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
38pub(crate) struct DispatchActionListener {
39 pub(crate) action_type: TypeId,
40 pub(crate) listener: ArenaRef<dyn Fn(&dyn Any, DispatchPhase, &mut WindowContext)>,
41}
42
43impl DispatchTree {
44 pub fn new(keymap: Arc<Mutex<Keymap>>, action_registry: Rc<ActionRegistry>) -> Self {
45 Self {
46 node_stack: Vec::new(),
47 context_stack: Vec::new(),
48 nodes: Vec::new(),
49 focusable_node_ids: HashMap::default(),
50 keystroke_matchers: HashMap::default(),
51 keymap,
52 action_registry,
53 }
54 }
55
56 pub fn clear(&mut self) {
57 self.node_stack.clear();
58 self.nodes.clear();
59 self.context_stack.clear();
60 self.focusable_node_ids.clear();
61 self.keystroke_matchers.clear();
62 }
63
64 pub fn push_node(&mut self, context: Option<KeyContext>) {
65 let parent = self.node_stack.last().copied();
66 let node_id = DispatchNodeId(self.nodes.len());
67 self.nodes.push(DispatchNode {
68 parent,
69 ..Default::default()
70 });
71 self.node_stack.push(node_id);
72 if let Some(context) = context {
73 self.active_node().context = Some(context.clone());
74 self.context_stack.push(context);
75 }
76 }
77
78 pub fn pop_node(&mut self) {
79 let node_id = self.node_stack.pop().unwrap();
80 if self.nodes[node_id.0].context.is_some() {
81 self.context_stack.pop();
82 }
83 }
84
85 pub fn clear_pending_keystrokes(&mut self) {
86 self.keystroke_matchers.clear();
87 }
88
89 /// Preserve keystroke matchers from previous frames to support multi-stroke
90 /// bindings across multiple frames.
91 pub fn preserve_pending_keystrokes(&mut self, old_tree: &mut Self, focus_id: Option<FocusId>) {
92 if let Some(node_id) = focus_id.and_then(|focus_id| self.focusable_node_id(focus_id)) {
93 let dispatch_path = self.dispatch_path(node_id);
94
95 self.context_stack.clear();
96 for node_id in dispatch_path {
97 let node = self.node(node_id);
98 if let Some(context) = node.context.clone() {
99 self.context_stack.push(context);
100 }
101
102 if let Some((context_stack, matcher)) = old_tree
103 .keystroke_matchers
104 .remove_entry(self.context_stack.as_slice())
105 {
106 self.keystroke_matchers.insert(context_stack, matcher);
107 }
108 }
109 }
110 }
111
112 pub fn on_key_event(&mut self, listener: KeyListener) {
113 self.active_node().key_listeners.push(listener);
114 }
115
116 pub fn on_action(
117 &mut self,
118 action_type: TypeId,
119 listener: ArenaRef<dyn Fn(&dyn Any, DispatchPhase, &mut WindowContext)>,
120 ) {
121 self.active_node()
122 .action_listeners
123 .push(DispatchActionListener {
124 action_type,
125 listener,
126 });
127 }
128
129 pub fn make_focusable(&mut self, focus_id: FocusId) {
130 let node_id = self.active_node_id();
131 self.active_node().focus_id = Some(focus_id);
132 self.focusable_node_ids.insert(focus_id, node_id);
133 }
134
135 pub fn focus_contains(&self, parent: FocusId, child: FocusId) -> bool {
136 if parent == child {
137 return true;
138 }
139
140 if let Some(parent_node_id) = self.focusable_node_ids.get(&parent) {
141 let mut current_node_id = self.focusable_node_ids.get(&child).copied();
142 while let Some(node_id) = current_node_id {
143 if node_id == *parent_node_id {
144 return true;
145 }
146 current_node_id = self.nodes[node_id.0].parent;
147 }
148 }
149 false
150 }
151
152 pub fn available_actions(&self, target: DispatchNodeId) -> Vec<Box<dyn Action>> {
153 let mut actions = Vec::<Box<dyn Action>>::new();
154 for node_id in self.dispatch_path(target) {
155 let node = &self.nodes[node_id.0];
156 for DispatchActionListener { action_type, .. } in &node.action_listeners {
157 if let Err(ix) = actions.binary_search_by_key(action_type, |a| a.as_any().type_id())
158 {
159 // Intentionally silence these errors without logging.
160 // If an action cannot be built by default, it's not available.
161 let action = self.action_registry.build_action_type(action_type).ok();
162 if let Some(action) = action {
163 actions.insert(ix, action);
164 }
165 }
166 }
167 }
168 actions
169 }
170
171 pub fn is_action_available(&self, action: &dyn Action, target: DispatchNodeId) -> bool {
172 for node_id in self.dispatch_path(target) {
173 let node = &self.nodes[node_id.0];
174 if node
175 .action_listeners
176 .iter()
177 .any(|listener| listener.action_type == action.as_any().type_id())
178 {
179 return true;
180 }
181 }
182 false
183 }
184
185 pub fn bindings_for_action(
186 &self,
187 action: &dyn Action,
188 context_stack: &Vec<KeyContext>,
189 ) -> Vec<KeyBinding> {
190 self.keymap
191 .lock()
192 .bindings_for_action(action.type_id())
193 .filter(|candidate| {
194 if !candidate.action.partial_eq(action) {
195 return false;
196 }
197 for i in 1..context_stack.len() {
198 if candidate.matches_context(&context_stack[0..=i]) {
199 return true;
200 }
201 }
202 return false;
203 })
204 .cloned()
205 .collect()
206 }
207
208 pub fn dispatch_key(
209 &mut self,
210 keystroke: &Keystroke,
211 context: &[KeyContext],
212 ) -> Vec<Box<dyn Action>> {
213 if !self.keystroke_matchers.contains_key(context) {
214 let keystroke_contexts = context.iter().cloned().collect();
215 self.keystroke_matchers.insert(
216 keystroke_contexts,
217 KeystrokeMatcher::new(self.keymap.clone()),
218 );
219 }
220
221 let keystroke_matcher = self.keystroke_matchers.get_mut(context).unwrap();
222 if let KeyMatch::Some(actions) = keystroke_matcher.match_keystroke(keystroke, context) {
223 // Clear all pending keystrokes when an action has been found.
224 for keystroke_matcher in self.keystroke_matchers.values_mut() {
225 keystroke_matcher.clear_pending();
226 }
227
228 actions
229 } else {
230 vec![]
231 }
232 }
233
234 pub fn has_pending_keystrokes(&self) -> bool {
235 self.keystroke_matchers
236 .iter()
237 .any(|(_, matcher)| matcher.has_pending_keystrokes())
238 }
239
240 pub fn dispatch_path(&self, target: DispatchNodeId) -> SmallVec<[DispatchNodeId; 32]> {
241 let mut dispatch_path: SmallVec<[DispatchNodeId; 32]> = SmallVec::new();
242 let mut current_node_id = Some(target);
243 while let Some(node_id) = current_node_id {
244 dispatch_path.push(node_id);
245 current_node_id = self.nodes[node_id.0].parent;
246 }
247 dispatch_path.reverse(); // Reverse the path so it goes from the root to the focused node.
248 dispatch_path
249 }
250
251 pub fn focus_path(&self, focus_id: FocusId) -> SmallVec<[FocusId; 8]> {
252 let mut focus_path: SmallVec<[FocusId; 8]> = SmallVec::new();
253 let mut current_node_id = self.focusable_node_ids.get(&focus_id).copied();
254 while let Some(node_id) = current_node_id {
255 let node = self.node(node_id);
256 if let Some(focus_id) = node.focus_id {
257 focus_path.push(focus_id);
258 }
259 current_node_id = node.parent;
260 }
261 focus_path.reverse(); // Reverse the path so it goes from the root to the focused node.
262 focus_path
263 }
264
265 pub fn node(&self, node_id: DispatchNodeId) -> &DispatchNode {
266 &self.nodes[node_id.0]
267 }
268
269 pub fn node_mut(&mut self, node_id: DispatchNodeId) -> &mut DispatchNode {
270 &mut self.nodes[node_id.0]
271 }
272
273 fn active_node(&mut self) -> &mut DispatchNode {
274 let active_node_id = self.active_node_id();
275 &mut self.nodes[active_node_id.0]
276 }
277
278 pub fn focusable_node_id(&self, target: FocusId) -> Option<DispatchNodeId> {
279 self.focusable_node_ids.get(&target).copied()
280 }
281
282 pub fn root_node_id(&self) -> DispatchNodeId {
283 debug_assert!(!self.nodes.is_empty());
284 DispatchNodeId(0)
285 }
286
287 fn active_node_id(&self) -> DispatchNodeId {
288 *self.node_stack.last().unwrap()
289 }
290}