1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154

use crate::{read::Readable, ReadableRef, Signal, SignalData};
use dioxus_core::IntoDynNode;
use std::ops::Deref;

use crate::{default_impl, read_impls};
use dioxus_core::{prelude::IntoAttributeValue, ScopeId};
use generational_box::{BorrowResult, Storage, UnsyncStorage};

/// A signal that can only be read from.
pub struct ReadOnlySignal<T: 'static, S: Storage<SignalData<T>> = UnsyncStorage> {
    inner: Signal<T, S>,
}

impl<T: 'static, S: Storage<SignalData<T>>> From<Signal<T, S>> for ReadOnlySignal<T, S> {
    fn from(inner: Signal<T, S>) -> Self {
        Self { inner }
    }
}

impl<T: 'static> ReadOnlySignal<T> {
    /// Create a new read-only signal.
    #[track_caller]
    pub fn new(signal: Signal<T>) -> Self {
        Self::new_maybe_sync(signal)
    }
}

impl<T: 'static, S: Storage<SignalData<T>>> ReadOnlySignal<T, S> {
    /// Create a new read-only signal that is maybe sync.
    #[track_caller]
    pub fn new_maybe_sync(signal: Signal<T, S>) -> Self {
        Self { inner: signal }
    }

    /// Get the scope that the signal was created in.
    pub fn origin_scope(&self) -> ScopeId {
        self.inner.origin_scope()
    }

    /// Get the id of the signal.
    pub fn id(&self) -> generational_box::GenerationalBoxId {
        self.inner.id()
    }

    #[doc(hidden)]
    /// This should only be used by the `rsx!` macro.
    pub fn __set(&mut self, value: T) {
        use crate::write::Writable;
        use warnings::Warning;
        // This is only called when converting T -> ReadOnlySignal<T> which will not cause loops
        crate::warnings::signal_write_in_component_body::allow(|| {
            crate::warnings::signal_read_and_write_in_reactive_scope::allow(|| {
                self.inner.set(value);
            });
        });
    }

    #[doc(hidden)]
    /// This should only be used by the `rsx!` macro.
    pub fn __take(&self) -> T {
        self.inner
            .manually_drop()
            .expect("Signal has already been dropped")
    }
}

impl<T, S: Storage<SignalData<T>>> Readable for ReadOnlySignal<T, S> {
    type Target = T;
    type Storage = S;

    #[track_caller]
    fn try_read_unchecked(
        &self,
    ) -> Result<ReadableRef<'static, Self>, generational_box::BorrowError> {
        self.inner.try_read_unchecked()
    }

    /// Get the current value of the signal. **Unlike read, this will not subscribe the current scope to the signal which can cause parts of your UI to not update.**
    ///
    /// If the signal has been dropped, this will panic.
    #[track_caller]
    fn try_peek_unchecked(&self) -> BorrowResult<S::Ref<'static, T>> {
        self.inner.try_peek_unchecked()
    }
}

#[cfg(feature = "serialize")]
impl<T: serde::Serialize + 'static, Store: Storage<SignalData<T>>> serde::Serialize
    for ReadOnlySignal<T, Store>
{
    fn serialize<S: serde::Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
        self.read().serialize(serializer)
    }
}

#[cfg(feature = "serialize")]
impl<'de, T: serde::Deserialize<'de> + 'static, Store: Storage<SignalData<T>>>
    serde::Deserialize<'de> for ReadOnlySignal<T, Store>
{
    fn deserialize<D: serde::Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error> {
        Ok(Self::new_maybe_sync(Signal::new_maybe_sync(
            T::deserialize(deserializer)?,
        )))
    }
}

impl<T> IntoAttributeValue for ReadOnlySignal<T>
where
    T: Clone + IntoAttributeValue,
{
    fn into_value(self) -> dioxus_core::AttributeValue {
        self.with(|f| f.clone().into_value())
    }
}

impl<T> IntoDynNode for ReadOnlySignal<T>
where
    T: Clone + IntoDynNode,
{
    fn into_dyn_node(self) -> dioxus_core::DynamicNode {
        self().into_dyn_node()
    }
}

impl<T: 'static, S: Storage<SignalData<T>>> PartialEq for ReadOnlySignal<T, S> {
    fn eq(&self, other: &Self) -> bool {
        self.inner == other.inner
    }
}

impl<T: Clone, S: Storage<SignalData<T>> + 'static> Deref for ReadOnlySignal<T, S> {
    type Target = dyn Fn() -> T;

    fn deref(&self) -> &Self::Target {
        Readable::deref_impl(self)
    }
}

read_impls!(
    ReadOnlySignal<T, S> where
        S: Storage<SignalData<T>>
);
default_impl!(
    ReadOnlySignal<T, S> where
    S: Storage<SignalData<T>>
);

impl<T: 'static, S: Storage<SignalData<T>>> Clone for ReadOnlySignal<T, S> {
    fn clone(&self) -> Self {
        *self
    }
}

impl<T: 'static, S: Storage<SignalData<T>>> Copy for ReadOnlySignal<T, S> {}