1use anyhow::{Context as _, Result};
2use collections::HashMap;
3pub use gpui_macros::Action;
4pub use no_action::{NoAction, is_no_action};
5use serde_json::json;
6use std::{
7 any::{Any, TypeId},
8 fmt::Display,
9};
10
11/// Defines and registers unit structs that can be used as actions. For more complex data types, derive `Action`.
12///
13/// For example:
14///
15/// ```
16/// actions!(editor, [MoveUp, MoveDown, MoveLeft, MoveRight, Newline]);
17/// ```
18///
19/// This will create actions with names like `editor::MoveUp`, `editor::MoveDown`, etc.
20///
21/// The namespace argument `editor` can also be omitted, though it is required for Zed actions.
22#[macro_export]
23macro_rules! actions {
24 ($namespace:path, [ $( $(#[$attr:meta])* $name:ident),* $(,)? ]) => {
25 $(
26 #[derive(::std::clone::Clone, ::std::cmp::PartialEq, ::std::default::Default, ::std::fmt::Debug, gpui::Action)]
27 #[action(namespace = $namespace)]
28 $(#[$attr])*
29 pub struct $name;
30 )*
31 };
32 ([ $( $(#[$attr:meta])* $name:ident),* $(,)? ]) => {
33 $(
34 #[derive(::std::clone::Clone, ::std::cmp::PartialEq, ::std::default::Default, ::std::fmt::Debug, gpui::Action)]
35 $(#[$attr])*
36 pub struct $name;
37 )*
38 };
39}
40
41/// Actions are used to implement keyboard-driven UI. When you declare an action, you can bind keys
42/// to the action in the keymap and listeners for that action in the element tree.
43///
44/// To declare a list of simple actions, you can use the actions! macro, which defines a simple unit
45/// struct action for each listed action name in the given namespace.
46///
47/// ```
48/// actions!(editor, [MoveUp, MoveDown, MoveLeft, MoveRight, Newline]);
49/// ```
50///
51/// Registering the actions with the same name will result in a panic during `App` creation.
52///
53/// # Derive Macro
54///
55/// More complex data types can also be actions, by using the derive macro for `Action`:
56///
57/// ```
58/// #[derive(Clone, PartialEq, serde::Deserialize, schemars::JsonSchema, Action)]
59/// #[action(namespace = editor)]
60/// pub struct SelectNext {
61/// pub replace_newest: bool,
62/// }
63/// ```
64///
65/// The derive macro for `Action` requires that the type implement `Clone` and `PartialEq`. It also
66/// requires `serde::Deserialize` and `schemars::JsonSchema` unless `#[action(no_json)]` is
67/// specified. In Zed these trait impls are used to load keymaps from JSON.
68///
69/// Multiple arguments separated by commas may be specified in `#[action(...)]`:
70///
71/// - `namespace = some_namespace` sets the namespace. In Zed this is required.
72///
73/// - `name = "ActionName"` overrides the action's name. This must not contain `::`.
74///
75/// - `no_json` causes the `build` method to always error and `action_json_schema` to return `None`,
76/// and allows actions not implement `serde::Serialize` and `schemars::JsonSchema`.
77///
78/// - `no_register` skips registering the action. This is useful for implementing the `Action` trait
79/// while not supporting invocation by name or JSON deserialization.
80///
81/// - `deprecated_aliases = ["editor::SomeAction"]` specifies deprecated old names for the action.
82/// These action names should *not* correspond to any actions that are registered. These old names
83/// can then still be used to refer to invoke this action. In Zed, the keymap JSON schema will
84/// accept these old names and provide warnings.
85///
86/// - `deprecated = "Message about why this action is deprecation"` specifies a deprecation message.
87/// In Zed, the keymap JSON schema will cause this to be displayed as a warning.
88///
89/// # Manual Implementation
90///
91/// If you want to control the behavior of the action trait manually, you can use the lower-level
92/// `#[register_action]` macro, which only generates the code needed to register your action before
93/// `main`.
94///
95/// ```
96/// #[derive(gpui::private::serde::Deserialize, std::cmp::PartialEq, std::clone::Clone)]
97/// pub struct Paste {
98/// pub content: SharedString,
99/// }
100///
101/// impl gpui::Action for Paste {
102/// ///...
103/// }
104/// register_action!(Paste);
105/// ```
106pub trait Action: Any + Send {
107 /// Clone the action into a new box
108 fn boxed_clone(&self) -> Box<dyn Action>;
109
110 /// Do a partial equality check on this action and the other
111 fn partial_eq(&self, action: &dyn Action) -> bool;
112
113 /// Get the name of this action, for displaying in UI
114 fn name(&self) -> &'static str;
115
116 /// Get the name of this action type (static)
117 fn name_for_type() -> &'static str
118 where
119 Self: Sized;
120
121 /// Build this action from a JSON value. This is used to construct actions from the keymap.
122 /// A value of `{}` will be passed for actions that don't have any parameters.
123 fn build(value: serde_json::Value) -> Result<Box<dyn Action>>
124 where
125 Self: Sized;
126
127 /// Optional JSON schema for the action's input data.
128 fn action_json_schema(_: &mut schemars::SchemaGenerator) -> Option<schemars::Schema>
129 where
130 Self: Sized,
131 {
132 None
133 }
134
135 /// A list of alternate, deprecated names for this action. These names can still be used to
136 /// invoke the action. In Zed, the keymap JSON schema will accept these old names and provide
137 /// warnings.
138 fn deprecated_aliases() -> &'static [&'static str]
139 where
140 Self: Sized,
141 {
142 &[]
143 }
144
145 /// Returns the deprecation message for this action, if any. In Zed, the keymap JSON schema will
146 /// cause this to be displayed as a warning.
147 fn deprecation_message() -> Option<&'static str>
148 where
149 Self: Sized,
150 {
151 None
152 }
153}
154
155impl std::fmt::Debug for dyn Action {
156 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
157 f.debug_struct("dyn Action")
158 .field("name", &self.name())
159 .finish()
160 }
161}
162
163impl dyn Action {
164 /// Type-erase Action type.
165 pub fn as_any(&self) -> &dyn Any {
166 self as &dyn Any
167 }
168}
169
170/// Error type for `Keystroke::parse`. This is used instead of `anyhow::Error` so that Zed can use
171/// markdown to display it.
172#[derive(Debug)]
173pub enum ActionBuildError {
174 /// Indicates that an action with this name has not been registered.
175 NotFound {
176 /// Name of the action that was not found.
177 name: String,
178 },
179 /// Indicates that an error occurred while building the action, typically a JSON deserialization
180 /// error.
181 BuildError {
182 /// Name of the action that was attempting to be built.
183 name: String,
184 /// Error that occurred while building the action.
185 error: anyhow::Error,
186 },
187}
188
189impl std::error::Error for ActionBuildError {
190 fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
191 match self {
192 ActionBuildError::NotFound { .. } => None,
193 ActionBuildError::BuildError { error, .. } => error.source(),
194 }
195 }
196}
197
198impl Display for ActionBuildError {
199 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
200 match self {
201 ActionBuildError::NotFound { name } => {
202 write!(f, "Didn't find an action named \"{name}\"")
203 }
204 ActionBuildError::BuildError { name, error } => {
205 write!(f, "Error while building action \"{name}\": {error}")
206 }
207 }
208 }
209}
210
211type ActionBuilder = fn(json: serde_json::Value) -> anyhow::Result<Box<dyn Action>>;
212
213pub(crate) struct ActionRegistry {
214 by_name: HashMap<&'static str, ActionData>,
215 names_by_type_id: HashMap<TypeId, &'static str>,
216 all_names: Vec<&'static str>, // So we can return a static slice.
217 deprecated_aliases: HashMap<&'static str, &'static str>, // deprecated name -> preferred name
218 deprecation_messages: HashMap<&'static str, &'static str>, // action name -> deprecation message
219}
220
221impl Default for ActionRegistry {
222 fn default() -> Self {
223 let mut this = ActionRegistry {
224 by_name: Default::default(),
225 names_by_type_id: Default::default(),
226 all_names: Default::default(),
227 deprecated_aliases: Default::default(),
228 deprecation_messages: Default::default(),
229 };
230
231 this.load_actions();
232
233 this
234 }
235}
236
237struct ActionData {
238 pub build: ActionBuilder,
239 pub json_schema: fn(&mut schemars::SchemaGenerator) -> Option<schemars::Schema>,
240}
241
242/// This type must be public so that our macros can build it in other crates.
243/// But this is an implementation detail and should not be used directly.
244#[doc(hidden)]
245pub struct MacroActionBuilder(pub fn() -> MacroActionData);
246
247/// This type must be public so that our macros can build it in other crates.
248/// But this is an implementation detail and should not be used directly.
249#[doc(hidden)]
250pub struct MacroActionData {
251 pub name: &'static str,
252 pub type_id: TypeId,
253 pub build: ActionBuilder,
254 pub json_schema: fn(&mut schemars::SchemaGenerator) -> Option<schemars::Schema>,
255 pub deprecated_aliases: &'static [&'static str],
256 pub deprecation_message: Option<&'static str>,
257}
258
259inventory::collect!(MacroActionBuilder);
260
261impl ActionRegistry {
262 /// Load all registered actions into the registry.
263 pub(crate) fn load_actions(&mut self) {
264 for builder in inventory::iter::<MacroActionBuilder> {
265 let action = builder.0();
266 self.insert_action(action);
267 }
268 }
269
270 #[cfg(test)]
271 pub(crate) fn load_action<A: Action>(&mut self) {
272 self.insert_action(MacroActionData {
273 name: A::name_for_type(),
274 type_id: TypeId::of::<A>(),
275 build: A::build,
276 json_schema: A::action_json_schema,
277 deprecated_aliases: A::deprecated_aliases(),
278 deprecation_message: A::deprecation_message(),
279 });
280 }
281
282 fn insert_action(&mut self, action: MacroActionData) {
283 let name = action.name;
284 if self.by_name.contains_key(name) {
285 panic!(
286 "Action with name `{name}` already registered \
287 (might be registered in `#[action(deprecated_aliases = [...])]`."
288 );
289 }
290 self.by_name.insert(
291 name,
292 ActionData {
293 build: action.build,
294 json_schema: action.json_schema,
295 },
296 );
297 for &alias in action.deprecated_aliases {
298 if self.by_name.contains_key(alias) {
299 panic!(
300 "Action with name `{alias}` already registered. \
301 `{alias}` is specified in `#[action(deprecated_aliases = [...])]` for action `{name}`."
302 );
303 }
304 self.by_name.insert(
305 alias,
306 ActionData {
307 build: action.build,
308 json_schema: action.json_schema,
309 },
310 );
311 self.deprecated_aliases.insert(alias, name);
312 self.all_names.push(alias);
313 }
314 self.names_by_type_id.insert(action.type_id, name);
315 self.all_names.push(name);
316 if let Some(deprecation_msg) = action.deprecation_message {
317 self.deprecation_messages.insert(name, deprecation_msg);
318 }
319 }
320
321 /// Construct an action based on its name and optional JSON parameters sourced from the keymap.
322 pub fn build_action_type(&self, type_id: &TypeId) -> Result<Box<dyn Action>> {
323 let name = self
324 .names_by_type_id
325 .get(type_id)
326 .with_context(|| format!("no action type registered for {type_id:?}"))?;
327
328 Ok(self.build_action(name, None)?)
329 }
330
331 /// Construct an action based on its name and optional JSON parameters sourced from the keymap.
332 pub fn build_action(
333 &self,
334 name: &str,
335 params: Option<serde_json::Value>,
336 ) -> std::result::Result<Box<dyn Action>, ActionBuildError> {
337 let build_action = self
338 .by_name
339 .get(name)
340 .ok_or_else(|| ActionBuildError::NotFound {
341 name: name.to_owned(),
342 })?
343 .build;
344 (build_action)(params.unwrap_or_else(|| json!({}))).map_err(|e| {
345 ActionBuildError::BuildError {
346 name: name.to_owned(),
347 error: e,
348 }
349 })
350 }
351
352 pub fn all_action_names(&self) -> &[&'static str] {
353 self.all_names.as_slice()
354 }
355
356 pub fn action_schemas(
357 &self,
358 generator: &mut schemars::SchemaGenerator,
359 ) -> Vec<(&'static str, Option<schemars::Schema>)> {
360 // Use the order from all_names so that the resulting schema has sensible order.
361 self.all_names
362 .iter()
363 .map(|name| {
364 let action_data = self
365 .by_name
366 .get(name)
367 .expect("All actions in all_names should be registered");
368 (*name, (action_data.json_schema)(generator))
369 })
370 .collect::<Vec<_>>()
371 }
372
373 pub fn deprecated_aliases(&self) -> &HashMap<&'static str, &'static str> {
374 &self.deprecated_aliases
375 }
376
377 pub fn deprecation_messages(&self) -> &HashMap<&'static str, &'static str> {
378 &self.deprecation_messages
379 }
380}
381
382/// Generate a list of all the registered actions.
383/// Useful for transforming the list of available actions into a
384/// format suited for static analysis such as in validating keymaps, or
385/// generating documentation.
386pub fn generate_list_of_all_registered_actions() -> Vec<MacroActionData> {
387 let mut actions = Vec::new();
388 for builder in inventory::iter::<MacroActionBuilder> {
389 actions.push(builder.0());
390 }
391 actions
392}
393
394mod no_action {
395 use crate as gpui;
396 use std::any::Any as _;
397
398 actions!(
399 zed,
400 [
401 /// Action with special handling which unbinds the keybinding this is associated with,
402 /// if it is the highest precedence match.
403 NoAction
404 ]
405 );
406
407 /// Returns whether or not this action represents a removed key binding.
408 pub fn is_no_action(action: &dyn gpui::Action) -> bool {
409 action.as_any().type_id() == (NoAction {}).type_id()
410 }
411}