Reuse menu::Item trait in picker (#2814)

* Refactor menu::Item to accomodate external state

Will be useful for storing editor state when reused by pickers.

* Add some type aliases for readability

* Reuse menu::Item trait in picker

This opens the way for merging the menu and picker code in the
future, since a picker is essentially a menu + prompt. More
excitingly, this change will also allow aligning items in the
picker, which would be useful (for example) in the command palette
for aligning the descriptions to the left and the keybinds to
the right in two separate columns.

The item formatting of each picker has been kept as is, even though
there is room for improvement now that we can format the data into
columns, since that is better tackled in a separate PR.

* Rename menu::Item::EditorData to Data

* Call and inline filter_text() in sort_text() completion

* Rename diagnostic picker's Item::Data

8 files changed, 341 insertions, 217 deletions

diff --git a/helix-term/src/commands.rs b/helix-term/src/commands.rs
index 59ca2e3b..df4867fc 100644
--- a/helix-term/src/commands.rs
+++ b/helix-term/src/commands.rs
@@ -45,6 +45,7 @@ use movement::Movement;
 use crate::{
     args,
     compositor::{self, Component, Compositor},
+    keymap::ReverseKeymap,
     ui::{self, overlay::overlayed, FilePicker, Picker, Popup, Prompt, PromptEvent},
 };
 
@@ -1744,8 +1745,42 @@ fn search_selection(cx: &mut Context) {
 }
 
 fn global_search(cx: &mut Context) {
-    let (all_matches_sx, all_matches_rx) =
-        tokio::sync::mpsc::unbounded_channel::<(usize, PathBuf)>();
+    #[derive(Debug)]
+    struct FileResult {
+        path: PathBuf,
+        /// 0 indexed lines
+        line_num: usize,
+    }
+
+    impl FileResult {
+        fn new(path: &Path, line_num: usize) -> Self {
+            Self {
+                path: path.to_path_buf(),
+                line_num,
+            }
+        }
+    }
+
+    impl ui::menu::Item for FileResult {
+        type Data = Option<PathBuf>;
+
+        fn label(&self, current_path: &Self::Data) -> Spans {
+            let relative_path = helix_core::path::get_relative_path(&self.path)
+                .to_string_lossy()
+                .into_owned();
+            if current_path
+                .as_ref()
+                .map(|p| p == &self.path)
+                .unwrap_or(false)
+            {
+                format!("{} (*)", relative_path).into()
+            } else {
+                relative_path.into()
+            }
+        }
+    }
+
+    let (all_matches_sx, all_matches_rx) = tokio::sync::mpsc::unbounded_channel::<FileResult>();
     let config = cx.editor.config();
     let smart_case = config.search.smart_case;
     let file_picker_config = config.file_picker.clone();
@@ -1809,7 +1844,7 @@ fn global_search(cx: &mut Context) {
                                 entry.path(),
                                 sinks::UTF8(|line_num, _| {
                                     all_matches_sx
-                                        .send((line_num as usize - 1, entry.path().to_path_buf()))
+                                        .send(FileResult::new(entry.path(), line_num as usize - 1))
                                         .unwrap();
 
                                     Ok(true)
@@ -1836,7 +1871,7 @@ fn global_search(cx: &mut Context) {
     let current_path = doc_mut!(cx.editor).path().cloned();
 
     let show_picker = async move {
-        let all_matches: Vec<(usize, PathBuf)> =
+        let all_matches: Vec<FileResult> =
             UnboundedReceiverStream::new(all_matches_rx).collect().await;
         let call: job::Callback =
             Box::new(move |editor: &mut Editor, compositor: &mut Compositor| {
@@ -1847,17 +1882,8 @@ fn global_search(cx: &mut Context) {
 
                 let picker = FilePicker::new(
                     all_matches,
-                    move |(_line_num, path)| {
-                        let relative_path = helix_core::path::get_relative_path(path)
-                            .to_string_lossy()
-                            .into_owned();
-                        if current_path.as_ref().map(|p| p == path).unwrap_or(false) {
-                            format!("{} (*)", relative_path).into()
-                        } else {
-                            relative_path.into()
-                        }
-                    },
-                    move |cx, (line_num, path), action| {
+                    current_path,
+                    move |cx, FileResult { path, line_num }, action| {
                         match cx.editor.open(path, action) {
                             Ok(_) => {}
                             Err(e) => {
@@ -1879,7 +1905,9 @@ fn global_search(cx: &mut Context) {
                         doc.set_selection(view.id, Selection::single(start, end));
                         align_view(doc, view, Align::Center);
                     },
-                    |_editor, (line_num, path)| Some((path.clone(), Some((*line_num, *line_num)))),
+                    |_editor, FileResult { path, line_num }| {
+                        Some((path.clone(), Some((*line_num, *line_num))))
+                    },
                 );
                 compositor.push(Box::new(overlayed(picker)));
             });
@@ -2172,8 +2200,10 @@ fn buffer_picker(cx: &mut Context) {
         is_current: bool,
     }
 
-    impl BufferMeta {
-        fn format(&self) -> Spans {
+    impl ui::menu::Item for BufferMeta {
+        type Data = ();
+
+        fn label(&self, _data: &Self::Data) -> Spans {
             let path = self
                 .path
                 .as_deref()
@@ -2213,7 +2243,7 @@ fn buffer_picker(cx: &mut Context) {
             .iter()
             .map(|(_, doc)| new_meta(doc))
             .collect(),
-        BufferMeta::format,
+        (),
         |cx, meta, action| {
             cx.editor.switch(meta.id, action);
         },
@@ -2230,6 +2260,38 @@ fn buffer_picker(cx: &mut Context) {
     cx.push_layer(Box::new(overlayed(picker)));
 }
 
+impl ui::menu::Item for MappableCommand {
+    type Data = ReverseKeymap;
+
+    fn label(&self, keymap: &Self::Data) -> Spans {
+        // formats key bindings, multiple bindings are comma separated,
+        // individual key presses are joined with `+`
+        let fmt_binding = |bindings: &Vec<Vec<KeyEvent>>| -> String {
+            bindings
+                .iter()
+                .map(|bind| {
+                    bind.iter()
+                        .map(|key| key.to_string())
+                        .collect::<Vec<String>>()
+                        .join("+")
+                })
+                .collect::<Vec<String>>()
+                .join(", ")
+        };
+
+        match self {
+            MappableCommand::Typable { doc, name, .. } => match keymap.get(name as &String) {
+                Some(bindings) => format!("{} ({})", doc, fmt_binding(bindings)).into(),
+                None => doc.as_str().into(),
+            },
+            MappableCommand::Static { doc, name, .. } => match keymap.get(*name) {
+                Some(bindings) => format!("{} ({})", doc, fmt_binding(bindings)).into(),
+                None => (*doc).into(),
+            },
+        }
+    }
+}
+
 pub fn command_palette(cx: &mut Context) {
     cx.callback = Some(Box::new(
         move |compositor: &mut Compositor, cx: &mut compositor::Context| {
@@ -2246,44 +2308,17 @@ pub fn command_palette(cx: &mut Context) {
                 }
             }));
 
-            // formats key bindings, multiple bindings are comma separated,
-            // individual key presses are joined with `+`
-            let fmt_binding = |bindings: &Vec<Vec<KeyEvent>>| -> String {
-                bindings
-                    .iter()
-                    .map(|bind| {
-                        bind.iter()
-                            .map(|key| key.key_sequence_format())
-                            .collect::<String>()
-                    })
-                    .collect::<Vec<String>>()
-                    .join(", ")
-            };
-
-            let picker = Picker::new(
-                commands,
-                move |command| match command {
-                    MappableCommand::Typable { doc, name, .. } => match keymap.get(name) {
-                        Some(bindings) => format!("{} ({})", doc, fmt_binding(bindings)).into(),
-                        None => doc.as_str().into(),
-                    },
-                    MappableCommand::Static { doc, name, .. } => match keymap.get(*name) {
-                        Some(bindings) => format!("{} ({})", doc, fmt_binding(bindings)).into(),
-                        None => (*doc).into(),
-                    },
-                },
-                move |cx, command, _action| {
-                    let mut ctx = Context {
-                        register: None,
-                        count: std::num::NonZeroUsize::new(1),
-                        editor: cx.editor,
-                        callback: None,
-                        on_next_key_callback: None,
-                        jobs: cx.jobs,
-                    };
-                    command.execute(&mut ctx);
-                },
-            );
+            let picker = Picker::new(commands, keymap, move |cx, command, _action| {
+                let mut ctx = Context {
+                    register: None,
+                    count: std::num::NonZeroUsize::new(1),
+                    editor: cx.editor,
+                    callback: None,
+                    on_next_key_callback: None,
+                    jobs: cx.jobs,
+                };
+                command.execute(&mut ctx);
+            });
             compositor.push(Box::new(overlayed(picker)));
         },
     ));
diff --git a/helix-term/src/commands/dap.rs b/helix-term/src/commands/dap.rs
index b897b2d5..9f6f4c15 100644
--- a/helix-term/src/commands/dap.rs
+++ b/helix-term/src/commands/dap.rs
@@ -4,13 +4,15 @@ use crate::{
     job::{Callback, Jobs},
     ui::{self, overlay::overlayed, FilePicker, Picker, Popup, Prompt, PromptEvent, Text},
 };
-use helix_core::syntax::{DebugArgumentValue, DebugConfigCompletion};
+use dap::{StackFrame, Thread, ThreadStates};
+use helix_core::syntax::{DebugArgumentValue, DebugConfigCompletion, DebugTemplate};
 use helix_dap::{self as dap, Client};
 use helix_lsp::block_on;
 use helix_view::editor::Breakpoint;
 
 use serde_json::{to_value, Value};
 use tokio_stream::wrappers::UnboundedReceiverStream;
+use tui::text::Spans;
 
 use std::collections::HashMap;
 use std::future::Future;
@@ -20,6 +22,38 @@ use anyhow::{anyhow, bail};
 
 use helix_view::handlers::dap::{breakpoints_changed, jump_to_stack_frame, select_thread_id};
 
+impl ui::menu::Item for StackFrame {
+    type Data = ();
+
+    fn label(&self, _data: &Self::Data) -> Spans {
+        self.name.as_str().into() // TODO: include thread_states in the label
+    }
+}
+
+impl ui::menu::Item for DebugTemplate {
+    type Data = ();
+
+    fn label(&self, _data: &Self::Data) -> Spans {
+        self.name.as_str().into()
+    }
+}
+
+impl ui::menu::Item for Thread {
+    type Data = ThreadStates;
+
+    fn label(&self, thread_states: &Self::Data) -> Spans {
+        format!(
+            "{} ({})",
+            self.name,
+            thread_states
+                .get(&self.id)
+                .map(|state| state.as_str())
+                .unwrap_or("unknown")
+        )
+        .into()
+    }
+}
+
 fn thread_picker(
     cx: &mut Context,
     callback_fn: impl Fn(&mut Editor, &dap::Thread) + Send + 'static,
@@ -41,17 +75,7 @@ fn thread_picker(
             let thread_states = debugger.thread_states.clone();
             let picker = FilePicker::new(
                 threads,
-                move |thread| {
-                    format!(
-                        "{} ({})",
-                        thread.name,
-                        thread_states
-                            .get(&thread.id)
-                            .map(|state| state.as_str())
-                            .unwrap_or("unknown")
-                    )
-                    .into()
-                },
+                thread_states,
                 move |cx, thread, _action| callback_fn(cx.editor, thread),
                 move |editor, thread| {
                     let frames = editor.debugger.as_ref()?.stack_frames.get(&thread.id)?;
@@ -243,7 +267,7 @@ pub fn dap_launch(cx: &mut Context) {
 
     cx.push_layer(Box::new(overlayed(Picker::new(
         templates,
-        |template| template.name.as_str().into(),
+        (),
         |cx, template, _action| {
             let completions = template.completion.clone();
             let name = template.name.clone();
@@ -475,7 +499,7 @@ pub fn dap_variables(cx: &mut Context) {
 
     for scope in scopes.iter() {
         // use helix_view::graphics::Style;
-        use tui::text::{Span, Spans};
+        use tui::text::Span;
         let response = block_on(debugger.variables(scope.variables_reference));
 
         variables.push(Spans::from(Span::styled(
@@ -652,7 +676,7 @@ pub fn dap_switch_stack_frame(cx: &mut Context) {
 
     let picker = FilePicker::new(
         frames,
-        |frame| frame.name.as_str().into(), // TODO: include thread_states in the label
+        (),
         move |cx, frame, _action| {
             let debugger = debugger!(cx.editor);
             // TODO: this should be simpler to find
diff --git a/helix-term/src/commands/lsp.rs b/helix-term/src/commands/lsp.rs
index d11c44cd..7f82394a 100644
--- a/helix-term/src/commands/lsp.rs
+++ b/helix-term/src/commands/lsp.rs
@@ -19,7 +19,8 @@ use crate::{
     ui::{self, overlay::overlayed, FileLocation, FilePicker, Popup, PromptEvent},
 };
 
-use std::{borrow::Cow, collections::BTreeMap};
+use std::collections::BTreeMap;
+use std::{borrow::Cow, path::PathBuf};
 
 /// Gets the language server that is attached to a document, and
 /// if it's not active displays a status message. Using this macro
@@ -39,6 +40,112 @@ macro_rules! language_server {
     };
 }
 
+impl ui::menu::Item for lsp::Location {
+    /// Current working directory.
+    type Data = PathBuf;
+
+    fn label(&self, cwdir: &Self::Data) -> Spans {
+        let file: Cow<'_, str> = (self.uri.scheme() == "file")
+            .then(|| {
+                self.uri
+                    .to_file_path()
+                    .map(|path| {
+                        // strip root prefix
+                        path.strip_prefix(&cwdir)
+                            .map(|path| path.to_path_buf())
+                            .unwrap_or(path)
+                    })
+                    .map(|path| Cow::from(path.to_string_lossy().into_owned()))
+                    .ok()
+            })
+            .flatten()
+            .unwrap_or_else(|| self.uri.as_str().into());
+        let line = self.range.start.line;
+        format!("{}:{}", file, line).into()
+    }
+}
+
+impl ui::menu::Item for lsp::SymbolInformation {
+    /// Path to currently focussed document
+    type Data = Option<lsp::Url>;
+
+    fn label(&self, current_doc_path: &Self::Data) -> Spans {
+        if current_doc_path.as_ref() == Some(&self.location.uri) {
+            self.name.as_str().into()
+        } else {
+            match self.location.uri.to_file_path() {
+                Ok(path) => {
+                    let relative_path = helix_core::path::get_relative_path(path.as_path())
+                        .to_string_lossy()
+                        .into_owned();
+                    format!("{} ({})", &self.name, relative_path).into()
+                }
+                Err(_) => format!("{} ({})", &self.name, &self.location.uri).into(),
+            }
+        }
+    }
+}
+
+struct DiagnosticStyles {
+    hint: Style,
+    info: Style,
+    warning: Style,
+    error: Style,
+}
+
+struct PickerDiagnostic {
+    url: lsp::Url,
+    diag: lsp::Diagnostic,
+}
+
+impl ui::menu::Item for PickerDiagnostic {
+    type Data = DiagnosticStyles;
+
+    fn label(&self, styles: &Self::Data) -> Spans {
+        let mut style = self
+            .diag
+            .severity
+            .map(|s| match s {
+                DiagnosticSeverity::HINT => styles.hint,
+                DiagnosticSeverity::INFORMATION => styles.info,
+                DiagnosticSeverity::WARNING => styles.warning,
+                DiagnosticSeverity::ERROR => styles.error,
+                _ => Style::default(),
+            })
+            .unwrap_or_default();
+
+        // remove background as it is distracting in the picker list
+        style.bg = None;
+
+        let code = self
+            .diag
+            .code
+            .as_ref()
+            .map(|c| match c {
+                NumberOrString::Number(n) => n.to_string(),
+                NumberOrString::String(s) => s.to_string(),
+            })
+            .unwrap_or_default();
+
+        let truncated_path = path::get_truncated_path(self.url.path())
+            .to_string_lossy()
+            .into_owned();
+
+        Spans::from(vec![
+            Span::styled(
+                self.diag.source.clone().unwrap_or_default(),
+                style.add_modifier(Modifier::BOLD),
+            ),
+            Span::raw(": "),
+            Span::styled(truncated_path, style),
+            Span::raw(" - "),
+            Span::styled(code, style.add_modifier(Modifier::BOLD)),
+            Span::raw(": "),
+            Span::styled(&self.diag.message, style),
+        ])
+    }
+}
+
 fn location_to_file_location(location: &lsp::Location) -> FileLocation {
     let path = location.uri.to_file_path().unwrap();
     let line = Some((
@@ -93,29 +200,14 @@ fn sym_picker(
     offset_encoding: OffsetEncoding,
 ) -> FilePicker<lsp::SymbolInformation> {
     // TODO: drop current_path comparison and instead use workspace: bool flag?
-    let current_path2 = current_path.clone();
     FilePicker::new(
         symbols,
-        move |symbol| {
-            if current_path.as_ref() == Some(&symbol.location.uri) {
-                symbol.name.as_str().into()
-            } else {
-                match symbol.location.uri.to_file_path() {
-                    Ok(path) => {
-                        let relative_path = helix_core::path::get_relative_path(path.as_path())
-                            .to_string_lossy()
-                            .into_owned();
-                        format!("{} ({})", &symbol.name, relative_path).into()
-                    }
-                    Err(_) => format!("{} ({})", &symbol.name, &symbol.location.uri).into(),
-                }
-            }
-        },
+        current_path.clone(),
         move |cx, symbol, action| {
             let (view, doc) = current!(cx.editor);
             push_jump(view, doc);
 
-            if current_path2.as_ref() != Some(&symbol.location.uri) {
+            if current_path.as_ref() != Some(&symbol.location.uri) {
                 let uri = &symbol.location.uri;
                 let path = match uri.to_file_path() {
                     Ok(path) => path,
@@ -155,7 +247,7 @@ fn diag_picker(
     diagnostics: BTreeMap<lsp::Url, Vec<lsp::Diagnostic>>,
     current_path: Option<lsp::Url>,
     offset_encoding: OffsetEncoding,
-) -> FilePicker<(lsp::Url, lsp::Diagnostic)> {
+) -> FilePicker<PickerDiagnostic> {
     // TODO: drop current_path comparison and instead use workspace: bool flag?
 
     // flatten the map to a vec of (url, diag) pairs
@@ -163,59 +255,24 @@ fn diag_picker(
     for (url, diags) in diagnostics {
         flat_diag.reserve(diags.len());
         for diag in diags {
-            flat_diag.push((url.clone(), diag));
+            flat_diag.push(PickerDiagnostic {
+                url: url.clone(),
+                diag,
+            });
         }
     }
 
-    let hint = cx.editor.theme.get("hint");
-    let info = cx.editor.theme.get("info");
-    let warning = cx.editor.theme.get("warning");
-    let error = cx.editor.theme.get("error");
+    let styles = DiagnosticStyles {
+        hint: cx.editor.theme.get("hint"),
+        info: cx.editor.theme.get("info"),
+        warning: cx.editor.theme.get("warning"),
+        error: cx.editor.theme.get("error"),
+    };
 
     FilePicker::new(
         flat_diag,
-        move |(url, diag)| {
-            let mut style = diag
-                .severity
-                .map(|s| match s {
-                    DiagnosticSeverity::HINT => hint,
-                    DiagnosticSeverity::INFORMATION => info,
-                    DiagnosticSeverity::WARNING => warning,
-                    DiagnosticSeverity::ERROR => error,
-                    _ => Style::default(),
-                })
-                .unwrap_or_default();
-
-            // remove background as it is distracting in the picker list
-            style.bg = None;
-
-            let code = diag
-                .code
-                .as_ref()
-                .map(|c| match c {
-                    NumberOrString::Number(n) => n.to_string(),
-                    NumberOrString::String(s) => s.to_string(),
-                })
-                .unwrap_or_default();
-
-            let truncated_path = path::get_truncated_path(url.path())
-                .to_string_lossy()
-                .into_owned();
-
-            Spans::from(vec![
-                Span::styled(
-                    diag.source.clone().unwrap_or_default(),
-                    style.add_modifier(Modifier::BOLD),
-                ),
-                Span::raw(": "),
-                Span::styled(truncated_path, style),
-                Span::raw(" - "),
-                Span::styled(code, style.add_modifier(Modifier::BOLD)),
-                Span::raw(": "),
-                Span::styled(&diag.message, style),
-            ])
-        },
-        move |cx, (url, diag), action| {
+        styles,
+        move |cx, PickerDiagnostic { url, diag }, action| {
             if current_path.as_ref() == Some(url) {
                 let (view, doc) = current!(cx.editor);
                 push_jump(view, doc);
@@ -233,7 +290,7 @@ fn diag_picker(
                 align_view(doc, view, Align::Center);
             }
         },
-        move |_editor, (url, diag)| {
+        move |_editor, PickerDiagnostic { url, diag }| {
             let location = lsp::Location::new(url.clone(), diag.range);
             Some(location_to_file_location(&location))
         },
@@ -343,10 +400,11 @@ pub fn workspace_diagnostics_picker(cx: &mut Context) {
 }
 
 impl ui::menu::Item for lsp::CodeActionOrCommand {
-    fn label(&self) -> &str {
+    type Data = ();
+    fn label(&self, _data: &Self::Data) -> Spans {
         match self {
-            lsp::CodeActionOrCommand::CodeAction(action) => action.title.as_str(),
-            lsp::CodeActionOrCommand::Command(command) => command.title.as_str(),
+            lsp::CodeActionOrCommand::CodeAction(action) => action.title.as_str().into(),
+            lsp::CodeActionOrCommand::Command(command) => command.title.as_str().into(),
         }
     }
 }
@@ -391,7 +449,7 @@ pub fn code_action(cx: &mut Context) {
                 return;
             }
 
-            let mut picker = ui::Menu::new(actions, move |editor, code_action, event| {
+            let mut picker = ui::Menu::new(actions, (), move |editor, code_action, event| {
                 if event != PromptEvent::Validate {
                     return;
                 }
@@ -619,6 +677,7 @@ pub fn apply_workspace_edit(
         }
     }
 }
+
 fn goto_impl(
     editor: &mut Editor,
     compositor: &mut Compositor,
@@ -637,26 +696,7 @@ fn goto_impl(
         _locations => {
             let picker = FilePicker::new(
                 locations,
-                move |location| {
-                    let file: Cow<'_, str> = (location.uri.scheme() == "file")
-                        .then(|| {
-                            location
-                                .uri
-                                .to_file_path()
-                                .map(|path| {
-                                    // strip root prefix
-                                    path.strip_prefix(&cwdir)
-                                        .map(|path| path.to_path_buf())
-                                        .unwrap_or(path)
-                                })
-                                .map(|path| Cow::from(path.to_string_lossy().into_owned()))
-                                .ok()
-                        })
-                        .flatten()
-                        .unwrap_or_else(|| location.uri.as_str().into());
-                    let line = location.range.start.line;
-                    format!("{}:{}", file, line).into()
-                },
+                cwdir,
                 move |cx, location, action| {
                     jump_to_location(cx.editor, location, offset_encoding, action)
                 },
diff --git a/helix-term/src/keymap.rs b/helix-term/src/keymap.rs
index db958833..59204889 100644
--- a/helix-term/src/keymap.rs
+++ b/helix-term/src/keymap.rs
@@ -208,18 +208,17 @@ pub struct Keymap {
     root: KeyTrie,
 }
 
+/// A map of command names to keybinds that will execute the command.
+pub type ReverseKeymap = HashMap<String, Vec<Vec<KeyEvent>>>;
+
 impl Keymap {
     pub fn new(root: KeyTrie) -> Self {
         Keymap { root }
     }
 
-    pub fn reverse_map(&self) -> HashMap<String, Vec<Vec<KeyEvent>>> {
+    pub fn reverse_map(&self) -> ReverseKeymap {
         // recursively visit all nodes in keymap
-        fn map_node(
-            cmd_map: &mut HashMap<String, Vec<Vec<KeyEvent>>>,
-            node: &KeyTrie,
-            keys: &mut Vec<KeyEvent>,
-        ) {
+        fn map_node(cmd_map: &mut ReverseKeymap, node: &KeyTrie, keys: &mut Vec<KeyEvent>) {
             match node {
                 KeyTrie::Leaf(cmd) => match cmd {
                     MappableCommand::Typable { name, .. } => {
diff --git a/helix-term/src/ui/completion.rs b/helix-term/src/ui/completion.rs
index 38005aad..a3637415 100644
--- a/helix-term/src/ui/completion.rs
+++ b/helix-term/src/ui/completion.rs
@@ -2,6 +2,7 @@ use crate::compositor::{Component, Context, EventResult};
 use crossterm::event::{Event, KeyCode, KeyEvent};
 use helix_view::editor::CompleteAction;
 use tui::buffer::Buffer as Surface;
+use tui::text::Spans;
 
 use std::borrow::Cow;
 
@@ -15,19 +16,25 @@ use helix_lsp::{lsp, util};
 use lsp::CompletionItem;
 
 impl menu::Item for CompletionItem {
-    fn sort_text(&self) -> &str {
-        self.filter_text.as_ref().unwrap_or(&self.label).as_str()
+    type Data = ();
+    fn sort_text(&self, data: &Self::Data) -> Cow<str> {
+        self.filter_text(data)
     }
 
-    fn filter_text(&self) -> &str {
-        self.filter_text.as_ref().unwrap_or(&self.label).as_str()
+    #[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) -> &str {
-        self.label.as_str()
+    fn label(&self, _data: &Self::Data) -> Spans {
+        self.label.as_str().into()
     }
 
-    fn row(&self) -> menu::Row {
+    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 {
@@ -85,7 +92,7 @@ impl Completion {
         start_offset: usize,
         trigger_offset: usize,
     ) -> Self {
-        let menu = Menu::new(items, move |editor: &mut Editor, item, event| {
+        let menu = Menu::new(items, (), move |editor: &mut Editor, item, event| {
             fn item_to_transaction(
                 doc: &Document,
                 item: &CompletionItem,
diff --git a/helix-term/src/ui/menu.rs b/helix-term/src/ui/menu.rs
index 0519374a..6bb64139 100644
--- a/helix-term/src/ui/menu.rs
+++ b/helix-term/src/ui/menu.rs
@@ -1,9 +1,11 @@
+use std::{borrow::Cow, path::PathBuf};
+
 use crate::{
     compositor::{Callback, Component, Compositor, Context, EventResult},
     ctrl, key, shift,
 };
 use crossterm::event::Event;
-use tui::{buffer::Buffer as Surface, widgets::Table};
+use tui::{buffer::Buffer as Surface, text::Spans, widgets::Table};
 
 pub use tui::widgets::{Cell, Row};
 
@@ -14,22 +16,41 @@ use helix_view::{graphics::Rect, Editor};
 use tui::layout::Constraint;
 
 pub trait Item {
-    fn label(&self) -> &str;
+    /// Additional editor state that is used for label calculation.
+    type Data;
+
+    fn label(&self, data: &Self::Data) -> Spans;
+
+    fn sort_text(&self, data: &Self::Data) -> Cow<str> {
+        let label: String = self.label(data).into();
+        label.into()
+    }
 
-    fn sort_text(&self) -> &str {
-        self.label()
+    fn filter_text(&self, data: &Self::Data) -> Cow<str> {
+        let label: String = self.label(data).into();
+        label.into()
     }
-    fn filter_text(&self) -> &str {
-        self.label()
+
+    fn row(&self, data: &Self::Data) -> Row {
+        Row::new(vec![Cell::from(self.label(data))])
     }
+}
 
-    fn row(&self) -> Row {
-        Row::new(vec![Cell::from(self.label())])
+impl Item for PathBuf {
+    /// Root prefix to strip.
+    type Data = PathBuf;
+
+    fn label(&self, root_path: &Self::Data) -> Spans {
+        self.strip_prefix(&root_path)
+            .unwrap_or(self)
+            .to_string_lossy()
+            .into()
     }
 }
 
 pub struct Menu<T: Item> {
     options: Vec<T>,
+    editor_data: T::Data,
 
     cursor: Option<usize>,
 
@@ -54,10 +75,12 @@ impl<T: Item> Menu<T> {
     // rendering)
     pub fn new(
         options: Vec<T>,
+        editor_data: <T as Item>::Data,
         callback_fn: impl Fn(&mut Editor, Option<&T>, MenuEvent) + 'static,
     ) -> Self {
         let mut menu = Self {
             options,
+            editor_data,
             matcher: Box::new(Matcher::default()),
             matches: Vec::new(),
             cursor: None,
@@ -83,16 +106,17 @@ impl<T: Item> Menu<T> {
                 .iter()
                 .enumerate()
                 .filter_map(|(index, option)| {
-                    let text = option.filter_text();
+                    let text: String = option.filter_text(&self.editor_data).into();
                     // TODO: using fuzzy_indices could give us the char idx for match highlighting
                     self.matcher
-                        .fuzzy_match(text, pattern)
+                        .fuzzy_match(&text, pattern)
                         .map(|score| (index, score))
                 }),
         );
         // matches.sort_unstable_by_key(|(_, score)| -score);
-        self.matches
-            .sort_unstable_by_key(|(index, _score)| self.options[*index].sort_text());
+        self.matches.sort_unstable_by_key(|(index, _score)| {
+            self.options[*index].sort_text(&self.editor_data)
+        });
 
         // reset cursor position
         self.cursor = None;
@@ -127,10 +151,10 @@ impl<T: Item> Menu<T> {
         let n = self
             .options
             .first()
-            .map(|option| option.row().cells.len())
+            .map(|option| option.row(&self.editor_data).cells.len())
             .unwrap_or_default();
         let max_lens = self.options.iter().fold(vec![0; n], |mut acc, option| {
-            let row = option.row();
+            let row = option.row(&self.editor_data);
             // maintain max for each column
             for (acc, cell) in acc.iter_mut().zip(row.cells.iter()) {
                 let width = cell.content.width();
@@ -300,7 +324,7 @@ impl<T: Item + 'static> Component for Menu<T> {
         let scroll_line = (win_height - scroll_height) * scroll
             / std::cmp::max(1, len.saturating_sub(win_height));
 
-        let rows = options.iter().map(|option| option.row());
+        let rows = options.iter().map(|option| option.row(&self.editor_data));
         let table = Table::new(rows)
             .style(style)
             .highlight_style(selected)
diff --git a/helix-term/src/ui/mod.rs b/helix-term/src/ui/mod.rs
index 948a5f2b..8d2bd325 100644
--- a/helix-term/src/ui/mod.rs
+++ b/helix-term/src/ui/mod.rs
@@ -23,8 +23,6 @@ pub use text::Text;
 use helix_core::regex::Regex;
 use helix_core::regex::RegexBuilder;
 use helix_view::{Document, Editor, View};
-use tui;
-use tui::text::Spans;
 
 use std::path::PathBuf;
 
@@ -172,10 +170,7 @@ pub fn file_picker(root: PathBuf, config: &helix_view::editor::Config) -> FilePi
 
     FilePicker::new(
         files,
-        move |path: &PathBuf| {
-            // format_fn
-            Spans::from(path.strip_prefix(&root).unwrap_or(path).to_string_lossy())
-        },
+        root,
         move |cx, path: &PathBuf, action| {
             if let Err(e) = cx.editor.open(path, action) {
                 let err = if let Some(err) = e.source() {
diff --git a/helix-term/src/ui/picker.rs b/helix-term/src/ui/picker.rs
index 1581b0a1..01fea718 100644
--- a/helix-term/src/ui/picker.rs
+++ b/helix-term/src/ui/picker.rs
@@ -6,7 +6,6 @@ use crate::{
 use crossterm::event::Event;
 use tui::{
     buffer::Buffer as Surface,
-    text::Spans,
     widgets::{Block, BorderType, Borders},
 };
 
@@ -30,6 +29,8 @@ use helix_view::{
     Document, Editor,
 };
 
+use super::menu::Item;
+
 pub const MIN_AREA_WIDTH_FOR_PREVIEW: u16 = 72;
 /// Biggest file size to preview in bytes
 pub const MAX_FILE_SIZE_FOR_PREVIEW: u64 = 10 * 1024 * 1024;
@@ -37,7 +38,7 @@ pub const MAX_FILE_SIZE_FOR_PREVIEW: u64 = 10 * 1024 * 1024;
 /// File path and range of lines (used to align and highlight lines)
 pub type FileLocation = (PathBuf, Option<(usize, usize)>);
 
-pub struct FilePicker<T> {
+pub struct FilePicker<T: Item> {
     picker: Picker<T>,
     pub truncate_start: bool,
     /// Caches paths to documents
@@ -84,15 +85,15 @@ impl Preview<'_, '_> {
     }
 }
 
-impl<T> FilePicker<T> {
+impl<T: Item> FilePicker<T> {
     pub fn new(
         options: Vec<T>,
-        format_fn: impl Fn(&T) -> Spans + 'static,
+        editor_data: T::Data,
         callback_fn: impl Fn(&mut Context, &T, Action) + 'static,
         preview_fn: impl Fn(&Editor, &T) -> Option<FileLocation> + 'static,
     ) -> Self {
         let truncate_start = true;
-        let mut picker = Picker::new(options, format_fn, callback_fn);
+        let mut picker = Picker::new(options, editor_data, callback_fn);
         picker.truncate_start = truncate_start;
 
         Self {
@@ -163,7 +164,7 @@ impl<T> FilePicker<T> {
     }
 }
 
-impl<T: 'static> Component for FilePicker<T> {
+impl<T: Item + 'static> Component for FilePicker<T> {
     fn render(&mut self, area: Rect, surface: &mut Surface, cx: &mut Context) {
         // +---------+ +---------+
         // |prompt   | |preview  |
@@ -280,8 +281,9 @@ impl<T: 'static> Component for FilePicker<T> {
     }
 }
 
-pub struct Picker<T> {
+pub struct Picker<T: Item> {
     options: Vec<T>,
+    editor_data: T::Data,
     // filter: String,
     matcher: Box<Matcher>,
     /// (index, score)
@@ -299,14 +301,13 @@ pub struct Picker<T> {
     /// Whether to truncate the start (default true)
     pub truncate_start: bool,
 
-    format_fn: Box<dyn Fn(&T) -> Spans>,
     callback_fn: Box<dyn Fn(&mut Context, &T, Action)>,
 }
 
-impl<T> Picker<T> {
+impl<T: Item> Picker<T> {
     pub fn new(
         options: Vec<T>,
-        format_fn: impl Fn(&T) -> Spans + 'static,
+        editor_data: T::Data,
         callback_fn: impl Fn(&mut Context, &T, Action) + 'static,
     ) -> Self {
         let prompt = Prompt::new(
@@ -318,6 +319,7 @@ impl<T> Picker<T> {
 
         let mut picker = Self {
             options,
+            editor_data,
             matcher: Box::new(Matcher::default()),
             matches: Vec::new(),
             filters: Vec::new(),
@@ -325,7 +327,6 @@ impl<T> Picker<T> {
             prompt,
             previous_pattern: String::new(),
             truncate_start: true,
-            format_fn: Box::new(format_fn),
             callback_fn: Box::new(callback_fn),
             completion_height: 0,
         };
@@ -371,9 +372,9 @@ impl<T> Picker<T> {
             #[allow(unstable_name_collisions)]
             self.matches.retain_mut(|(index, score)| {
                 let option = &self.options[*index];
-                // TODO: maybe using format_fn isn't the best idea here
-                let line: String = (self.format_fn)(option).into();
-                match self.matcher.fuzzy_match(&line, pattern) {
+                let text = option.sort_text(&self.editor_data);
+
+                match self.matcher.fuzzy_match(&text, pattern) {
                     Some(s) => {
                         // Update the score
                         *score = s;
@@ -399,11 +400,10 @@ impl<T> Picker<T> {
                             self.filters.binary_search(&index).ok()?;
                         }
 
-                        // TODO: maybe using format_fn isn't the best idea here
-                        let line: String = (self.format_fn)(option).into();
+                        let text = option.filter_text(&self.editor_data);
 
                         self.matcher
-                            .fuzzy_match(&line, pattern)
+                            .fuzzy_match(&text, pattern)
                             .map(|score| (index, score))
                     }),
             );
@@ -477,7 +477,7 @@ impl<T> Picker<T> {
 // - on input change:
 //  - score all the names in relation to input
 
-impl<T: 'static> Component for Picker<T> {
+impl<T: Item + 'static> Component for Picker<T> {
     fn required_size(&mut self, viewport: (u16, u16)) -> Option<(u16, u16)> {
         self.completion_height = viewport.1.saturating_sub(4);
         Some(viewport)
@@ -610,7 +610,7 @@ impl<T: 'static> Component for Picker<T> {
                 surface.set_string(inner.x.saturating_sub(2), inner.y + i as u16, ">", selected);
             }
 
-            let spans = (self.format_fn)(option);
+            let spans = option.label(&self.editor_data);
             let (_score, highlights) = self
                 .matcher
                 .fuzzy_indices(&String::from(&spans), self.prompt.line())