Creating Interaction with ActionScript > Creating a scrolling text field

Creating a scrolling text field

You can use the scroll and maxscroll properties to create a scrolling text field. To scroll the text, click the buttons in the movie.

In the Text Options panel, you can assign a variable to any text field set to Input Text or Dynamic Text. The text field acts like a window that displays the value of that variable.

Each variable associated with a text field has a scroll and a maxscroll property. You can use these properties to scroll text in a text field. The scroll property returns the number of the topmost visible line in a text field; you can set and retrieve it. The maxscroll property returns the topmost visible line in a text field when the bottom line of text is visible; you can read, but not set, this property.

For example, suppose you have a text field that is four lines long. If it contains the variable speech, that would fill nine lines of the text field, and only part of the speech variable can be displayed at one time (identified by the solid box):

You can access these properties using dot syntax, as in the following:

textFieldVariable.scroll 
myMovieClip.textFieldVariable.scroll
textFieldVariable.maxscroll
myMovieClip.textFieldVariable.maxscroll

To create a scrolling text field:

1 Drag a text field on the Stage.
2 Choose Window > Panels > Text Options.
3 Choose Input Text from the pop-up menu.
4 Enter the variable name text in the Variable field.
5 Drag the text field's bottom right corner to resize the text field.
6 Choose Window > Actions.
7 Select frame 1 in the main Timeline and assign a set variable action that sets the value of text.
No text will appear in the field until the variable is set. Therefore, although you can assign this action to any frame, button, or movie clip, it's a good idea to assign the action to frame 1 on the main Timeline, as shown here:
8 Choose Window > Common Libraries > Buttons, and drag a button to the Stage.
9 Press Alt (Windows) or Option (Macintosh) and drag the button to create a copy.
10 Select the top button and choose Window > Actions.
11 Drag the set variables action from the toolbox to the Script window in the Actions panel.
12 Enter text.scroll in the Variable box.
13 Enter text.scroll -1 in the Value box and select the Expression check box.
14 Select the Down Arrow button and assign the following set variables action:
text.scroll = text.scroll+1;
15 Choose Control > Test Movie to test the scrolling text field.

For more information about the scroll and maxscroll properties, see their entries in the ActionScript Dictionary.