Welcome to Open GPUI!

Open GPUI is a hybrid immediate and retained mode, GPU accelerated UI framework for Rust, forked from Zed's GPUI framework code.

Getting Started

Open GPUI is still in active development and is pre-1.0. There will often be breaking changes between versions. You'll also need to use the latest version of stable Rust and be on macOS or Linux. Add the following to your Cargo.toml:

open_gpui = { package = "open-gpui", version = "0.1.0" }
open_gpui_platform = { package = "open-gpui-platform", version = "0.1.0" }

Everything in Open GPUI starts with an Application. You can create one with open_gpui_platform::application(), and kick off your application by passing a callback to Application::run(). Inside this callback, you can create a new window with App::open_window(), and register your first root view.

Dependencies

Open GPUI has various system dependencies that it needs in order to work.

macOS

On macOS, Open GPUI uses Metal for rendering. In order to use Metal, you need to do the following:

Install Xcode from the macOS App Store, or from the Apple Developer website. Note this requires a developer account.

Ensure you launch Xcode after installing, and install the macOS components, which is the default option.

Install Xcode command line tools
```
xcode-select --install
```
Ensure that the Xcode command line tools are using your newly installed copy of Xcode:
```
sudo xcode-select --switch /Applications/Xcode.app/Contents/Developer
```

The Big Picture

Open GPUI offers three different registers depending on your needs:

State management and communication with Entity's. Whenever you need to store application state that communicates between different parts of your application, you'll want to use Open GPUI's entities. Entities are owned by Open GPUI and are only accessible through an owned smart pointer similar to an Rc. See the app::context module for more information.
High level, declarative UI with views. All UI in Open GPUI starts with a view. A view is simply an Entity that can be rendered, by implementing the Render trait. At the start of each frame, Open GPUI will call this render method on the root view of a given window. Views build a tree of elements, lay them out and style them with a tailwind-style API, and then give them to Open GPUI to turn into pixels. See the div element for an all purpose swiss-army knife of rendering.
Low level, imperative UI with Elements. Elements are the building blocks of UI in Open GPUI, and they provide a nice wrapper around an imperative API that provides as much flexibility and control as you need. Elements have total control over how they and their child elements are rendered and can be used for making efficient views into large lists, implement custom layouting for a code editor, and anything else you can think of. See the element module for more information.

Each of these registers has one or more corresponding contexts that can be accessed from all Open GPUI services. This context is your main interface to Open GPUI, and is used extensively throughout the framework.

Other Resources

In addition to the systems above, Open GPUI provides a range of smaller services that are useful for building complex applications:

Actions are user-defined structs that are used for converting keystrokes into logical operations in your UI. Use this for implementing keyboard shortcuts, such as cmd-q. See the action module for more information.
Platform services, such as quit the app or open a URL are available as methods on the app::App.
An async executor that is integrated with the platform's event loop. See the executor module for more information.,
The [open_gpui::test] macro provides a convenient way to write tests for your Open GPUI applications. Tests also have their own kind of context, a TestAppContext which provides ways of simulating common platform input. See app::test_context and test modules for more details.

Currently, the best way to learn about these APIs is to read the Open GPUI examples and the framework source. This repository is a fork of Zed GPUI, but it is maintained as an independent Open GPUI workspace.

License and Attribution

Open GPUI is licensed under Apache-2.0 and is forked from Zed's Apache-2.0 GPUI framework code. See this package's LICENSE-APACHE and NOTICE files for fork attribution, and the repository root README.md for full dependency attribution and release license guidance.