Retrieve completion options on ctrl-x.

helix-lsp/src/client.rs

@@ -196,6 +196,12 @@ impl Client {
             root_uri: None, // set to project root in the future
             initialization_options: None,
             capabilities: lsp::ClientCapabilities {
+                // text_document:
+                // { completion: {
+                //      dynamic_registration: bool
+                //      completion_item: { snippet, documentation_format, ... }
+                //      completion_item_kind: {  }
+                // } }
                 ..Default::default()
             },
             trace: None,
@@ -358,4 +364,41 @@ impl Client {
     pub async fn text_document_did_save(&self) -> anyhow::Result<()> {
         unimplemented!()
     }
+
+    pub async fn completion(&self, doc: &Document) -> anyhow::Result<Vec<lsp::CompletionItem>> {
+        // TODO: figure out what should happen when you complete with multiple cursors
+
+        let params = lsp::CompletionParams {
+            text_document_position: lsp::TextDocumentPositionParams {
+                text_document: text_document_identifier(doc),
+                position: crate::util::pos_to_lsp_pos(
+                    &doc.text().slice(..),
+                    doc.selection().cursor(),
+                ),
+            },
+            // TODO: support these tokens by async receiving and updating the choice list
+            work_done_progress_params: lsp::WorkDoneProgressParams {
+                work_done_token: None,
+            },
+            partial_result_params: lsp::PartialResultParams {
+                partial_result_token: None,
+            },
+            context: None,
+            // lsp::CompletionContext { trigger_kind: , trigger_character: Some(), }
+        };
+
+        let response = self.request::<lsp::request::Completion>(params).await?;
+
+        let items = match response {
+            Some(lsp::CompletionResponse::Array(items)) => items,
+            // TODO: do something with is_incomplete
+            Some(lsp::CompletionResponse::List(lsp::CompletionList {
+                is_incomplete: _is_incomplete,
+                items,
+            })) => items,
+            None => Vec::new(),
+        };
+
+        Ok(items)
+    }
 }

helix-term/src/application.rs

@@ -69,10 +69,15 @@ impl Application {
 
     fn render(&mut self) {
         let executor = &self.executor;
+        let language_servers = &self.language_servers;
         let editor = &mut self.editor;
         let compositor = &self.compositor;
 
-        let mut cx = crate::compositor::Context { editor, executor };
+        let mut cx = crate::compositor::Context {
+            editor,
+            executor,
+            language_servers,
+        };
         let area = self.terminal.size().unwrap();
 
         compositor.render(area, self.terminal.current_buffer_mut(), &mut cx);
@@ -113,6 +118,7 @@ impl Application {
         let mut cx = crate::compositor::Context {
             editor: &mut self.editor,
             executor: &self.executor,
+            language_servers: &self.language_servers,
         };
         // Handle key events
         let should_redraw = match event {

helix-term/src/commands.rs

@@ -22,6 +22,7 @@ pub struct Context<'a, 'b> {
     pub count: usize,
     pub view: &'a mut View,
     pub executor: &'a smol::Executor<'b>,
+    pub language_servers: &'a helix_lsp::Registry,
 
     pub callback: Option<crate::compositor::Callback>,
 }
@@ -831,3 +832,31 @@ pub fn save(cx: &mut Context) {
     // TODO: handle save errors somehow?
     cx.executor.spawn(cx.view.doc.save()).detach();
 }
+
+pub fn completion(cx: &mut Context) {
+    let language_server = cx.language_servers.get("rust", &cx.executor).unwrap();
+    use log::info;
+
+    // TODO: blocking here is not ideal
+    let res = smol::block_on(language_server.completion(&cx.view.doc)).expect("completion failed!");
+
+    let picker = ui::Picker::new(
+        res,
+        |item| {
+            // format_fn
+            item.label.as_str().into()
+        },
+        |editor: &mut Editor, item| {
+            //
+        },
+    );
+
+    cx.callback = Some(Box::new(
+        move |compositor: &mut Compositor, editor: &mut Editor| {
+            compositor.push(Box::new(picker));
+        },
+    ));
+
+    // TODO: when iterating over items, show the docs in popup
+    // language server client needs to be accessible via a registry of some sort
+}

helix-term/src/compositor.rs

@@ -39,6 +39,7 @@ use helix_view::{Editor, View};
 // shared with commands.rs
 pub struct Context<'a> {
     pub editor: &'a mut Editor,
+    pub language_servers: &'a helix_lsp::Registry,
     pub executor: &'static smol::Executor<'static>,
 }
 

helix-term/src/keymap.rs

@@ -208,6 +208,8 @@ pub fn default() -> Keymaps {
                     code: KeyCode::Tab,
                     modifiers: Modifiers::NONE
                 }] => commands::insert::insert_tab,
+
+                vec![ctrl!('x')] => commands::completion,
             ),
             Mode::Goto => hashmap!(
                 vec![Key {

helix-term/src/ui/editor.rs

@@ -263,6 +263,7 @@ impl Component for EditorView {
                     let mut cx = commands::Context {
                         view,
                         executor: cx.executor,
+                        language_servers: cx.language_servers,
                         count: 1,
                         callback: None,
                     };

helix-term/src/ui/picker.rs

@@ -201,7 +201,8 @@ impl<T> Component for Picker<T> {
         for y in area.top()..area.bottom() {
             for x in area.left()..area.right() {
                 let cell = surface.get_mut(x, y);
-                cell.symbol.clear();
+                cell.reset();
+                // cell.symbol.clear();
                 cell.set_style(background);
             }
         }