script/
routed_promise.rs

1/* This Source Code Form is subject to the terms of the Mozilla Public
2 * License, v. 2.0. If a copy of the MPL was not distributed with this
3 * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
4
5use std::rc::Rc;
6
7use js::context::JSContext;
8use serde::Serialize;
9use serde::de::DeserializeOwned;
10use servo_base::generic_channel::GenericCallback;
11
12use crate::dom::bindings::refcounted::{Trusted, TrustedPromise};
13use crate::dom::bindings::reflector::DomObject;
14use crate::dom::promise::Promise;
15use crate::task_source::TaskSource;
16
17pub(crate) trait RoutedPromiseListener<R: Serialize + DeserializeOwned + Send> {
18    fn handle_response(&self, cx: &mut JSContext, response: R, promise: &Rc<Promise>);
19}
20
21pub(crate) struct RoutedPromiseContext<
22    R: Serialize + DeserializeOwned + Send,
23    T: RoutedPromiseListener<R> + DomObject,
24> {
25    trusted: TrustedPromise,
26    receiver: Trusted<T>,
27    _phantom: std::marker::PhantomData<R>,
28}
29
30impl<R: Serialize + DeserializeOwned + Send, T: RoutedPromiseListener<R> + DomObject>
31    RoutedPromiseContext<R, T>
32{
33    fn response(self, cx: &mut JSContext, response: R) {
34        let promise = self.trusted.root();
35        self.receiver.root().handle_response(cx, response, &promise);
36    }
37}
38
39pub(crate) fn callback_promise<
40    R: Serialize + DeserializeOwned + Send + 'static,
41    T: RoutedPromiseListener<R> + DomObject + 'static,
42>(
43    promise: &Rc<Promise>,
44    receiver: &T,
45    task_source: TaskSource,
46) -> GenericCallback<R> {
47    let task_source = task_source.to_sendable();
48    let mut trusted: Option<TrustedPromise> = Some(TrustedPromise::new(promise.clone()));
49    let trusted_receiver = Trusted::new(receiver);
50    GenericCallback::new(move |message| {
51        let trusted = if let Some(trusted) = trusted.take() {
52            trusted
53        } else {
54            error!("RoutedPromiseListener callback called twice!");
55            return;
56        };
57
58        let context = RoutedPromiseContext {
59            trusted,
60            receiver: trusted_receiver.clone(),
61            _phantom: Default::default(),
62        };
63        task_source.queue(task!(routed_promise_task: move|cx| {
64            context.response(cx, message.unwrap());
65        }));
66    })
67    .expect("Could not create callback in script.")
68}
script/routed_promise.rs

script/
routed_promise.rs
