keymap.rs

  1mod binding;
  2mod context;
  3
  4pub use binding::*;
  5pub use context::*;
  6
  7use crate::{Action, Keystroke, is_no_action};
  8use collections::HashMap;
  9use smallvec::SmallVec;
 10use std::any::TypeId;
 11
 12/// An opaque identifier of which version of the keymap is currently active.
 13/// The keymap's version is changed whenever bindings are added or removed.
 14#[derive(Copy, Clone, Eq, PartialEq, Default)]
 15pub struct KeymapVersion(usize);
 16
 17/// A collection of key bindings for the user's application.
 18#[derive(Default)]
 19pub struct Keymap {
 20    bindings: Vec<KeyBinding>,
 21    binding_indices_by_action_id: HashMap<TypeId, SmallVec<[usize; 3]>>,
 22    no_action_binding_indices: Vec<usize>,
 23    version: KeymapVersion,
 24}
 25
 26impl Keymap {
 27    /// Create a new keymap with the given bindings.
 28    pub fn new(bindings: Vec<KeyBinding>) -> Self {
 29        let mut this = Self::default();
 30        this.add_bindings(bindings);
 31        this
 32    }
 33
 34    /// Get the current version of the keymap.
 35    pub fn version(&self) -> KeymapVersion {
 36        self.version
 37    }
 38
 39    /// Add more bindings to the keymap.
 40    pub fn add_bindings<T: IntoIterator<Item = KeyBinding>>(&mut self, bindings: T) {
 41        for binding in bindings {
 42            let action_id = binding.action().as_any().type_id();
 43            if is_no_action(&*binding.action) {
 44                self.no_action_binding_indices.push(self.bindings.len());
 45            } else {
 46                self.binding_indices_by_action_id
 47                    .entry(action_id)
 48                    .or_default()
 49                    .push(self.bindings.len());
 50            }
 51            self.bindings.push(binding);
 52        }
 53
 54        self.version.0 += 1;
 55    }
 56
 57    /// Reset this keymap to its initial state.
 58    pub fn clear(&mut self) {
 59        self.bindings.clear();
 60        self.binding_indices_by_action_id.clear();
 61        self.no_action_binding_indices.clear();
 62        self.version.0 += 1;
 63    }
 64
 65    /// Iterate over all bindings, in the order they were added.
 66    pub fn bindings(&self) -> impl DoubleEndedIterator<Item = &KeyBinding> {
 67        self.bindings.iter()
 68    }
 69
 70    /// Iterate over all bindings for the given action, in the order they were added. For display,
 71    /// the last binding should take precedence.
 72    pub fn bindings_for_action<'a>(
 73        &'a self,
 74        action: &'a dyn Action,
 75    ) -> impl 'a + DoubleEndedIterator<Item = &'a KeyBinding> {
 76        let action_id = action.type_id();
 77        let binding_indices = self
 78            .binding_indices_by_action_id
 79            .get(&action_id)
 80            .map_or(&[] as _, SmallVec::as_slice)
 81            .iter();
 82
 83        binding_indices.filter_map(|ix| {
 84            let binding = &self.bindings[*ix];
 85            if !binding.action().partial_eq(action) {
 86                return None;
 87            }
 88
 89            for null_ix in &self.no_action_binding_indices {
 90                if null_ix > ix {
 91                    let null_binding = &self.bindings[*null_ix];
 92                    if null_binding.keystrokes == binding.keystrokes {
 93                        let null_binding_matches =
 94                            match (&null_binding.context_predicate, &binding.context_predicate) {
 95                                (None, _) => true,
 96                                (Some(_), None) => false,
 97                                (Some(null_predicate), Some(predicate)) => {
 98                                    null_predicate.is_superset(predicate)
 99                                }
100                            };
101                        if null_binding_matches {
102                            return None;
103                        }
104                    }
105                }
106            }
107
108            Some(binding)
109        })
110    }
111
112    /// Returns all bindings that might match the input without checking context. The bindings
113    /// returned in precedence order (reverse of the order they were added to the keymap).
114    pub fn all_bindings_for_input(&self, input: &[Keystroke]) -> Vec<KeyBinding> {
115        self.bindings()
116            .rev()
117            .filter_map(|binding| {
118                binding.match_keystrokes(input).filter(|pending| !pending)?;
119                Some(binding.clone())
120            })
121            .collect()
122    }
123
124    /// Returns a list of bindings that match the given input, and a boolean indicating whether or
125    /// not more bindings might match if the input was longer. Bindings are returned in precedence
126    /// order.
127    ///
128    /// Precedence is defined by the depth in the tree (matches on the Editor take precedence over
129    /// matches on the Pane, then the Workspace, etc.). Bindings with no context are treated as the
130    /// same as the deepest context.
131    ///
132    /// In the case of multiple bindings at the same depth, the ones added to the keymap later take
133    /// precedence. User bindings are added after built-in bindings so that they take precedence.
134    ///
135    /// If a user has disabled a binding with `"x": null` it will not be returned. Disabled bindings
136    /// are evaluated with the same precedence rules so you can disable a rule in a given context
137    /// only.
138    pub fn bindings_for_input(
139        &self,
140        input: &[Keystroke],
141        context_stack: &[KeyContext],
142    ) -> (SmallVec<[KeyBinding; 1]>, bool) {
143        let possibilities = self.bindings().rev().filter_map(|binding| {
144            binding
145                .match_keystrokes(input)
146                .map(|pending| (binding, pending))
147        });
148
149        let mut bindings: SmallVec<[(KeyBinding, usize); 1]> = SmallVec::new();
150
151        // (pending, is_no_action, depth, keystrokes)
152        let mut pending_info_opt: Option<(bool, bool, usize, &[Keystroke])> = None;
153
154        'outer: for (binding, pending) in possibilities {
155            for depth in (0..=context_stack.len()).rev() {
156                if self.binding_enabled(binding, &context_stack[0..depth]) {
157                    let is_no_action = is_no_action(&*binding.action);
158                    // We only want to consider a binding pending if it has an action
159                    // This, however, means that if we have both a NoAction binding and a binding
160                    // with an action at the same depth, we should still set is_pending to true.
161                    if let Some(pending_info) = pending_info_opt.as_mut() {
162                        let (
163                            already_pending,
164                            pending_is_no_action,
165                            pending_depth,
166                            pending_keystrokes,
167                        ) = *pending_info;
168
169                        // We only want to change the pending status if it's not already pending AND if
170                        // the existing pending status was set by a NoAction binding. This avoids a NoAction
171                        // binding erroneously setting the pending status to true when a binding with an action
172                        // already set it to false
173                        //
174                        // We also want to change the pending status if the keystrokes don't match,
175                        // meaning it's different keystrokes than the NoAction that set pending to false
176                        if pending
177                            && !already_pending
178                            && pending_is_no_action
179                            && (pending_depth == depth
180                                || pending_keystrokes != binding.keystrokes())
181                        {
182                            pending_info.0 = !is_no_action;
183                        }
184                    } else {
185                        pending_info_opt = Some((
186                            pending && !is_no_action,
187                            is_no_action,
188                            depth,
189                            binding.keystrokes(),
190                        ));
191                    }
192
193                    if !pending {
194                        bindings.push((binding.clone(), depth));
195                        continue 'outer;
196                    }
197                }
198            }
199        }
200        bindings.sort_by(|a, b| a.1.cmp(&b.1).reverse());
201        let bindings = bindings
202            .into_iter()
203            .map_while(|(binding, _)| {
204                if is_no_action(&*binding.action) {
205                    None
206                } else {
207                    Some(binding)
208                }
209            })
210            .collect();
211
212        (bindings, pending_info_opt.unwrap_or_default().0)
213    }
214
215    /// Check if the given binding is enabled, given a certain key context.
216    fn binding_enabled(&self, binding: &KeyBinding, context: &[KeyContext]) -> bool {
217        // If binding has a context predicate, it must match the current context,
218        if let Some(predicate) = &binding.context_predicate {
219            if !predicate.eval(context) {
220                return false;
221            }
222        }
223
224        true
225    }
226
227    /// WARN: Assumes the bindings are in the order they were added to the keymap
228    /// returns the last binding for the given bindings, which
229    /// should be the user's binding in their keymap.json if they've set one,
230    /// otherwise, the last declared binding for this action in the base keymaps
231    /// (with Vim mode bindings being considered as declared later if Vim mode
232    /// is enabled)
233    ///
234    /// If you are considering changing the behavior of this function
235    /// (especially to fix a user reported issue) see issues #23621, #24931,
236    /// and possibly others as evidence that it has swapped back and forth a
237    /// couple times. The decision as of now is to pick a side and leave it
238    /// as is, until we have a better way to decide which binding to display
239    /// that is consistent and not confusing.
240    pub fn binding_to_display_from_bindings(mut bindings: Vec<KeyBinding>) -> Option<KeyBinding> {
241        bindings.pop()
242    }
243
244    /// Returns the first binding present in the iterator, which tends to be the
245    /// default binding without any key context. This is useful for cases where no
246    /// key context is available on binding display. Otherwise, bindings with a
247    /// more specific key context would take precedence and result in a
248    /// potentially invalid keybind being returned.
249    pub fn default_binding_from_bindings_iterator<'a>(
250        mut bindings: impl Iterator<Item = &'a KeyBinding>,
251    ) -> Option<&'a KeyBinding> {
252        bindings.next()
253    }
254}
255
256#[cfg(test)]
257mod tests {
258    use super::*;
259    use crate as gpui;
260    use gpui::{NoAction, actions};
261
262    actions!(
263        keymap_test,
264        [ActionAlpha, ActionBeta, ActionGamma, ActionDelta,]
265    );
266
267    #[test]
268    fn test_keymap() {
269        let bindings = [
270            KeyBinding::new("ctrl-a", ActionAlpha {}, None),
271            KeyBinding::new("ctrl-a", ActionBeta {}, Some("pane")),
272            KeyBinding::new("ctrl-a", ActionGamma {}, Some("editor && mode==full")),
273        ];
274
275        let mut keymap = Keymap::default();
276        keymap.add_bindings(bindings.clone());
277
278        // global bindings are enabled in all contexts
279        assert!(keymap.binding_enabled(&bindings[0], &[]));
280        assert!(keymap.binding_enabled(&bindings[0], &[KeyContext::parse("terminal").unwrap()]));
281
282        // contextual bindings are enabled in contexts that match their predicate
283        assert!(!keymap.binding_enabled(&bindings[1], &[KeyContext::parse("barf x=y").unwrap()]));
284        assert!(keymap.binding_enabled(&bindings[1], &[KeyContext::parse("pane x=y").unwrap()]));
285
286        assert!(!keymap.binding_enabled(&bindings[2], &[KeyContext::parse("editor").unwrap()]));
287        assert!(keymap.binding_enabled(
288            &bindings[2],
289            &[KeyContext::parse("editor mode=full").unwrap()]
290        ));
291    }
292
293    #[test]
294    fn test_keymap_disabled() {
295        let bindings = [
296            KeyBinding::new("ctrl-a", ActionAlpha {}, Some("editor")),
297            KeyBinding::new("ctrl-b", ActionAlpha {}, Some("editor")),
298            KeyBinding::new("ctrl-a", NoAction {}, Some("editor && mode==full")),
299            KeyBinding::new("ctrl-b", NoAction {}, None),
300        ];
301
302        let mut keymap = Keymap::default();
303        keymap.add_bindings(bindings.clone());
304
305        // binding is only enabled in a specific context
306        assert!(
307            keymap
308                .bindings_for_input(
309                    &[Keystroke::parse("ctrl-a").unwrap()],
310                    &[KeyContext::parse("barf").unwrap()],
311                )
312                .0
313                .is_empty()
314        );
315        assert!(
316            !keymap
317                .bindings_for_input(
318                    &[Keystroke::parse("ctrl-a").unwrap()],
319                    &[KeyContext::parse("editor").unwrap()],
320                )
321                .0
322                .is_empty()
323        );
324
325        // binding is disabled in a more specific context
326        assert!(
327            keymap
328                .bindings_for_input(
329                    &[Keystroke::parse("ctrl-a").unwrap()],
330                    &[KeyContext::parse("editor mode=full").unwrap()],
331                )
332                .0
333                .is_empty()
334        );
335
336        // binding is globally disabled
337        assert!(
338            keymap
339                .bindings_for_input(
340                    &[Keystroke::parse("ctrl-b").unwrap()],
341                    &[KeyContext::parse("barf").unwrap()],
342                )
343                .0
344                .is_empty()
345        );
346    }
347
348    #[test]
349    /// Tests for https://github.com/zed-industries/zed/issues/30259
350    fn test_multiple_keystroke_binding_disabled() {
351        let bindings = [
352            KeyBinding::new("space w w", ActionAlpha {}, Some("workspace")),
353            KeyBinding::new("space w w", NoAction {}, Some("editor")),
354        ];
355
356        let mut keymap = Keymap::default();
357        keymap.add_bindings(bindings.clone());
358
359        let space = || Keystroke::parse("space").unwrap();
360        let w = || Keystroke::parse("w").unwrap();
361
362        let space_w = [space(), w()];
363        let space_w_w = [space(), w(), w()];
364
365        let workspace_context = || [KeyContext::parse("workspace").unwrap()];
366
367        let editor_workspace_context = || {
368            [
369                KeyContext::parse("workspace").unwrap(),
370                KeyContext::parse("editor").unwrap(),
371            ]
372        };
373
374        // Ensure `space` results in pending input on the workspace, but not editor
375        let space_workspace = keymap.bindings_for_input(&[space()], &workspace_context());
376        assert!(space_workspace.0.is_empty());
377        assert_eq!(space_workspace.1, true);
378
379        let space_editor = keymap.bindings_for_input(&[space()], &editor_workspace_context());
380        assert!(space_editor.0.is_empty());
381        assert_eq!(space_editor.1, false);
382
383        // Ensure `space w` results in pending input on the workspace, but not editor
384        let space_w_workspace = keymap.bindings_for_input(&space_w, &workspace_context());
385        assert!(space_w_workspace.0.is_empty());
386        assert_eq!(space_w_workspace.1, true);
387
388        let space_w_editor = keymap.bindings_for_input(&space_w, &editor_workspace_context());
389        assert!(space_w_editor.0.is_empty());
390        assert_eq!(space_w_editor.1, false);
391
392        // Ensure `space w w` results in the binding in the workspace, but not in the editor
393        let space_w_w_workspace = keymap.bindings_for_input(&space_w_w, &workspace_context());
394        assert!(!space_w_w_workspace.0.is_empty());
395        assert_eq!(space_w_w_workspace.1, false);
396
397        let space_w_w_editor = keymap.bindings_for_input(&space_w_w, &editor_workspace_context());
398        assert!(space_w_w_editor.0.is_empty());
399        assert_eq!(space_w_w_editor.1, false);
400
401        // Now test what happens if we have another binding defined AFTER the NoAction
402        // that should result in pending
403        let bindings = [
404            KeyBinding::new("space w w", ActionAlpha {}, Some("workspace")),
405            KeyBinding::new("space w w", NoAction {}, Some("editor")),
406            KeyBinding::new("space w x", ActionAlpha {}, Some("editor")),
407        ];
408        let mut keymap = Keymap::default();
409        keymap.add_bindings(bindings.clone());
410
411        let space_editor = keymap.bindings_for_input(&[space()], &editor_workspace_context());
412        assert!(space_editor.0.is_empty());
413        assert_eq!(space_editor.1, true);
414
415        // Now test what happens if we have another binding defined BEFORE the NoAction
416        // that should result in pending
417        let bindings = [
418            KeyBinding::new("space w w", ActionAlpha {}, Some("workspace")),
419            KeyBinding::new("space w x", ActionAlpha {}, Some("editor")),
420            KeyBinding::new("space w w", NoAction {}, Some("editor")),
421        ];
422        let mut keymap = Keymap::default();
423        keymap.add_bindings(bindings.clone());
424
425        let space_editor = keymap.bindings_for_input(&[space()], &editor_workspace_context());
426        assert!(space_editor.0.is_empty());
427        assert_eq!(space_editor.1, true);
428
429        // Now test what happens if we have another binding defined at a higher context
430        // that should result in pending
431        let bindings = [
432            KeyBinding::new("space w w", ActionAlpha {}, Some("workspace")),
433            KeyBinding::new("space w x", ActionAlpha {}, Some("workspace")),
434            KeyBinding::new("space w w", NoAction {}, Some("editor")),
435        ];
436        let mut keymap = Keymap::default();
437        keymap.add_bindings(bindings.clone());
438
439        let space_editor = keymap.bindings_for_input(&[space()], &editor_workspace_context());
440        assert!(space_editor.0.is_empty());
441        assert_eq!(space_editor.1, true);
442    }
443
444    #[test]
445    fn test_bindings_for_action() {
446        let bindings = [
447            KeyBinding::new("ctrl-a", ActionAlpha {}, Some("pane")),
448            KeyBinding::new("ctrl-b", ActionBeta {}, Some("editor && mode == full")),
449            KeyBinding::new("ctrl-c", ActionGamma {}, Some("workspace")),
450            KeyBinding::new("ctrl-a", NoAction {}, Some("pane && active")),
451            KeyBinding::new("ctrl-b", NoAction {}, Some("editor")),
452        ];
453
454        let mut keymap = Keymap::default();
455        keymap.add_bindings(bindings.clone());
456
457        assert_bindings(&keymap, &ActionAlpha {}, &["ctrl-a"]);
458        assert_bindings(&keymap, &ActionBeta {}, &[]);
459        assert_bindings(&keymap, &ActionGamma {}, &["ctrl-c"]);
460
461        #[track_caller]
462        fn assert_bindings(keymap: &Keymap, action: &dyn Action, expected: &[&str]) {
463            let actual = keymap
464                .bindings_for_action(action)
465                .map(|binding| binding.keystrokes[0].unparse())
466                .collect::<Vec<_>>();
467            assert_eq!(actual, expected, "{:?}", action);
468        }
469    }
470}