determine the point in a text or field cast member that is closest to a specific character, use
the charPosToLoc() function.
• To determine the character that is closest to a specific point in a text or field cast member, use
the locToCharPos() function.
• To check or set the distance from the top of the line that is currently visible to the top of the
box for a scrolling field or text cast member, test or set the scrollTop cast member property.
Checking for specific text with Lingo
The Lingo operators contains and the equals symbol (=) are useful for checking strings. The
contains operator compares two strings to see whether one string contains the other. The equals
symbol operator can determine whether a string is exactly the same as the contents of a field cast
member. Use these operators to check whether a specified string is in a field cast member. See
contains in the Lingo Dictionary.
You can also use Lingo to evaluate strings returned by the
text property of a text or field cast
member. See
text in the Lingo Dictionary.