Checkpoint

crates/gpui3/src/element.rs

@@ -33,7 +33,7 @@ pub trait Element: 'static + Send + Sync + IntoAnyElement<Self::ViewState> {
 }
 
 #[derive(Deref, DerefMut, Default, Clone, Debug, Eq, PartialEq, Hash)]
-pub(crate) struct GlobalElementId(SmallVec<[ElementId; 8]>);
+pub struct GlobalElementId(SmallVec<[ElementId; 8]>);
 
 pub trait ElementIdentity: 'static + Send + Sync {
     fn id(&self) -> Option<ElementId>;

crates/gpui3/src/elements/div.rs

@@ -1,10 +1,10 @@
 use crate::{
     Active, Anonymous, AnyElement, AppContext, BorrowWindow, Bounds, Click, DispatchPhase, Element,
     ElementFocusability, ElementId, ElementIdentity, EventListeners, Focus, FocusHandle, Focusable,
-    Hover, Identified, Interactive, IntoAnyElement, KeyDownEvent, KeyMatch, LayoutId,
-    MouseClickEvent, MouseDownEvent, MouseMoveEvent, MouseUpEvent, NonFocusable, Overflow,
-    ParentElement, Pixels, Point, ScrollWheelEvent, SharedString, Style, StyleRefinement, Styled,
-    ViewContext,
+    GlobalElementId, Hover, Identified, Interactive, IntoAnyElement, KeyDownEvent, KeyMatch,
+    LayoutId, MouseClickEvent, MouseDownEvent, MouseMoveEvent, MouseUpEvent, NonFocusable,
+    Overflow, ParentElement, Pixels, Point, ScrollWheelEvent, SharedString, Style, StyleRefinement,
+    Styled, ViewContext,
 };
 use collections::HashMap;
 use parking_lot::Mutex;
@@ -188,12 +188,12 @@ where
     fn with_element_id<R>(
         &mut self,
         cx: &mut ViewContext<V>,
-        f: impl FnOnce(&mut Self, &mut ViewContext<V>) -> R,
+        f: impl FnOnce(&mut Self, Option<GlobalElementId>, &mut ViewContext<V>) -> R,
     ) -> R {
         if let Some(id) = self.id() {
-            cx.with_element_id(id, |cx| f(self, cx))
+            cx.with_element_id(id, |global_id, cx| f(self, Some(global_id), cx))
         } else {
-            f(self, cx)
+            f(self, None, cx)
         }
     }
 
@@ -424,46 +424,49 @@ where
         element_state: Option<Self::ElementState>,
         cx: &mut ViewContext<Self::ViewState>,
     ) -> Self::ElementState {
-        let element_state = element_state.unwrap_or_default();
-        for listener in self.listeners.focus.iter().cloned() {
-            cx.on_focus_changed(move |view, event, cx| listener(view, event, cx));
-        }
+        self.with_element_id(cx, |this, global_id, cx| {
+            let element_state = element_state.unwrap_or_default();
+            for listener in this.listeners.focus.iter().cloned() {
+                cx.on_focus_changed(move |view, event, cx| listener(view, event, cx));
+            }
 
-        let mut key_listeners = mem::take(&mut self.listeners.key);
+            let mut key_listeners = mem::take(&mut this.listeners.key);
 
-        if let Some(id) = self.id() {
-            key_listeners.push((
-                TypeId::of::<KeyDownEvent>(),
-                Arc::new(move |_, key_down, phase, cx| {
-                    if phase == DispatchPhase::Bubble {
-                        let key_down = key_down.downcast_ref::<KeyDownEvent>().unwrap();
-                        if let KeyMatch::Some(action) = cx.match_keystroke(&id, &key_down.keystroke)
-                        {
-                            return Some(action);
+            if let Some(global_id) = global_id {
+                key_listeners.push((
+                    TypeId::of::<KeyDownEvent>(),
+                    Arc::new(move |_, key_down, phase, cx| {
+                        if phase == DispatchPhase::Bubble {
+                            let key_down = key_down.downcast_ref::<KeyDownEvent>().unwrap();
+                            if let KeyMatch::Some(action) =
+                                cx.match_keystroke(&global_id, &key_down.keystroke)
+                            {
+                                return Some(action);
+                            }
                         }
-                    }
 
-                    None
-                }),
-            ));
-        }
+                        None
+                    }),
+                ));
+            }
 
-        cx.with_key_listeners(&key_listeners, |cx| {
-            if let Some(focus_handle) = self.focusability.focus_handle().cloned() {
-                cx.with_focus(focus_handle, |cx| {
-                    for child in &mut self.children {
+            cx.with_key_listeners(&key_listeners, |cx| {
+                if let Some(focus_handle) = this.focusability.focus_handle().cloned() {
+                    cx.with_focus(focus_handle, |cx| {
+                        for child in &mut this.children {
+                            child.initialize(view_state, cx);
+                        }
+                    })
+                } else {
+                    for child in &mut this.children {
                         child.initialize(view_state, cx);
                     }
-                })
-            } else {
-                for child in &mut self.children {
-                    child.initialize(view_state, cx);
                 }
-            }
-        });
-        self.listeners.key = key_listeners;
+            });
+            this.listeners.key = key_listeners;
 
-        element_state
+            element_state
+        })
     }
 
     fn layout(
@@ -474,7 +477,7 @@ where
     ) -> LayoutId {
         let style = self.compute_style(Bounds::default(), element_state, cx);
         style.apply_text_style(cx, |cx| {
-            self.with_element_id(cx, |this, cx| {
+            self.with_element_id(cx, |this, _global_id, cx| {
                 let layout_ids = this
                     .children
                     .iter_mut()
@@ -492,7 +495,7 @@ where
         element_state: &mut Self::ElementState,
         cx: &mut ViewContext<Self::ViewState>,
     ) {
-        self.with_element_id(cx, |this, cx| {
+        self.with_element_id(cx, |this, _global_id, cx| {
             if let Some(group) = this.group.clone() {
                 cx.default_global::<GroupBounds>()
                     .0

crates/gpui3/src/events.rs

@@ -1,5 +1,5 @@
 use crate::{
-    point, AnyBox, Bounds, DispatchPhase, FocusHandle, Keystroke, Modifiers, Pixels, Point,
+    point, Action, Bounds, DispatchPhase, FocusHandle, Keystroke, Modifiers, Pixels, Point,
     ViewContext,
 };
 use smallvec::SmallVec;
@@ -256,7 +256,7 @@ pub type ScrollWheelListener<V> = Arc<
 >;
 
 pub type KeyListener<V> = Arc<
-    dyn Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) -> Option<AnyBox>
+    dyn Fn(&mut V, &dyn Any, DispatchPhase, &mut ViewContext<V>) -> Option<Box<dyn Action>>
         + Send
         + Sync
         + 'static,

crates/gpui3/src/gpui3.rs

@@ -11,7 +11,7 @@ mod geometry;
 mod hover;
 mod image_cache;
 mod interactive;
-mod keymap;
+mod keymap_matcher;
 mod platform;
 mod scene;
 mod style;
@@ -39,7 +39,7 @@ pub use gpui3_macros::*;
 pub use hover::*;
 pub use image_cache::*;
 pub use interactive::*;
-pub use keymap::*;
+pub use keymap_matcher::*;
 pub use platform::*;
 pub use refineable::*;
 pub use scene::*;

crates/gpui3/src/keymap.rs

@@ -1,16 +0,0 @@
-use crate::{AnyBox, Keystroke};
-
-#[derive(Default)]
-pub struct KeyMatcher;
-
-impl KeyMatcher {
-    pub fn push_keystroke(&mut self, keystroke: Keystroke) -> KeyMatch {
-        todo!()
-    }
-}
-
-pub enum KeyMatch {
-    None,
-    Pending,
-    Some(AnyBox),
-}

crates/gpui3/src/keymap_matcher.rs

@@ -0,0 +1,488 @@
+mod binding;
+mod keymap;
+mod keymap_context;
+
+pub use binding::*;
+pub use keymap::*;
+pub use keymap_context::*;
+
+use crate::Keystroke;
+use smallvec::SmallVec;
+use std::any::{Any, TypeId};
+
+pub trait Action: Any + Send + Sync {
+    fn partial_eq(&self, action: &dyn Action) -> bool;
+    fn boxed_clone(&self) -> Box<dyn Action>;
+    fn as_any(&self) -> &dyn Any;
+}
+
+pub struct KeymapMatcher {
+    pending_keystrokes: Vec<Keystroke>,
+    keymap: Keymap,
+    keymap_version: KeymapVersion,
+}
+
+impl KeymapMatcher {
+    pub fn new(keymap: Keymap) -> Self {
+        Self {
+            pending_keystrokes: Vec::new(),
+            keymap_version: keymap.version(),
+            keymap,
+        }
+    }
+
+    pub fn bindings_for_action(&self, action_id: TypeId) -> impl Iterator<Item = &Binding> {
+        self.keymap.bindings_for_action(action_id)
+    }
+
+    pub fn clear_pending(&mut self) {
+        self.pending_keystrokes.clear();
+    }
+
+    pub fn has_pending_keystrokes(&self) -> bool {
+        !self.pending_keystrokes.is_empty()
+    }
+
+    /// Pushes a keystroke onto the matcher.
+    /// The result of the new keystroke is returned:
+    ///     KeyMatch::None =>
+    ///         No match is valid for this key given any pending keystrokes.
+    ///     KeyMatch::Pending =>
+    ///         There exist bindings which are still waiting for more keys.
+    ///     KeyMatch::Complete(matches) =>
+    ///         One or more bindings have received the necessary key presses.
+    ///         Bindings added later will take precedence over earlier bindings.
+    pub fn match_keystroke(
+        &mut self,
+        keystroke: &Keystroke,
+        context_stack: &[KeymapContext],
+    ) -> KeyMatch {
+        // Clear pending keystrokes if the keymap has changed since the last matched keystroke.
+        if self.keymap.version() != self.keymap_version {
+            self.keymap_version = self.keymap.version();
+            self.pending_keystrokes.clear();
+        }
+
+        let mut pending_key = None;
+
+        for binding in self.keymap.bindings().iter().rev() {
+            for candidate in keystroke.match_candidates() {
+                self.pending_keystrokes.push(candidate.clone());
+                match binding.match_keystrokes(&self.pending_keystrokes, context_stack) {
+                    KeyMatch::Some(action) => {
+                        self.clear_pending();
+                        return KeyMatch::Some(action);
+                    }
+                    KeyMatch::Pending => {
+                        pending_key.get_or_insert(candidate);
+                    }
+                    KeyMatch::None => {}
+                }
+                self.pending_keystrokes.pop();
+            }
+        }
+
+        if let Some(pending_key) = pending_key {
+            self.pending_keystrokes.push(pending_key);
+        }
+
+        if self.pending_keystrokes.is_empty() {
+            KeyMatch::None
+        } else {
+            KeyMatch::Pending
+        }
+    }
+
+    pub fn keystrokes_for_action(
+        &self,
+        action: &dyn Action,
+        contexts: &[KeymapContext],
+    ) -> Option<SmallVec<[Keystroke; 2]>> {
+        self.keymap
+            .bindings()
+            .iter()
+            .rev()
+            .find_map(|binding| binding.keystrokes_for_action(action, contexts))
+    }
+}
+
+impl Default for KeymapMatcher {
+    fn default() -> Self {
+        Self::new(Keymap::default())
+    }
+}
+
+pub enum KeyMatch {
+    None,
+    Pending,
+    Some(Box<dyn Action>),
+}
+
+impl KeyMatch {
+    pub fn is_some(&self) -> bool {
+        matches!(self, KeyMatch::Some(_))
+    }
+}
+
+// #[cfg(test)]
+// mod tests {
+//     use anyhow::Result;
+//     use serde::Deserialize;
+
+//     use crate::{actions, impl_actions, keymap_matcher::KeymapContext};
+
+//     use super::*;
+
+//     #[test]
+//     fn test_keymap_and_view_ordering() -> Result<()> {
+//         actions!(test, [EditorAction, ProjectPanelAction]);
+
+//         let mut editor = KeymapContext::default();
+//         editor.add_identifier("Editor");
+
+//         let mut project_panel = KeymapContext::default();
+//         project_panel.add_identifier("ProjectPanel");
+
+//         // Editor 'deeper' in than project panel
+//         let dispatch_path = vec![(2, editor), (1, project_panel)];
+
+//         // But editor actions 'higher' up in keymap
+//         let keymap = Keymap::new(vec![
+//             Binding::new("left", EditorAction, Some("Editor")),
+//             Binding::new("left", ProjectPanelAction, Some("ProjectPanel")),
+//         ]);
+
+//         let mut matcher = KeymapMatcher::new(keymap);
+
+//         assert_eq!(
+//             matcher.match_keystroke(Keystroke::parse("left")?, dispatch_path.clone()),
+//             KeyMatch::Matches(vec![
+//                 (2, Box::new(EditorAction)),
+//                 (1, Box::new(ProjectPanelAction)),
+//             ]),
+//         );
+
+//         Ok(())
+//     }
+
+//     #[test]
+//     fn test_push_keystroke() -> Result<()> {
+//         actions!(test, [B, AB, C, D, DA, E, EF]);
+
+//         let mut context1 = KeymapContext::default();
+//         context1.add_identifier("1");
+
+//         let mut context2 = KeymapContext::default();
+//         context2.add_identifier("2");
+
+//         let dispatch_path = vec![(2, context2), (1, context1)];
+
+//         let keymap = Keymap::new(vec![
+//             Binding::new("a b", AB, Some("1")),
+//             Binding::new("b", B, Some("2")),
+//             Binding::new("c", C, Some("2")),
+//             Binding::new("d", D, Some("1")),
+//             Binding::new("d", D, Some("2")),
+//             Binding::new("d a", DA, Some("2")),
+//         ]);
+
+//         let mut matcher = KeymapMatcher::new(keymap);
+
+//         // Binding with pending prefix always takes precedence
+//         assert_eq!(
+//             matcher.match_keystroke(Keystroke::parse("a")?, dispatch_path.clone()),
+//             KeyMatch::Pending,
+//         );
+//         // B alone doesn't match because a was pending, so AB is returned instead
+//         assert_eq!(
+//             matcher.match_keystroke(Keystroke::parse("b")?, dispatch_path.clone()),
+//             KeyMatch::Matches(vec![(1, Box::new(AB))]),
+//         );
+//         assert!(!matcher.has_pending_keystrokes());
+
+//         // Without an a prefix, B is dispatched like expected
+//         assert_eq!(
+//             matcher.match_keystroke(Keystroke::parse("b")?, dispatch_path.clone()),
+//             KeyMatch::Matches(vec![(2, Box::new(B))]),
+//         );
+//         assert!(!matcher.has_pending_keystrokes());
+
+//         // If a is prefixed, C will not be dispatched because there
+//         // was a pending binding for it
+//         assert_eq!(
+//             matcher.match_keystroke(Keystroke::parse("a")?, dispatch_path.clone()),
+//             KeyMatch::Pending,
+//         );
+//         assert_eq!(
+//             matcher.match_keystroke(Keystroke::parse("c")?, dispatch_path.clone()),
+//             KeyMatch::None,
+//         );
+//         assert!(!matcher.has_pending_keystrokes());
+
+//         // If a single keystroke matches multiple bindings in the tree
+//         // all of them are returned so that we can fallback if the action
+//         // handler decides to propagate the action
+//         assert_eq!(
+//             matcher.match_keystroke(Keystroke::parse("d")?, dispatch_path.clone()),
+//             KeyMatch::Matches(vec![(2, Box::new(D)), (1, Box::new(D))]),
+//         );
+
+//         // If none of the d action handlers consume the binding, a pending
+//         // binding may then be used
+//         assert_eq!(
+//             matcher.match_keystroke(Keystroke::parse("a")?, dispatch_path.clone()),
+//             KeyMatch::Matches(vec![(2, Box::new(DA))]),
+//         );
+//         assert!(!matcher.has_pending_keystrokes());
+
+//         Ok(())
+//     }
+
+//     #[test]
+//     fn test_keystroke_parsing() -> Result<()> {
+//         assert_eq!(
+//             Keystroke::parse("ctrl-p")?,
+//             Keystroke {
+//                 key: "p".into(),
+//                 ctrl: true,
+//                 alt: false,
+//                 shift: false,
+//                 cmd: false,
+//                 function: false,
+//                 ime_key: None,
+//             }
+//         );
+
+//         assert_eq!(
+//             Keystroke::parse("alt-shift-down")?,
+//             Keystroke {
+//                 key: "down".into(),
+//                 ctrl: false,
+//                 alt: true,
+//                 shift: true,
+//                 cmd: false,
+//                 function: false,
+//                 ime_key: None,
+//             }
+//         );
+
+//         assert_eq!(
+//             Keystroke::parse("shift-cmd--")?,
+//             Keystroke {
+//                 key: "-".into(),
+//                 ctrl: false,
+//                 alt: false,
+//                 shift: true,
+//                 cmd: true,
+//                 function: false,
+//                 ime_key: None,
+//             }
+//         );
+
+//         Ok(())
+//     }
+
+//     #[test]
+//     fn test_context_predicate_parsing() -> Result<()> {
+//         use KeymapContextPredicate::*;
+
+//         assert_eq!(
+//             KeymapContextPredicate::parse("a && (b == c || d != e)")?,
+//             And(
+//                 Box::new(Identifier("a".into())),
+//                 Box::new(Or(
+//                     Box::new(Equal("b".into(), "c".into())),
+//                     Box::new(NotEqual("d".into(), "e".into())),
+//                 ))
+//             )
+//         );
+
+//         assert_eq!(
+//             KeymapContextPredicate::parse("!a")?,
+//             Not(Box::new(Identifier("a".into())),)
+//         );
+
+//         Ok(())
+//     }
+
+//     #[test]
+//     fn test_context_predicate_eval() {
+//         let predicate = KeymapContextPredicate::parse("a && b || c == d").unwrap();
+
+//         let mut context = KeymapContext::default();
+//         context.add_identifier("a");
+//         assert!(!predicate.eval(&[context]));
+
+//         let mut context = KeymapContext::default();
+//         context.add_identifier("a");
+//         context.add_identifier("b");
+//         assert!(predicate.eval(&[context]));
+
+//         let mut context = KeymapContext::default();
+//         context.add_identifier("a");
+//         context.add_key("c", "x");
+//         assert!(!predicate.eval(&[context]));
+
+//         let mut context = KeymapContext::default();
+//         context.add_identifier("a");
+//         context.add_key("c", "d");
+//         assert!(predicate.eval(&[context]));
+
+//         let predicate = KeymapContextPredicate::parse("!a").unwrap();
+//         assert!(predicate.eval(&[KeymapContext::default()]));
+//     }
+
+//     #[test]
+//     fn test_context_child_predicate_eval() {
+//         let predicate = KeymapContextPredicate::parse("a && b > c").unwrap();
+//         let contexts = [
+//             context_set(&["e", "f"]),
+//             context_set(&["c", "d"]), // match this context
+//             context_set(&["a", "b"]),
+//         ];
+
+//         assert!(!predicate.eval(&contexts[0..]));
+//         assert!(predicate.eval(&contexts[1..]));
+//         assert!(!predicate.eval(&contexts[2..]));
+
+//         let predicate = KeymapContextPredicate::parse("a && b > c && !d > e").unwrap();
+//         let contexts = [
+//             context_set(&["f"]),
+//             context_set(&["e"]), // only match this context
+//             context_set(&["c"]),
+//             context_set(&["a", "b"]),
+//             context_set(&["e"]),
+//             context_set(&["c", "d"]),
+//             context_set(&["a", "b"]),
+//         ];
+
+//         assert!(!predicate.eval(&contexts[0..]));
+//         assert!(predicate.eval(&contexts[1..]));
+//         assert!(!predicate.eval(&contexts[2..]));
+//         assert!(!predicate.eval(&contexts[3..]));
+//         assert!(!predicate.eval(&contexts[4..]));
+//         assert!(!predicate.eval(&contexts[5..]));
+//         assert!(!predicate.eval(&contexts[6..]));
+
+//         fn context_set(names: &[&str]) -> KeymapContext {
+//             let mut keymap = KeymapContext::new();
+//             names
+//                 .iter()
+//                 .for_each(|name| keymap.add_identifier(name.to_string()));
+//             keymap
+//         }
+//     }
+
+//     #[test]
+//     fn test_matcher() -> Result<()> {
+//         #[derive(Clone, Deserialize, PartialEq, Eq, Debug)]
+//         pub struct A(pub String);
+//         impl_actions!(test, [A]);
+//         actions!(test, [B, Ab, Dollar, Quote, Ess, Backtick]);
+
+//         #[derive(Clone, Debug, Eq, PartialEq)]
+//         struct ActionArg {
+//             a: &'static str,
+//         }
+
+//         let keymap = Keymap::new(vec![
+//             Binding::new("a", A("x".to_string()), Some("a")),
+//             Binding::new("b", B, Some("a")),
+//             Binding::new("a b", Ab, Some("a || b")),
+//             Binding::new("$", Dollar, Some("a")),
+//             Binding::new("\"", Quote, Some("a")),
+//             Binding::new("alt-s", Ess, Some("a")),
+//             Binding::new("ctrl-`", Backtick, Some("a")),
+//         ]);
+
+//         let mut context_a = KeymapContext::default();
+//         context_a.add_identifier("a");
+
+//         let mut context_b = KeymapContext::default();
+//         context_b.add_identifier("b");
+
+//         let mut matcher = KeymapMatcher::new(keymap);
+
+//         // Basic match
+//         assert_eq!(
+//             matcher.match_keystroke(Keystroke::parse("a")?, vec![(1, context_a.clone())]),
+//             KeyMatch::Matches(vec![(1, Box::new(A("x".to_string())))])
+//         );
+//         matcher.clear_pending();
+
+//         // Multi-keystroke match
+//         assert_eq!(
+//             matcher.match_keystroke(Keystroke::parse("a")?, vec![(1, context_b.clone())]),
+//             KeyMatch::Pending
+//         );
+//         assert_eq!(
+//             matcher.match_keystroke(Keystroke::parse("b")?, vec![(1, context_b.clone())]),
+//             KeyMatch::Matches(vec![(1, Box::new(Ab))])
+//         );
+//         matcher.clear_pending();
+
+//         // Failed matches don't interfere with matching subsequent keys
+//         assert_eq!(
+//             matcher.match_keystroke(Keystroke::parse("x")?, vec![(1, context_a.clone())]),
+//             KeyMatch::None
+//         );
+//         assert_eq!(
+//             matcher.match_keystroke(Keystroke::parse("a")?, vec![(1, context_a.clone())]),
+//             KeyMatch::Matches(vec![(1, Box::new(A("x".to_string())))])
+//         );
+//         matcher.clear_pending();
+
+//         // Pending keystrokes are cleared when the context changes
+//         assert_eq!(
+//             matcher.match_keystroke(Keystroke::parse("a")?, vec![(1, context_b.clone())]),
+//             KeyMatch::Pending
+//         );
+//         assert_eq!(
+//             matcher.match_keystroke(Keystroke::parse("b")?, vec![(1, context_a.clone())]),
+//             KeyMatch::None
+//         );
+//         matcher.clear_pending();
+
+//         let mut context_c = KeymapContext::default();
+//         context_c.add_identifier("c");
+
+//         // Pending keystrokes are maintained per-view
+//         assert_eq!(
+//             matcher.match_keystroke(
+//                 Keystroke::parse("a")?,
+//                 vec![(1, context_b.clone()), (2, context_c.clone())]
+//             ),
+//             KeyMatch::Pending
+//         );
+//         assert_eq!(
+//             matcher.match_keystroke(Keystroke::parse("b")?, vec![(1, context_b.clone())]),
+//             KeyMatch::Matches(vec![(1, Box::new(Ab))])
+//         );
+
+//         // handle Czech $ (option + 4 key)
+//         assert_eq!(
+//             matcher.match_keystroke(Keystroke::parse("alt-ç->$")?, vec![(1, context_a.clone())]),
+//             KeyMatch::Matches(vec![(1, Box::new(Dollar))])
+//         );
+
+//         // handle Brazillian quote (quote key then space key)
+//         assert_eq!(
+//             matcher.match_keystroke(Keystroke::parse("space->\"")?, vec![(1, context_a.clone())]),
+//             KeyMatch::Matches(vec![(1, Box::new(Quote))])
+//         );
+
+//         // handle ctrl+` on a brazillian keyboard
+//         assert_eq!(
+//             matcher.match_keystroke(Keystroke::parse("ctrl-->`")?, vec![(1, context_a.clone())]),
+//             KeyMatch::Matches(vec![(1, Box::new(Backtick))])
+//         );
+
+//         // handle alt-s on a US keyboard
+//         assert_eq!(
+//             matcher.match_keystroke(Keystroke::parse("alt-s->ß")?, vec![(1, context_a.clone())]),
+//             KeyMatch::Matches(vec![(1, Box::new(Ess))])
+//         );
+
+//         Ok(())
+//     }
+// }

crates/gpui3/src/keymap_matcher/binding.rs

@@ -0,0 +1,80 @@
+use crate::{Action, KeyMatch, KeymapContext, KeymapContextPredicate, Keystroke};
+use anyhow::Result;
+use smallvec::SmallVec;
+
+pub struct Binding {
+    action: Box<dyn Action>,
+    pub(super) keystrokes: SmallVec<[Keystroke; 2]>,
+    pub(super) context_predicate: Option<KeymapContextPredicate>,
+}
+
+impl Binding {
+    pub fn new<A: Action>(keystrokes: &str, action: A, context_predicate: Option<&str>) -> Self {
+        Self::load(keystrokes, Box::new(action), context_predicate).unwrap()
+    }
+
+    pub fn load(keystrokes: &str, action: Box<dyn Action>, context: Option<&str>) -> Result<Self> {
+        let context = if let Some(context) = context {
+            Some(KeymapContextPredicate::parse(context)?)
+        } else {
+            None
+        };
+
+        let keystrokes = keystrokes
+            .split_whitespace()
+            .map(Keystroke::parse)
+            .collect::<Result<_>>()?;
+
+        Ok(Self {
+            keystrokes,
+            action,
+            context_predicate: context,
+        })
+    }
+
+    pub fn matches_context(&self, contexts: &[KeymapContext]) -> bool {
+        self.context_predicate
+            .as_ref()
+            .map(|predicate| predicate.eval(contexts))
+            .unwrap_or(true)
+    }
+
+    pub fn match_keystrokes(
+        &self,
+        pending_keystrokes: &[Keystroke],
+        contexts: &[KeymapContext],
+    ) -> KeyMatch {
+        if self.keystrokes.as_ref().starts_with(&pending_keystrokes)
+            && self.matches_context(contexts)
+        {
+            // If the binding is completed, push it onto the matches list
+            if self.keystrokes.as_ref().len() == pending_keystrokes.len() {
+                KeyMatch::Some(self.action.boxed_clone())
+            } else {
+                KeyMatch::Pending
+            }
+        } else {
+            KeyMatch::None
+        }
+    }
+
+    pub fn keystrokes_for_action(
+        &self,
+        action: &dyn Action,
+        contexts: &[KeymapContext],
+    ) -> Option<SmallVec<[Keystroke; 2]>> {
+        if self.action.partial_eq(action) && self.matches_context(contexts) {
+            Some(self.keystrokes.clone())
+        } else {
+            None
+        }
+    }
+
+    pub fn keystrokes(&self) -> &[Keystroke] {
+        self.keystrokes.as_slice()
+    }
+
+    pub fn action(&self) -> &dyn Action {
+        self.action.as_ref()
+    }
+}

crates/gpui3/src/keymap_matcher/keymap.rs

@@ -0,0 +1,400 @@
+use crate::{Binding, KeymapContextPredicate, Keystroke};
+use collections::HashSet;
+use smallvec::SmallVec;
+use std::{any::TypeId, collections::HashMap};
+
+#[derive(Copy, Clone, Eq, PartialEq, Default)]
+pub struct KeymapVersion(usize);
+
+#[derive(Default)]
+pub struct Keymap {
+    bindings: Vec<Binding>,
+    binding_indices_by_action_id: HashMap<TypeId, SmallVec<[usize; 3]>>,
+    disabled_keystrokes: HashMap<SmallVec<[Keystroke; 2]>, HashSet<Option<KeymapContextPredicate>>>,
+    version: KeymapVersion,
+}
+
+impl Keymap {
+    pub fn new(bindings: Vec<Binding>) -> Self {
+        let mut this = Self::default();
+        this.add_bindings(bindings);
+        this
+    }
+
+    pub fn version(&self) -> KeymapVersion {
+        self.version
+    }
+
+    pub(crate) fn bindings_for_action(
+        &self,
+        action_id: TypeId,
+    ) -> impl Iterator<Item = &'_ Binding> {
+        self.binding_indices_by_action_id
+            .get(&action_id)
+            .map(SmallVec::as_slice)
+            .unwrap_or(&[])
+            .iter()
+            .map(|ix| &self.bindings[*ix])
+            .filter(|binding| !self.binding_disabled(binding))
+    }
+
+    pub fn add_bindings<T: IntoIterator<Item = Binding>>(&mut self, bindings: T) {
+        // todo!("no action")
+        // let no_action_id = (NoAction {}).id();
+        let mut new_bindings = Vec::new();
+        let has_new_disabled_keystrokes = false;
+        for binding in bindings {
+            // if binding.action().id() == no_action_id {
+            //     has_new_disabled_keystrokes |= self
+            //         .disabled_keystrokes
+            //         .entry(binding.keystrokes)
+            //         .or_default()
+            //         .insert(binding.context_predicate);
+            // } else {
+            new_bindings.push(binding);
+            // }
+        }
+
+        if has_new_disabled_keystrokes {
+            self.binding_indices_by_action_id.retain(|_, indices| {
+                indices.retain(|ix| {
+                    let binding = &self.bindings[*ix];
+                    match self.disabled_keystrokes.get(&binding.keystrokes) {
+                        Some(disabled_predicates) => {
+                            !disabled_predicates.contains(&binding.context_predicate)
+                        }
+                        None => true,
+                    }
+                });
+                !indices.is_empty()
+            });
+        }
+
+        for new_binding in new_bindings {
+            if !self.binding_disabled(&new_binding) {
+                self.binding_indices_by_action_id
+                    .entry(new_binding.action().as_any().type_id())
+                    .or_default()
+                    .push(self.bindings.len());
+                self.bindings.push(new_binding);
+            }
+        }
+
+        self.version.0 += 1;
+    }
+
+    pub fn clear(&mut self) {
+        self.bindings.clear();
+        self.binding_indices_by_action_id.clear();
+        self.disabled_keystrokes.clear();
+        self.version.0 += 1;
+    }
+
+    pub fn bindings(&self) -> Vec<&Binding> {
+        self.bindings
+            .iter()
+            .filter(|binding| !self.binding_disabled(binding))
+            .collect()
+    }
+
+    fn binding_disabled(&self, binding: &Binding) -> bool {
+        match self.disabled_keystrokes.get(&binding.keystrokes) {
+            Some(disabled_predicates) => disabled_predicates.contains(&binding.context_predicate),
+            None => false,
+        }
+    }
+}
+
+// #[cfg(test)]
+// mod tests {
+//     use crate::actions;
+
+//     use super::*;
+
+//     actions!(
+//         keymap_test,
+//         [Present1, Present2, Present3, Duplicate, Missing]
+//     );
+
+//     #[test]
+//     fn regular_keymap() {
+//         let present_1 = Binding::new("ctrl-q", Present1 {}, None);
+//         let present_2 = Binding::new("ctrl-w", Present2 {}, Some("pane"));
+//         let present_3 = Binding::new("ctrl-e", Present3 {}, Some("editor"));
+//         let keystroke_duplicate_to_1 = Binding::new("ctrl-q", Duplicate {}, None);
+//         let full_duplicate_to_2 = Binding::new("ctrl-w", Present2 {}, Some("pane"));
+//         let missing = Binding::new("ctrl-r", Missing {}, None);
+//         let all_bindings = [
+//             &present_1,
+//             &present_2,
+//             &present_3,
+//             &keystroke_duplicate_to_1,
+//             &full_duplicate_to_2,
+//             &missing,
+//         ];
+
+//         let mut keymap = Keymap::default();
+//         assert_absent(&keymap, &all_bindings);
+//         assert!(keymap.bindings().is_empty());
+
+//         keymap.add_bindings([present_1.clone(), present_2.clone(), present_3.clone()]);
+//         assert_absent(&keymap, &[&keystroke_duplicate_to_1, &missing]);
+//         assert_present(
+//             &keymap,
+//             &[(&present_1, "q"), (&present_2, "w"), (&present_3, "e")],
+//         );
+
+//         keymap.add_bindings([
+//             keystroke_duplicate_to_1.clone(),
+//             full_duplicate_to_2.clone(),
+//         ]);
+//         assert_absent(&keymap, &[&missing]);
+//         assert!(
+//             !keymap.binding_disabled(&keystroke_duplicate_to_1),
+//             "Duplicate binding 1 was added and should not be disabled"
+//         );
+//         assert!(
+//             !keymap.binding_disabled(&full_duplicate_to_2),
+//             "Duplicate binding 2 was added and should not be disabled"
+//         );
+
+//         assert_eq!(
+//             keymap
+//                 .bindings_for_action(keystroke_duplicate_to_1.action().id())
+//                 .map(|binding| &binding.keystrokes)
+//                 .flatten()
+//                 .collect::<Vec<_>>(),
+//             vec![&Keystroke {
+//                 ctrl: true,
+//                 alt: false,
+//                 shift: false,
+//                 cmd: false,
+//                 function: false,
+//                 key: "q".to_string(),
+//                 ime_key: None,
+//             }],
+//             "{keystroke_duplicate_to_1:?} should have the expected keystroke in the keymap"
+//         );
+//         assert_eq!(
+//             keymap
+//                 .bindings_for_action(full_duplicate_to_2.action().id())
+//                 .map(|binding| &binding.keystrokes)
+//                 .flatten()
+//                 .collect::<Vec<_>>(),
+//             vec![
+//                 &Keystroke {
+//                     ctrl: true,
+//                     alt: false,
+//                     shift: false,
+//                     cmd: false,
+//                     function: false,
+//                     key: "w".to_string(),
+//                     ime_key: None,
+//                 },
+//                 &Keystroke {
+//                     ctrl: true,
+//                     alt: false,
+//                     shift: false,
+//                     cmd: false,
+//                     function: false,
+//                     key: "w".to_string(),
+//                     ime_key: None,
+//                 }
+//             ],
+//             "{full_duplicate_to_2:?} should have a duplicated keystroke in the keymap"
+//         );
+
+//         let updated_bindings = keymap.bindings();
+//         let expected_updated_bindings = vec![
+//             &present_1,
+//             &present_2,
+//             &present_3,
+//             &keystroke_duplicate_to_1,
+//             &full_duplicate_to_2,
+//         ];
+//         assert_eq!(
+//             updated_bindings.len(),
+//             expected_updated_bindings.len(),
+//             "Unexpected updated keymap bindings {updated_bindings:?}"
+//         );
+//         for (i, expected) in expected_updated_bindings.iter().enumerate() {
+//             let keymap_binding = &updated_bindings[i];
+//             assert_eq!(
+//                 keymap_binding.context_predicate, expected.context_predicate,
+//                 "Unexpected context predicate for keymap {i} element: {keymap_binding:?}"
+//             );
+//             assert_eq!(
+//                 keymap_binding.keystrokes, expected.keystrokes,
+//                 "Unexpected keystrokes for keymap {i} element: {keymap_binding:?}"
+//             );
+//         }
+
+//         keymap.clear();
+//         assert_absent(&keymap, &all_bindings);
+//         assert!(keymap.bindings().is_empty());
+//     }
+
+//     #[test]
+//     fn keymap_with_ignored() {
+//         let present_1 = Binding::new("ctrl-q", Present1 {}, None);
+//         let present_2 = Binding::new("ctrl-w", Present2 {}, Some("pane"));
+//         let present_3 = Binding::new("ctrl-e", Present3 {}, Some("editor"));
+//         let keystroke_duplicate_to_1 = Binding::new("ctrl-q", Duplicate {}, None);
+//         let full_duplicate_to_2 = Binding::new("ctrl-w", Present2 {}, Some("pane"));
+//         let ignored_1 = Binding::new("ctrl-q", NoAction {}, None);
+//         let ignored_2 = Binding::new("ctrl-w", NoAction {}, Some("pane"));
+//         let ignored_3_with_other_context =
+//             Binding::new("ctrl-e", NoAction {}, Some("other_context"));
+
+//         let mut keymap = Keymap::default();
+
+//         keymap.add_bindings([
+//             ignored_1.clone(),
+//             ignored_2.clone(),
+//             ignored_3_with_other_context.clone(),
+//         ]);
+//         assert_absent(&keymap, &[&present_3]);
+//         assert_disabled(
+//             &keymap,
+//             &[
+//                 &present_1,
+//                 &present_2,
+//                 &ignored_1,
+//                 &ignored_2,
+//                 &ignored_3_with_other_context,
+//             ],
+//         );
+//         assert!(keymap.bindings().is_empty());
+//         keymap.clear();
+
+//         keymap.add_bindings([
+//             present_1.clone(),
+//             present_2.clone(),
+//             present_3.clone(),
+//             ignored_1.clone(),
+//             ignored_2.clone(),
+//             ignored_3_with_other_context.clone(),
+//         ]);
+//         assert_present(&keymap, &[(&present_3, "e")]);
+//         assert_disabled(
+//             &keymap,
+//             &[
+//                 &present_1,
+//                 &present_2,
+//                 &ignored_1,
+//                 &ignored_2,
+//                 &ignored_3_with_other_context,
+//             ],
+//         );
+//         keymap.clear();
+
+//         keymap.add_bindings([
+//             present_1.clone(),
+//             present_2.clone(),
+//             present_3.clone(),
+//             ignored_1.clone(),
+//         ]);
+//         assert_present(&keymap, &[(&present_2, "w"), (&present_3, "e")]);
+//         assert_disabled(&keymap, &[&present_1, &ignored_1]);
+//         assert_absent(&keymap, &[&ignored_2, &ignored_3_with_other_context]);
+//         keymap.clear();
+
+//         keymap.add_bindings([
+//             present_1.clone(),
+//             present_2.clone(),
+//             present_3.clone(),
+//             keystroke_duplicate_to_1.clone(),
+//             full_duplicate_to_2.clone(),
+//             ignored_1.clone(),
+//             ignored_2.clone(),
+//             ignored_3_with_other_context.clone(),
+//         ]);
+//         assert_present(&keymap, &[(&present_3, "e")]);
+//         assert_disabled(
+//             &keymap,
+//             &[
+//                 &present_1,
+//                 &present_2,
+//                 &keystroke_duplicate_to_1,
+//                 &full_duplicate_to_2,
+//                 &ignored_1,
+//                 &ignored_2,
+//                 &ignored_3_with_other_context,
+//             ],
+//         );
+//         keymap.clear();
+//     }
+
+//     #[track_caller]
+//     fn assert_present(keymap: &Keymap, expected_bindings: &[(&Binding, &str)]) {
+//         let keymap_bindings = keymap.bindings();
+//         assert_eq!(
+//             expected_bindings.len(),
+//             keymap_bindings.len(),
+//             "Unexpected keymap bindings {keymap_bindings:?}"
+//         );
+//         for (i, (expected, expected_key)) in expected_bindings.iter().enumerate() {
+//             assert!(
+//                 !keymap.binding_disabled(expected),
+//                 "{expected:?} should not be disabled as it was added into keymap for element {i}"
+//             );
+//             assert_eq!(
+//                 keymap
+//                     .bindings_for_action(expected.action().id())
+//                     .map(|binding| &binding.keystrokes)
+//                     .flatten()
+//                     .collect::<Vec<_>>(),
+//                 vec![&Keystroke {
+//                     ctrl: true,
+//                     alt: false,
+//                     shift: false,
+//                     cmd: false,
+//                     function: false,
+//                     key: expected_key.to_string(),
+//                     ime_key: None,
+//                 }],
+//                 "{expected:?} should have the expected keystroke with key '{expected_key}' in the keymap for element {i}"
+//             );
+
+//             let keymap_binding = &keymap_bindings[i];
+//             assert_eq!(
+//                 keymap_binding.context_predicate, expected.context_predicate,
+//                 "Unexpected context predicate for keymap {i} element: {keymap_binding:?}"
+//             );
+//             assert_eq!(
+//                 keymap_binding.keystrokes, expected.keystrokes,
+//                 "Unexpected keystrokes for keymap {i} element: {keymap_binding:?}"
+//             );
+//         }
+//     }
+
+//     #[track_caller]
+//     fn assert_absent(keymap: &Keymap, bindings: &[&Binding]) {
+//         for binding in bindings.iter() {
+//             assert!(
+//                 !keymap.binding_disabled(binding),
+//                 "{binding:?} should not be disabled in the keymap where was not added"
+//             );
+//             assert_eq!(
+//                 keymap.bindings_for_action(binding.action().id()).count(),
+//                 0,
+//                 "{binding:?} should have no actions in the keymap where was not added"
+//             );
+//         }
+//     }
+
+//     #[track_caller]
+//     fn assert_disabled(keymap: &Keymap, bindings: &[&Binding]) {
+//         for binding in bindings.iter() {
+//             assert!(
+//                 keymap.binding_disabled(binding),
+//                 "{binding:?} should be disabled in the keymap"
+//             );
+//             assert_eq!(
+//                 keymap.bindings_for_action(binding.action().id()).count(),
+//                 0,
+//                 "{binding:?} should have no actions in the keymap where it was disabled"
+//             );
+//         }
+//     }
+// }

crates/gpui3/src/keymap_matcher/keymap_context.rs

@@ -0,0 +1,325 @@
+use anyhow::{anyhow, Result};
+use collections::{HashMap, HashSet};
+use std::borrow::Cow;
+
+#[derive(Clone, Debug, Default, Eq, PartialEq)]
+pub struct KeymapContext {
+    set: HashSet<Cow<'static, str>>,
+    map: HashMap<Cow<'static, str>, Cow<'static, str>>,
+}
+
+impl KeymapContext {
+    pub fn new() -> Self {
+        KeymapContext {
+            set: HashSet::default(),
+            map: HashMap::default(),
+        }
+    }
+
+    pub fn clear(&mut self) {
+        self.set.clear();
+        self.map.clear();
+    }
+
+    pub fn extend(&mut self, other: &Self) {
+        for v in &other.set {
+            self.set.insert(v.clone());
+        }
+        for (k, v) in &other.map {
+            self.map.insert(k.clone(), v.clone());
+        }
+    }
+
+    pub fn add_identifier<I: Into<Cow<'static, str>>>(&mut self, identifier: I) {
+        self.set.insert(identifier.into());
+    }
+
+    pub fn add_key<S1: Into<Cow<'static, str>>, S2: Into<Cow<'static, str>>>(
+        &mut self,
+        key: S1,
+        value: S2,
+    ) {
+        self.map.insert(key.into(), value.into());
+    }
+}
+
+#[derive(Clone, Debug, Eq, PartialEq, Hash)]
+pub enum KeymapContextPredicate {
+    Identifier(String),
+    Equal(String, String),
+    NotEqual(String, String),
+    Child(Box<KeymapContextPredicate>, Box<KeymapContextPredicate>),
+    Not(Box<KeymapContextPredicate>),
+    And(Box<KeymapContextPredicate>, Box<KeymapContextPredicate>),
+    Or(Box<KeymapContextPredicate>, Box<KeymapContextPredicate>),
+}
+
+impl KeymapContextPredicate {
+    pub fn parse(source: &str) -> Result<Self> {
+        let source = Self::skip_whitespace(source);
+        let (predicate, rest) = Self::parse_expr(source, 0)?;
+        if let Some(next) = rest.chars().next() {
+            Err(anyhow!("unexpected character {next:?}"))
+        } else {
+            Ok(predicate)
+        }
+    }
+
+    pub fn eval(&self, contexts: &[KeymapContext]) -> bool {
+        let Some(context) = contexts.first() else {
+            return false;
+        };
+        match self {
+            Self::Identifier(name) => (&context.set).contains(name.as_str()),
+            Self::Equal(left, right) => context
+                .map
+                .get(left.as_str())
+                .map(|value| value == right)
+                .unwrap_or(false),
+            Self::NotEqual(left, right) => context
+                .map
+                .get(left.as_str())
+                .map(|value| value != right)
+                .unwrap_or(true),
+            Self::Not(pred) => !pred.eval(contexts),
+            Self::Child(parent, child) => parent.eval(&contexts[1..]) && child.eval(contexts),
+            Self::And(left, right) => left.eval(contexts) && right.eval(contexts),
+            Self::Or(left, right) => left.eval(contexts) || right.eval(contexts),
+        }
+    }
+
+    fn parse_expr(mut source: &str, min_precedence: u32) -> anyhow::Result<(Self, &str)> {
+        type Op =
+            fn(KeymapContextPredicate, KeymapContextPredicate) -> Result<KeymapContextPredicate>;
+
+        let (mut predicate, rest) = Self::parse_primary(source)?;
+        source = rest;
+
+        'parse: loop {
+            for (operator, precedence, constructor) in [
+                (">", PRECEDENCE_CHILD, Self::new_child as Op),
+                ("&&", PRECEDENCE_AND, Self::new_and as Op),
+                ("||", PRECEDENCE_OR, Self::new_or as Op),
+                ("==", PRECEDENCE_EQ, Self::new_eq as Op),
+                ("!=", PRECEDENCE_EQ, Self::new_neq as Op),
+            ] {
+                if source.starts_with(operator) && precedence >= min_precedence {
+                    source = Self::skip_whitespace(&source[operator.len()..]);
+                    let (right, rest) = Self::parse_expr(source, precedence + 1)?;
+                    predicate = constructor(predicate, right)?;
+                    source = rest;
+                    continue 'parse;
+                }
+            }
+            break;
+        }
+
+        Ok((predicate, source))
+    }
+
+    fn parse_primary(mut source: &str) -> anyhow::Result<(Self, &str)> {
+        let next = source
+            .chars()
+            .next()
+            .ok_or_else(|| anyhow!("unexpected eof"))?;
+        match next {
+            '(' => {
+                source = Self::skip_whitespace(&source[1..]);
+                let (predicate, rest) = Self::parse_expr(source, 0)?;
+                if rest.starts_with(')') {
+                    source = Self::skip_whitespace(&rest[1..]);
+                    Ok((predicate, source))
+                } else {
+                    Err(anyhow!("expected a ')'"))
+                }
+            }
+            '!' => {
+                let source = Self::skip_whitespace(&source[1..]);
+                let (predicate, source) = Self::parse_expr(&source, PRECEDENCE_NOT)?;
+                Ok((KeymapContextPredicate::Not(Box::new(predicate)), source))
+            }
+            _ if next.is_alphanumeric() || next == '_' => {
+                let len = source
+                    .find(|c: char| !(c.is_alphanumeric() || c == '_'))
+                    .unwrap_or(source.len());
+                let (identifier, rest) = source.split_at(len);
+                source = Self::skip_whitespace(rest);
+                Ok((
+                    KeymapContextPredicate::Identifier(identifier.into()),
+                    source,
+                ))
+            }
+            _ => Err(anyhow!("unexpected character {next:?}")),
+        }
+    }
+
+    fn skip_whitespace(source: &str) -> &str {
+        let len = source
+            .find(|c: char| !c.is_whitespace())
+            .unwrap_or(source.len());
+        &source[len..]
+    }
+
+    fn new_or(self, other: Self) -> Result<Self> {
+        Ok(Self::Or(Box::new(self), Box::new(other)))
+    }
+
+    fn new_and(self, other: Self) -> Result<Self> {
+        Ok(Self::And(Box::new(self), Box::new(other)))
+    }
+
+    fn new_child(self, other: Self) -> Result<Self> {
+        Ok(Self::Child(Box::new(self), Box::new(other)))
+    }
+
+    fn new_eq(self, other: Self) -> Result<Self> {
+        if let (Self::Identifier(left), Self::Identifier(right)) = (self, other) {
+            Ok(Self::Equal(left, right))
+        } else {
+            Err(anyhow!("operands must be identifiers"))
+        }
+    }
+
+    fn new_neq(self, other: Self) -> Result<Self> {
+        if let (Self::Identifier(left), Self::Identifier(right)) = (self, other) {
+            Ok(Self::NotEqual(left, right))
+        } else {
+            Err(anyhow!("operands must be identifiers"))
+        }
+    }
+}
+
+const PRECEDENCE_CHILD: u32 = 1;
+const PRECEDENCE_OR: u32 = 2;
+const PRECEDENCE_AND: u32 = 3;
+const PRECEDENCE_EQ: u32 = 4;
+const PRECEDENCE_NOT: u32 = 5;
+
+#[cfg(test)]
+mod tests {
+    use super::KeymapContextPredicate::{self, *};
+
+    #[test]
+    fn test_parse_identifiers() {
+        // Identifiers
+        assert_eq!(
+            KeymapContextPredicate::parse("abc12").unwrap(),
+            Identifier("abc12".into())
+        );
+        assert_eq!(
+            KeymapContextPredicate::parse("_1a").unwrap(),
+            Identifier("_1a".into())
+        );
+    }
+
+    #[test]
+    fn test_parse_negations() {
+        assert_eq!(
+            KeymapContextPredicate::parse("!abc").unwrap(),
+            Not(Box::new(Identifier("abc".into())))
+        );
+        assert_eq!(
+            KeymapContextPredicate::parse(" ! ! abc").unwrap(),
+            Not(Box::new(Not(Box::new(Identifier("abc".into())))))
+        );
+    }
+
+    #[test]
+    fn test_parse_equality_operators() {
+        assert_eq!(
+            KeymapContextPredicate::parse("a == b").unwrap(),
+            Equal("a".into(), "b".into())
+        );
+        assert_eq!(
+            KeymapContextPredicate::parse("c!=d").unwrap(),
+            NotEqual("c".into(), "d".into())
+        );
+        assert_eq!(
+            KeymapContextPredicate::parse("c == !d")
+                .unwrap_err()
+                .to_string(),
+            "operands must be identifiers"
+        );
+    }
+
+    #[test]
+    fn test_parse_boolean_operators() {
+        assert_eq!(
+            KeymapContextPredicate::parse("a || b").unwrap(),
+            Or(
+                Box::new(Identifier("a".into())),
+                Box::new(Identifier("b".into()))
+            )
+        );
+        assert_eq!(
+            KeymapContextPredicate::parse("a || !b && c").unwrap(),
+            Or(
+                Box::new(Identifier("a".into())),
+                Box::new(And(
+                    Box::new(Not(Box::new(Identifier("b".into())))),
+                    Box::new(Identifier("c".into()))
+                ))
+            )
+        );
+        assert_eq!(
+            KeymapContextPredicate::parse("a && b || c&&d").unwrap(),
+            Or(
+                Box::new(And(
+                    Box::new(Identifier("a".into())),
+                    Box::new(Identifier("b".into()))
+                )),
+                Box::new(And(
+                    Box::new(Identifier("c".into())),
+                    Box::new(Identifier("d".into()))
+                ))
+            )
+        );
+        assert_eq!(
+            KeymapContextPredicate::parse("a == b && c || d == e && f").unwrap(),
+            Or(
+                Box::new(And(
+                    Box::new(Equal("a".into(), "b".into())),
+                    Box::new(Identifier("c".into()))
+                )),
+                Box::new(And(
+                    Box::new(Equal("d".into(), "e".into())),
+                    Box::new(Identifier("f".into()))
+                ))
+            )
+        );
+        assert_eq!(
+            KeymapContextPredicate::parse("a && b && c && d").unwrap(),
+            And(
+                Box::new(And(
+                    Box::new(And(
+                        Box::new(Identifier("a".into())),
+                        Box::new(Identifier("b".into()))
+                    )),
+                    Box::new(Identifier("c".into())),
+                )),
+                Box::new(Identifier("d".into()))
+            ),
+        );
+    }
+
+    #[test]
+    fn test_parse_parenthesized_expressions() {
+        assert_eq!(
+            KeymapContextPredicate::parse("a && (b == c || d != e)").unwrap(),
+            And(
+                Box::new(Identifier("a".into())),
+                Box::new(Or(
+                    Box::new(Equal("b".into(), "c".into())),
+                    Box::new(NotEqual("d".into(), "e".into())),
+                )),
+            ),
+        );
+        assert_eq!(
+            KeymapContextPredicate::parse(" ( a || b ) ").unwrap(),
+            Or(
+                Box::new(Identifier("a".into())),
+                Box::new(Identifier("b".into())),
+            )
+        );
+    }
+}

crates/gpui3/src/platform/keystroke.rs

@@ -1,29 +1,54 @@
 use anyhow::anyhow;
 use serde::Deserialize;
+use smallvec::SmallVec;
 use std::fmt::Write;
 
-#[derive(Clone, Copy, Debug, Eq, PartialEq, Default, Deserialize, Hash)]
-pub struct Modifiers {
-    pub control: bool,
-    pub alt: bool,
-    pub shift: bool,
-    pub command: bool,
-    pub function: bool,
-}
-
-impl Modifiers {
-    pub fn modified(&self) -> bool {
-        self.control || self.alt || self.shift || self.command || self.function
-    }
-}
-
-#[derive(Clone, Debug, Eq, PartialEq, Deserialize, Hash)]
+#[derive(Clone, Debug, Eq, PartialEq, Default, Deserialize, Hash)]
 pub struct Keystroke {
-    pub key: String,
     pub modifiers: Modifiers,
+    /// key is the character printed on the key that was pressed
+    /// e.g. for option-s, key is "s"
+    pub key: String,
+    /// ime_key is the character inserted by the IME engine when that key was pressed.
+    /// e.g. for option-s, ime_key is "ß"
+    pub ime_key: Option<String>,
 }
 
 impl Keystroke {
+    // When matching a key we cannot know whether the user intended to type
+    // the ime_key or the key. On some non-US keyboards keys we use in our
+    // bindings are behind option (for example `$` is typed `alt-ç` on a Czech keyboard),
+    // and on some keyboards the IME handler converts a sequence of keys into a
+    // specific character (for example `"` is typed as `" space` on a brazillian keyboard).
+    pub fn match_candidates(&self) -> SmallVec<[Keystroke; 2]> {
+        let mut possibilities = SmallVec::new();
+        match self.ime_key.as_ref() {
+            None => possibilities.push(self.clone()),
+            Some(ime_key) => {
+                possibilities.push(Keystroke {
+                    modifiers: Modifiers {
+                        control: self.modifiers.control,
+                        alt: false,
+                        shift: false,
+                        command: false,
+                        function: false,
+                    },
+                    key: ime_key.to_string(),
+                    ime_key: None,
+                });
+                possibilities.push(Keystroke {
+                    ime_key: None,
+                    ..self.clone()
+                });
+            }
+        }
+        possibilities
+    }
+
+    /// key syntax is:
+    /// [ctrl-][alt-][shift-][cmd-][fn-]key[->ime_key]
+    /// ime_key is only used for generating test events,
+    /// when matching a key with an ime_key set will be matched without it.
     pub fn parse(source: &str) -> anyhow::Result<Self> {
         let mut control = false;
         let mut alt = false;
@@ -31,6 +56,7 @@ impl Keystroke {
         let mut command = false;
         let mut function = false;
         let mut key = None;
+        let mut ime_key = None;
 
         let mut components = source.split('-').peekable();
         while let Some(component) = components.next() {
@@ -41,10 +67,14 @@ impl Keystroke {
                 "cmd" => command = true,
                 "fn" => function = true,
                 _ => {
-                    if let Some(component) = components.peek() {
-                        if component.is_empty() && source.ends_with('-') {
+                    if let Some(next) = components.peek() {
+                        if next.is_empty() && source.ends_with('-') {
                             key = Some(String::from("-"));
                             break;
+                        } else if next.len() > 1 && next.starts_with('>') {
+                            key = Some(String::from(component));
+                            ime_key = Some(String::from(&next[1..]));
+                            components.next();
                         } else {
                             return Err(anyhow!("Invalid keystroke `{}`", source));
                         }
@@ -66,40 +96,25 @@ impl Keystroke {
                 function,
             },
             key,
+            ime_key,
         })
     }
-
-    pub fn modified(&self) -> bool {
-        self.modifiers.modified()
-    }
 }
 
 impl std::fmt::Display for Keystroke {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        let Modifiers {
-            control,
-            alt,
-            shift,
-            command,
-            function,
-        } = self.modifiers;
-
-        if control {
+        if self.modifiers.control {
             f.write_char('^')?;
         }
-        if alt {
-            f.write_char('⎇')?;
+        if self.modifiers.alt {
+            f.write_char('⌥')?;
         }
-        if command {
+        if self.modifiers.command {
             f.write_char('⌘')?;
         }
-        if shift {
+        if self.modifiers.shift {
             f.write_char('⇧')?;
         }
-        if function {
-            f.write_char('𝙛')?;
-        }
-
         let key = match self.key.as_str() {
             "backspace" => '⌫',
             "up" => '↑',
@@ -119,3 +134,18 @@ impl std::fmt::Display for Keystroke {
         f.write_char(key)
     }
 }
+
+#[derive(Copy, Clone, Debug, Eq, PartialEq, Default, Deserialize, Hash)]
+pub struct Modifiers {
+    pub control: bool,
+    pub alt: bool,
+    pub shift: bool,
+    pub command: bool,
+    pub function: bool,
+}
+
+impl Modifiers {
+    pub fn modified(&self) -> bool {
+        self.control || self.alt || self.shift || self.command || self.function
+    }
+}

crates/gpui3/src/platform/mac/events.rs

@@ -325,6 +325,7 @@ unsafe fn parse_keystroke(native_event: id) -> Keystroke {
             function,
         },
         key,
+        ime_key: None,
     }
 }
 

crates/gpui3/src/platform/mac/window.rs

@@ -1043,6 +1043,7 @@ extern "C" fn handle_key_event(this: &Object, native_event: id, key_equivalent:
                                 // we don't match cmd/fn because they don't seem to use IME
                                 modifiers: Default::default(),
                                 key: ime_text.clone().unwrap(),
+                                ime_key: None, // todo!("handle IME key")
                             },
                         };
                         handled = callback(InputEvent::KeyDown(event_with_ime_text));
@@ -1203,6 +1204,7 @@ extern "C" fn cancel_operation(this: &Object, _sel: Sel, _sender: id) {
     let keystroke = Keystroke {
         modifiers: Default::default(),
         key: ".".into(),
+        ime_key: None,
     };
     let event = InputEvent::KeyDown(KeyDownEvent {
         keystroke: keystroke.clone(),

crates/gpui3/src/text_system.rs

@@ -219,8 +219,8 @@ impl TextSystem {
         Ok(lines)
     }
 
-    pub fn end_frame(&self) {
-        self.line_layout_cache.end_frame()
+    pub fn start_frame(&self) {
+        self.line_layout_cache.start_frame()
     }
 
     pub fn line_wrapper(

crates/gpui3/src/text_system/line_layout.rs

@@ -167,7 +167,7 @@ impl LineLayoutCache {
         }
     }
 
-    pub fn end_frame(&self) {
+    pub fn start_frame(&self) {
         let mut prev_frame = self.prev_frame.lock();
         let mut curr_frame = self.curr_frame.write();
         std::mem::swap(&mut *prev_frame, &mut *curr_frame);

crates/gpui3/src/view.rs

@@ -164,7 +164,7 @@ impl<V: Send + Sync + 'static> ViewObject for View<V> {
     }
 
     fn initialize(&mut self, cx: &mut WindowContext) -> AnyBox {
-        cx.with_element_id(self.entity_id(), |cx| {
+        cx.with_element_id(self.entity_id(), |_global_id, cx| {
             self.state.update(cx, |state, cx| {
                 let mut any_element = Box::new((self.render)(state, cx));
                 any_element.initialize(state, cx);
@@ -174,7 +174,7 @@ impl<V: Send + Sync + 'static> ViewObject for View<V> {
     }
 
     fn layout(&mut self, element: &mut AnyBox, cx: &mut WindowContext) -> LayoutId {
-        cx.with_element_id(self.entity_id(), |cx| {
+        cx.with_element_id(self.entity_id(), |_global_id, cx| {
             self.state.update(cx, |state, cx| {
                 let element = element.downcast_mut::<AnyElement<V>>().unwrap();
                 element.layout(state, cx)
@@ -183,7 +183,7 @@ impl<V: Send + Sync + 'static> ViewObject for View<V> {
     }
 
     fn paint(&mut self, _: Bounds<Pixels>, element: &mut AnyBox, cx: &mut WindowContext) {
-        cx.with_element_id(self.entity_id(), |cx| {
+        cx.with_element_id(self.entity_id(), |_global_id, cx| {
             self.state.update(cx, |state, cx| {
                 let element = element.downcast_mut::<AnyElement<V>>().unwrap();
                 element.paint(state, None, cx);

crates/gpui3/src/window.rs

@@ -1,12 +1,13 @@
 use crate::{
-    px, size, AnyBox, AnyView, AppContext, AsyncWindowContext, AvailableSpace, BorrowAppContext,
-    Bounds, BoxShadow, Context, Corners, DevicePixels, DisplayId, Edges, Effect, Element, EntityId,
-    EventEmitter, FocusEvent, FontId, GlobalElementId, GlyphId, Handle, Hsla, ImageData,
-    InputEvent, IsZero, KeyListener, KeyMatch, Keystroke, LayoutId, MainThread, MainThreadOnly,
-    MonochromeSprite, MouseMoveEvent, Path, Pixels, Platform, PlatformAtlas, PlatformWindow, Point,
-    PolychromeSprite, Quad, Reference, RenderGlyphParams, RenderImageParams, RenderSvgParams,
-    ScaledPixels, SceneBuilder, Shadow, SharedString, Size, Style, Subscription, TaffyLayoutEngine,
-    Task, Underline, UnderlineStyle, WeakHandle, WindowOptions, SUBPIXEL_VARIANTS,
+    px, size, Action, AnyBox, AnyView, AppContext, AsyncWindowContext, AvailableSpace,
+    BorrowAppContext, Bounds, BoxShadow, Context, Corners, DevicePixels, DisplayId, Edges, Effect,
+    Element, EntityId, EventEmitter, FocusEvent, FontId, GlobalElementId, GlyphId, Handle, Hsla,
+    ImageData, InputEvent, IsZero, KeyListener, KeyMatch, KeymapMatcher, Keystroke, LayoutId,
+    MainThread, MainThreadOnly, MonochromeSprite, MouseMoveEvent, Path, Pixels, Platform,
+    PlatformAtlas, PlatformWindow, Point, PolychromeSprite, Quad, Reference, RenderGlyphParams,
+    RenderImageParams, RenderSvgParams, ScaledPixels, SceneBuilder, Shadow, SharedString, Size,
+    Style, Subscription, TaffyLayoutEngine, Task, Underline, UnderlineStyle, WeakHandle,
+    WindowOptions, SUBPIXEL_VARIANTS,
 };
 use anyhow::Result;
 use collections::HashMap;
@@ -46,7 +47,10 @@ pub enum DispatchPhase {
 
 type AnyListener = Arc<dyn Fn(&dyn Any, DispatchPhase, &mut WindowContext) + Send + Sync + 'static>;
 type AnyKeyListener = Arc<
-    dyn Fn(&dyn Any, DispatchPhase, &mut WindowContext) -> Option<AnyBox> + Send + Sync + 'static,
+    dyn Fn(&dyn Any, DispatchPhase, &mut WindowContext) -> Option<Box<dyn Action>>
+        + Send
+        + Sync
+        + 'static,
 >;
 type AnyFocusListener = Arc<dyn Fn(&FocusEvent, &mut WindowContext) + Send + Sync + 'static>;
 
@@ -144,8 +148,10 @@ pub struct Window {
     layout_engine: TaffyLayoutEngine,
     pub(crate) root_view: Option<AnyView>,
     pub(crate) element_id_stack: GlobalElementId,
-    prev_element_states: HashMap<GlobalElementId, AnyBox>,
+    prev_frame_element_states: HashMap<GlobalElementId, AnyBox>,
     element_states: HashMap<GlobalElementId, AnyBox>,
+    prev_frame_key_matchers: HashMap<GlobalElementId, KeymapMatcher>,
+    key_matchers: HashMap<GlobalElementId, KeymapMatcher>,
     z_index_stack: StackingOrder,
     content_mask_stack: Vec<ContentMask<Pixels>>,
     mouse_listeners: HashMap<TypeId, Vec<(StackingOrder, AnyListener)>>,
@@ -217,8 +223,10 @@ impl Window {
             layout_engine: TaffyLayoutEngine::new(),
             root_view: None,
             element_id_stack: GlobalElementId::default(),
-            prev_element_states: HashMap::default(),
+            prev_frame_element_states: HashMap::default(),
             element_states: HashMap::default(),
+            prev_frame_key_matchers: HashMap::default(),
+            key_matchers: HashMap::default(),
             z_index_stack: StackingOrder(SmallVec::new()),
             content_mask_stack: Vec::new(),
             mouse_listeners: HashMap::default(),
@@ -767,7 +775,6 @@ impl<'a, 'w> WindowContext<'a, 'w> {
 
             cx.window.root_view = Some(root_view);
             let scene = cx.window.scene_builder.build();
-            cx.end_frame();
 
             cx.run_on_main(view, |_, cx| {
                 cx.window
@@ -797,13 +804,28 @@ impl<'a, 'w> WindowContext<'a, 'w> {
     }
 
     fn start_frame(&mut self) {
-        // Make the current element states the previous, and then clear the current.
-        // The empty element states map will be populated for any element states we
-        // reference during the upcoming frame.
+        self.text_system().start_frame();
+
         let window = &mut *self.window;
-        mem::swap(&mut window.element_states, &mut window.prev_element_states);
+
+        // Move the current frame element states to the previous frame.
+        // The new empty element states map will be populated for any element states we
+        // reference during the upcoming frame.
+        mem::swap(
+            &mut window.element_states,
+            &mut window.prev_frame_element_states,
+        );
         window.element_states.clear();
 
+        // Make the current key matchers the previous, and then clear the current.
+        // An empty key matcher map will be created for every identified element in the
+        // upcoming frame.
+        mem::swap(
+            &mut window.key_matchers,
+            &mut window.prev_frame_key_matchers,
+        );
+        window.key_matchers.clear();
+
         // Clear mouse event listeners, because elements add new element listeners
         // when the upcoming frame is painted.
         window.mouse_listeners.values_mut().for_each(Vec::clear);
@@ -816,10 +838,6 @@ impl<'a, 'w> WindowContext<'a, 'w> {
         window.key_events_enabled = true;
     }
 
-    fn end_frame(&mut self) {
-        self.text_system().end_frame();
-    }
-
     fn dispatch_event(&mut self, event: InputEvent) -> bool {
         if let Some(any_mouse_event) = event.mouse_event() {
             if let Some(MouseMoveEvent { position, .. }) = any_mouse_event.downcast_ref() {
@@ -905,15 +923,32 @@ impl<'a, 'w> WindowContext<'a, 'w> {
         true
     }
 
-    pub fn match_keystroke(&mut self, element_id: &ElementId, keystroke: &Keystroke) -> KeyMatch {
-        todo!();
+    pub fn match_keystroke(
+        &mut self,
+        element_id: &GlobalElementId,
+        keystroke: &Keystroke,
+    ) -> KeyMatch {
+        let key_match = self
+            .window
+            .key_matchers
+            .get_mut(element_id)
+            .unwrap()
+            .match_keystroke(keystroke, &[]);
+
+        if key_match.is_some() {
+            for matcher in self.window.key_matchers.values_mut() {
+                matcher.clear_pending();
+            }
+        }
+
+        key_match
     }
 
-    fn dispatch_action(&mut self, action: AnyBox, listeners: &[(TypeId, AnyKeyListener)]) {
+    fn dispatch_action(&mut self, action: Box<dyn Action>, listeners: &[(TypeId, AnyKeyListener)]) {
         let action_type = action.type_id();
         for (event_type, listener) in listeners {
             if action_type == *event_type {
-                listener(action.as_ref(), DispatchPhase::Capture, self);
+                listener(action.as_any(), DispatchPhase::Capture, self);
                 if !self.window.propagate {
                     break;
                 }
@@ -923,7 +958,7 @@ impl<'a, 'w> WindowContext<'a, 'w> {
         if self.window.propagate {
             for (event_type, listener) in listeners.iter().rev() {
                 if action_type == *event_type {
-                    listener(action.as_ref(), DispatchPhase::Capture, self);
+                    listener(action.as_any(), DispatchPhase::Capture, self);
                     if !self.window.propagate {
                         break;
                     }
@@ -998,10 +1033,11 @@ pub trait BorrowWindow: BorrowAppContext {
     fn with_element_id<R>(
         &mut self,
         id: impl Into<ElementId>,
-        f: impl FnOnce(&mut Self) -> R,
+        f: impl FnOnce(GlobalElementId, &mut Self) -> R,
     ) -> R {
         self.window_mut().element_id_stack.push(id.into());
-        let result = f(self);
+        let global_id = self.window_mut().element_id_stack.clone();
+        let result = f(global_id, self);
         self.window_mut().element_id_stack.pop();
         result
     }
@@ -1023,13 +1059,12 @@ pub trait BorrowWindow: BorrowAppContext {
         id: ElementId,
         f: impl FnOnce(Option<S>, &mut Self) -> (R, S),
     ) -> R {
-        self.with_element_id(id, |cx| {
-            let global_id = cx.window_mut().element_id_stack.clone();
+        self.with_element_id(id, |global_id, cx| {
             if let Some(any) = cx
                 .window_mut()
                 .element_states
                 .remove(&global_id)
-                .or_else(|| cx.window_mut().prev_element_states.remove(&global_id))
+                .or_else(|| cx.window_mut().prev_frame_element_states.remove(&global_id))
             {
                 // Using the extra inner option to avoid needing to reallocate a new box.
                 let mut state_box = any