Lightweight Python UI runtime inspired by Pythonista.ui

[o-murphy]

HI there!

I'm trying to develop a lightweight UI toolkit that aims to be
conceptually compatible with Pythonista.ui public API.

Highlights:

• Uses custom python+rust based runtime emulation of original drawing context
• Displaying windows and handling input devices (mouse and touch, keyboard in the future) possible with sdl or winit+softbuffer
• Aims to have shim to make it possible use in the native Pythonista.ui
• Aims to simulate UIKit controls with smooth animations
• TTF fonts support

The main idea is to create the ability to develop graphical applications for Pythonista on a non-Mac PC, and as a side-effect have very simple softbuffer-based gui framework for systems like RaspberryPi
Contributions and feedback are welcome.

The bellow is a proof that same ui app example be launched on linux and on Pythonista.ui

_20260222_180135.webm

pytoui_ios.mp4

[o-murphy]

update

I got same fonts drawing behavior on both platforms Pythonista and PC

[o-murphy]

@omz Can i get more info about ui module? I'm not asking about internal sources, I just ask about public class/methods signatures that is not fully declared in docs and examples

[o-murphy]

update

• Seems like I fixed flex issues
• Also I did refactor a View props to protect it from direct change, that makes my View behave much more like original ones and simplifies inheritance. It also guarantees the Children views will have same attributes with no explicit super().init().

I did added few examples that work on PC same as on Pythonista app
I still have issues with init args/kwargs. The inspect isn't work, so I spend a lot of time to resolve it to be able to run some examples from the Pythonista app for behavior testing. I wanna complete some things before I'll continue to implement other views like scrollview and textedit, etc.

[o-murphy]

update

• I did internal view logic incapsulation, to make it's public interface looks much more native for the Pythonista.ui.
• Fixed Rect.inset() behaviour
• I work on Path.add_clip(), not works as needed so some of my custom views drawing unexpected

[o-murphy]

update

• I almost done with all common mouse gestures like clicks drags wheel scroll
  • proposes custom pc-only handlers for mouse_down / dragged / up / move / scroll events are supported, left / right / wheel button IDs too
  • if no custom mouse handlers defined for a view -> commonevents like clicks and drags will be redirected to touch_began / move / end handlers
• added: default fonts collection, mapping and resolver from tags like <system>, .SFUI
• some animate fixes
• fix: mouse wheel scroll resolution for winit and sdl

[o-murphy]

update!

• I got first complete build of binary wheels that can be installed with uv/pip
  https://github.com/o-murphy/pytoui/actions/runs/22502655519#artifacts
• README now contains the command to get it on Pythonista and also it loads examples that can be launched right there

[o-murphy]

update

• add: Hot-keys support
• factor: Refactored HID constants
• attempt to make compatible ScrollView implementation

[o-murphy]

update

• HiDPI scaling fix for winit
• basic ScrollView implemented with fallback to native one

[jinwandalaohu66]

• • Can I try it with my app？

[o-murphy]

Yes. In the README you can read the way how to install it, but be careful, I make some fixes right now

[jinwandalaohu66]

https://apps.apple.com/cn/app/python-ide/id6753987304

[jinwandalaohu66]

Can I try it with my app?

[o-murphy]

I don't think it would be simple, due to requirements

• On Pythonista, the GUI runtime uses: pythonista.ui and pythonista.objc_util modules, which are wrappers for the native iOS UIKit API
• On PC, a custom compiled GUI runtime based on Rust
  • tiny-skia + fontdue based engine for rendering
  • pysdl2/winit+softbuffer for OS windowing and HID support

But due to pytoui is modular (backend/runtime can be replaced) you able to add support in few ways

• embedding (compile-time)
  • you can embed my pytoui/deps/osdbuf engine into your app
  • you can implement your own runtime for displaying GUI and handle HID
• otherwice you can try to recreate Pythonista.ui or compatible UIKit wrappers in your environment
  this is that what I try to do for PC is simulate Pythonista.ui and partially UIKit

[o-murphy]

P.S.: the winit, tiny-skia and fontdue are fully compilable for iOS/MacOS (darwin) arm64 arch

[o-murphy]

update

• CALayers simulation
• DatePicker view
• Some heavy calculations moved to rust
• Touches bubbling
• Tint-color propagation
• Updated some animations