pub trait StateMachineChild {
// Required method
fn id(&self) -> Arc<SourceID>;
// Provided methods
fn init(
&self,
driver: &Weak<Driver>,
) -> Result<Box<dyn StateMachineWrapper>, Error> { ... }
fn apply_children(
&self,
_: &mut dyn FnMut(&dyn StateMachineChild) -> Result<()>,
) -> Result<()> { ... }
}Expand description
Represents any potentially stateful component. All components must implement this trait
because all components are tracked by the state manager even if they are stateless. A
derive macro feather_macro::StateMachineChild is provided to make it easier for
stateless components to correctly implement StateMachineChild and correctly propagate
events to their children. It is important that this is done correctly, as a component
can be stateless itself, but have stateful children.
§Examples
use feather_ui::component::ChildOf;
use feather_ui::layout::fixed;
use feather_ui::{ StateMachineChild, SourceID};
use std::sync::Arc;
use std::rc::Rc;
pub struct MyComponent<T> {
pub id: Arc<SourceID>,
pub props: Rc<T>,
pub children: im::Vector<Option<Box<ChildOf<dyn fixed::Prop>>>>,
}
impl<T: Default> StateMachineChild for MyComponent<T> {
fn id(&self) -> std::sync::Arc<SourceID> {
self.id.clone()
}
fn apply_children(
&self,
f: &mut dyn FnMut(&dyn StateMachineChild) -> eyre::Result<()>,
) -> eyre::Result<()> {
self.children
.iter()
.try_for_each(|x| f(x.as_ref().unwrap().as_ref()))
}
}