A safe, lightweight wrapper over libui-ng-sys.
libui is a C library that provides a neutral interface to native GUI technologies (e.g., windows, widgets) on major OSes. libui-ng is the "next generation" of libui, developed and maintained separately. libui-ng-sys provides Rust bindings to libui-ng, and boing is a safe yet fairly unopinionated layer on top of libui-ng-sys.
Currently, boing only links with libui-ng—not the original libui. However, libui-ng-sys may be updated in the future to support a libui feature flag, in which case it should be trivial to update boing as well.
In the context that boing uses them, the terms "widget" and "control" are not interchangeable. A widget is an interactive visual element, while controls are a specific subset of widgets that implement DerefMut<Target = boing::Control>. In particular, all widgets are controls except for Menu and MenuItem.
See DESIGN.md for an explanation of how boing was designed.
boing currently boxes callbacks passed to methods such as Window::on_closing and Button::on_clicked. This incurs a small performance and memory cost. However, this is an intentional choice for the purpose of convenience. For example, if callbacks were instead borrowed rather than owned by a transfer of ownership, the following code would fail to compile:
```rust use boing::{Button, Error, Ui, Window};
fn main() -> Result<(), Error> { let ui: Ui; let window: Window;
let mut button = create_button(&ui, "Hello World!".into())?;
window.set_child(&mut button);
window.show();
ui.run();
Ok(())
}
fn createbutton<'cb>(ui: &Ui, text: &'cb String) -> Result
button.on_clicked(
// This closure is dropped at the end of scope, so its lifetime ends before that of
// `button`. It is not coerced to `fn()` because it captures `text`.
&|| println!("{}", text),
);
button
} ```
In this case, the closure passed to Button::on_clicked would need to be routed through create_button as an argument. Such a hindrance was deemed untenable, hence the current callback design.
| Feature | Docs? | Impl? | libui-ng Type |
| ------------- | ----- | ----- | --------------- |
| Area | ☐ | ☐ | uiArea
| Button | ☐ | ☑ | uiButton
| Checkbox | ☐ | ☑ | uiCheckbox
| Combobox | ☐ | ☐ | uiCombobox
| FontButton | ☐ | ☐ | uiFontButton
| Form | ☐ | ☐ | uiForm
| FormEntry | ☐ | ☐ | uiEntry
| Grid | ☐ | ☐ | uiGrid
| Group | ☐ | ☑ | uiGroup
| Image | ☐ | ☑ | uiImage
| Label | ☐ | ☑ | uiLabel
| Menu | ☐ | ☑ | uiMenu
| MenuItem | ☐ | ☑ | uiMenuItem
| Path | ☐ | ☐ | uiDrawPath
| ProgressBar | ☐ | ☑ | uiProgressBar
| RadioButtons| ☐ | ☐ | uiRadioButtons
| Separator | ☐ | ☐ | uiSeparator
| Slider | ☐ | ☑ | uiSlider
| Spinbox | ☐ | ☑ | uiSpinbox
| Tab | ☐ | ☑ | uiTab
| Table | ☐ | ☐ | uiTable
| UniBox | ☐ | ☑ | uiBox
| Window | ☐ | ☑ | uiWindow