CRY-D / multiline-label

Java Swing component to display multiline plain text.

multiline-label

Java Swing component to display a plain, left-to-right text (single line or multiline). Allows to specify preferred wrapping width (in pixels) for cases when there is not enough room to display the text as a single line.

Motivation: Though standard Swing provides a number of options to display multiline text (e.g. JLabel with HTML, read-only JTextArea, etc.), none of them IMHO is very convenient and straightforward. The goal of this component is to provide a multiline label with predictable and easily configurable behavior.

The label allows to specify custom separator characters (a space character by default). See MultilineLabel.setSeparators. The label always honors line breaks (e.g. \n) if they are present in the text.

The label implements javax.swing.Scrollable interface to support scrolling. By default, up to 20 lines will be displayed without vertical scroll bar. See MultilineLabel.setPreferredViewportLineCount.

The MultilineLabel class provides a number of static methods to support multiline text painting on components other than the MultilineLabel. For example, MultilineLabel.calculatePreferredSize method.

Example:

import javax.swing.border.EmptyBorder;
import java.util.Set;

import io.github.parubok.text.multiline.MultilineLabel;

var label = new MultilineLabel();
label.setText(myText); // set text - possibly requiring multiline presentation
label.setPreferredWidthLimit(330); // the label's preferred width won't exceed 330 pixels
label.setLineSpacing(1.2f); // relative spacing between adjacent text lines
label.setMaxLines(30); // limit the label to 30 lines of text
label.setBorder(new EmptyBorder(10, 5, 10, 5));
label.setSeparators(Set.of(' ', '/', '|', '(', ')')); // allow separators other than space
panel.add(label); // add label to its parent container

A demo application is provided. See io.github.parubok.text.multiline.demo.Demo.

This library is packaged as a Java 9 module io.github.parubok.text.multiline (with a single dependency on a system module java.desktop).

This project has no external dependencies (except JUnit 5, for testing).

Requires Java 11 or later.

License

This project is licensed under Apache License, version 2.0

Installation

Releases are available in Maven Central

Maven

Add this snippet to the pom.xml dependencies section:

<dependency>
    <groupId>io.github.parubok</groupId>
    <artifactId>multiline-label</artifactId>
    <version>1.20</version>
</dependency>