1use crate::{
2 arena::ArenaRef, Action, ActionRegistry, DispatchPhase, FocusId, KeyBinding, KeyContext,
3 KeyMatch, Keymap, Keystroke, KeystrokeMatcher, WindowContext,
4};
5use collections::HashMap;
6use parking_lot::Mutex;
7use smallvec::SmallVec;
8use std::{
9 any::{Any, TypeId},
10 rc::Rc,
11 sync::Arc,
12};
13
14#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]
15pub struct DispatchNodeId(usize);
16
17pub(crate) struct DispatchTree {
18 node_stack: Vec<DispatchNodeId>,
19 pub(crate) context_stack: Vec<KeyContext>,
20 nodes: Vec<DispatchNode>,
21 focusable_node_ids: HashMap<FocusId, DispatchNodeId>,
22 keystroke_matchers: HashMap<SmallVec<[KeyContext; 4]>, KeystrokeMatcher>,
23 keymap: Arc<Mutex<Keymap>>,
24 action_registry: Rc<ActionRegistry>,
25}
26
27#[derive(Default)]
28pub(crate) struct DispatchNode {
29 pub key_listeners: Vec<KeyListener>,
30 pub action_listeners: Vec<DispatchActionListener>,
31 pub context: Option<KeyContext>,
32 focus_id: Option<FocusId>,
33 parent: Option<DispatchNodeId>,
34}
35
36type KeyListener = ArenaRef<dyn Fn(&dyn Any, DispatchPhase, &mut WindowContext)>;
37
38#[derive(Clone)]
39pub(crate) struct DispatchActionListener {
40 pub(crate) action_type: TypeId,
41 pub(crate) listener: ArenaRef<dyn Fn(&dyn Any, DispatchPhase, &mut WindowContext)>,
42}
43
44impl DispatchTree {
45 pub fn new(keymap: Arc<Mutex<Keymap>>, action_registry: Rc<ActionRegistry>) -> Self {
46 Self {
47 node_stack: Vec::new(),
48 context_stack: Vec::new(),
49 nodes: Vec::new(),
50 focusable_node_ids: HashMap::default(),
51 keystroke_matchers: HashMap::default(),
52 keymap,
53 action_registry,
54 }
55 }
56
57 pub fn clear(&mut self) {
58 self.node_stack.clear();
59 self.nodes.clear();
60 self.context_stack.clear();
61 self.focusable_node_ids.clear();
62 self.keystroke_matchers.clear();
63 }
64
65 pub fn push_node(&mut self, context: Option<KeyContext>) {
66 let parent = self.node_stack.last().copied();
67 let node_id = DispatchNodeId(self.nodes.len());
68 self.nodes.push(DispatchNode {
69 parent,
70 ..Default::default()
71 });
72 self.node_stack.push(node_id);
73 if let Some(context) = context {
74 self.active_node().context = Some(context.clone());
75 self.context_stack.push(context);
76 }
77 }
78
79 pub fn pop_node(&mut self) {
80 let node_id = self.node_stack.pop().unwrap();
81 if self.nodes[node_id.0].context.is_some() {
82 self.context_stack.pop();
83 }
84 }
85
86 pub fn clear_pending_keystrokes(&mut self) {
87 self.keystroke_matchers.clear();
88 }
89
90 /// Preserve keystroke matchers from previous frames to support multi-stroke
91 /// bindings across multiple frames.
92 pub fn preserve_pending_keystrokes(&mut self, old_tree: &mut Self, focus_id: Option<FocusId>) {
93 if let Some(node_id) = focus_id.and_then(|focus_id| self.focusable_node_id(focus_id)) {
94 let dispatch_path = self.dispatch_path(node_id);
95
96 self.context_stack.clear();
97 for node_id in dispatch_path {
98 let node = self.node(node_id);
99 if let Some(context) = node.context.clone() {
100 self.context_stack.push(context);
101 }
102
103 if let Some((context_stack, matcher)) = old_tree
104 .keystroke_matchers
105 .remove_entry(self.context_stack.as_slice())
106 {
107 self.keystroke_matchers.insert(context_stack, matcher);
108 }
109 }
110 }
111 }
112
113 pub fn on_key_event(&mut self, listener: KeyListener) {
114 self.active_node().key_listeners.push(listener);
115 }
116
117 pub fn on_action(
118 &mut self,
119 action_type: TypeId,
120 listener: ArenaRef<dyn Fn(&dyn Any, DispatchPhase, &mut WindowContext)>,
121 ) {
122 self.active_node()
123 .action_listeners
124 .push(DispatchActionListener {
125 action_type,
126 listener,
127 });
128 }
129
130 pub fn make_focusable(&mut self, focus_id: FocusId) {
131 let node_id = self.active_node_id();
132 self.active_node().focus_id = Some(focus_id);
133 self.focusable_node_ids.insert(focus_id, node_id);
134 }
135
136 pub fn focus_contains(&self, parent: FocusId, child: FocusId) -> bool {
137 if parent == child {
138 return true;
139 }
140
141 if let Some(parent_node_id) = self.focusable_node_ids.get(&parent) {
142 let mut current_node_id = self.focusable_node_ids.get(&child).copied();
143 while let Some(node_id) = current_node_id {
144 if node_id == *parent_node_id {
145 return true;
146 }
147 current_node_id = self.nodes[node_id.0].parent;
148 }
149 }
150 false
151 }
152
153 pub fn available_actions(&self, target: DispatchNodeId) -> Vec<Box<dyn Action>> {
154 let mut actions = Vec::<Box<dyn Action>>::new();
155 for node_id in self.dispatch_path(target) {
156 let node = &self.nodes[node_id.0];
157 for DispatchActionListener { action_type, .. } in &node.action_listeners {
158 if let Err(ix) = actions.binary_search_by_key(action_type, |a| a.as_any().type_id())
159 {
160 // Intentionally silence these errors without logging.
161 // If an action cannot be built by default, it's not available.
162 let action = self.action_registry.build_action_type(action_type).ok();
163 if let Some(action) = action {
164 actions.insert(ix, action);
165 }
166 }
167 }
168 }
169 actions
170 }
171
172 pub fn is_action_available(&self, action: &dyn Action, target: DispatchNodeId) -> bool {
173 for node_id in self.dispatch_path(target) {
174 let node = &self.nodes[node_id.0];
175 if node
176 .action_listeners
177 .iter()
178 .any(|listener| listener.action_type == action.as_any().type_id())
179 {
180 return true;
181 }
182 }
183 false
184 }
185
186 pub fn bindings_for_action(
187 &self,
188 action: &dyn Action,
189 context_stack: &Vec<KeyContext>,
190 ) -> Vec<KeyBinding> {
191 self.keymap
192 .lock()
193 .bindings_for_action(action.type_id())
194 .filter(|candidate| {
195 if !candidate.action.partial_eq(action) {
196 return false;
197 }
198 for i in 1..context_stack.len() {
199 if candidate.matches_context(&context_stack[0..=i]) {
200 return true;
201 }
202 }
203 return false;
204 })
205 .cloned()
206 .collect()
207 }
208
209 pub fn dispatch_key(
210 &mut self,
211 keystroke: &Keystroke,
212 context: &[KeyContext],
213 ) -> Vec<Box<dyn Action>> {
214 if !self.keystroke_matchers.contains_key(context) {
215 let keystroke_contexts = context.iter().cloned().collect();
216 self.keystroke_matchers.insert(
217 keystroke_contexts,
218 KeystrokeMatcher::new(self.keymap.clone()),
219 );
220 }
221
222 let keystroke_matcher = self.keystroke_matchers.get_mut(context).unwrap();
223 if let KeyMatch::Some(actions) = keystroke_matcher.match_keystroke(keystroke, context) {
224 // Clear all pending keystrokes when an action has been found.
225 for keystroke_matcher in self.keystroke_matchers.values_mut() {
226 keystroke_matcher.clear_pending();
227 }
228
229 actions
230 } else {
231 vec![]
232 }
233 }
234
235 pub fn has_pending_keystrokes(&self) -> bool {
236 self.keystroke_matchers
237 .iter()
238 .any(|(_, matcher)| matcher.has_pending_keystrokes())
239 }
240
241 pub fn dispatch_path(&self, target: DispatchNodeId) -> SmallVec<[DispatchNodeId; 32]> {
242 let mut dispatch_path: SmallVec<[DispatchNodeId; 32]> = SmallVec::new();
243 let mut current_node_id = Some(target);
244 while let Some(node_id) = current_node_id {
245 dispatch_path.push(node_id);
246 current_node_id = self.nodes[node_id.0].parent;
247 }
248 dispatch_path.reverse(); // Reverse the path so it goes from the root to the focused node.
249 dispatch_path
250 }
251
252 pub fn focus_path(&self, focus_id: FocusId) -> SmallVec<[FocusId; 8]> {
253 let mut focus_path: SmallVec<[FocusId; 8]> = SmallVec::new();
254 let mut current_node_id = self.focusable_node_ids.get(&focus_id).copied();
255 while let Some(node_id) = current_node_id {
256 let node = self.node(node_id);
257 if let Some(focus_id) = node.focus_id {
258 focus_path.push(focus_id);
259 }
260 current_node_id = node.parent;
261 }
262 focus_path.reverse(); // Reverse the path so it goes from the root to the focused node.
263 focus_path
264 }
265
266 pub fn node(&self, node_id: DispatchNodeId) -> &DispatchNode {
267 &self.nodes[node_id.0]
268 }
269
270 fn active_node(&mut self) -> &mut DispatchNode {
271 let active_node_id = self.active_node_id();
272 &mut self.nodes[active_node_id.0]
273 }
274
275 pub fn focusable_node_id(&self, target: FocusId) -> Option<DispatchNodeId> {
276 self.focusable_node_ids.get(&target).copied()
277 }
278
279 pub fn root_node_id(&self) -> DispatchNodeId {
280 debug_assert!(!self.nodes.is_empty());
281 DispatchNodeId(0)
282 }
283
284 fn active_node_id(&self) -> DispatchNodeId {
285 *self.node_stack.last().unwrap()
286 }
287}