Kolibri - A GUI framework made to be as lightweight as its namesake

What is Kolibri?

Kolibri is an embedded Immediate Mode GUI mini-framework very strongly inspired by egui.

Current State

Kolibri is maturing at a fast pace. Right now, it already has everything you need for a small, basic application. It's still in alpha tho, so breaking changes are to be expected for now.

If you're interested in contributing, feel free to open an issue or a pull request.

You can also generally find me in the embedded graphics matrix channel if you have any questions.

Implemented and Planned Features

Basic Features

• embedded-graphics based ui rendering
• basic widgets (button, label, checkbox, ...)
• icons
• incremental rendering (only redraw what's actually needed)
• optional buffer-based rendering
• styling

Advanced (and granular)

• layout

  • right-to-left top-to-bottom layout
  • aligns (center, right, bottom, ...)
  • side panels (right)
  • side panels (all sides)
  • layers (e.g. drawing a modal in front of the ui)

• styling

  • Styling System
  • Premade Styles for RGB565
  • Premade Styles for other color types
  • Sub-UIs for editing styles on the fly

• Widgets

  • Button
  • Label
  • Checkbox
  • Icon
  • Spacer
  • IconButton
  • ListBox
  • Something like a ScrollArea
  • ProgressBar
  • Toggle
  • Graph

• performance

  • heap-less if necessary
  • small buffer to draw everything
  • incremental redraws

• input

  • generic input system
  • smartstate-reactive basic widgets
  • custom gestures

Something missing? Add an issue with the features you believe would be good.

Sidenote: What is a Kolibri?

Kolibri is the german word for Hummingbird, which is a small bird that is very fast and agile. There is also an OS with a similar name (KolibriOS), for similar reasons: It is small and fast. This library is in no way associated with the KolibriOS project, but I do encourage you to check it out if you're interested.

Why another GUI framework?

Actually, it's in some ways the first, at least in its very, very specific niche. The embedded-graphics environment is awesome, although fairly low-level. The goal of this library is to make creating simple to somewhat-complex GUIs trivially easy. There is nothing that does this, really, at least at the time of writing this library.

What is this not?

Kolibri is not a high-end GUI framework. It is not meant to be used for creating very complicated or super nice-looking user interfaces. If that's something you're interested in, check out the rust bindings for lvgl or slint (not free for commercial use).

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.