diff options
Diffstat (limited to 'helix-term/src/handlers/signature_help.rs')
| -rw-r--r-- | helix-term/src/handlers/signature_help.rs | 335 |
1 files changed, 335 insertions, 0 deletions
diff --git a/helix-term/src/handlers/signature_help.rs b/helix-term/src/handlers/signature_help.rs new file mode 100644 index 00000000..3c746548 --- /dev/null +++ b/helix-term/src/handlers/signature_help.rs @@ -0,0 +1,335 @@ +use std::sync::Arc; +use std::time::Duration; + +use helix_core::syntax::LanguageServerFeature; +use helix_event::{ + cancelable_future, cancelation, register_hook, send_blocking, CancelRx, CancelTx, +}; +use helix_lsp::lsp; +use helix_stdx::rope::RopeSliceExt; +use helix_view::document::Mode; +use helix_view::events::{DocumentDidChange, SelectionDidChange}; +use helix_view::handlers::lsp::{SignatureHelpEvent, SignatureHelpInvoked}; +use helix_view::Editor; +use tokio::sync::mpsc::Sender; +use tokio::time::Instant; + +use crate::commands::Open; +use crate::compositor::Compositor; +use crate::events::{OnModeSwitch, PostInsertChar}; +use crate::handlers::Handlers; +use crate::ui::lsp::SignatureHelp; +use crate::ui::Popup; +use crate::{job, ui}; + +#[derive(Debug)] +enum State { + Open, + Closed, + Pending { request: CancelTx }, +} + +/// debounce timeout in ms, value taken from VSCode +/// TODO: make this configurable? +const TIMEOUT: u64 = 120; + +#[derive(Debug)] +pub(super) struct SignatureHelpHandler { + trigger: Option<SignatureHelpInvoked>, + state: State, +} + +impl SignatureHelpHandler { + pub fn new() -> SignatureHelpHandler { + SignatureHelpHandler { + trigger: None, + state: State::Closed, + } + } +} + +impl helix_event::AsyncHook for SignatureHelpHandler { + type Event = SignatureHelpEvent; + + fn handle_event( + &mut self, + event: Self::Event, + timeout: Option<tokio::time::Instant>, + ) -> Option<Instant> { + match event { + SignatureHelpEvent::Invoked => { + self.trigger = Some(SignatureHelpInvoked::Manual); + self.state = State::Closed; + self.finish_debounce(); + return None; + } + SignatureHelpEvent::Trigger => {} + SignatureHelpEvent::ReTrigger => { + // don't retrigger if we aren't open/pending yet + if matches!(self.state, State::Closed) { + return timeout; + } + } + SignatureHelpEvent::Cancel => { + self.state = State::Closed; + return None; + } + SignatureHelpEvent::RequestComplete { open } => { + // don't cancel rerequest that was already triggered + if let State::Pending { request } = &self.state { + if !request.is_closed() { + return timeout; + } + } + self.state = if open { State::Open } else { State::Closed }; + return timeout; + } + } + if self.trigger.is_none() { + self.trigger = Some(SignatureHelpInvoked::Automatic) + } + Some(Instant::now() + Duration::from_millis(TIMEOUT)) + } + + fn finish_debounce(&mut self) { + let invocation = self.trigger.take().unwrap(); + let (tx, rx) = cancelation(); + self.state = State::Pending { request: tx }; + job::dispatch_blocking(move |editor, _| request_signature_help(editor, invocation, rx)) + } +} + +pub fn request_signature_help( + editor: &mut Editor, + invoked: SignatureHelpInvoked, + cancel: CancelRx, +) { + let (view, doc) = current!(editor); + + // TODO merge multiple language server signature help into one instead of just taking the first language server that supports it + let future = doc + .language_servers_with_feature(LanguageServerFeature::SignatureHelp) + .find_map(|language_server| { + let pos = doc.position(view.id, language_server.offset_encoding()); + language_server.text_document_signature_help(doc.identifier(), pos, None) + }); + + let Some(future) = future else { + // Do not show the message if signature help was invoked + // automatically on backspace, trigger characters, etc. + if invoked == SignatureHelpInvoked::Manual { + editor + .set_error("No configured language server supports signature-help"); + } + return; + }; + + tokio::spawn(async move { + match cancelable_future(future, cancel).await { + Some(Ok(res)) => { + job::dispatch(move |editor, compositor| { + show_signature_help(editor, compositor, invoked, res) + }) + .await + } + Some(Err(err)) => log::error!("signature help request failed: {err}"), + None => (), + } + }); +} + +pub fn show_signature_help( + editor: &mut Editor, + compositor: &mut Compositor, + invoked: SignatureHelpInvoked, + response: Option<lsp::SignatureHelp>, +) { + let config = &editor.config(); + + if !(config.lsp.auto_signature_help + || SignatureHelp::visible_popup(compositor).is_some() + || invoked == SignatureHelpInvoked::Manual) + { + return; + } + + // If the signature help invocation is automatic, don't show it outside of Insert Mode: + // it very probably means the server was a little slow to respond and the user has + // already moved on to something else, making a signature help popup will just be an + // annoyance, see https://github.com/helix-editor/helix/issues/3112 + // For the most part this should not be needed as the request gets canceled automatically now + // but it's technically possible for the mode change to just preempt this callback so better safe than sorry + if invoked == SignatureHelpInvoked::Automatic && editor.mode != Mode::Insert { + return; + } + + let response = match response { + // According to the spec the response should be None if there + // are no signatures, but some servers don't follow this. + Some(s) if !s.signatures.is_empty() => s, + _ => { + send_blocking( + &editor.handlers.signature_hints, + SignatureHelpEvent::RequestComplete { open: false }, + ); + compositor.remove(SignatureHelp::ID); + return; + } + }; + send_blocking( + &editor.handlers.signature_hints, + SignatureHelpEvent::RequestComplete { open: true }, + ); + + let doc = doc!(editor); + let language = doc.language_name().unwrap_or(""); + + let signature = match response + .signatures + .get(response.active_signature.unwrap_or(0) as usize) + { + Some(s) => s, + None => return, + }; + let mut contents = SignatureHelp::new( + signature.label.clone(), + language.to_string(), + Arc::clone(&editor.syn_loader), + ); + + let signature_doc = if config.lsp.display_signature_help_docs { + signature.documentation.as_ref().map(|doc| match doc { + lsp::Documentation::String(s) => s.clone(), + lsp::Documentation::MarkupContent(markup) => markup.value.clone(), + }) + } else { + None + }; + + contents.set_signature_doc(signature_doc); + + let active_param_range = || -> Option<(usize, usize)> { + let param_idx = signature + .active_parameter + .or(response.active_parameter) + .unwrap_or(0) as usize; + let param = signature.parameters.as_ref()?.get(param_idx)?; + match ¶m.label { + lsp::ParameterLabel::Simple(string) => { + let start = signature.label.find(string.as_str())?; + Some((start, start + string.len())) + } + lsp::ParameterLabel::LabelOffsets([start, end]) => { + // LS sends offsets based on utf-16 based string representation + // but highlighting in helix is done using byte offset. + use helix_core::str_utils::char_to_byte_idx; + let from = char_to_byte_idx(&signature.label, *start as usize); + let to = char_to_byte_idx(&signature.label, *end as usize); + Some((from, to)) + } + } + }; + contents.set_active_param_range(active_param_range()); + + let old_popup = compositor.find_id::<Popup<SignatureHelp>>(SignatureHelp::ID); + let mut popup = Popup::new(SignatureHelp::ID, contents) + .position(old_popup.and_then(|p| p.get_position())) + .position_bias(Open::Above) + .ignore_escape_key(true); + + // Don't create a popup if it intersects the auto-complete menu. + let size = compositor.size(); + if compositor + .find::<ui::EditorView>() + .unwrap() + .completion + .as_mut() + .map(|completion| completion.area(size, editor)) + .filter(|area| area.intersects(popup.area(size, editor))) + .is_some() + { + return; + } + + compositor.replace_or_push(SignatureHelp::ID, popup); +} + +fn signature_help_post_insert_char_hook( + tx: &Sender<SignatureHelpEvent>, + PostInsertChar { cx, .. }: &mut PostInsertChar<'_, '_>, +) -> anyhow::Result<()> { + if !cx.editor.config().lsp.auto_signature_help { + return Ok(()); + } + let (view, doc) = current!(cx.editor); + // TODO support multiple language servers (not just the first that is found), likely by merging UI somehow + let Some(language_server) = doc + .language_servers_with_feature(LanguageServerFeature::SignatureHelp) + .next() + else { + return Ok(()); + }; + + let capabilities = language_server.capabilities(); + + if let lsp::ServerCapabilities { + signature_help_provider: + Some(lsp::SignatureHelpOptions { + trigger_characters: Some(triggers), + // TODO: retrigger_characters + .. + }), + .. + } = capabilities + { + let mut text = doc.text().slice(..); + let cursor = doc.selection(view.id).primary().cursor(text); + text = text.slice(..cursor); + if triggers.iter().any(|trigger| text.ends_with(trigger)) { + send_blocking(tx, SignatureHelpEvent::Trigger) + } + } + Ok(()) +} + +pub(super) fn register_hooks(handlers: &Handlers) { + let tx = handlers.signature_hints.clone(); + register_hook!(move |event: &mut OnModeSwitch<'_, '_>| { + match (event.old_mode, event.new_mode) { + (Mode::Insert, _) => { + send_blocking(&tx, SignatureHelpEvent::Cancel); + event.cx.callback.push(Box::new(|compositor, _| { + compositor.remove(SignatureHelp::ID); + })); + } + (_, Mode::Insert) => { + if event.cx.editor.config().lsp.auto_signature_help { + send_blocking(&tx, SignatureHelpEvent::Trigger); + } + } + _ => (), + } + Ok(()) + }); + + let tx = handlers.signature_hints.clone(); + register_hook!( + move |event: &mut PostInsertChar<'_, '_>| signature_help_post_insert_char_hook(&tx, event) + ); + + let tx = handlers.signature_hints.clone(); + register_hook!(move |event: &mut DocumentDidChange<'_>| { + if event.doc.config.load().lsp.auto_signature_help { + send_blocking(&tx, SignatureHelpEvent::ReTrigger); + } + Ok(()) + }); + + let tx = handlers.signature_hints.clone(); + register_hook!(move |event: &mut SelectionDidChange<'_>| { + if event.doc.config.load().lsp.auto_signature_help { + send_blocking(&tx, SignatureHelpEvent::ReTrigger); + } + Ok(()) + }); +} |