Make Your Vaadin App Smarter, Prettier, and Faster With These Advanced Styling Hacks

This article is part of the series: ‘Towards Vaadin Developer Certification,’ which aims to explain the fundamentals of Vaadin while I study for this certification. The topics covered here are an integral part of the ‘Vaadin Developer’ Certification.

Styling in Vaadin goes beyond simple theme definitions. Some components, like Grid, require dynamic styling. Additionally, fonts and images must be properly managed within the theme folder. This article explores advanced styling techniques.

1. Dynamic Styling in Grid Components

Grids often need row- or cell-specific styles based on data. This can be achieved using part names:

Then, define styles in styles.css:

2. Lazy Loading Stylesheets

If a stylesheet is required only in certain views, it can be loaded dynamically using @StyleSheet:

3. Styling Using Custom Fonts

In Vaadin, custom fonts are treated as static resources, just like images or other assets. While the recommended approach is to leverage Vaadin’s built-in styling options, there are cases where overriding the default Lumo font style is necessary to achieve a unique look for your application.

Below, we will guide you through the process of integrating a custom font into your Vaadin theme.

3.1 Steps to Define a Custom Font

a) Obtain the Font Files

You have two options to acquire the necessary font files:

• Google Fonts: Many fonts are freely available and can be used directly.
• Font Conversion Tools: If you have a .TTF or .OTF font file, use an online tool such as Webfont Generator to convert it into web-friendly formats.

Once converted, the ZIP file will contain:

• .WOFF – Web Open Font Format (recommended for modern browsers)
• .WOFF2 – Optimized version of .WOFF, offering better compression
• stylesheet.css – Defines @font-face rules for the font

b) Add the Font to Your Theme

Inside your project’s theme folder (frontend/themes/your-theme), create a new fonts directory and place the following files inside:

c) Inject the Font into Your Stylesheet

Inside your theme’s global stylesheet (styles.css), import the font definitions:

d) Override Lumo’s Default Font

To apply the custom font across your entire application, override the --lumo-font-family property:

Conclusion

Advanced styling in Vaadin includes dynamic grid styling, lazy-loaded stylesheets, and custom fonts. Mastering these techniques ensures highly customizable and performant applications.

Disclaimer

This content is drawn from studies and notes related to the Vaadin 24 certification. For deeper details, please consult the official documentation and learning materials for Vaadin certification. AI tools assisted in the structuring of this content; however, the writing and original content are solely done by the author.

Authors

Paulo B. A. is an ‘Oracle Certified Java Developer’ and ‘Spring Certified Professional’ with a deep passion for Vaadin Flow. He crafts UIs with Vaadin and strives to make it the leading frontend framework for full-stack Java developers worldwide. He loves teaching, sharing knowledge, and creating content. While he enjoys learning theory through certifications, he always advocates for a practical approach.

• Linkedin.com/in/pbalves
• X.com/p_b_alves
• Mastodon.social/@pbalves

Staff Writer: Fábio A. P. is a technology enthusiast, self-taught writer, and scholar of society’s relationship with technology. Passionate about sharing insights, he provides reliable perspectives on how technology shapes our lives. With clear and precise writing, Fábio simplifies complex topics, empowering readers to navigate the digital age with confidence.