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(
129 _: &mut schemars::r#gen::SchemaGenerator,
130 ) -> Option<schemars::schema::Schema>
131 where
132 Self: Sized,
133 {
134 None
135 }
136
137 /// A list of alternate, deprecated names for this action. These names can still be used to
138 /// invoke the action. In Zed, the keymap JSON schema will accept these old names and provide
139 /// warnings.
140 fn deprecated_aliases() -> &'static [&'static str]
141 where
142 Self: Sized,
143 {
144 &[]
145 }
146
147 /// Returns the deprecation message for this action, if any. In Zed, the keymap JSON schema will
148 /// cause this to be displayed as a warning.
149 fn deprecation_message() -> Option<&'static str>
150 where
151 Self: Sized,
152 {
153 None
154 }
155}
156
157impl std::fmt::Debug for dyn Action {
158 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
159 f.debug_struct("dyn Action")
160 .field("name", &self.name())
161 .finish()
162 }
163}
164
165impl dyn Action {
166 /// Type-erase Action type.
167 pub fn as_any(&self) -> &dyn Any {
168 self as &dyn Any
169 }
170}
171
172/// Error type for `Keystroke::parse`. This is used instead of `anyhow::Error` so that Zed can use
173/// markdown to display it.
174#[derive(Debug)]
175pub enum ActionBuildError {
176 /// Indicates that an action with this name has not been registered.
177 NotFound {
178 /// Name of the action that was not found.
179 name: String,
180 },
181 /// Indicates that an error occurred while building the action, typically a JSON deserialization
182 /// error.
183 BuildError {
184 /// Name of the action that was attempting to be built.
185 name: String,
186 /// Error that occurred while building the action.
187 error: anyhow::Error,
188 },
189}
190
191impl std::error::Error for ActionBuildError {
192 fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
193 match self {
194 ActionBuildError::NotFound { .. } => None,
195 ActionBuildError::BuildError { error, .. } => error.source(),
196 }
197 }
198}
199
200impl Display for ActionBuildError {
201 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
202 match self {
203 ActionBuildError::NotFound { name } => {
204 write!(f, "Didn't find an action named \"{name}\"")
205 }
206 ActionBuildError::BuildError { name, error } => {
207 write!(f, "Error while building action \"{name}\": {error}")
208 }
209 }
210 }
211}
212
213type ActionBuilder = fn(json: serde_json::Value) -> anyhow::Result<Box<dyn Action>>;
214
215pub(crate) struct ActionRegistry {
216 by_name: HashMap<&'static str, ActionData>,
217 names_by_type_id: HashMap<TypeId, &'static str>,
218 all_names: Vec<&'static str>, // So we can return a static slice.
219 deprecated_aliases: HashMap<&'static str, &'static str>, // deprecated name -> preferred name
220 deprecation_messages: HashMap<&'static str, &'static str>, // action name -> deprecation message
221}
222
223impl Default for ActionRegistry {
224 fn default() -> Self {
225 let mut this = ActionRegistry {
226 by_name: Default::default(),
227 names_by_type_id: Default::default(),
228 all_names: Default::default(),
229 deprecated_aliases: Default::default(),
230 deprecation_messages: Default::default(),
231 };
232
233 this.load_actions();
234
235 this
236 }
237}
238
239struct ActionData {
240 pub build: ActionBuilder,
241 pub json_schema: fn(&mut schemars::r#gen::SchemaGenerator) -> Option<schemars::schema::Schema>,
242}
243
244/// This type must be public so that our macros can build it in other crates.
245/// But this is an implementation detail and should not be used directly.
246#[doc(hidden)]
247pub struct MacroActionBuilder(pub fn() -> MacroActionData);
248
249/// This type must be public so that our macros can build it in other crates.
250/// But this is an implementation detail and should not be used directly.
251#[doc(hidden)]
252pub struct MacroActionData {
253 pub name: &'static str,
254 pub type_id: TypeId,
255 pub build: ActionBuilder,
256 pub json_schema: fn(&mut schemars::r#gen::SchemaGenerator) -> Option<schemars::schema::Schema>,
257 pub deprecated_aliases: &'static [&'static str],
258 pub deprecation_message: Option<&'static str>,
259}
260
261inventory::collect!(MacroActionBuilder);
262
263impl ActionRegistry {
264 /// Load all registered actions into the registry.
265 pub(crate) fn load_actions(&mut self) {
266 for builder in inventory::iter::<MacroActionBuilder> {
267 let action = builder.0();
268 self.insert_action(action);
269 }
270 }
271
272 #[cfg(test)]
273 pub(crate) fn load_action<A: Action>(&mut self) {
274 self.insert_action(MacroActionData {
275 name: A::name_for_type(),
276 type_id: TypeId::of::<A>(),
277 build: A::build,
278 json_schema: A::action_json_schema,
279 deprecated_aliases: A::deprecated_aliases(),
280 deprecation_message: A::deprecation_message(),
281 });
282 }
283
284 fn insert_action(&mut self, action: MacroActionData) {
285 let name = action.name;
286 if self.by_name.contains_key(name) {
287 panic!(
288 "Action with name `{name}` already registered \
289 (might be registered in `#[action(deprecated_aliases = [...])]`."
290 );
291 }
292 self.by_name.insert(
293 name,
294 ActionData {
295 build: action.build,
296 json_schema: action.json_schema,
297 },
298 );
299 for &alias in action.deprecated_aliases {
300 if self.by_name.contains_key(alias) {
301 panic!(
302 "Action with name `{alias}` already registered. \
303 `{alias}` is specified in `#[action(deprecated_aliases = [...])]` for action `{name}`."
304 );
305 }
306 self.by_name.insert(
307 alias,
308 ActionData {
309 build: action.build,
310 json_schema: action.json_schema,
311 },
312 );
313 self.deprecated_aliases.insert(alias, name);
314 self.all_names.push(alias);
315 }
316 self.names_by_type_id.insert(action.type_id, name);
317 self.all_names.push(name);
318 if let Some(deprecation_msg) = action.deprecation_message {
319 self.deprecation_messages.insert(name, deprecation_msg);
320 }
321 }
322
323 /// Construct an action based on its name and optional JSON parameters sourced from the keymap.
324 pub fn build_action_type(&self, type_id: &TypeId) -> Result<Box<dyn Action>> {
325 let name = self
326 .names_by_type_id
327 .get(type_id)
328 .with_context(|| format!("no action type registered for {type_id:?}"))?;
329
330 Ok(self.build_action(name, None)?)
331 }
332
333 /// Construct an action based on its name and optional JSON parameters sourced from the keymap.
334 pub fn build_action(
335 &self,
336 name: &str,
337 params: Option<serde_json::Value>,
338 ) -> std::result::Result<Box<dyn Action>, ActionBuildError> {
339 let build_action = self
340 .by_name
341 .get(name)
342 .ok_or_else(|| ActionBuildError::NotFound {
343 name: name.to_owned(),
344 })?
345 .build;
346 (build_action)(params.unwrap_or_else(|| json!({}))).map_err(|e| {
347 ActionBuildError::BuildError {
348 name: name.to_owned(),
349 error: e,
350 }
351 })
352 }
353
354 pub fn all_action_names(&self) -> &[&'static str] {
355 self.all_names.as_slice()
356 }
357
358 pub fn action_schemas(
359 &self,
360 generator: &mut schemars::r#gen::SchemaGenerator,
361 ) -> Vec<(&'static str, Option<schemars::schema::Schema>)> {
362 // Use the order from all_names so that the resulting schema has sensible order.
363 self.all_names
364 .iter()
365 .map(|name| {
366 let action_data = self
367 .by_name
368 .get(name)
369 .expect("All actions in all_names should be registered");
370 (*name, (action_data.json_schema)(generator))
371 })
372 .collect::<Vec<_>>()
373 }
374
375 pub fn deprecated_aliases(&self) -> &HashMap<&'static str, &'static str> {
376 &self.deprecated_aliases
377 }
378
379 pub fn deprecation_messages(&self) -> &HashMap<&'static str, &'static str> {
380 &self.deprecation_messages
381 }
382}
383
384/// Generate a list of all the registered actions.
385/// Useful for transforming the list of available actions into a
386/// format suited for static analysis such as in validating keymaps, or
387/// generating documentation.
388pub fn generate_list_of_all_registered_actions() -> Vec<MacroActionData> {
389 let mut actions = Vec::new();
390 for builder in inventory::iter::<MacroActionBuilder> {
391 actions.push(builder.0());
392 }
393 actions
394}
395
396mod no_action {
397 use crate as gpui;
398 use std::any::Any as _;
399
400 actions!(
401 zed,
402 [
403 /// Action with special handling which unbinds the keybinding this is associated with,
404 /// if it is the highest precedence match.
405 NoAction
406 ]
407 );
408
409 /// Returns whether or not this action represents a removed key binding.
410 pub fn is_no_action(action: &dyn gpui::Action) -> bool {
411 action.as_any().type_id() == (NoAction {}).type_id()
412 }
413}