This Flutter package includes the widget ExpandableText which you can use to initially only show a defined number of lines of a probably long text. The widget appends a configurable text link which let's the user expand the full text, or collapse it again.

Add this to your package's pubspec.yaml file:

dependencies:
  expandable_text: 1.3.2

Next, import the package into your dart code:

import 'package:expandable_text/expandable_text.dart';

Example which shows an expandable text if longText exceeds one line:

Widget build(BuildContext context) {
    return ExpandableText(
        longText,
        expandText: 'show more',
        collapseText: 'show less',
        maxLines: 1,
        linkColor: Colors.blue,
    );
}

• Link to expand the collapsed text (expandText)
• Optional link to collapse the expanded text (collapseText)
• Configure the style of the link (linkStyle / linkColor)
• Control whether the ellipsis is part of the link (linkEllipsis)
• Optional prefix text with style and tap callback (prefixText, prefixStyle, onPrefixTap)
• Configure the number of visible lines of the collapsed text (maxLines)
• Control the default expanded state (expanded)
• Callback for expanded changed event (onExpandedChanged)

Have a bug or a feature request? Please first search for existing and closed issues. If your problem or idea is not addressed yet, please open a new issue.

Code copyright 2020–2021 Florian Weinaug. Code released under the MIT license.