Feat: LSP Type Hints (#5934)

* misc: missing inline, outdated link

* doc: Add new theme keys and config option to book

* fix: don't panic in Tree::try_get(view_id)

Necessary for later, where we could be receiving an LSP response
for a closed window, in which case we don't want to crash while
checking for its existence

* fix: reset idle timer on all mouse events

* refacto: Introduce Overlay::new and InlineAnnotation::new

* refacto: extract make_job_callback from Context::callback

* feat: add LSP display_inlay_hint option to config

* feat: communicate inlay hints support capabilities of helix to LSP server

* feat: Add function to request range of inlay hint from LSP

* feat: Save inlay hints in document, per view

* feat: Update inlay hints on document changes

* feat: Compute inlay hints on idle timeout

* nit: Add todo's about inlay hints for later

* fix: compute text annotations for current view in view.rs, not document.rs

* doc: Improve Document::text_annotations() description

* nit: getters don't use 'get_' in front

* fix: Drop inlay hints annotations on config refresh if necessary

* fix: padding theming for LSP inlay hints

* fix: tracking of outdated inlay hints should not be dependant on document revision (because of undos and such)

* fix: follow LSP spec and don't highlight padding as virtual text

* config: add some LSP inlay hint configs

1 files changed, 32 insertions, 0 deletions

diff --git a/helix-lsp/src/client.rs b/helix-lsp/src/client.rs
index 9fa118fb..9cb7c147 100644
--- a/helix-lsp/src/client.rs
+++ b/helix-lsp/src/client.rs
@@ -315,6 +315,9 @@ impl Client {
                     execute_command: Some(lsp::DynamicRegistrationClientCapabilities {
                         dynamic_registration: Some(false),
                     }),
+                    inlay_hint: Some(lsp::InlayHintWorkspaceClientCapabilities {
+                        refresh_support: Some(false),
+                    }),
                     ..Default::default()
                 }),
                 text_document: Some(lsp::TextDocumentClientCapabilities {
@@ -386,6 +389,10 @@ impl Client {
                     publish_diagnostics: Some(lsp::PublishDiagnosticsClientCapabilities {
                         ..Default::default()
                     }),
+                    inlay_hint: Some(lsp::InlayHintClientCapabilities {
+                        dynamic_registration: Some(false),
+                        resolve_support: None,
+                    }),
                     ..Default::default()
                 }),
                 window: Some(lsp::WindowClientCapabilities {
@@ -726,6 +733,31 @@ impl Client {
         Some(self.call::<lsp::request::SignatureHelpRequest>(params))
     }
 
+    pub fn text_document_range_inlay_hints(
+        &self,
+        text_document: lsp::TextDocumentIdentifier,
+        range: lsp::Range,
+        work_done_token: Option<lsp::ProgressToken>,
+    ) -> Option<impl Future<Output = Result<Value>>> {
+        let capabilities = self.capabilities.get().unwrap();
+
+        match capabilities.inlay_hint_provider {
+            Some(
+                lsp::OneOf::Left(true)
+                | lsp::OneOf::Right(lsp::InlayHintServerCapabilities::Options(_)),
+            ) => (),
+            _ => return None,
+        }
+
+        let params = lsp::InlayHintParams {
+            text_document,
+            range,
+            work_done_progress_params: lsp::WorkDoneProgressParams { work_done_token },
+        };
+
+        Some(self.call::<lsp::request::InlayHintRequest>(params))
+    }
+
     pub fn text_document_hover(
         &self,
         text_document: lsp::TextDocumentIdentifier,