GUI

GUI support is optional and is gated behind the ui Cargo feature.

Build with GUI support

cargo build --features ui --release

Then run a GUI program with:

eng run examples/25_window_counter.eng --ui

Window

Make a window called app titled "Counter".

Label

Add a label to app labeled "Count: 0".

Button

Add a button to app labeled "Increment".

Text field

The parser also recognizes text fields:

Add a text field to app labeled "Name".

The UI widget declarations are only available in a build with the ui feature.

Button events

When the Increment button is clicked, run increment.

The handler refers to a function by name.

Updating a label

Set the label text of count_label to count.

The UI bridge converts the ENG value to text before updating the label.

Why UI is optional

The default interpreter has no GUI dependency. The ui feature enables eframe and egui, keeping the normal interpreter usable in headless environments such as CI and terminal-only environments.