Color swatches ( 🟩 green 🟥 #ffaaaa )

book/src/editor.md

@@ -146,6 +146,7 @@ The following statusline elements can be configured:
 | `display-messages`    | Display LSP progress messages below statusline[^1]          | `false` |
 | `auto-signature-help` | Enable automatic popup of signature help (parameter hints)  | `true`  |
 | `display-inlay-hints` | Display inlay hints[^2]                                     | `false` |
+| `display-color-swatches` | Shows color swatches next to colors | `true` |
 | `display-signature-help-docs` | Display docs under signature help popup             | `true`  |
 | `snippets`      | Enables snippet completions. Requires a server restart (`:lsp-restart`) to take effect after `:config-reload`/`:set`. | `true`  |
 | `goto-reference-include-declaration` | Include declaration in the goto references popup. | `true`  |

helix-core/src/syntax.rs

@@ -334,6 +334,7 @@ pub enum LanguageServerFeature {
     Diagnostics,
     RenameSymbol,
     InlayHints,
+    ColorProvider,
 }
 
 impl Display for LanguageServerFeature {
@@ -357,6 +358,7 @@ impl Display for LanguageServerFeature {
             Diagnostics => "diagnostics",
             RenameSymbol => "rename-symbol",
             InlayHints => "inlay-hints",
+            ColorProvider => "color-provider",
         };
         write!(f, "{feature}",)
     }

helix-lsp/src/client.rs

@@ -353,6 +353,7 @@ impl Client {
                 capabilities.inlay_hint_provider,
                 Some(OneOf::Left(true) | OneOf::Right(InlayHintServerCapabilities::Options(_)))
             ),
+            LanguageServerFeature::ColorProvider => capabilities.color_provider.is_some(),
         }
     }
 
@@ -1114,6 +1115,29 @@ impl Client {
         Some(self.call::<lsp::request::InlayHintRequest>(params))
     }
 
+    pub fn text_document_color_swatches(
+        &self,
+        text_document: lsp::TextDocumentIdentifier,
+        work_done_token: Option<lsp::ProgressToken>,
+    ) -> Option<impl Future<Output = Result<Value>>> {
+        match self.capabilities.get().unwrap().color_provider {
+            Some(_) => (),
+            _ => return None,
+        }
+
+        let params = lsp::DocumentColorParams {
+            text_document,
+            work_done_progress_params: lsp::WorkDoneProgressParams {
+                work_done_token: work_done_token.clone(),
+            },
+            partial_result_params: helix_lsp_types::PartialResultParams {
+                partial_result_token: work_done_token,
+            },
+        };
+
+        Some(self.call::<lsp::request::DocumentColor>(params))
+    }
+
     pub fn text_document_hover(
         &self,
         text_document: lsp::TextDocumentIdentifier,

helix-term/src/commands/lsp.rs

@@ -18,10 +18,10 @@ use helix_core::{
 };
 use helix_stdx::path;
 use helix_view::{
-    document::{DocumentInlayHints, DocumentInlayHintsId},
+    document::{ColorSwatchesId, DocumentColorSwatches, DocumentInlayHints, DocumentInlayHintsId},
     editor::Action,
     handlers::lsp::SignatureHelpInvoked,
-    theme::Style,
+    theme::{Color, Style},
     Document, View,
 };
 
@@ -1254,6 +1254,25 @@ pub fn compute_inlay_hints_for_all_views(editor: &mut Editor, jobs: &mut crate::
     }
 }
 
+fn lsp_annotations_area(view: &View, doc: &Document) -> (usize, usize) {
+    // Compute ~3 times the current view heigh, that way some scrolling
+    // will not show half the view with annoations half without while still being faster
+    // than computing all the hints for the full file
+    let doc_text = doc.text();
+    let len_lines = doc_text.len_lines();
+
+    let view_height = view.inner_height();
+    let first_visible_line =
+        doc_text.char_to_line(doc.view_offset(view.id).anchor.min(doc_text.len_chars()));
+
+    let first_line = first_visible_line.saturating_sub(view_height);
+    let last_line = first_visible_line
+        .saturating_add(view_height.saturating_mul(2))
+        .min(len_lines);
+
+    (first_line, last_line)
+}
+
 fn compute_inlay_hints_for_view(
     view: &View,
     doc: &Document,
@@ -1265,20 +1284,7 @@ fn compute_inlay_hints_for_view(
         .language_servers_with_feature(LanguageServerFeature::InlayHints)
         .next()?;
 
-    let doc_text = doc.text();
-    let len_lines = doc_text.len_lines();
-
-    // Compute ~3 times the current view height of inlay hints, that way some scrolling
-    // will not show half the view with hints and half without while still being faster
-    // than computing all the hints for the full file (which could be dozens of time
-    // longer than the view is).
-    let view_height = view.inner_height();
-    let first_visible_line =
-        doc_text.char_to_line(doc.view_offset(view_id).anchor.min(doc_text.len_chars()));
-    let first_line = first_visible_line.saturating_sub(view_height);
-    let last_line = first_visible_line
-        .saturating_add(view_height.saturating_mul(2))
-        .min(len_lines);
+    let (first_line, last_line) = lsp_annotations_area(view, doc);
 
     let new_doc_inlay_hints_id = DocumentInlayHintsId {
         first_line,
@@ -1293,6 +1299,7 @@ fn compute_inlay_hints_for_view(
         return None;
     }
 
+    let doc_text = doc.text();
     let doc_slice = doc_text.slice(..);
     let first_char_in_range = doc_slice.line_to_char(first_line);
     let last_char_in_range = doc_slice.line_to_char(last_line);
@@ -1398,3 +1405,120 @@ fn compute_inlay_hints_for_view(
 
     Some(callback)
 }
+
+pub fn compute_color_swatches_for_all_views(editor: &mut Editor, jobs: &mut crate::job::Jobs) {
+    if !editor.config().lsp.display_color_swatches {
+        return;
+    }
+
+    for (view, _) in editor.tree.views() {
+        let doc = match editor.documents.get(&view.doc) {
+            Some(doc) => doc,
+            None => continue,
+        };
+        if let Some(callback) = compute_color_swatches_for_view(view, doc) {
+            jobs.callback(callback);
+        }
+    }
+}
+
+fn compute_color_swatches_for_view(
+    view: &View,
+    doc: &Document,
+) -> Option<std::pin::Pin<Box<impl Future<Output = Result<crate::job::Callback, anyhow::Error>>>>> {
+    let view_id = view.id;
+    let doc_id = view.doc;
+
+    let language_server = doc
+        .language_servers_with_feature(LanguageServerFeature::ColorProvider)
+        .next()?;
+
+    let (first_line, last_line) = lsp_annotations_area(view, doc);
+
+    let new_doc_color_swatches_id = ColorSwatchesId {
+        first_line,
+        last_line,
+    };
+
+    // Don't recompute the color swatches in case nothing has changed about the view
+    if !doc.color_swatches_outdated
+        && doc
+            .color_swatches(view_id)
+            .map_or(false, |dih| dih.id == new_doc_color_swatches_id)
+    {
+        return None;
+    }
+
+    let offset_encoding = language_server.offset_encoding();
+
+    let callback = super::make_job_callback(
+        language_server.text_document_color_swatches(doc.identifier(), None)?,
+        move |editor, _compositor, response: Option<Vec<lsp::ColorInformation>>| {
+            // The config was modified or the window was closed while the request was in flight
+            if !editor.config().lsp.display_color_swatches || editor.tree.try_get(view_id).is_none()
+            {
+                return;
+            }
+
+            // Add annotations to relevant document, not the current one (it may have changed in between)
+            let doc = match editor.documents.get_mut(&doc_id) {
+                Some(doc) => doc,
+                None => return,
+            };
+
+            // If we have neither color swatches nor an LSP, empty the color swatches since they're now oudated
+            let mut swatches = match response {
+                Some(swatches) if !swatches.is_empty() => swatches,
+                _ => {
+                    doc.set_color_swatches(
+                        view_id,
+                        DocumentColorSwatches::empty_with_id(new_doc_color_swatches_id),
+                    );
+                    doc.color_swatches_outdated = false;
+                    return;
+                }
+            };
+
+            // Most language servers will already send them sorted but ensure this is the case to
+            // avoid errors on our end.
+            swatches.sort_by_key(|inlay_hint| inlay_hint.range.start);
+
+            let mut color_swatches = Vec::with_capacity(swatches.len());
+            let mut colors = Vec::with_capacity(swatches.len());
+
+            let doc_text = doc.text();
+
+            for swatch in swatches {
+                let char_idx = match helix_lsp::util::lsp_pos_to_pos(
+                    doc_text,
+                    swatch.range.start,
+                    offset_encoding,
+                ) {
+                    Some(pos) => pos,
+                    // Skip color swatches that have no "real" position
+                    None => continue,
+                };
+
+                color_swatches.push(InlineAnnotation::new(char_idx, "■ "));
+                colors.push(Color::Rgb(
+                    (swatch.color.red * 255.) as u8,
+                    (swatch.color.green * 255.) as u8,
+                    (swatch.color.blue * 255.) as u8,
+                ));
+            }
+
+            doc.set_color_swatches(
+                view_id,
+                DocumentColorSwatches {
+                    id: new_doc_color_swatches_id,
+                    colors,
+                    color_swatches,
+                },
+            );
+
+            doc.color_swatches_outdated = false;
+        },
+    );
+
+    Some(callback)
+}

helix-term/src/ui/document.rs

@@ -216,7 +216,8 @@ pub fn render_text(
                 .unwrap_or((Style::default(), usize::MAX));
         }
 
-        let grapheme_style = if let GraphemeSource::VirtualText { highlight } = grapheme.source {
+        let mut grapheme_style = if let GraphemeSource::VirtualText { highlight } = grapheme.source
+        {
             let mut style = renderer.text_style;
             if let Some(highlight) = highlight {
                 style = style.patch(theme.highlight(highlight.0));
@@ -231,7 +232,8 @@ pub fn render_text(
                 overlay_style: overlay_style_span.0,
             }
         };
-        decorations.decorate_grapheme(renderer, &grapheme);
+
+        decorations.decorate_grapheme(renderer, &grapheme, &mut grapheme_style.syntax_style);
 
         let virt = grapheme.is_virtual();
         let grapheme_width = renderer.draw_grapheme(

helix-term/src/ui/editor.rs

@@ -35,6 +35,8 @@ use std::{mem::take, num::NonZeroUsize, path::PathBuf, rc::Rc, sync::Arc};
 
 use tui::{buffer::Buffer as Surface, text::Span};
 
+use super::text_decorations::ColorSwatch;
+
 pub struct EditorView {
     pub keymaps: Keymaps,
     on_next_key: Option<(OnKeyCallback, OnKeyCallbackKind)>,
@@ -205,6 +207,11 @@ impl EditorView {
             inline_diagnostic_config,
             config.end_of_line_diagnostics,
         ));
+        if let Some(swatches) = doc.color_swatches(view.id) {
+            for (swatch, color) in swatches.color_swatches.iter().zip(swatches.colors.iter()) {
+                decorations.add_decoration(ColorSwatch::new(*color, swatch.char_idx));
+            }
+        }
         render_document(
             surface,
             inner,
@@ -1112,6 +1119,7 @@ impl EditorView {
 
     pub fn handle_idle_timeout(&mut self, cx: &mut commands::Context) -> EventResult {
         commands::compute_inlay_hints_for_all_views(cx.editor, cx.jobs);
+        commands::compute_color_swatches_for_all_views(cx.editor, cx.jobs);
 
         EventResult::Ignored(None)
     }

helix-term/src/ui/text_decorations.rs

@@ -2,7 +2,10 @@ use std::cmp::Ordering;
 
 use helix_core::doc_formatter::FormattedGrapheme;
 use helix_core::Position;
-use helix_view::editor::CursorCache;
+use helix_view::{
+    editor::CursorCache,
+    theme::{Color, Style},
+};
 
 use crate::ui::document::{LinePos, TextRenderer};
 
@@ -81,6 +84,7 @@ pub trait Decoration {
         &mut self,
         _renderer: &mut TextRenderer,
         _grapheme: &FormattedGrapheme,
+        _style: &mut Style,
     ) -> usize {
         usize::MAX
     }
@@ -108,7 +112,12 @@ impl<'a> DecorationManager<'a> {
         }
     }
 
-    pub fn decorate_grapheme(&mut self, renderer: &mut TextRenderer, grapheme: &FormattedGrapheme) {
+    pub fn decorate_grapheme(
+        &mut self,
+        renderer: &mut TextRenderer,
+        grapheme: &FormattedGrapheme,
+        style: &mut Style,
+    ) {
         for (decoration, hook_char_idx) in &mut self.decorations {
             loop {
                 match (*hook_char_idx).cmp(&grapheme.char_idx) {
@@ -117,7 +126,7 @@ impl<'a> DecorationManager<'a> {
                         *hook_char_idx = decoration.skip_concealed_anchor(grapheme.char_idx)
                     }
                     Ordering::Equal => {
-                        *hook_char_idx = decoration.decorate_grapheme(renderer, grapheme)
+                        *hook_char_idx = decoration.decorate_grapheme(renderer, grapheme, style)
                     }
                     Ordering::Greater => break,
                 }
@@ -144,6 +153,37 @@ impl<'a> DecorationManager<'a> {
     }
 }
 
+pub struct ColorSwatch {
+    color: Color,
+    pos: usize,
+}
+
+impl ColorSwatch {
+    pub fn new(color: Color, pos: usize) -> Self {
+        ColorSwatch { color, pos }
+    }
+}
+
+impl Decoration for ColorSwatch {
+    fn decorate_grapheme(
+        &mut self,
+        _renderer: &mut TextRenderer,
+        _grapheme: &FormattedGrapheme,
+        style: &mut Style,
+    ) -> usize {
+        style.fg = Some(self.color);
+        usize::MAX
+    }
+
+    fn reset_pos(&mut self, pos: usize) -> usize {
+        if self.pos >= pos {
+            self.pos
+        } else {
+            usize::MAX
+        }
+    }
+}
+
 /// Cursor rendering is done externally so all the cursor decoration
 /// does is save the position of primary cursor
 pub struct Cursor<'a> {
@@ -163,6 +203,7 @@ impl Decoration for Cursor<'_> {
         &mut self,
         renderer: &mut TextRenderer,
         grapheme: &FormattedGrapheme,
+        _style: &mut Style,
     ) -> usize {
         if renderer.column_in_bounds(grapheme.visual_pos.col, grapheme.width())
             && renderer.offset.row < grapheme.visual_pos.row

helix-term/src/ui/text_decorations/diagnostics.rs

@@ -307,6 +307,7 @@ impl Decoration for InlineDiagnostics<'_> {
         &mut self,
         renderer: &mut TextRenderer,
         grapheme: &FormattedGrapheme,
+        _style: &mut Style,
     ) -> usize {
         self.state
             .proccess_anchor(grapheme, renderer.viewport.width, renderer.offset.col)