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use crate::html::Scope;
use crate::{html, Callback, Children, Component, Context, Html, Properties};
use slab::Slab;
use std::cell::RefCell;
#[derive(Debug, Clone, PartialEq, Properties)]
pub struct ContextProviderProps<T: Clone + PartialEq> {
pub context: T,
pub children: Children,
}
#[derive(Debug)]
pub struct ContextProvider<T: Clone + PartialEq + 'static> {
context: T,
children: Children,
consumers: RefCell<Slab<Callback<T>>>,
}
#[derive(Debug)]
pub struct ContextHandle<T: Clone + PartialEq + 'static> {
provider: Scope<ContextProvider<T>>,
key: usize,
}
impl<T: Clone + PartialEq + 'static> Drop for ContextHandle<T> {
fn drop(&mut self) {
if let Some(component) = self.provider.get_component() {
component.consumers.borrow_mut().remove(self.key);
}
}
}
impl<T: Clone + PartialEq> ContextProvider<T> {
pub(crate) fn subscribe_consumer(
&self,
callback: Callback<T>,
scope: Scope<Self>,
) -> (T, ContextHandle<T>) {
let ctx = self.context.clone();
let key = self.consumers.borrow_mut().insert(callback);
(
ctx,
ContextHandle {
provider: scope,
key,
},
)
}
fn notify_consumers(&mut self) {
let consumers: Vec<Callback<T>> = self
.consumers
.borrow()
.iter()
.map(|(_, v)| v.clone())
.collect();
for consumer in consumers {
consumer.emit(self.context.clone());
}
}
}
impl<T: Clone + PartialEq + 'static> Component for ContextProvider<T> {
type Message = ();
type Properties = ContextProviderProps<T>;
fn create(ctx: &Context<Self>) -> Self {
let props = ctx.props();
Self {
children: props.children.clone(),
context: props.context.clone(),
consumers: RefCell::new(Slab::new()),
}
}
fn changed(&mut self, ctx: &Context<Self>) -> bool {
let props = ctx.props();
let should_render = if self.children == props.children {
false
} else {
self.children = props.children.clone();
true
};
if self.context != props.context {
self.context = props.context.clone();
self.notify_consumers();
}
should_render
}
fn view(&self, _ctx: &Context<Self>) -> Html {
html! { <>{ self.children.clone() }</> }
}
}