1use crate::SharedString;
2use anyhow::{anyhow, Context, Result};
3use collections::HashMap;
4pub use no_action::NoAction;
5use serde_json::json;
6use std::any::{Any, TypeId};
7
8/// Actions are used to implement keyboard-driven UI.
9/// When you declare an action, you can bind keys to the action in the keymap and
10/// listeners for that action in the element tree.
11///
12/// To declare a list of simple actions, you can use the actions! macro, which defines a simple unit struct
13/// action for each listed action name in the given namespace.
14/// ```rust
15/// actions!(editor, [MoveUp, MoveDown, MoveLeft, MoveRight, Newline]);
16/// ```
17/// More complex data types can also be actions, providing they implement Clone, PartialEq,
18/// and serde_derive::Deserialize.
19/// Use `impl_actions!` to automatically implement the action in the given namespace.
20/// ```
21/// #[derive(Clone, PartialEq, serde_derive::Deserialize)]
22/// pub struct SelectNext {
23/// pub replace_newest: bool,
24/// }
25/// impl_actions!(editor, [SelectNext]);
26/// ```
27///
28/// If you want to control the behavior of the action trait manually, you can use the lower-level `#[register_action]`
29/// macro, which only generates the code needed to register your action before `main`.
30///
31/// ```
32/// #[derive(gpui::private::serde::Deserialize, std::cmp::PartialEq, std::clone::Clone)]
33/// pub struct Paste {
34/// pub content: SharedString,
35/// }
36///
37/// impl gpui::Action for Paste {
38/// ///...
39/// }
40/// register_action!(Paste);
41/// ```
42pub trait Action: 'static {
43 fn boxed_clone(&self) -> Box<dyn Action>;
44 fn as_any(&self) -> &dyn Any;
45 fn partial_eq(&self, action: &dyn Action) -> bool;
46 fn name(&self) -> &str;
47
48 fn debug_name() -> &'static str
49 where
50 Self: Sized;
51 fn build(value: serde_json::Value) -> Result<Box<dyn Action>>
52 where
53 Self: Sized;
54}
55
56impl std::fmt::Debug for dyn Action {
57 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
58 f.debug_struct("dyn Action")
59 .field("name", &self.name())
60 .finish()
61 }
62}
63
64impl dyn Action {
65 pub fn type_id(&self) -> TypeId {
66 self.as_any().type_id()
67 }
68}
69
70type ActionBuilder = fn(json: serde_json::Value) -> anyhow::Result<Box<dyn Action>>;
71
72pub(crate) struct ActionRegistry {
73 builders_by_name: HashMap<SharedString, ActionBuilder>,
74 names_by_type_id: HashMap<TypeId, SharedString>,
75 all_names: Vec<SharedString>, // So we can return a static slice.
76}
77
78impl Default for ActionRegistry {
79 fn default() -> Self {
80 let mut this = ActionRegistry {
81 builders_by_name: Default::default(),
82 names_by_type_id: Default::default(),
83 all_names: Default::default(),
84 };
85
86 this.load_actions();
87
88 this
89 }
90}
91
92/// This type must be public so that our macros can build it in other crates.
93/// But this is an implementation detail and should not be used directly.
94#[doc(hidden)]
95pub type MacroActionBuilder = fn() -> ActionData;
96
97/// This type must be public so that our macros can build it in other crates.
98/// But this is an implementation detail and should not be used directly.
99#[doc(hidden)]
100pub struct ActionData {
101 pub name: &'static str,
102 pub type_id: TypeId,
103 pub build: ActionBuilder,
104}
105
106/// This constant must be public to be accessible from other crates.
107/// But its existence is an implementation detail and should not be used directly.
108#[doc(hidden)]
109#[linkme::distributed_slice]
110pub static __GPUI_ACTIONS: [MacroActionBuilder];
111
112impl ActionRegistry {
113 /// Load all registered actions into the registry.
114 pub(crate) fn load_actions(&mut self) {
115 for builder in __GPUI_ACTIONS {
116 let action = builder();
117 self.insert_action(action);
118 }
119 }
120
121 #[cfg(test)]
122 pub(crate) fn load_action<A: Action>(&mut self) {
123 self.insert_action(ActionData {
124 name: A::debug_name(),
125 type_id: TypeId::of::<A>(),
126 build: A::build,
127 });
128 }
129
130 fn insert_action(&mut self, action: ActionData) {
131 let name: SharedString = action.name.into();
132 self.builders_by_name.insert(name.clone(), action.build);
133 self.names_by_type_id.insert(action.type_id, name.clone());
134 self.all_names.push(name);
135 }
136
137 /// Construct an action based on its name and optional JSON parameters sourced from the keymap.
138 pub fn build_action_type(&self, type_id: &TypeId) -> Result<Box<dyn Action>> {
139 let name = self
140 .names_by_type_id
141 .get(type_id)
142 .ok_or_else(|| anyhow!("no action type registered for {:?}", type_id))?
143 .clone();
144
145 self.build_action(&name, None)
146 }
147
148 /// Construct an action based on its name and optional JSON parameters sourced from the keymap.
149 pub fn build_action(
150 &self,
151 name: &str,
152 params: Option<serde_json::Value>,
153 ) -> Result<Box<dyn Action>> {
154 let build_action = self
155 .builders_by_name
156 .get(name)
157 .ok_or_else(|| anyhow!("no action type registered for {}", name))?;
158 (build_action)(params.unwrap_or_else(|| json!({})))
159 .with_context(|| format!("Attempting to build action {}", name))
160 }
161
162 pub fn all_action_names(&self) -> &[SharedString] {
163 self.all_names.as_slice()
164 }
165}
166
167/// Defines unit structs that can be used as actions.
168/// To use more complex data types as actions, use `impl_actions!`
169#[macro_export]
170macro_rules! actions {
171 ($namespace:path, [ $($name:ident),* $(,)? ]) => {
172 $(
173 #[derive(::std::cmp::PartialEq, ::std::clone::Clone, ::std::default::Default, ::std::fmt::Debug, gpui::private::serde_derive::Deserialize)]
174 #[serde(crate = "gpui::private::serde")]
175 pub struct $name;
176
177 gpui::__impl_action!($namespace, $name,
178 fn build(_: gpui::private::serde_json::Value) -> gpui::Result<::std::boxed::Box<dyn gpui::Action>> {
179 Ok(Box::new(Self))
180 }
181 );
182
183 gpui::register_action!($name);
184 )*
185 };
186}
187
188/// Implements the Action trait for any struct that implements Clone, Default, PartialEq, and serde_deserialize::Deserialize
189#[macro_export]
190macro_rules! impl_actions {
191 ($namespace:path, [ $($name:ident),* $(,)? ]) => {
192 $(
193 gpui::__impl_action!($namespace, $name,
194 fn build(value: gpui::private::serde_json::Value) -> gpui::Result<::std::boxed::Box<dyn gpui::Action>> {
195 Ok(std::boxed::Box::new(gpui::private::serde_json::from_value::<Self>(value)?))
196 }
197 );
198
199 gpui::register_action!($name);
200 )*
201 };
202}
203
204#[doc(hidden)]
205#[macro_export]
206macro_rules! __impl_action {
207 ($namespace:path, $name:ident, $build:item) => {
208 impl gpui::Action for $name {
209 fn name(&self) -> &'static str
210 {
211 concat!(
212 stringify!($namespace),
213 "::",
214 stringify!($name),
215 )
216 }
217
218 fn debug_name() -> &'static str
219 where
220 Self: ::std::marker::Sized
221 {
222 concat!(
223 stringify!($namespace),
224 "::",
225 stringify!($name),
226 )
227 }
228
229 $build
230
231 fn partial_eq(&self, action: &dyn gpui::Action) -> bool {
232 action
233 .as_any()
234 .downcast_ref::<Self>()
235 .map_or(false, |a| self == a)
236 }
237
238 fn boxed_clone(&self) -> std::boxed::Box<dyn gpui::Action> {
239 ::std::boxed::Box::new(self.clone())
240 }
241
242 fn as_any(&self) -> &dyn ::std::any::Any {
243 self
244 }
245 }
246 };
247}
248
249mod no_action {
250 use crate as gpui;
251
252 actions!(zed, [NoAction]);
253}