1use std::any::{Any, TypeId};
2
3pub trait Action: 'static {
4 fn id(&self) -> TypeId;
5 fn namespace(&self) -> &'static str;
6 fn name(&self) -> &'static str;
7 fn as_any(&self) -> &dyn Any;
8 fn boxed_clone(&self) -> Box<dyn Action>;
9 fn eq(&self, other: &dyn Action) -> bool;
10
11 fn qualified_name() -> &'static str
12 where
13 Self: Sized;
14 fn from_json_str(json: &str) -> anyhow::Result<Box<dyn Action>>
15 where
16 Self: Sized;
17}
18
19impl std::fmt::Debug for dyn Action {
20 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
21 f.debug_struct("dyn Action")
22 .field("namespace", &self.namespace())
23 .field("name", &self.name())
24 .finish()
25 }
26}
27/// Define a set of unit struct types that all implement the `Action` trait.
28///
29/// The first argument is a namespace that will be associated with each of
30/// the given action types, to ensure that they have globally unique
31/// qualified names for use in keymap files.
32#[macro_export]
33macro_rules! actions {
34 ($namespace:path, [ $($name:ident),* $(,)? ]) => {
35 $(
36 #[derive(Clone, Debug, Default, PartialEq, Eq)]
37 pub struct $name;
38 $crate::__impl_action! {
39 $namespace,
40 $name,
41 fn from_json_str(_: &str) -> $crate::anyhow::Result<Box<dyn $crate::Action>> {
42 Ok(Box::new(Self))
43 }
44 }
45 )*
46 };
47}
48
49/// Implement the `Action` trait for a set of existing types.
50///
51/// The first argument is a namespace that will be associated with each of
52/// the given action types, to ensure that they have globally unique
53/// qualified names for use in keymap files.
54#[macro_export]
55macro_rules! impl_actions {
56 ($namespace:path, [ $($name:ident),* $(,)? ]) => {
57 $(
58 $crate::__impl_action! {
59 $namespace,
60 $name,
61 fn from_json_str(json: &str) -> $crate::anyhow::Result<Box<dyn $crate::Action>> {
62 Ok(Box::new($crate::serde_json::from_str::<Self>(json)?))
63 }
64 }
65 )*
66 };
67}
68
69/// Implement the `Action` trait for a set of existing types that are
70/// not intended to be constructed via a keymap file, but only dispatched
71/// internally.
72#[macro_export]
73macro_rules! impl_internal_actions {
74 ($namespace:path, [ $($name:ident),* $(,)? ]) => {
75 $(
76 $crate::__impl_action! {
77 $namespace,
78 $name,
79 fn from_json_str(_: &str) -> $crate::anyhow::Result<Box<dyn $crate::Action>> {
80 Err($crate::anyhow::anyhow!("internal action"))
81 }
82 }
83 )*
84 };
85}
86
87#[doc(hidden)]
88#[macro_export]
89macro_rules! __impl_action {
90 ($namespace:path, $name:ident, $from_json_fn:item) => {
91 impl $crate::action::Action for $name {
92 fn namespace(&self) -> &'static str {
93 stringify!($namespace)
94 }
95
96 fn name(&self) -> &'static str {
97 stringify!($name)
98 }
99
100 fn qualified_name() -> &'static str {
101 concat!(
102 stringify!($namespace),
103 "::",
104 stringify!($name),
105 )
106 }
107
108 fn id(&self) -> std::any::TypeId {
109 std::any::TypeId::of::<$name>()
110 }
111
112 fn as_any(&self) -> &dyn std::any::Any {
113 self
114 }
115
116 fn boxed_clone(&self) -> Box<dyn $crate::Action> {
117 Box::new(self.clone())
118 }
119
120 fn eq(&self, other: &dyn $crate::Action) -> bool {
121 if let Some(other) = other.as_any().downcast_ref::<Self>() {
122 self == other
123 } else {
124 false
125 }
126 }
127
128 $from_json_fn
129 }
130 };
131}