euv_ui/hook/lazy/
struct.rs

1use super::*;
2
3/// A lazy component that defers factory invocation until
4/// first access.
5///
6/// Use `LazyComponent::new(factory)` to construct, then
7/// `get()` to read (which triggers the factory on first
8/// call) or `prefetch()` to trigger without reading.
9///
10/// # Why use `Rc<dyn Fn() -> T>`?
11///
12/// Because the factory must be callable multiple times
13/// (e.g. after a `reset()`), and `dyn Fn` lets the user
14/// pass any closure that produces a `T`. The factory is
15/// stored as `Rc<dyn Fn() -> T>` (not `Box<dyn Fn>`) so
16/// `LazyComponent` can be cloned cheaply and shared
17/// between hook contexts.
18#[derive(Clone, Data)]
19pub struct LazyComponent<T: Clone + PartialEq + 'static> {
20    /// The reactive load state.
21    ///
22    /// Public because `ui/tests/lazy/fn.rs` reads it
23    /// through `get_state()`.
24    pub state: Signal<LoadState<T>>,
25    /// The deferred value factory.
26    ///
27    /// `get_factory()` has no caller outside this crate
28    /// (`impl.rs` invokes it internally), so the generated
29    /// getter, mutable getter and setter are all
30    /// `pub(crate)`.
31    #[get(pub(crate))]
32    #[get_mut(pub(crate))]
33    #[set(pub(crate))]
34    pub(crate) factory: Rc<dyn Fn() -> T>,
35}
euv_ui/hook/lazy/struct.rs

euv_ui/hook/lazy/
struct.rs
