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Remove generic Hasher and Event from subscription::Recipe

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Héctor Ramón Jiménez 2023-03-05 04:15:10 +01:00
parent 5fed065dc3
commit f4cf488e0b
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20 changed files with 341 additions and 406 deletions
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316
futures/src/subscription.rs
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@ -3,7 +3,18 @@ mod tracker;
pub use tracker::Tracker;
use crate::BoxStream;
use crate::core::event::{self, Event};
use crate::core::window;
use crate::core::Hasher;
use crate::futures::{Future, Stream};
use crate::{BoxStream, MaybeSend};
use std::hash::Hash;
/// A stream of runtime events.
///
/// It is the input of a [`Subscription`].
pub type EventStream = BoxStream<(Event, event::Status)>;
/// A request to listen to external events.
///
@ -16,19 +27,13 @@ use crate::BoxStream;
/// For instance, you can use a [`Subscription`] to listen to a WebSocket
/// connection, keyboard presses, mouse events, time ticks, etc.
///
/// This type is normally aliased by runtimes with a specific `Event` and/or
/// `Hasher`.
///
/// [`Command`]: crate::Command
#[must_use = "`Subscription` must be returned to runtime to take effect"]
pub struct Subscription<Hasher, Event, Output> {
recipes: Vec<Box<dyn Recipe<Hasher, Event, Output = Output>>>,
pub struct Subscription<Message> {
recipes: Vec<Box<dyn Recipe<Output = Message>>>,
}
impl<H, E, O> Subscription<H, E, O>
where
H: std::hash::Hasher,
{
impl<Message> Subscription<Message> {
/// Returns an empty [`Subscription`] that will not produce any output.
pub fn none() -> Self {
Self {
@ -38,7 +43,7 @@ where
/// Creates a [`Subscription`] from a [`Recipe`] describing it.
pub fn from_recipe(
recipe: impl Recipe<H, E, Output = O> + 'static,
recipe: impl Recipe<Output = Message> + 'static,
) -> Self {
Self {
recipes: vec![Box::new(recipe)],
@ -48,7 +53,7 @@ where
/// Batches all the provided subscriptions and returns the resulting
/// [`Subscription`].
pub fn batch(
subscriptions: impl IntoIterator<Item = Subscription<H, E, O>>,
subscriptions: impl IntoIterator<Item = Subscription<Message>>,
) -> Self {
Self {
recipes: subscriptions
@ -59,18 +64,16 @@ where
}
/// Returns the different recipes of the [`Subscription`].
pub fn recipes(self) -> Vec<Box<dyn Recipe<H, E, Output = O>>> {
pub fn into_recipes(self) -> Vec<Box<dyn Recipe<Output = Message>>> {
self.recipes
}
/// Adds a value to the [`Subscription`] context.
///
/// The value will be part of the identity of a [`Subscription`].
pub fn with<T>(mut self, value: T) -> Subscription<H, E, (T, O)>
pub fn with<T>(mut self, value: T) -> Subscription<(T, Message)>
where
H: 'static,
E: 'static,
O: 'static,
Message: 'static,
T: std::hash::Hash + Clone + Send + Sync + 'static,
{
Subscription {
@ -79,18 +82,16 @@ where
.drain(..)
.map(|recipe| {
Box::new(With::new(recipe, value.clone()))
as Box<dyn Recipe<H, E, Output = (T, O)>>
as Box<dyn Recipe<Output = (T, Message)>>
})
.collect(),
}
}
/// Transforms the [`Subscription`] output with the given function.
pub fn map<A>(mut self, f: fn(O) -> A) -> Subscription<H, E, A>
pub fn map<A>(mut self, f: fn(Message) -> A) -> Subscription<A>
where
H: 'static,
E: 'static,
O: 'static,
Message: 'static,
A: 'static,
{
Subscription {
@ -98,15 +99,14 @@ where
.recipes
.drain(..)
.map(|recipe| {
Box::new(Map::new(recipe, f))
as Box<dyn Recipe<H, E, Output = A>>
Box::new(Map::new(recipe, f)) as Box<dyn Recipe<Output = A>>
})
.collect(),
}
}
}
impl<I, O, H> std::fmt::Debug for Subscription<I, O, H> {
impl<Message> std::fmt::Debug for Subscription<Message> {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
f.debug_struct("Subscription").finish()
}
@ -129,7 +129,7 @@ impl<I, O, H> std::fmt::Debug for Subscription<I, O, H> {
/// [examples]: https://github.com/iced-rs/iced/tree/0.8/examples
/// [`download_progress`]: https://github.com/iced-rs/iced/tree/0.8/examples/download_progress
/// [`stopwatch`]: https://github.com/iced-rs/iced/tree/0.8/examples/stopwatch
pub trait Recipe<Hasher: std::hash::Hasher, Event> {
pub trait Recipe {
/// The events that will be produced by a [`Subscription`] with this
/// [`Recipe`].
type Output;
@ -141,45 +141,33 @@ pub trait Recipe<Hasher: std::hash::Hasher, Event> {
/// Executes the [`Recipe`] and produces the stream of events of its
/// [`Subscription`].
///
/// It receives some stream of generic events, which is normally defined by
/// shells.
fn stream(
self: Box<Self>,
input: BoxStream<Event>,
) -> BoxStream<Self::Output>;
fn stream(self: Box<Self>, input: EventStream) -> BoxStream<Self::Output>;
}
struct Map<Hasher, Event, A, B> {
recipe: Box<dyn Recipe<Hasher, Event, Output = A>>,
struct Map<A, B> {
recipe: Box<dyn Recipe<Output = A>>,
mapper: fn(A) -> B,
}
impl<H, E, A, B> Map<H, E, A, B> {
fn new(
recipe: Box<dyn Recipe<H, E, Output = A>>,
mapper: fn(A) -> B,
) -> Self {
impl<A, B> Map<A, B> {
fn new(recipe: Box<dyn Recipe<Output = A>>, mapper: fn(A) -> B) -> Self {
Map { recipe, mapper }
}
}
impl<H, E, A, B> Recipe<H, E> for Map<H, E, A, B>
impl<A, B> Recipe for Map<A, B>
where
A: 'static,
B: 'static,
H: std::hash::Hasher,
{
type Output = B;
fn hash(&self, state: &mut H) {
use std::hash::Hash;
fn hash(&self, state: &mut Hasher) {
self.recipe.hash(state);
self.mapper.hash(state);
}
fn stream(self: Box<Self>, input: BoxStream<E>) -> BoxStream<Self::Output> {
fn stream(self: Box<Self>, input: EventStream) -> BoxStream<Self::Output> {
use futures::StreamExt;
let mapper = self.mapper;
@ -188,34 +176,31 @@ where
}
}
struct With<Hasher, Event, A, B> {
recipe: Box<dyn Recipe<Hasher, Event, Output = A>>,
struct With<A, B> {
recipe: Box<dyn Recipe<Output = A>>,
value: B,
}
impl<H, E, A, B> With<H, E, A, B> {
fn new(recipe: Box<dyn Recipe<H, E, Output = A>>, value: B) -> Self {
impl<A, B> With<A, B> {
fn new(recipe: Box<dyn Recipe<Output = A>>, value: B) -> Self {
With { recipe, value }
}
}
impl<H, E, A, B> Recipe<H, E> for With<H, E, A, B>
impl<A, B> Recipe for With<A, B>
where
A: 'static,
B: 'static + std::hash::Hash + Clone + Send + Sync,
H: std::hash::Hasher,
{
type Output = (B, A);
fn hash(&self, state: &mut H) {
use std::hash::Hash;
fn hash(&self, state: &mut Hasher) {
std::any::TypeId::of::<B>().hash(state);
self.value.hash(state);
self.recipe.hash(state);
}
fn stream(self: Box<Self>, input: BoxStream<E>) -> BoxStream<Self::Output> {
fn stream(self: Box<Self>, input: EventStream) -> BoxStream<Self::Output> {
use futures::StreamExt;
let value = self.value;
@ -227,3 +212,222 @@ where
)
}
}
/// Returns a [`Subscription`] to all the ignored runtime events.
///
/// This subscription will notify your application of any [`Event`] that was
/// not captured by any widget.
pub fn events() -> Subscription<Event> {
events_with(|event, status| match status {
event::Status::Ignored => Some(event),
event::Status::Captured => None,
})
}
/// Returns a [`Subscription`] that filters all the runtime events with the
/// provided function, producing messages accordingly.
///
/// This subscription will call the provided function for every [`Event`]
/// handled by the runtime. If the function:
///
/// - Returns `None`, the [`Event`] will be discarded.
/// - Returns `Some` message, the `Message` will be produced.
pub fn events_with<Message>(
f: fn(Event, event::Status) -> Option<Message>,
) -> Subscription<Message>
where
Message: 'static + MaybeSend,
{
#[derive(Hash)]
struct EventsWith;
Subscription::from_recipe(Runner {
id: (EventsWith, f),
spawn: move |events| {
use futures::future;
use futures::stream::StreamExt;
events.filter_map(move |(event, status)| {
future::ready(match event {
Event::Window(window::Event::RedrawRequested(_)) => None,
_ => f(event, status),
})
})
},
})
}
/// Returns a [`Subscription`] that produces a message for every runtime event,
/// including the redraw request events.
///
/// **Warning:** This [`Subscription`], if unfiltered, may produce messages in
/// an infinite loop.
pub fn raw_events<Message>(
f: fn(Event, event::Status) -> Option<Message>,
) -> Subscription<Message>
where
Message: 'static + MaybeSend,
{
#[derive(Hash)]
struct RawEvents;
Subscription::from_recipe(Runner {
id: (RawEvents, f),
spawn: move |events| {
use futures::future;
use futures::stream::StreamExt;
events.filter_map(move |(event, status)| {
future::ready(f(event, status))
})
},
})
}
/// Returns a [`Subscription`] that will call the given function to create and
/// asynchronously run the given [`Stream`].
pub fn run<S, Message>(builder: fn() -> S) -> Subscription<Message>
where
S: Stream<Item = Message> + MaybeSend + 'static,
Message: 'static,
{
Subscription::from_recipe(Runner {
id: builder,
spawn: move |_| builder(),
})
}
/// Returns a [`Subscription`] that will create and asynchronously run the
/// given [`Stream`].
///
/// The `id` will be used to uniquely identify the [`Subscription`].
pub fn run_with_id<I, S, Message>(id: I, stream: S) -> Subscription<Message>
where
I: Hash + 'static,
S: Stream<Item = Message> + MaybeSend + 'static,
Message: 'static,
{
Subscription::from_recipe(Runner {
id,
spawn: move |_| stream,
})
}
/// Returns a [`Subscription`] that will create and asynchronously run a
/// [`Stream`] that will call the provided closure to produce every `Message`.
///
/// The `id` will be used to uniquely identify the [`Subscription`].
///
/// # Creating an asynchronous worker with bidirectional communication
/// You can leverage this helper to create a [`Subscription`] that spawns
/// an asynchronous worker in the background and establish a channel of
/// communication with an `iced` application.
///
/// You can achieve this by creating an `mpsc` channel inside the closure
/// and returning the `Sender` as a `Message` for the `Application`:
///
/// ```
/// use iced_futures::subscription::{self, Subscription};
/// use iced_futures::futures;
///
/// use futures::channel::mpsc;
///
/// pub enum Event {
/// Ready(mpsc::Sender<Input>),
/// WorkFinished,
/// // ...
/// }
///
/// enum Input {
/// DoSomeWork,
/// // ...
/// }
///
/// enum State {
/// Starting,
/// Ready(mpsc::Receiver<Input>),
/// }
///
/// fn some_worker() -> Subscription<Event> {
/// struct SomeWorker;
///
/// subscription::unfold(std::any::TypeId::of::<SomeWorker>(), State::Starting, |state| async move {
/// match state {
/// State::Starting => {
/// // Create channel
/// let (sender, receiver) = mpsc::channel(100);
///
/// (Some(Event::Ready(sender)), State::Ready(receiver))
/// }
/// State::Ready(mut receiver) => {
/// use futures::StreamExt;
///
/// // Read next input sent from `Application`
/// let input = receiver.select_next_some().await;
///
/// match input {
/// Input::DoSomeWork => {
/// // Do some async work...
///
/// // Finally, we can optionally return a message to tell the
/// // `Application` the work is done
/// (Some(Event::WorkFinished), State::Ready(receiver))
/// }
/// }
/// }
/// }
/// })
/// }
/// ```
///
/// Check out the [`websocket`] example, which showcases this pattern to maintain a WebSocket
/// connection open.
///
/// [`websocket`]: https://github.com/iced-rs/iced/tree/0.8/examples/websocket
pub fn unfold<I, T, Fut, Message>(
id: I,
initial: T,
mut f: impl FnMut(T) -> Fut + MaybeSend + Sync + 'static,
) -> Subscription<Message>
where
I: Hash + 'static,
T: MaybeSend + 'static,
Fut: Future<Output = (Option<Message>, T)> + MaybeSend + 'static,
Message: 'static + MaybeSend,
{
use futures::future::{self, FutureExt};
use futures::stream::StreamExt;
run_with_id(
id,
futures::stream::unfold(initial, move |state| f(state).map(Some))
.filter_map(future::ready),
)
}
struct Runner<I, F, S, Message>
where
F: FnOnce(EventStream) -> S,
S: Stream<Item = Message>,
{
id: I,
spawn: F,
}
impl<I, S, F, Message> Recipe for Runner<I, F, S, Message>
where
I: Hash + 'static,
F: FnOnce(EventStream) -> S,
S: Stream<Item = Message> + MaybeSend + 'static,
{
type Output = Message;
fn hash(&self, state: &mut Hasher) {
std::any::TypeId::of::<I>().hash(state);
self.id.hash(state);
}
fn stream(self: Box<Self>, input: EventStream) -> BoxStream<Self::Output> {
crate::boxed_stream((self.spawn)(input))
}
}