Eclipse Theia 1.25 Release: News and Noteworthy

May 9, 2022 | 6 min Read

We are happy to announce the Eclipse Theia 1.25 release! This release contains 48 merged pull requests and we welcome eight new contributors. In this article we will highlight some selected improvements and provide an overview of the latest news around Theia.

You don’t know about Eclipse Theia, yet? It is the next-generation platform for building IDEs and tools for the web or desktop, based on modern state-of-the-art web technologies. For more details, please refer to this article and visit the Theia website.

We are happy to welcome new adopters on our website. A personal highlight is VUEngine Studio, a full-featured Nintendo Virtual Boy game development application. They added a screenshot to our gallery of selected tools based on Theia (see also screenshot below). This is a good example of the great variety of tools and IDEs is built upon Theia.

If you adopt Theia and you want to be listed on our website, just follow these instructions. If you want to share a screenshot, just open a PR here. The community is always interested in learning about new adopters and tools!

In April, the second Cloud IDE Days, organized by the Eclipse CloudDev Tools working group took place. Naturally, Eclipse Theia as a next generation platform for cloud IDEs was one of the core and overarching topics. It was amazing to learn about the different use cases and integrations. In case you missed it, here you will find here are all the talk recordings and in particular this talk about getting started with Eclipse Theia.

If you are adopting Eclipse Theia, you might be also interested in this discussion about the frequency of the release cycle. In a nutshell, the community is discussing how the monthly release cycle, a driver of continuous innovation, can potentially be augmented with a less frequent cycle of community releases. Please provide your feedback. Theia is an open community of adopters and contributors, so you can influence the ecosystem by raising an opinion.

In the development month leading up to the 1.25 release, we are happy to welcome eight new contributors, adding up to a total number of 111 active contributors within the last 12 months. Thanks to all the great work from the contributors, Eclipse Theia continues to be one the most active projects at Eclipse.

If you are looking for a simple way to check out the new release, please download Theia Blueprint, which has just been updated to 1.25.

As an adopter, building your own tool based on Eclipse Theia, you will certainly benefit from the added features highlighted below when updating to the new version. Please also check out the release notes and the migration guide.

Further, please continue to ask questions in the community forum and consider filing issues for bugs and features.

Eclipse Theia 1.25: Selected features and improvements

In the following, we will highlight some selected improvements in the new release. As usual we cannot mention all 48 improvements, however we will focus on the most notable changes as well as changes visible to end users. The corresponding pull requests are linked under the respective heading.

Documentation and Project Goals

For the last six months, we have been continuously working on improving the available documentation and the project website. Contributions from several companies and individuals, including STMicroelectronics and EclipseSource puts Theia on a level of being very well documented (confirmed by Checkout the available documentation on the Theia website. For the 1.25 release we added four new sections:

Introduce custom select component

Theia as a platform is ideal if you want to provide custom UI, e.g. in domain-specific views. To implement these custom views, you can use any HTML UI framework of choice, e.g. React. Additionally, Theia as a framework provides some base components, as an example a React Widget, which is already fully integrated with the Theia workbench. With 1.25, Theia introduces support for an extensible select component (provided as a React component). As you can see in the screenshot below, it allows you to, for example, display explanations for the available options in a drop down menu.

Consistent decoration of tree views

By extending Theia via Theia extensions or VS Code extensions, you can decorate tree items. As an example, the Git extension decorates files with local changes. In the Theia 1.25 release, we have extended this decoration to all tree views of the core platform. In the screenshot below, you will see a decorated file in the file explorer, in the list of open editors and in the Git staging view.

Improve tab bar styling

As with every release, Theia 1.25 also refines the look and feel, for example, we introduced a new tab bar styling.  Especially noticeable is the difference in themes with a high contrast, e.g. in the “Github Dark” theme as shown in the following screenshot:

Improved support for VS Code extensions

Eclipse Theia supports running VS Code extensions. This means, you can extend Theia-based applications with the same extensions used for VS Code, too. This leverages the huge ecosystem of VS Code extensions, e.g. available on openVSX. Be aware that Theia also supports a second, more powerful extension mechanism called “Theia extensions”. Please see this comparison between VS Code Extensions and Theia Extensions.

As the VS Code extension API continuously evolves, almost every Theia release also contains new API in this area. For instance, Theia 1.25 provides full support for the accessibility API. As another example, 1.25.0 supports all fields of the status bar, including selected lines (see following screenshot)

Theia 1.25 adds support for complex snippet suggestions, which include a user choice. As shown in the following screenshot, a snippet can not only provide a static text, but also options. When the user of a tool selects a snippet, they can subsequently tab through the available choices and adapt the snippet directly in the code editor.

Improvements for Theia Blueprint

Last, but not least, the new Theia Blueprint version contains all improvements of the 1.25 release and Blueprint specific items such as an improved update flow. You can simply download Theia Blueprint to check out the new release. If you already have Theia Blueprint installed, it will trigger an update automatically

All these features and improvements (in total 48) were the result of one month of intensive development. Eclipse Theia follows a monthly release schedule.We are looking forward to the next release due at the end of May, stay tuned! To be notified about future releases, follow Theia on Twitter and register to our mailing list.

If you are interested in building custom tools or IDEs based on Eclipse Theia, EclipseSource provides consulting and implementation services for Eclipse Theia as well as for web-based tools in general. Furthermore, if you want to extend Theia with features such as the toolbar or the test framework, EclipseSource provides sponsored development for Theia, too. Get in contact with us, to discuss your use case!

Jonas, Maximilian & Philip

Jonas Helming, Maximilian Koegel and Philip Langer co-lead EclipseSource. They work as consultants and software engineers for building web-based and desktop-based tools. …