38 lines
1.1 KiB
Markdown
38 lines
1.1 KiB
Markdown
---
|
|
title: Extensions
|
|
slug: /extensions
|
|
---
|
|
|
|
OSUI Extensions are a practical way to extend the possibilities with OSUI, Extensions allow for there to be a specific use or functionality that may otherwise be bloat or the opposite behavior of the use case.
|
|
|
|
### `screen.extension(&mut self, ext: Extension)`
|
|
|
|
You likely noticed that we used this function in the [Hello World App With Velocity](/docs/0.0.9/#hello-world-app-with-velocity) example, this function simply allows for structures implementing [Extension](/docs/0.0.9/extensions#trait-extension) to be included in the program.
|
|
|
|
---
|
|
|
|
## `Handler<E: Event>`
|
|
|
|
A `Handler` is a `Component` that is called when a specific event is dispatched, typically through a `Extension`.
|
|
|
|
### 📦 Usage
|
|
|
|
```rust
|
|
rsx!{
|
|
@Handler::new(|widget, t: &TickEvent| {}
|
|
"Hello World"
|
|
}
|
|
```
|
|
|
|
---
|
|
|
|
## Trait `Extension`
|
|
|
|
### `init(&mut self, _screen: Arc<Screen>)`
|
|
|
|
Runs right after the Transform component is applied to every widget.
|
|
|
|
### `render(&mut self, _scope: &mut RenderScope, _widget: &Arc<Widget>)`
|
|
|
|
Runs right before the `Element::render` is called.
|