Tweak word completions more (#37697)

Follow-up of https://github.com/zed-industries/zed/pull/37352
Closes https://github.com/zed-industries/zed/issues/37132

* disabled word completions in the agent panel's editor
* if not disabled, allow to trigger word completions with an action even
if the completions threshold is not reached

Release Notes:

- Fixed word completions appearing in the agent panel's editor and not
appearing when triggered with the action before the completion threshold
is reached

crates/editor/src/editor.rs

@@ -1030,6 +1030,7 @@ pub struct Editor {
     inline_diagnostics_update: Task<()>,
     inline_diagnostics_enabled: bool,
     diagnostics_enabled: bool,
+    word_completions_enabled: bool,
     inline_diagnostics: Vec<(Anchor, InlineDiagnostic)>,
     soft_wrap_mode_override: Option<language_settings::SoftWrap>,
     hard_wrap: Option<usize>,
@@ -2163,6 +2164,7 @@ impl Editor {
             },
             inline_diagnostics_enabled: full_mode,
             diagnostics_enabled: full_mode,
+            word_completions_enabled: full_mode,
             inline_value_cache: InlineValueCache::new(inlay_hint_settings.show_value_hints),
             inlay_hint_cache: InlayHintCache::new(inlay_hint_settings),
             gutter_hovered: false,
@@ -4892,8 +4894,15 @@ impl Editor {
             });
 
         match completions_source {
-            Some(CompletionsMenuSource::Words) => {
-                self.show_word_completions(&ShowWordCompletions, window, cx)
+            Some(CompletionsMenuSource::Words { .. }) => {
+                self.open_or_update_completions_menu(
+                    Some(CompletionsMenuSource::Words {
+                        ignore_threshold: false,
+                    }),
+                    None,
+                    window,
+                    cx,
+                );
             }
             Some(CompletionsMenuSource::Normal)
             | Some(CompletionsMenuSource::SnippetChoices)
@@ -5401,7 +5410,14 @@ impl Editor {
         window: &mut Window,
         cx: &mut Context<Self>,
     ) {
-        self.open_or_update_completions_menu(Some(CompletionsMenuSource::Words), None, window, cx);
+        self.open_or_update_completions_menu(
+            Some(CompletionsMenuSource::Words {
+                ignore_threshold: true,
+            }),
+            None,
+            window,
+            cx,
+        );
     }
 
     pub fn show_completions(
@@ -5450,9 +5466,13 @@ impl Editor {
 
         drop(multibuffer_snapshot);
 
+        let mut ignore_word_threshold = false;
         let provider = match requested_source {
             Some(CompletionsMenuSource::Normal) | None => self.completion_provider.clone(),
-            Some(CompletionsMenuSource::Words) => None,
+            Some(CompletionsMenuSource::Words { ignore_threshold }) => {
+                ignore_word_threshold = ignore_threshold;
+                None
+            }
             Some(CompletionsMenuSource::SnippetChoices) => {
                 log::error!("bug: SnippetChoices requested_source is not handled");
                 None
@@ -5573,10 +5593,12 @@ impl Editor {
             .as_ref()
             .is_none_or(|query| !query.chars().any(|c| c.is_digit(10)));
 
-        let omit_word_completions = match &query {
-            Some(query) => query.chars().count() < completion_settings.words_min_length,
-            None => completion_settings.words_min_length != 0,
-        };
+        let omit_word_completions = !self.word_completions_enabled
+            || (!ignore_word_threshold
+                && match &query {
+                    Some(query) => query.chars().count() < completion_settings.words_min_length,
+                    None => completion_settings.words_min_length != 0,
+                });
 
         let (mut words, provider_responses) = match &provider {
             Some(provider) => {
@@ -17121,6 +17143,10 @@ impl Editor {
         self.inline_diagnostics.clear();
     }
 
+    pub fn disable_word_completions(&mut self) {
+        self.word_completions_enabled = false;
+    }
+
     pub fn diagnostics_enabled(&self) -> bool {
         self.diagnostics_enabled && self.mode.is_full()
     }