use std::fmt::{Debug, Display, Formatter};
use std::hash::Hash;
use std::ops::{AddAssign, Deref, DerefMut, DivAssign, MulAssign, SubAssign};
use crate::effect::EFFECTS;
use crate::*;
type WeakEffectCallback = Weak<RefCell<dyn FnMut()>>;
type EffectCallbackPtr = *const RefCell<dyn FnMut()>;
pub(crate) type SignalEmitterInner = RefCell<IndexMap<EffectCallbackPtr, WeakEffectCallback>>;
#[derive(Default, Clone)]
pub struct SignalEmitter(pub(crate) Rc<SignalEmitterInner>);
impl std::fmt::Debug for SignalEmitter {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
f.debug_struct("SignalEmitter").finish()
}
}
#[derive(Default, Clone)]
pub(crate) struct WeakSignalEmitter(pub Weak<SignalEmitterInner>);
impl WeakSignalEmitter {
pub fn upgrade(&self) -> Option<SignalEmitter> {
self.0.upgrade().map(SignalEmitter)
}
}
impl SignalEmitter {
pub(crate) fn downgrade(&self) -> WeakSignalEmitter {
WeakSignalEmitter(Rc::downgrade(&self.0))
}
pub(crate) fn subscribe(&self, cb: WeakEffectCallback) {
self.0.borrow_mut().insert(cb.as_ptr(), cb);
}
pub(crate) fn unsubscribe(&self, cb: EffectCallbackPtr) {
self.0.borrow_mut().remove(&cb);
}
pub fn track(&self) {
EFFECTS.with(|effects| {
if let Some(last) = effects.borrow().last() {
let last = unsafe { &mut **last };
last.add_dependency(self.downgrade());
}
});
}
pub fn trigger_subscribers(&self) {
let subscribers = self.0.take().into_values();
for subscriber in subscribers.rev() {
if let Some(callback) = subscriber.upgrade() {
callback.borrow_mut()();
}
}
}
}
pub struct ReadSignal<T> {
value: RefCell<Rc<T>>,
emitter: SignalEmitter,
}
impl<T> ReadSignal<T> {
#[must_use = "to only subscribe the signal without using the value, use .track() instead"]
pub fn get(&self) -> Rc<T> {
self.emitter.track();
self.value.borrow().clone()
}
#[must_use = "discarding the returned value does nothing"]
pub fn get_untracked(&self) -> Rc<T> {
self.value.borrow().clone()
}
#[must_use]
pub fn map<'a, U>(
&'a self,
cx: Scope<'a>,
mut f: impl FnMut(&T) -> U + 'a,
) -> &'a ReadSignal<U> {
create_memo(cx, move || f(&self.get()))
}
pub fn track(&self) {
self.emitter.track();
}
}
pub struct Signal<T>(ReadSignal<T>);
impl<T> Signal<T> {
pub(crate) fn new(value: T) -> Self {
Self(ReadSignal {
value: RefCell::new(Rc::new(value)),
emitter: Default::default(),
})
}
pub fn set(&self, value: T) {
self.set_silent(value);
self.trigger_subscribers();
}
pub fn set_rc(&self, value: Rc<T>) {
self.set_rc_silent(value);
self.trigger_subscribers();
}
pub fn set_silent(&self, value: T) {
self.set_rc_silent(Rc::new(value));
}
pub fn set_rc_silent(&self, value: Rc<T>) {
*self.0.value.borrow_mut() = value;
}
pub fn split(&self) -> (impl Fn() -> Rc<T> + Copy + '_, impl Fn(T) + Copy + '_) {
let getter = move || self.get();
let setter = move |x| self.set(x);
(getter, setter)
}
pub fn trigger_subscribers(&self) {
self.0.emitter.trigger_subscribers()
}
}
#[derive(Debug)]
pub struct Modify<'a, T>(Option<T>, &'a Signal<T>);
impl<'a, T> Deref for Modify<'a, T> {
type Target = T;
fn deref(&self) -> &Self::Target {
self.0.as_ref().unwrap()
}
}
impl<'a, T> DerefMut for Modify<'a, T> {
fn deref_mut(&mut self) -> &mut Self::Target {
self.0.as_mut().unwrap()
}
}
impl<T> Drop for Modify<'_, T> {
fn drop(&mut self) {
self.1.set(self.0.take().unwrap())
}
}
impl<T: Clone> Signal<T> {
pub fn modify(&self) -> Modify<T> {
Modify(Some(self.value.borrow().as_ref().clone()), self)
}
}
impl<T: Default> Signal<T> {
pub fn take(&self) -> Rc<T> {
let ret = self.0.value.take();
self.trigger_subscribers();
ret
}
pub fn take_silent(&self) -> Rc<T> {
self.0.value.take()
}
}
impl<T> Deref for Signal<T> {
type Target = ReadSignal<T>;
fn deref(&self) -> &Self::Target {
&self.0
}
}
impl<T: AddAssign + Copy> AddAssign<T> for &Signal<T> {
fn add_assign(&mut self, other: T) {
let mut value = **self.0.value.borrow();
value += other;
self.set(value);
}
}
impl<T: SubAssign + Copy> SubAssign<T> for &Signal<T> {
fn sub_assign(&mut self, other: T) {
let mut value = **self.0.value.borrow();
value -= other;
self.set(value);
}
}
impl<T: MulAssign + Copy> MulAssign<T> for &Signal<T> {
fn mul_assign(&mut self, other: T) {
let mut value = **self.0.value.borrow();
value *= other;
self.set(value);
}
}
impl<T: DivAssign + Copy> DivAssign<T> for &Signal<T> {
fn div_assign(&mut self, other: T) {
let mut value = **self.0.value.borrow();
value /= other;
self.set(value);
}
}
pub trait AnyReadSignal<'a> {
fn track(&self);
}
impl<'a, T> AnyReadSignal<'a> for RcSignal<T> {
fn track(&self) {
self.deref().deref().track();
}
}
impl<'a, T> AnyReadSignal<'a> for Signal<T> {
fn track(&self) {
self.deref().track();
}
}
impl<'a, T> AnyReadSignal<'a> for ReadSignal<T> {
fn track(&self) {
self.track();
}
}
pub fn create_signal<T>(cx: Scope, value: T) -> &Signal<T> {
let signal = Signal::new(value);
create_ref(cx, signal)
}
pub fn create_signal_from_rc<T>(cx: Scope, value: Rc<T>) -> &Signal<T> {
let signal = Signal(ReadSignal {
value: RefCell::new(value),
emitter: Default::default(),
});
create_ref(cx, signal)
}
pub struct RcSignal<T>(Rc<Signal<T>>);
impl<T> Deref for RcSignal<T> {
type Target = Signal<T>;
fn deref(&self) -> &Self::Target {
self.0.as_ref()
}
}
impl<T> Clone for RcSignal<T> {
fn clone(&self) -> Self {
Self(self.0.clone())
}
}
pub fn create_rc_signal<T>(value: T) -> RcSignal<T> {
RcSignal(Rc::new(Signal::new(value)))
}
pub fn create_rc_signal_from_rc<T>(value: Rc<T>) -> RcSignal<T> {
RcSignal(Rc::new(Signal(ReadSignal {
value: RefCell::new(value),
emitter: Default::default(),
})))
}
impl<T: Display> Display for RcSignal<T> {
fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
self.get().fmt(f)
}
}
impl<T: Display> Display for Signal<T> {
fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
self.get().fmt(f)
}
}
impl<T: Display> Display for ReadSignal<T> {
fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
self.get().fmt(f)
}
}
impl<T: Debug> Debug for RcSignal<T> {
fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
f.debug_tuple("RcSignal").field(&self.get()).finish()
}
}
impl<T: Debug> Debug for Signal<T> {
fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
f.debug_tuple("Signal").field(&self.get()).finish()
}
}
impl<T: Debug> Debug for ReadSignal<T> {
fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
f.debug_tuple("ReadSignal").field(&self.get()).finish()
}
}
impl<T: Default> Default for RcSignal<T> {
fn default() -> Self {
create_rc_signal(T::default())
}
}
impl<T: PartialEq> PartialEq for RcSignal<T> {
fn eq(&self, other: &Self) -> bool {
self.get_untracked().eq(&other.get_untracked())
}
}
impl<T: PartialEq> PartialEq for Signal<T> {
fn eq(&self, other: &Self) -> bool {
self.get_untracked().eq(&other.get_untracked())
}
}
impl<T: PartialEq> PartialEq for ReadSignal<T> {
fn eq(&self, other: &Self) -> bool {
self.get_untracked().eq(&other.get_untracked())
}
}
impl<T: Eq> Eq for RcSignal<T> {}
impl<T: Eq> Eq for Signal<T> {}
impl<T: Eq> Eq for ReadSignal<T> {}
impl<T: Hash> Hash for RcSignal<T> {
fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
self.get_untracked().hash(state)
}
}
impl<T: Hash> Hash for Signal<T> {
fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
self.get_untracked().hash(state)
}
}
impl<T: Hash> Hash for ReadSignal<T> {
fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
self.get_untracked().hash(state)
}
}
#[cfg(feature = "serde")]
impl<T: serde::Serialize> serde::Serialize for RcSignal<T> {
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: serde::Serializer,
{
self.get().serialize(serializer)
}
}
#[cfg(feature = "serde")]
impl<'de, T: serde::Deserialize<'de>> serde::Deserialize<'de> for RcSignal<T> {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: serde::Deserializer<'de>,
{
Ok(create_rc_signal(T::deserialize(deserializer)?))
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn signal() {
create_scope_immediate(|cx| {
let state = create_signal(cx, 0);
assert_eq!(*state.get(), 0);
state.set(1);
assert_eq!(*state.get(), 1);
});
}
#[test]
fn signal_composition() {
create_scope_immediate(|cx| {
let state = create_signal(cx, 0);
let double = || *state.get() * 2;
assert_eq!(double(), 0);
state.set(1);
assert_eq!(double(), 2);
});
}
#[test]
fn set_silent_signal() {
create_scope_immediate(|cx| {
let state = create_signal(cx, 0);
let double = state.map(cx, |&x| x * 2);
assert_eq!(*double.get(), 0);
state.set_silent(1);
assert_eq!(*double.get(), 0); });
}
#[test]
fn read_signal() {
create_scope_immediate(|cx| {
let state = create_signal(cx, 0);
let readonly: &ReadSignal<i32> = state.deref();
assert_eq!(*readonly.get(), 0);
state.set(1);
assert_eq!(*readonly.get(), 1);
});
}
#[test]
fn map_signal() {
create_scope_immediate(|cx| {
let state = create_signal(cx, 0);
let double = state.map(cx, |&x| x * 2);
assert_eq!(*double.get(), 0);
state.set(1);
assert_eq!(*double.get(), 2);
});
}
#[test]
fn take_signal() {
create_scope_immediate(|cx| {
let state = create_signal(cx, 123);
let x = state.take();
assert_eq!(*x, 123);
assert_eq!(*state.get(), 0);
});
}
#[test]
fn take_silent_signal() {
create_scope_immediate(|cx| {
let state = create_signal(cx, 123);
let double = state.map(cx, |&x| x * 2);
state.take_silent();
assert_eq!(*state.get(), 0);
assert_eq!(*double.get(), 246);
});
}
#[test]
fn signal_split() {
create_scope_immediate(|cx| {
let (state, set_state) = create_signal(cx, 0).split();
assert_eq!(*state(), 0);
set_state(1);
assert_eq!(*state(), 1);
});
}
#[test]
fn rc_signal() {
let mut outer = None;
create_scope_immediate(|cx| {
let rc_state = create_rc_signal(0);
let rc_state_cloned = rc_state.clone();
let double = create_memo(cx, move || *rc_state_cloned.get() * 2);
assert_eq!(*double.get(), 0);
rc_state.set(1);
assert_eq!(*double.get(), 2);
outer = Some(rc_state);
});
assert_eq!(*outer.unwrap().get(), 1);
}
#[test]
fn signal_display() {
create_scope_immediate(|cx| {
let signal = create_signal(cx, 0);
assert_eq!(format!("{signal}"), "0");
let read_signal: &ReadSignal<_> = signal;
assert_eq!(format!("{read_signal}"), "0");
let rcsignal = create_rc_signal(0);
assert_eq!(format!("{rcsignal}"), "0");
});
}
#[test]
fn signal_debug() {
create_scope_immediate(|cx| {
let signal = create_signal(cx, 0);
assert_eq!(format!("{signal:?}"), "Signal(0)");
let read_signal: &ReadSignal<_> = signal;
assert_eq!(format!("{read_signal:?}"), "ReadSignal(0)");
let rcsignal = create_rc_signal(0);
assert_eq!(format!("{rcsignal:?}"), "RcSignal(0)");
});
}
#[test]
fn signal_add_assign_update() {
create_scope_immediate(|cx| {
let mut signal = create_signal(cx, 0);
let counter = create_signal(cx, 0);
create_effect(cx, || {
signal.track();
counter.set(*counter.get_untracked() + 1);
});
signal += 1;
signal -= 1;
signal *= 1;
signal /= 1;
assert_eq!(*counter.get(), 5);
});
}
#[test]
fn signal_modify() {
create_scope_immediate(|cx| {
let signal = create_signal(cx, "Hello ".to_string());
let counter = create_signal(cx, 0);
create_effect(cx, || {
signal.track();
counter.set(*counter.get_untracked() + 1);
});
signal.modify().push_str("World!");
assert_eq!(*signal.get(), "Hello World!");
assert_eq!(*counter.get(), 2);
});
}
#[test]
fn create_signals_from_rc_value() {
create_scope_immediate(|cx| {
let _signal: &Signal<i32> = create_signal_from_rc(cx, Rc::new(0));
let _rc_signal: RcSignal<i32> = create_rc_signal_from_rc(Rc::new(0));
});
}
}