refactor completion and signature help using hooks

3 files changed, 82 insertions, 98 deletions

diff --git a/helix-term/src/ui/completion.rs b/helix-term/src/ui/completion.rs
index 7c6a0055..48d97fbd 100644
--- a/helix-term/src/ui/completion.rs
+++ b/helix-term/src/ui/completion.rs
@@ -1,8 +1,12 @@
-use crate::compositor::{Component, Context, Event, EventResult};
+use crate::{
+    compositor::{Component, Context, Event, EventResult},
+    handlers::trigger_auto_completion,
+};
 use helix_view::{
     document::SavePoint,
     editor::CompleteAction,
     graphics::Margin,
+    handlers::lsp::SignatureHelpInvoked,
     theme::{Modifier, Style},
     ViewId,
 };
@@ -10,7 +14,7 @@ use tui::{buffer::Buffer as Surface, text::Span};
 
 use std::{borrow::Cow, sync::Arc};
 
-use helix_core::{Change, Transaction};
+use helix_core::{chars, Change, Transaction};
 use helix_view::{graphics::Rect, Document, Editor};
 
 use crate::commands;
@@ -95,10 +99,9 @@ pub struct CompletionItem {
 /// Wraps a Menu.
 pub struct Completion {
     popup: Popup<Menu<CompletionItem>>,
-    start_offset: usize,
     #[allow(dead_code)]
     trigger_offset: usize,
-    // TODO: maintain a completioncontext with trigger kind & trigger char
+    filter: String,
 }
 
 impl Completion {
@@ -108,7 +111,6 @@ impl Completion {
         editor: &Editor,
         savepoint: Arc<SavePoint>,
         mut items: Vec<CompletionItem>,
-        start_offset: usize,
         trigger_offset: usize,
     ) -> Self {
         let preview_completion_insert = editor.config().preview_completion_insert;
@@ -246,7 +248,7 @@ impl Completion {
                     // (also without sending the transaction to the LS) *before any further transaction is applied*.
                     // Otherwise incremental sync breaks (since the state of the LS doesn't match the state the transaction
                     // is applied to).
-                    if editor.last_completion.is_none() {
+                    if matches!(editor.last_completion, Some(CompleteAction::Triggered)) {
                         editor.last_completion = Some(CompleteAction::Selected {
                             savepoint: doc.savepoint(view),
                         })
@@ -324,8 +326,18 @@ impl Completion {
                             doc.apply(&transaction, view.id);
                         }
                     }
+                    // we could have just inserted a trigger char (like a `crate::` completion for rust
+                    // so we want to retrigger immediately when accepting a completion.
+                    trigger_auto_completion(&editor.handlers.completions, editor, true);
                 }
             };
+
+            // In case the popup was deleted because of an intersection w/ the auto-complete menu.
+            if event != PromptEvent::Update {
+                editor
+                    .handlers
+                    .trigger_signature_help(SignatureHelpInvoked::Automatic, editor);
+            }
         });
 
         let margin = if editor.menu_border() {
@@ -339,14 +351,30 @@ impl Completion {
             .ignore_escape_key(true)
             .margin(margin);
 
+        let (view, doc) = current_ref!(editor);
+        let text = doc.text().slice(..);
+        let cursor = doc.selection(view.id).primary().cursor(text);
+        let offset = text
+            .chars_at(cursor)
+            .reversed()
+            .take_while(|ch| chars::char_is_word(*ch))
+            .count();
+        let start_offset = cursor.saturating_sub(offset);
+
+        let fragment = doc.text().slice(start_offset..cursor);
         let mut completion = Self {
             popup,
-            start_offset,
             trigger_offset,
+            // TODO: expand nucleo api to allow moving straight to a Utf32String here
+            // and avoid allocation during matching
+            filter: String::from(fragment),
         };
 
         // need to recompute immediately in case start_offset != trigger_offset
-        completion.recompute_filter(editor);
+        completion
+            .popup
+            .contents_mut()
+            .score(&completion.filter, false);
 
         completion
     }
@@ -366,39 +394,22 @@ impl Completion {
         }
     }
 
-    pub fn recompute_filter(&mut self, editor: &Editor) {
+    /// Appends (`c: Some(c)`) or removes (`c: None`) a character to/from the filter
+    /// this should be called whenever the user types or deletes a character in insert mode.
+    pub fn update_filter(&mut self, c: Option<char>) {
         // recompute menu based on matches
         let menu = self.popup.contents_mut();
-        let (view, doc) = current_ref!(editor);
-
-        // cx.hooks()
-        // cx.add_hook(enum type,  ||)
-        // cx.trigger_hook(enum type, &str, ...) <-- there has to be enough to identify doc/view
-        // callback with editor & compositor
-        //
-        // trigger_hook sends event into channel, that's consumed in the global loop and
-        // triggers all registered callbacks
-        // TODO: hooks should get processed immediately so maybe do it after select!(), before
-        // looping?
-
-        let cursor = doc
-            .selection(view.id)
-            .primary()
-            .cursor(doc.text().slice(..));
-        if self.trigger_offset <= cursor {
-            let fragment = doc.text().slice(self.start_offset..cursor);
-            let text = Cow::from(fragment);
-            // TODO: logic is same as ui/picker
-            menu.score(&text);
-        } else {
-            // we backspaced before the start offset, clear the menu
-            // this will cause the editor to remove the completion popup
-            menu.clear();
+        match c {
+            Some(c) => self.filter.push(c),
+            None => {
+                self.filter.pop();
+                if self.filter.is_empty() {
+                    menu.clear();
+                    return;
+                }
+            }
         }
-    }
-
-    pub fn update(&mut self, cx: &mut commands::Context) {
-        self.recompute_filter(cx.editor)
+        menu.score(&self.filter, c.is_some());
     }
 
     pub fn is_empty(&self) -> bool {
diff --git a/helix-term/src/ui/editor.rs b/helix-term/src/ui/editor.rs
index 9f186d14..fef62a29 100644
--- a/helix-term/src/ui/editor.rs
+++ b/helix-term/src/ui/editor.rs
@@ -1,7 +1,6 @@
 use crate::{
     commands::{self, OnKeyCallback},
     compositor::{Component, Context, Event, EventResult},
-    job::{self, Callback},
     events::{OnModeSwitch, PostCommand},
     key,
     keymap::{KeymapResult, Keymaps},
@@ -34,8 +33,8 @@ use std::{mem::take, num::NonZeroUsize, path::PathBuf, rc::Rc, sync::Arc};
 
 use tui::{buffer::Buffer as Surface, text::Span};
 
+use super::document::LineDecoration;
 use super::{completion::CompletionItem, statusline};
-use super::{document::LineDecoration, lsp::SignatureHelp};
 
 pub struct EditorView {
     pub keymaps: Keymaps,
@@ -837,11 +836,8 @@ impl EditorView {
         let mut execute_command = |command: &commands::MappableCommand| {
             command.execute(cxt);
             helix_event::dispatch(PostCommand { command, cx: cxt });
+
             let current_mode = cxt.editor.mode();
-            match (last_mode, current_mode) {
-                (Mode::Normal, Mode::Insert) => {
-                    // HAXX: if we just entered insert mode from normal, clear key buf
-                    // and record the command that got us into this mode.
             if current_mode != last_mode {
                 helix_event::dispatch(OnModeSwitch {
                     old_mode: last_mode,
@@ -849,29 +845,16 @@ impl EditorView {
                     cx: cxt,
                 });
 
+                // HAXX: if we just entered insert mode from normal, clear key buf
+                // and record the command that got us into this mode.
+                if current_mode == Mode::Insert {
                     // how we entered insert mode is important, and we should track that so
                     // we can repeat the side effect.
                     self.last_insert.0 = command.clone();
                     self.last_insert.1.clear();
-
-                    commands::signature_help_impl(cxt, commands::SignatureHelpInvoked::Automatic);
-                }
-                (Mode::Insert, Mode::Normal) => {
-                    // if exiting insert mode, remove completion
-                    self.clear_completion(cxt.editor);
-                    cxt.editor.completion_request_handle = None;
-
-                    // TODO: Use an on_mode_change hook to remove signature help
-                    cxt.jobs.callback(async {
-                        let call: job::Callback =
-                            Callback::EditorCompositor(Box::new(|_editor, compositor| {
-                                compositor.remove(SignatureHelp::ID);
-                            }));
-                        Ok(call)
-                    });
                 }
-                _ => (),
             }
+
             last_mode = current_mode;
         };
 
@@ -999,12 +982,10 @@ impl EditorView {
         editor: &mut Editor,
         savepoint: Arc<SavePoint>,
         items: Vec<CompletionItem>,
-        start_offset: usize,
         trigger_offset: usize,
         size: Rect,
     ) -> Option<Rect> {
-        let mut completion =
-            Completion::new(editor, savepoint, items, start_offset, trigger_offset);
+        let mut completion = Completion::new(editor, savepoint, items, trigger_offset);
 
         if completion.is_empty() {
             // skip if we got no completion results
@@ -1025,6 +1006,7 @@ impl EditorView {
         self.completion = None;
         if let Some(last_completion) = editor.last_completion.take() {
             match last_completion {
+                CompleteAction::Triggered => (),
                 CompleteAction::Applied {
                     trigger_offset,
                     changes,
@@ -1038,9 +1020,6 @@ impl EditorView {
                 }
             }
         }
-
-        // Clear any savepoints
-        editor.clear_idle_timer(); // don't retrigger
     }
 
     pub fn handle_idle_timeout(&mut self, cx: &mut commands::Context) -> EventResult {
@@ -1054,13 +1033,7 @@ impl EditorView {
             };
         }
 
-        if cx.editor.mode != Mode::Insert || !cx.editor.config().auto_completion {
-            return EventResult::Ignored(None);
-        }
-
-        crate::commands::insert::idle_completion(cx);
-
-        EventResult::Consumed(None)
+        EventResult::Ignored(None)
     }
 }
 
@@ -1346,12 +1319,6 @@ impl Component for EditorView {
                                     if callback.is_some() {
                                         // assume close_fn
                                         self.clear_completion(cx.editor);
-
-                                        // In case the popup was deleted because of an intersection w/ the auto-complete menu.
-                                        commands::signature_help_impl(
-                                            &mut cx,
-                                            commands::SignatureHelpInvoked::Automatic,
-                                        );
                                     }
                                 }
                             }
@@ -1362,14 +1329,6 @@ impl Component for EditorView {
 
                                 // record last_insert key
                                 self.last_insert.1.push(InsertEvent::Key(key));
-
-                                // lastly we recalculate completion
-                                if let Some(completion) = &mut self.completion {
-                                    completion.update(&mut cx);
-                                    if completion.is_empty() {
-                                        self.clear_completion(cx.editor);
-                                    }
-                                }
                             }
                         }
                         mode => self.command_mode(mode, &mut cx, key),
diff --git a/helix-term/src/ui/menu.rs b/helix-term/src/ui/menu.rs
index 0ee64ce9..64127e3a 100644
--- a/helix-term/src/ui/menu.rs
+++ b/helix-term/src/ui/menu.rs
@@ -96,20 +96,34 @@ impl<T: Item> Menu<T> {
         }
     }
 
-    pub fn score(&mut self, pattern: &str) {
-        // reuse the matches allocation
-        self.matches.clear();
+    pub fn score(&mut self, pattern: &str, incremental: bool) {
         let mut matcher = MATCHER.lock();
         matcher.config = Config::DEFAULT;
         let pattern = Atom::new(pattern, CaseMatching::Ignore, AtomKind::Fuzzy, false);
         let mut buf = Vec::new();
-        let matches = self.options.iter().enumerate().filter_map(|(i, option)| {
-            let text = option.filter_text(&self.editor_data);
-            pattern
-                .score(Utf32Str::new(&text, &mut buf), &mut matcher)
-                .map(|score| (i as u32, score as u32))
-        });
-        self.matches.extend(matches);
+        if incremental {
+            self.matches.retain_mut(|(index, score)| {
+                let option = &self.options[*index as usize];
+                let text = option.filter_text(&self.editor_data);
+                let new_score = pattern.score(Utf32Str::new(&text, &mut buf), &mut matcher);
+                match new_score {
+                    Some(new_score) => {
+                        *score = new_score as u32;
+                        true
+                    }
+                    None => false,
+                }
+            })
+        } else {
+            self.matches.clear();
+            let matches = self.options.iter().enumerate().filter_map(|(i, option)| {
+                let text = option.filter_text(&self.editor_data);
+                pattern
+                    .score(Utf32Str::new(&text, &mut buf), &mut matcher)
+                    .map(|score| (i as u32, score as u32))
+            });
+            self.matches.extend(matches);
+        }
         self.matches
             .sort_unstable_by_key(|&(i, score)| (Reverse(score), i));