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 it's 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 //todo(remove)
118 let name: SharedString = action.name.into();
119 self.builders_by_name.insert(name.clone(), action.build);
120 self.names_by_type_id.insert(action.type_id, name.clone());
121 self.all_names.push(name);
122 }
123 }
124
125 /// Construct an action based on its name and optional JSON parameters sourced from the keymap.
126 pub fn build_action_type(&self, type_id: &TypeId) -> Result<Box<dyn Action>> {
127 let name = self
128 .names_by_type_id
129 .get(type_id)
130 .ok_or_else(|| anyhow!("no action type registered for {:?}", type_id))?
131 .clone();
132
133 self.build_action(&name, None)
134 }
135
136 /// Construct an action based on its name and optional JSON parameters sourced from the keymap.
137 pub fn build_action(
138 &self,
139 name: &str,
140 params: Option<serde_json::Value>,
141 ) -> Result<Box<dyn Action>> {
142 let build_action = self
143 .builders_by_name
144 .get(name)
145 .ok_or_else(|| anyhow!("no action type registered for {}", name))?;
146 (build_action)(params.unwrap_or_else(|| json!({})))
147 .with_context(|| format!("Attempting to build action {}", name))
148 }
149
150 pub fn all_action_names(&self) -> &[SharedString] {
151 self.all_names.as_slice()
152 }
153}
154
155/// Defines unit structs that can be used as actions.
156/// To use more complex data types as actions, use `impl_actions!`
157#[macro_export]
158macro_rules! actions {
159 ($namespace:path, [ $($name:ident),* $(,)? ]) => {
160 $(
161 #[derive(::std::cmp::PartialEq, ::std::clone::Clone, ::std::default::Default, gpui::private::serde_derive::Deserialize)]
162 #[serde(crate = "gpui::private::serde")]
163 pub struct $name;
164
165 gpui::__impl_action!($namespace, $name,
166 fn build(_: gpui::private::serde_json::Value) -> gpui::Result<::std::boxed::Box<dyn gpui::Action>> {
167 Ok(Box::new(Self))
168 }
169 );
170
171 gpui::register_action!($name);
172 )*
173 };
174}
175
176/// Implements the Action trait for any struct that implements Clone, Default, PartialEq, and serde_deserialize::Deserialize
177#[macro_export]
178macro_rules! impl_actions {
179 ($namespace:path, [ $($name:ident),* $(,)? ]) => {
180 $(
181 gpui::__impl_action!($namespace, $name,
182 fn build(value: gpui::private::serde_json::Value) -> gpui::Result<::std::boxed::Box<dyn gpui::Action>> {
183 Ok(std::boxed::Box::new(gpui::private::serde_json::from_value::<Self>(value)?))
184 }
185 );
186
187 gpui::register_action!($name);
188 )*
189 };
190}
191
192#[doc(hidden)]
193#[macro_export]
194macro_rules! __impl_action {
195 ($namespace:path, $name:ident, $build:item) => {
196 impl gpui::Action for $name {
197 fn name(&self) -> &'static str
198 {
199 concat!(
200 stringify!($namespace),
201 "::",
202 stringify!($name),
203 )
204 }
205
206 // todo!() why is this needed in addition to name?
207 fn debug_name() -> &'static str
208 where
209 Self: ::std::marker::Sized
210 {
211 concat!(
212 stringify!($namespace),
213 "::",
214 stringify!($name),
215 )
216 }
217
218 $build
219
220 fn partial_eq(&self, action: &dyn gpui::Action) -> bool {
221 action
222 .as_any()
223 .downcast_ref::<Self>()
224 .map_or(false, |a| self == a)
225 }
226
227 fn boxed_clone(&self) -> std::boxed::Box<dyn gpui::Action> {
228 ::std::boxed::Box::new(self.clone())
229 }
230
231 fn as_any(&self) -> &dyn ::std::any::Any {
232 self
233 }
234 }
235 };
236}
237
238mod no_action {
239 use crate as gpui;
240
241 actions!(zed, [NoAction]);
242}