update for review

crates/hir-ty/src/display.rs

@@ -62,7 +62,8 @@ pub struct HirFormatter<'a> {
     fmt: &'a mut dyn HirWrite,
     buf: String,
     curr_size: usize,
-    pub max_size: Option<usize>,
+    pub(crate) max_size: Option<usize>,
+    pub limited_size: Option<usize>,
     omit_verbose_types: bool,
     closure_style: ClosureStyle,
     display_target: DisplayTarget,
@@ -86,6 +87,7 @@ pub trait HirDisplay {
         &'a self,
         db: &'a dyn HirDatabase,
         max_size: Option<usize>,
+        limited_size: Option<usize>,
         omit_verbose_types: bool,
         display_target: DisplayTarget,
         closure_style: ClosureStyle,
@@ -101,6 +103,7 @@ pub trait HirDisplay {
             db,
             t: self,
             max_size,
+            limited_size,
             omit_verbose_types,
             display_target,
             closure_style,
@@ -117,6 +120,7 @@ pub trait HirDisplay {
             db,
             t: self,
             max_size: None,
+            limited_size: None,
             omit_verbose_types: false,
             closure_style: ClosureStyle::ImplFn,
             display_target: DisplayTarget::Diagnostics,
@@ -137,6 +141,28 @@ pub trait HirDisplay {
             db,
             t: self,
             max_size,
+            limited_size: None,
+            omit_verbose_types: true,
+            closure_style: ClosureStyle::ImplFn,
+            display_target: DisplayTarget::Diagnostics,
+        }
+    }
+
+    ///  Returns a `Display`able type that is human-readable and tries to limit the item inside this type.
+    /// Use this for showing types which may contain two many item when user hover on, like `trait`, `struct`, `enum`
+    fn display_limited<'a>(
+        &'a self,
+        db: &'a dyn HirDatabase,
+        limited_size: Option<usize>,
+    ) -> HirDisplayWrapper<'a, Self>
+    where
+        Self: Sized,
+    {
+        HirDisplayWrapper {
+            db,
+            t: self,
+            max_size: None,
+            limited_size,
             omit_verbose_types: true,
             closure_style: ClosureStyle::ImplFn,
             display_target: DisplayTarget::Diagnostics,
@@ -158,6 +184,7 @@ pub trait HirDisplay {
             buf: String::with_capacity(20),
             curr_size: 0,
             max_size: None,
+            limited_size: None,
             omit_verbose_types: false,
             closure_style: ClosureStyle::ImplFn,
             display_target: DisplayTarget::SourceCode { module_id, allow_opaque },
@@ -178,6 +205,7 @@ pub trait HirDisplay {
             db,
             t: self,
             max_size: None,
+            limited_size: None,
             omit_verbose_types: false,
             closure_style: ClosureStyle::ImplFn,
             display_target: DisplayTarget::Test,
@@ -295,6 +323,7 @@ pub struct HirDisplayWrapper<'a, T> {
     db: &'a dyn HirDatabase,
     t: &'a T,
     max_size: Option<usize>,
+    limited_size: Option<usize>,
     omit_verbose_types: bool,
     closure_style: ClosureStyle,
     display_target: DisplayTarget,
@@ -323,6 +352,7 @@ impl<T: HirDisplay> HirDisplayWrapper<'_, T> {
             buf: String::with_capacity(20),
             curr_size: 0,
             max_size: self.max_size,
+            limited_size: self.limited_size,
             omit_verbose_types: self.omit_verbose_types,
             display_target: self.display_target,
             closure_style: self.closure_style,

crates/hir/src/display.rs

@@ -598,7 +598,7 @@ impl HirDisplay for Trait {
 
         let assoc_items = self.items(f.db);
         let assoc_items_size = assoc_items.len();
-        let max_display_size = f.max_size.unwrap_or(assoc_items_size);
+        let limited_size = f.limited_size.unwrap_or(assoc_items_size);
         if assoc_items.is_empty() {
             f.write_str(" {}")?;
         } else {
@@ -617,7 +617,7 @@ impl HirDisplay for Trait {
                     }
                 };
                 f.write_str(",\n")?;
-                if index + 1 == max_display_size && index + 1 != assoc_items_size {
+                if index + 1 == limited_size && index + 1 != assoc_items_size {
                     f.write_str("    ...\n")?;
                     break;
                 }

crates/ide-db/src/defs.rs

@@ -24,12 +24,6 @@ use crate::documentation::{Documentation, HasDocs};
 use crate::famous_defs::FamousDefs;
 use crate::RootDatabase;
 
-#[derive(Default)]
-pub struct HoverDisplayConfig {
-    pub trait_item_display_num: Option<usize>,
-    // todo: add config for struct & enum
-}
-
 // FIXME: a more precise name would probably be `Symbol`?
 #[derive(Debug, PartialEq, Eq, Copy, Clone, Hash)]
 pub enum Definition {
@@ -219,7 +213,7 @@ impl Definition {
         })
     }
 
-    pub fn label(&self, db: &RootDatabase, hover_display_config: HoverDisplayConfig) -> String {
+    pub fn label(&self, db: &RootDatabase) -> String {
         match *self {
             Definition::Macro(it) => it.display(db).to_string(),
             Definition::Field(it) => it.display(db).to_string(),
@@ -230,9 +224,7 @@ impl Definition {
             Definition::Variant(it) => it.display(db).to_string(),
             Definition::Const(it) => it.display(db).to_string(),
             Definition::Static(it) => it.display(db).to_string(),
-            Definition::Trait(it) => {
+            Definition::Trait(it) => it.display(db).to_string(),
-                it.display_truncated(db, hover_display_config.trait_item_display_num).to_string()
-            }
             Definition::TraitAlias(it) => it.display(db).to_string(),
             Definition::TypeAlias(it) => it.display(db).to_string(),
             Definition::BuiltinType(it) => it.name().display(db).to_string(),

crates/ide/src/hover.rs

@@ -32,7 +32,7 @@ pub struct HoverConfig {
     pub documentation: bool,
     pub keywords: bool,
     pub format: HoverDocFormat,
-    pub trait_item_display_num: Option<usize>,
+    pub trait_assoc_items_size: Option<usize>,
 }
 
 #[derive(Copy, Clone, Debug, PartialEq, Eq)]

crates/ide/src/hover/render.rs

@@ -8,7 +8,7 @@ use hir::{
 };
 use ide_db::{
     base_db::SourceDatabase,
-    defs::{Definition, HoverDisplayConfig},
+    defs::Definition,
     documentation::HasDocs,
     famous_defs::FamousDefs,
     generated::lints::{CLIPPY_LINTS, DEFAULT_LINTS, FEATURES},
@@ -406,8 +406,12 @@ pub(super) fn definition(
     config: &HoverConfig,
 ) -> Markup {
     let mod_path = definition_mod_path(db, &def);
-    let hover_config = HoverDisplayConfig { trait_item_display_num: config.trait_item_display_num };
+    let label = match def {
-    let label = def.label(db, hover_config);
+        Definition::Trait(trait_) => {
+            trait_.display_limited(db, config.trait_assoc_items_size).to_string()
+        }
+        _ => def.label(db),
+    };
     let docs = def.docs(db, famous_defs);
     let value = (|| match def {
         Definition::Variant(it) => {

crates/ide/src/hover/tests.rs

@@ -17,7 +17,7 @@ const HOVER_BASE_CONFIG: HoverConfig = HoverConfig {
     documentation: true,
     format: HoverDocFormat::Markdown,
     keywords: true,
-    trait_item_display_num: Some(7),
+    trait_assoc_items_size: None,
 };
 
 fn check_hover_no_result(ra_fixture: &str) {

crates/ide/src/static_index.rs

@@ -4,7 +4,7 @@
 use hir::{db::HirDatabase, Crate, HirFileIdExt, Module, Semantics};
 use ide_db::{
     base_db::{FileId, FileRange, SourceDatabaseExt},
-    defs::{Definition, HoverDisplayConfig},
+    defs::Definition,
     documentation::Documentation,
     famous_defs::FamousDefs,
     helpers::get_definition,
@@ -166,7 +166,7 @@ impl StaticIndex<'_> {
             documentation: true,
             keywords: true,
             format: crate::HoverDocFormat::Markdown,
-            trait_item_display_num: None,
+            trait_assoc_items_size: None,
         };
         let tokens = tokens.filter(|token| {
             matches!(
@@ -197,7 +197,7 @@ impl StaticIndex<'_> {
                     enclosing_moniker: current_crate
                         .zip(def.enclosing_definition(self.db))
                         .and_then(|(cc, enclosing_def)| def_to_moniker(self.db, enclosing_def, cc)),
-                    signature: Some(def.label(self.db, HoverDisplayConfig::default())),
+                    signature: Some(def.label(self.db)),
                     kind: def_to_kind(self.db, def),
                 });
                 self.def_map.insert(def, it);

crates/rust-analyzer/src/config.rs

@@ -368,6 +368,9 @@ config_data! {
         /// How to render the size information in a memory layout hover.
         hover_memoryLayout_size: Option<MemoryLayoutHoverRenderKindDef> = "\"both\"",
 
+        /// How many associated items of a trait to display when hovering a trait.
+        hover_show_traitAssocItems: Option<usize> = "null",
+
         /// Whether to enforce the import granularity setting for all files. If set to false rust-analyzer will try to keep import styles consistent per file.
         imports_granularity_enforce: bool              = "false",
         /// How imports should be grouped into use statements.
@@ -590,9 +593,6 @@ config_data! {
         /// Show documentation.
         signatureInfo_documentation_enable: bool                       = "true",
 
-        /// How many trait item display on hover.
-        traitItemDisplayNum: Option<usize> = "7",
-
         /// Whether to insert closing angle brackets when typing an opening angle bracket of a generic argument list.
         typing_autoClosingAngleBrackets_enable: bool = "false",
 
@@ -1685,7 +1685,7 @@ impl Config {
                 }
             },
             keywords: self.data.hover_documentation_keywords_enable,
-            trait_item_display_num: self.data.traitItemDisplayNum,
+            trait_assoc_items_size: self.data.hover_show_traitAssocItems,
         }
     }
 

docs/user/generated_config.adoc

@@ -505,6 +505,11 @@ How to render the offset information in a memory layout hover.
 --
 How to render the size information in a memory layout hover.
 --
+[[rust-analyzer.hover.show.traitAssocItems]]rust-analyzer.hover.show.traitAssocItems (default: `null`)::
++
+--
+How many associated items of a trait to display when hovering a trait.
+--
 [[rust-analyzer.imports.granularity.enforce]]rust-analyzer.imports.granularity.enforce (default: `false`)::
 +
 --
@@ -927,11 +932,6 @@ Show full signature of the callable. Only shows parameters if disabled.
 --
 Show documentation.
 --
-[[rust-analyzer.traitItemDisplayNum]]rust-analyzer.traitItemDisplayNum (default: `7`)::
-+
---
-How many trait item display on hover.
---
 [[rust-analyzer.typing.autoClosingAngleBrackets.enable]]rust-analyzer.typing.autoClosingAngleBrackets.enable (default: `false`)::
 +
 --

editors/code/package.json

@@ -1119,6 +1119,15 @@
                         }
                     ]
                 },
+                "rust-analyzer.hover.show.traitAssocItems": {
+                    "markdownDescription": "How many associated items of a trait to display when hovering a trait.",
+                    "default": null,
+                    "type": [
+                        "null",
+                        "integer"
+                    ],
+                    "minimum": 0
+                },
                 "rust-analyzer.imports.granularity.enforce": {
                     "markdownDescription": "Whether to enforce the import granularity setting for all files. If set to false rust-analyzer will try to keep import styles consistent per file.",
                     "default": false,
@@ -1648,15 +1657,6 @@
                     "default": true,
                     "type": "boolean"
                 },
-                "rust-analyzer.traitItemDisplayNum": {
-                    "markdownDescription": "How many trait item display on hover.",
-                    "default": 7,
-                    "type": [
-                        "null",
-                        "integer"
-                    ],
-                    "minimum": 0
-                },
                 "rust-analyzer.typing.autoClosingAngleBrackets.enable": {
                     "markdownDescription": "Whether to insert closing angle brackets when typing an opening angle bracket of a generic argument list.",
                     "default": false,