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* misc: missing inline, outdated link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* fix: tracking of outdated inlay hints should not be dependant on document revision (because of undos and such)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

3 files changed, 32 insertions, 69 deletions

diff --git a/helix-core/src/diagnostic.rs b/helix-core/src/diagnostic.rs
index 6b5da17e..58ddb038 100644
--- a/helix-core/src/diagnostic.rs
+++ b/helix-core/src/diagnostic.rs
@@ -35,7 +35,7 @@ pub enum DiagnosticTag {
     Deprecated,
 }
 
-/// Corresponds to [`lsp_types::Diagnostic`](https://docs.rs/lsp-types/0.91.0/lsp_types/struct.Diagnostic.html)
+/// Corresponds to [`lsp_types::Diagnostic`](https://docs.rs/lsp-types/0.94.0/lsp_types/struct.Diagnostic.html)
 #[derive(Debug, Clone)]
 pub struct Diagnostic {
     pub range: Range,
diff --git a/helix-core/src/doc_formatter/test.rs b/helix-core/src/doc_formatter/test.rs
index e68b31fd..ac8918bb 100644
--- a/helix-core/src/doc_formatter/test.rs
+++ b/helix-core/src/doc_formatter/test.rs
@@ -119,16 +119,7 @@ fn overlay() {
             "foobar",
             0,
             false,
-            &[
-                Overlay {
-                    char_idx: 0,
-                    grapheme: "X".into(),
-                },
-                Overlay {
-                    char_idx: 2,
-                    grapheme: "\t".into(),
-                },
-            ]
+            &[Overlay::new(0, "X"), Overlay::new(2, "\t")],
         ),
         "Xo  bar "
     );
@@ -138,18 +129,9 @@ fn overlay() {
             0,
             true,
             &[
-                Overlay {
-                    char_idx: 2,
-                    grapheme: "\t".into(),
-                },
-                Overlay {
-                    char_idx: 5,
-                    grapheme: "\t".into(),
-                },
-                Overlay {
-                    char_idx: 16,
-                    grapheme: "X".into(),
-                },
+                Overlay::new(2, "\t"),
+                Overlay::new(5, "\t"),
+                Overlay::new(16, "X"),
             ]
         ),
         "fo   f  o foo \n.foo Xoo foo foo \n.foo foo foo  "
@@ -170,24 +152,14 @@ fn annotate_text(text: &str, softwrap: bool, annotations: &[InlineAnnotation]) -
 #[test]
 fn annotation() {
     assert_eq!(
-        annotate_text(
-            "bar",
-            false,
-            &[InlineAnnotation {
-                char_idx: 0,
-                text: "foo".into(),
-            }]
-        ),
+        annotate_text("bar", false, &[InlineAnnotation::new(0, "foo")]),
         "foobar "
     );
     assert_eq!(
         annotate_text(
             &"foo ".repeat(10),
             true,
-            &[InlineAnnotation {
-                char_idx: 0,
-                text: "foo ".into(),
-            }]
+            &[InlineAnnotation::new(0, "foo ")]
         ),
         "foo foo foo foo \n.foo foo foo foo \n.foo foo foo  "
     );
@@ -199,20 +171,8 @@ fn annotation_and_overlay() {
             "bbar".into(),
             &TextFormat::new_test(false),
             TextAnnotations::default()
-                .add_inline_annotations(
-                    Rc::new([InlineAnnotation {
-                        char_idx: 0,
-                        text: "fooo".into(),
-                    }]),
-                    None
-                )
-                .add_overlay(
-                    Rc::new([Overlay {
-                        char_idx: 0,
-                        grapheme: "\t".into(),
-                    }]),
-                    None
-                ),
+                .add_inline_annotations(Rc::new([InlineAnnotation::new(0, "fooo")]), None)
+                .add_overlay(Rc::new([Overlay::new(0, "\t")]), None),
             0,
         )
         .0
diff --git a/helix-core/src/text_annotations.rs b/helix-core/src/text_annotations.rs
index 1956f6b5..3e48de4d 100644
--- a/helix-core/src/text_annotations.rs
+++ b/helix-core/src/text_annotations.rs
@@ -15,6 +15,15 @@ pub struct InlineAnnotation {
     pub char_idx: usize,
 }
 
+impl InlineAnnotation {
+    pub fn new(char_idx: usize, text: impl Into<Tendril>) -> Self {
+        Self {
+            char_idx,
+            text: text.into(),
+        }
+    }
+}
+
 /// Represents a **single Grapheme** that is part of the document
 /// that start at `char_idx` that will be replaced with
 /// a different `grapheme`.
@@ -33,22 +42,13 @@ pub struct InlineAnnotation {
 /// use helix_core::text_annotations::Overlay;
 ///
 /// // replaces a
-/// Overlay {
-///   char_idx: 0,
-///   grapheme: "X".into(),
-/// };
+/// Overlay::new(0, "X");
 ///
 /// // replaces X͎̊͢͜͝͡
-/// Overlay{
-///   char_idx: 1,
-///   grapheme: "\t".into(),
-/// };
+/// Overlay::new(1, "\t");
 ///
 /// // replaces b
-/// Overlay{
-///   char_idx: 6,
-///   grapheme: "X̢̢̟͖̲͌̋̇͑͝".into(),
-/// };
+/// Overlay::new(6, "X̢̢̟͖̲͌̋̇͑͝");
 /// ```
 ///
 /// The following examples are invalid uses
@@ -57,16 +57,10 @@ pub struct InlineAnnotation {
 /// use helix_core::text_annotations::Overlay;
 ///
 /// // overlay is not aligned at grapheme boundary
-/// Overlay{
-///   char_idx: 3,
-///   grapheme: "x".into(),
-/// };
+/// Overlay::new(3, "x");
 ///
 /// // overlay contains multiple graphemes
-/// Overlay{
-///   char_idx: 0,
-///   grapheme: "xy".into(),
-/// };
+/// Overlay::new(0, "xy");
 /// ```
 #[derive(Debug, Clone)]
 pub struct Overlay {
@@ -74,6 +68,15 @@ pub struct Overlay {
     pub grapheme: Tendril,
 }
 
+impl Overlay {
+    pub fn new(char_idx: usize, grapheme: impl Into<Tendril>) -> Self {
+        Self {
+            char_idx,
+            grapheme: grapheme.into(),
+        }
+    }
+}
+
 /// Line annotations allow for virtual text between normal
 /// text lines. They cause `height` empty lines to be inserted
 /// below the document line that contains `anchor_char_idx`.