helix-mods/helix-term/src/ui/completion.rs
Michael Davis 9059c65a53
lsp: Check server provider capabilities (#3554)
Language Servers may signal that they do not support a method in
the initialization result (server capabilities). We can check these
when making LSP requests and hint in the status line when a method
is not supported by the server. This can also prevent crashes in
servers which assume that clients do not send requests for methods
which are disabled in the server capabilities.

There is an existing pattern the LSP client module where a method
returns `Option<impl Future<Output = Result<_>>>` with `None` signaling
no support in the server. This change extends this pattern to the rest
of the client functions. And we log an error to the statusline for
manually triggered LSP calls which return `None`.
2022-11-22 11:52:23 +09:00

471 lines
18 KiB
Rust

use crate::compositor::{Component, Context, Event, EventResult};
use helix_view::{apply_transaction, editor::CompleteAction};
use tui::buffer::Buffer as Surface;
use tui::text::Spans;
use std::borrow::Cow;
use helix_core::{Change, Transaction};
use helix_view::{
graphics::Rect,
input::{KeyCode, KeyEvent},
Document, Editor,
};
use crate::commands;
use crate::ui::{menu, Markdown, Menu, Popup, PromptEvent};
use helix_lsp::{lsp, util};
use lsp::CompletionItem;
impl menu::Item for CompletionItem {
type Data = ();
fn sort_text(&self, data: &Self::Data) -> Cow<str> {
self.filter_text(data)
}
#[inline]
fn filter_text(&self, _data: &Self::Data) -> Cow<str> {
self.filter_text
.as_ref()
.unwrap_or(&self.label)
.as_str()
.into()
}
fn label(&self, _data: &Self::Data) -> Spans {
self.label.as_str().into()
}
fn row(&self, _data: &Self::Data) -> menu::Row {
menu::Row::new(vec![
menu::Cell::from(self.label.as_str()),
menu::Cell::from(match self.kind {
Some(lsp::CompletionItemKind::TEXT) => "text",
Some(lsp::CompletionItemKind::METHOD) => "method",
Some(lsp::CompletionItemKind::FUNCTION) => "function",
Some(lsp::CompletionItemKind::CONSTRUCTOR) => "constructor",
Some(lsp::CompletionItemKind::FIELD) => "field",
Some(lsp::CompletionItemKind::VARIABLE) => "variable",
Some(lsp::CompletionItemKind::CLASS) => "class",
Some(lsp::CompletionItemKind::INTERFACE) => "interface",
Some(lsp::CompletionItemKind::MODULE) => "module",
Some(lsp::CompletionItemKind::PROPERTY) => "property",
Some(lsp::CompletionItemKind::UNIT) => "unit",
Some(lsp::CompletionItemKind::VALUE) => "value",
Some(lsp::CompletionItemKind::ENUM) => "enum",
Some(lsp::CompletionItemKind::KEYWORD) => "keyword",
Some(lsp::CompletionItemKind::SNIPPET) => "snippet",
Some(lsp::CompletionItemKind::COLOR) => "color",
Some(lsp::CompletionItemKind::FILE) => "file",
Some(lsp::CompletionItemKind::REFERENCE) => "reference",
Some(lsp::CompletionItemKind::FOLDER) => "folder",
Some(lsp::CompletionItemKind::ENUM_MEMBER) => "enum_member",
Some(lsp::CompletionItemKind::CONSTANT) => "constant",
Some(lsp::CompletionItemKind::STRUCT) => "struct",
Some(lsp::CompletionItemKind::EVENT) => "event",
Some(lsp::CompletionItemKind::OPERATOR) => "operator",
Some(lsp::CompletionItemKind::TYPE_PARAMETER) => "type_param",
Some(kind) => {
log::error!("Received unknown completion item kind: {:?}", kind);
""
}
None => "",
}),
// self.detail.as_deref().unwrap_or("")
// self.label_details
// .as_ref()
// .or(self.detail())
// .as_str(),
])
}
}
/// 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
}
impl Completion {
pub const ID: &'static str = "completion";
pub fn new(
editor: &Editor,
mut items: Vec<CompletionItem>,
offset_encoding: helix_lsp::OffsetEncoding,
start_offset: usize,
trigger_offset: usize,
) -> Self {
// Sort completion items according to their preselect status (given by the LSP server)
items.sort_by_key(|item| !item.preselect.unwrap_or(false));
// Then create the menu
let menu = Menu::new(items, (), move |editor: &mut Editor, item, event| {
fn item_to_transaction(
doc: &Document,
item: &CompletionItem,
offset_encoding: helix_lsp::OffsetEncoding,
start_offset: usize,
trigger_offset: usize,
) -> Transaction {
let transaction = if let Some(edit) = &item.text_edit {
let edit = match edit {
lsp::CompletionTextEdit::Edit(edit) => edit.clone(),
lsp::CompletionTextEdit::InsertAndReplace(item) => {
// TODO: support using "insert" instead of "replace" via user config
lsp::TextEdit::new(item.replace, item.new_text.clone())
}
};
util::generate_transaction_from_edits(
doc.text(),
vec![edit],
offset_encoding, // TODO: should probably transcode in Client
)
} else {
let text = item.insert_text.as_ref().unwrap_or(&item.label);
// Some LSPs just give you an insertText with no offset ¯\_(ツ)_/¯
// in these cases we need to check for a common prefix and remove it
let prefix = Cow::from(doc.text().slice(start_offset..trigger_offset));
let text = text.trim_start_matches::<&str>(&prefix);
Transaction::change(
doc.text(),
vec![(trigger_offset, trigger_offset, Some(text.into()))].into_iter(),
)
};
transaction
}
fn completion_changes(transaction: &Transaction, trigger_offset: usize) -> Vec<Change> {
transaction
.changes_iter()
.filter(|(start, end, _)| (*start..=*end).contains(&trigger_offset))
.collect()
}
let (view, doc) = current!(editor);
// if more text was entered, remove it
doc.restore(view);
match event {
PromptEvent::Abort => {
doc.restore(view);
editor.last_completion = None;
}
PromptEvent::Update => {
// always present here
let item = item.unwrap();
let transaction = item_to_transaction(
doc,
item,
offset_encoding,
start_offset,
trigger_offset,
);
// initialize a savepoint
doc.savepoint();
apply_transaction(&transaction, doc, view);
editor.last_completion = Some(CompleteAction {
trigger_offset,
changes: completion_changes(&transaction, trigger_offset),
});
}
PromptEvent::Validate => {
// always present here
let item = item.unwrap();
let transaction = item_to_transaction(
doc,
item,
offset_encoding,
start_offset,
trigger_offset,
);
apply_transaction(&transaction, doc, view);
editor.last_completion = Some(CompleteAction {
trigger_offset,
changes: completion_changes(&transaction, trigger_offset),
});
// apply additional edits, mostly used to auto import unqualified types
let resolved_item = if item
.additional_text_edits
.as_ref()
.map(|edits| !edits.is_empty())
.unwrap_or(false)
{
None
} else {
Self::resolve_completion_item(doc, item.clone())
};
if let Some(additional_edits) = resolved_item
.as_ref()
.and_then(|item| item.additional_text_edits.as_ref())
.or(item.additional_text_edits.as_ref())
{
if !additional_edits.is_empty() {
let transaction = util::generate_transaction_from_edits(
doc.text(),
additional_edits.clone(),
offset_encoding, // TODO: should probably transcode in Client
);
apply_transaction(&transaction, doc, view);
}
}
}
};
});
let popup = Popup::new(Self::ID, menu).with_scrollbar(false);
let mut completion = Self {
popup,
start_offset,
trigger_offset,
};
// need to recompute immediately in case start_offset != trigger_offset
completion.recompute_filter(editor);
completion
}
fn resolve_completion_item(
doc: &Document,
completion_item: lsp::CompletionItem,
) -> Option<CompletionItem> {
let language_server = doc.language_server()?;
let future = language_server.resolve_completion_item(completion_item)?;
let response = helix_lsp::block_on(future);
match response {
Ok(value) => serde_json::from_value(value).ok(),
Err(err) => {
log::error!("Failed to resolve completion item: {}", err);
None
}
}
}
pub fn recompute_filter(&mut self, editor: &Editor) {
// 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();
}
}
pub fn update(&mut self, cx: &mut commands::Context) {
self.recompute_filter(cx.editor)
}
pub fn is_empty(&self) -> bool {
self.popup.contents().is_empty()
}
fn replace_item(&mut self, old_item: lsp::CompletionItem, new_item: lsp::CompletionItem) {
self.popup.contents_mut().replace_option(old_item, new_item);
}
/// Asynchronously requests that the currently selection completion item is
/// resolved through LSP `completionItem/resolve`.
pub fn ensure_item_resolved(&mut self, cx: &mut commands::Context) -> bool {
// > If computing full completion items is expensive, servers can additionally provide a
// > handler for the completion item resolve request. ...
// > A typical use case is for example: the `textDocument/completion` request doesn't fill
// > in the `documentation` property for returned completion items since it is expensive
// > to compute. When the item is selected in the user interface then a
// > 'completionItem/resolve' request is sent with the selected completion item as a parameter.
// > The returned completion item should have the documentation property filled in.
// https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_completion
let current_item = match self.popup.contents().selection() {
Some(item) if item.documentation.is_none() => item.clone(),
_ => return false,
};
let language_server = match doc!(cx.editor).language_server() {
Some(language_server) => language_server,
None => return false,
};
// This method should not block the compositor so we handle the response asynchronously.
let future = match language_server.resolve_completion_item(current_item.clone()) {
Some(future) => future,
None => return false,
};
cx.callback(
future,
move |_editor, compositor, response: Option<lsp::CompletionItem>| {
let resolved_item = match response {
Some(item) => item,
None => return,
};
if let Some(completion) = &mut compositor
.find::<crate::ui::EditorView>()
.unwrap()
.completion
{
completion.replace_item(current_item, resolved_item);
}
},
);
true
}
}
impl Component for Completion {
fn handle_event(&mut self, event: &Event, cx: &mut Context) -> EventResult {
// let the Editor handle Esc instead
if let Event::Key(KeyEvent {
code: KeyCode::Esc, ..
}) = event
{
return EventResult::Ignored(None);
}
self.popup.handle_event(event, cx)
}
fn required_size(&mut self, viewport: (u16, u16)) -> Option<(u16, u16)> {
self.popup.required_size(viewport)
}
fn render(&mut self, area: Rect, surface: &mut Surface, cx: &mut Context) {
self.popup.render(area, surface, cx);
// if we have a selection, render a markdown popup on top/below with info
if let Some(option) = self.popup.contents().selection() {
// need to render:
// option.detail
// ---
// option.documentation
let (view, doc) = current!(cx.editor);
let language = doc.language_name().unwrap_or("");
let text = doc.text().slice(..);
let cursor_pos = doc.selection(view.id).primary().cursor(text);
let coords = helix_core::visual_coords_at_pos(text, cursor_pos, doc.tab_width());
let cursor_pos = (coords.row - view.offset.row) as u16;
let mut markdown_doc = match &option.documentation {
Some(lsp::Documentation::String(contents))
| Some(lsp::Documentation::MarkupContent(lsp::MarkupContent {
kind: lsp::MarkupKind::PlainText,
value: contents,
})) => {
// TODO: convert to wrapped text
Markdown::new(
format!(
"```{}\n{}\n```\n{}",
language,
option.detail.as_deref().unwrap_or_default(),
contents.clone()
),
cx.editor.syn_loader.clone(),
)
}
Some(lsp::Documentation::MarkupContent(lsp::MarkupContent {
kind: lsp::MarkupKind::Markdown,
value: contents,
})) => {
// TODO: set language based on doc scope
Markdown::new(
format!(
"```{}\n{}\n```\n{}",
language,
option.detail.as_deref().unwrap_or_default(),
contents.clone()
),
cx.editor.syn_loader.clone(),
)
}
None if option.detail.is_some() => {
// TODO: copied from above
// TODO: set language based on doc scope
Markdown::new(
format!(
"```{}\n{}\n```",
language,
option.detail.as_deref().unwrap_or_default(),
),
cx.editor.syn_loader.clone(),
)
}
None => return,
};
let (popup_x, popup_y) = self.popup.get_rel_position(area, cx);
let (popup_width, _popup_height) = self.popup.get_size();
let mut width = area
.width
.saturating_sub(popup_x)
.saturating_sub(popup_width);
let area = if width > 30 {
let mut height = area.height.saturating_sub(popup_y);
let x = popup_x + popup_width;
let y = popup_y;
if let Some((rel_width, rel_height)) = markdown_doc.required_size((width, height)) {
width = rel_width.min(width);
height = rel_height.min(height);
}
Rect::new(x, y, width, height)
} else {
let half = area.height / 2;
let height = 15.min(half);
// we want to make sure the cursor is visible (not hidden behind the documentation)
let y = if cursor_pos + area.y
>= (cx.editor.tree.area().height - height - 2/* statusline + commandline */)
{
0
} else {
// -2 to subtract command line + statusline. a bit of a hack, because of splits.
area.height.saturating_sub(height).saturating_sub(2)
};
Rect::new(0, y, area.width, height)
};
// clear area
let background = cx.editor.theme.get("ui.popup");
surface.clear_with(area, background);
markdown_doc.render(area, surface, cx);
}
}
}