Eclipse Theia 1.45 Release: News and Noteworthy

December 29, 2023 | 6 min Read

We are happy to announce the Eclipse Theia 1.45 release! The release contains 28 merged pull requests and we welcome four new contributors. In this article we will highlight some selected improvements and provide an overview of the latest news around Theia.

For those new to Eclipse Theia, 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.

Starting with the 1.45 release, the Theia project also releases a product, the Theia IDE. The Eclipse Theia IDE is a modern and open IDE for cloud and desktop aimed at end users. The Theia IDE is based on the Theia platform. For more details, see the feature section below.

If you are looking for a simple way to check out the new release, please download and install the Theia IDE, which is based on Theia 1.45.

Eclipse Theia 1.45: Selected features and improvements

In the following, we will highlight some selected improvements in the new release. As usual we cannot mention all 28 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 when applicable.

Theia IDE

Together with Theia 1.45, we are pleased to announce the beta release of the Theia IDE. The Eclipse Theia IDE is a modern and open IDE for cloud and desktop for end users (developers). Obviously, it is based on the solid foundation of the Theia platform. The Theia IDE is available as a downloadable desktop application. Also visit the new Theia IDE homepage for more information.

You can extend the Theia IDE at runtime by installing VS Code extensions, e.g. from the OpenVSX registry, an open marketplace for VS Code extensions. Just open the extension view or browse OpenVSX online.

Your feedback about the Theia IDE is invaluable to us, please report any issues and feature requests. We also invite you to participate in the ongoing development of the Eclipse Theia IDE. You can also try the latest version of the Theia IDE online. The online test version is limited to 30 minutes per session and hosted via Theia Cloud.

You might wonder what happened to Theia Blueprint, which has been published by Theia for over two years as a template IDE. The Eclipse Theia IDE evolves from the earlier Theia Blueprint. It has undergone extensive testing and refinement over several months, demonstrating the commitment and hard work of our community. However, like Theia Blueprint before, the Theia IDE also serves as a template for building custom tools and IDEs. Browse the documentation to help you customize and build your own Eclipse Theia-based product.

VSCode Extension API support up-to-date

As a regular reader of the Theia release announcements, you might have noticed that for nearly half a year, Theia has maintained full compatibility with the VS Code extension API. Therefore it is time to celebrate this continuous achievement! Also check out Mike’s nice article about Theia’s full Compatibility with VS Code Extension API and the story behind it.

In case you don’t know yet, you can use VS Code extensions in Eclipse Theia applications, including the Theia IDE. This enables you to enhance your Theia-based application with a pantheon of features from a huge ecosystem of available extensions available for VS Code, e.g. via the openVSX Registry.

VS Code extensions specify the minimum version of VS Code they require to run to ensure compatibility. The Theia release 1.45 raises the compatibility level to 1.84, which is only one month behind VS Code and allows the vast majority of extensions to be installed in their latest versions. With regular scans of new VS Code API updates, the Theia team keeps up with the latest advancements, continually integrating new features and capabilities.

Secondary Windows - size and position

For over a year, Theia supported detaching views from the main window into secondary windows, particularly for web views and the terminal view. With the 1.45 release, Theia improves the handling of the initial size and position of a secondary window when detaching a view. As shown in the screenshot below, the user can even influence the behavior in the settings by choosing of the following options:

  • originalSize (default): The position and size of the new window will be the same as the original widget that was detached,
  • halfWidth: The position and size of the new window will be half the width of the running Theia application
  • fullSize: The position and size of the new window will be the same size as the running Theia application

Save untitled files to the last active folder

Theia allows you to create new files without even choosing a location yet, e.g. by using “CTRL+N”. This is useful, e.g. to drop some text from the clipboard. When saving the file later, Theia 1.45 improves the usability by preselecting the folder as a default location that was last used/navigated in the file explorer (see screenshot below).

Improvements for adopters and users

The new Theia release contains several improvements for users of the Theia IDE as well as for adopters, i.e. stakeholders which adopt Theia to build their own custom tool or IDE.

Theia 1.45 introduces a new CLI parameter --electronUserData which allows you to explicitly set the Electron userData path. This is for example useful, if you want to run two instances of a Theia application completely separately and with different configurations. Please note that this is not necessary, if you just open two windows of the same application (e.g. using the Theia IDE).

As part of the current initiative to improve the start-up performance of Theia, the 1.45 release does not await the plugin deployment in the backend process anymore when starting the frontend. This further improves the start-up time. In the last months, the Theia start-up time has been reduced by an impressive 40-60%!

Finally we just improved the documentation on the addition of custom Plugin API in the plugin host. As we mentioned above, Theia is compatible with VS Code extensions. However, Theia goes beyond this, you can even extend the plugin API with custom members to support enhanced use cases that would not work in VS Code.

As always the 1.45 release contains much more than described in this article. All these features and improvements (28 improvements in total) are the result of one month of intensive development. Eclipse Theia follows a monthly release schedule. We are looking forward to the next release due next month, 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. Finally, we provide consulting and support for hosting web-based tools in the cloud. 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. …