Creating scrolling text

Flash Lite 1.1 supports the scroll and maxscroll text field properties, which let you create scrolling text fields. The scroll property specifies the first visible line in a text block; you can get and set its value. For example, the following code scrolls the text field whose variable name is story_text down by five lines:

story_text.scroll += 5;

The maxscroll property specifies the first visible line in a text block when the last line of the text is visible in the text block; this property is read-only. You can compare a text field’s maxscroll property to its scroll property to determine how far a user has scrolled within a text field. This is useful if you want to create a scroll bar that provides feedback about the user’s current scroll position relative to the maximum scroll position.

To create a scrolling text field and control it with ActionScript:

  1. In Flash, create a new mobile document.

  2. Using the Text tool, click the Stage, and then drag a text field approximately the size shown in the following image on the Stage:

  3. Select Multiline from the Line type pop-up menu in the Property inspector.

  4. Select Dynamic Text from the Text Type pop-up menu in the Property inspector.

  5. Select Use Device Fonts from the Font rendering method pop-up menu in the Property inspector.

  6. Select Text > Scrollable to make the text field scrollable.

  7. Type story in the Var text box in the Property inspector. This associates the ActionScript variable named story with the text field.

  8. Double-click inside the text field, and enter enough text so that one or more lines of text extend below its lower edge.

  9. Create a new button symbol, and add an instance of it to the Stage or in the area off the Stage.

    This button acts as key catcher button, and it doesn’t need to be visible to the user. For more information about creating key catcher buttons, see Creating a key catcher button.

  10. Select the button, and open the Actions panel (Window > Actions).

  11. Enter the following code in the Actions panel:

    on(keyPress "<Down>") { 
        story.scroll++; 
    } 
    on(keyPress "<Up>") { 
        story.scroll--; 
    }
  12. Select Control > Test Movie to test the application in the Adobe Device Central emulator.

    Press the Up and Down Arrow keys on your keyboard (or the Up and Down buttons on the emulator’s keypad) to scroll the text up or down.

For simplicity, this example lets you enter the text field’s content in the authoring tool. But you can easily modify the example so that the text field’s content is updated using ActionScript. To do this, you would write ActionScript that assigns the desired text to the variable name that you assigned to the multiline text field (story, in this example).

story = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Sed ipsum. Nam tempus. Nullam sed velit eget sem consectetuer tempor. Morbi eleifend venenatis pede. Cras ac lorem eget massa tincidunt iaculis...etc."