Show file preview in split pane in fuzzy finder

helix-term/src/commands.rs

@@ -31,7 +31,7 @@ use movement::Movement;
 
 use crate::{
     compositor::{self, Component, Compositor},
-    ui::{self, Popup, PreviewedPicker, Prompt, PromptEvent},
+    ui::{self, FilePicker, Popup, Prompt, PromptEvent},
 };
 
 use crate::job::{self, Job, Jobs};
@@ -2039,7 +2039,7 @@ fn file_picker(cx: &mut Context) {
 fn buffer_picker(cx: &mut Context) {
     let current = view!(cx.editor).doc;
 
-    let picker = PreviewedPicker::new(
+    let picker = FilePicker::new(
         cx.editor
             .documents
             .iter()
@@ -2123,7 +2123,7 @@ fn symbol_picker(cx: &mut Context) {
                     }
                 };
 
-                let picker = PreviewedPicker::new(
+                let picker = FilePicker::new(
                     symbols,
                     |symbol| (&symbol.name).into(),
                     move |editor: &mut Editor, symbol, _action| {
@@ -2177,7 +2177,7 @@ pub fn code_action(cx: &mut Context) {
               compositor: &mut Compositor,
               response: Option<lsp::CodeActionResponse>| {
             if let Some(actions) = response {
-                let picker = PreviewedPicker::new(
+                let picker = FilePicker::new(
                     actions,
                     |action| match action {
                         lsp::CodeActionOrCommand::CodeAction(action) => {
@@ -2525,7 +2525,7 @@ fn goto_impl(
             editor.set_error("No definition found.".to_string());
         }
         _locations => {
-            let picker = PreviewedPicker::new(
+            let picker = FilePicker::new(
                 locations,
                 |location| {
                     let file = location.uri.as_str();

helix-term/src/ui/mod.rs

@@ -13,7 +13,7 @@ pub use completion::Completion;
 pub use editor::EditorView;
 pub use markdown::Markdown;
 pub use menu::Menu;
-pub use picker::PreviewedPicker;
+pub use picker::FilePicker;
 pub use popup::Popup;
 pub use prompt::{Prompt, PromptEvent};
 pub use spinner::{ProgressSpinners, Spinner};
@@ -73,7 +73,7 @@ pub fn regex_prompt(
     )
 }
 
-pub fn file_picker(root: PathBuf) -> PreviewedPicker<PathBuf> {
+pub fn file_picker(root: PathBuf) -> FilePicker<PathBuf> {
     use ignore::Walk;
     use std::time;
     let files = Walk::new(root.clone()).filter_map(|entry| match entry {
@@ -109,7 +109,7 @@ pub fn file_picker(root: PathBuf) -> PreviewedPicker<PathBuf> {
 
     let files = files.into_iter().map(|(path, _)| path).collect();
 
-    PreviewedPicker::new(
+    FilePicker::new(
         files,
         move |path: &PathBuf| {
             // format_fn

helix-term/src/ui/picker.rs

@@ -1,5 +1,4 @@
 use crate::{
-    commands::{self, Align},
     compositor::{Component, Compositor, Context, EventResult},
     ui::EditorView,
 };
@@ -16,63 +15,72 @@ use tui::widgets::Widget;
 use std::{borrow::Cow, collections::HashMap, path::PathBuf};
 
 use crate::ui::{Prompt, PromptEvent};
-use helix_core::{hashmap, Position, Range, Selection};
+use helix_core::{Position, Selection};
 use helix_view::{
     document::canonicalize_path,
     editor::Action,
     graphics::{Color, CursorKind, Rect, Style},
-    Document, Editor, View,
+    Document, Editor, View, ViewId,
 };
 
-pub struct PreviewedPicker<T> {
+/// File path and line number
+type FileLocation = (PathBuf, usize);
+
+pub struct FilePicker<T> {
     picker: Picker<T>,
-    // Caches paths to docs to line number to view
-    preview_cache: HashMap<PathBuf, (Document, HashMap<usize, View>)>,
-    #[allow(clippy::type_complexity)]
-    preview_fn: Box<dyn Fn(&Editor, &T) -> Option<(PathBuf, usize)>>,
+    /// Caches paths to documents
+    preview_cache: HashMap<PathBuf, Document>,
+    /// Given an item in the picker, return the file path and line number to display.
+    file_fn: Box<dyn Fn(&Editor, &T) -> Option<FileLocation>>,
+    // A view id to be shared by all documents in the cache. Mostly a hack since a doc
+    // requires at least one selection.
+    _preview_view_id: ViewId,
 }
 
-impl<T> PreviewedPicker<T> {
+impl<T> FilePicker<T> {
     pub fn new(
         options: Vec<T>,
         format_fn: impl Fn(&T) -> Cow<str> + 'static,
         callback_fn: impl Fn(&mut Editor, &T, Action) + 'static,
-        preview_fn: impl Fn(&Editor, &T) -> Option<(PathBuf, usize)> + 'static,
+        preview_fn: impl Fn(&Editor, &T) -> Option<FileLocation> + 'static,
     ) -> Self {
         Self {
             picker: Picker::new(options, format_fn, callback_fn),
             preview_cache: HashMap::new(),
-            preview_fn: Box::new(preview_fn),
+            file_fn: Box::new(preview_fn),
+            _preview_view_id: ViewId::default(),
         }
     }
 
-    fn calculate_preview(&mut self, editor: &Editor) {
-        if let Some((path, line)) = self
-            .picker
+    fn current_file(&self, editor: &Editor) -> Option<FileLocation> {
+        self.picker
             .selection()
-            .and_then(|current| (self.preview_fn)(editor, current))
+            .and_then(|current| (self.file_fn)(editor, current))
             .and_then(|(path, line)| canonicalize_path(&path).ok().zip(Some(line)))
-        {
-            let &mut (ref mut doc, ref mut range_map) =
-                self.preview_cache.entry(path.clone()).or_insert_with(|| {
-                    let doc =
-                        Document::open(path, None, Some(&editor.theme), Some(&editor.syn_loader))
-                            .unwrap();
-                    let view = View::new(doc.id());
-                    (doc, hashmap!(line => view))
-                });
-            let view = range_map.entry(line).or_insert_with(|| View::new(doc.id()));
-
-            let range = Range::point(doc.text().line_to_char(line));
-            doc.set_selection(view.id, Selection::from(range));
-            // FIXME: gets aligned top instead of center
-            commands::align_view(doc, view, Align::Center);
+    }
+
+    fn calculate_preview(&mut self, editor: &Editor) {
+        if let Some((path, _line)) = self.current_file(editor) {
+            if !self.preview_cache.contains_key(&path) && editor.document_by_path(&path).is_none() {
+                let mut doc =
+                    Document::open(&path, None, Some(&editor.theme), Some(&editor.syn_loader))
+                        .unwrap();
+                // HACK: a doc needs atleast one selection
+                doc.set_selection(self._preview_view_id, Selection::point(0));
+                self.preview_cache.insert(path, doc);
+            }
         }
     }
 }
 
-impl<T: 'static> Component for PreviewedPicker<T> {
+impl<T: 'static> Component for FilePicker<T> {
     fn render(&self, area: Rect, surface: &mut Surface, cx: &mut Context) {
+        // |---------|  |---------|
+        // |prompt   |  |preview  |
+        // |---------|  |         |
+        // |picker   |  |         |
+        // |         |  |         |
+        // |---------|  |---------|
         let area = inner_rect(area);
         // -- Render the frame:
         // clear area
@@ -96,29 +104,39 @@ impl<T: 'static> Component for PreviewedPicker<T> {
 
         block.render(preview_area, surface);
 
-        if let Some((doc, view)) = self
-            .picker
-            .selection()
-            .and_then(|current| (self.preview_fn)(cx.editor, current))
-            .and_then(|(path, line)| canonicalize_path(&path).ok().zip(Some(line)))
-            .and_then(|(path, line)| {
-                self.preview_cache
-                    .get(&path)
-                    .and_then(|(doc, range_map)| Some((doc, range_map.get(&line)?)))
-            })
-        {
+        if let Some((doc, line)) = self.current_file(cx.editor).and_then(|(path, line)| {
+            cx.editor
+                .document_by_path(&path)
+                .or_else(|| self.preview_cache.get(&path))
+                .zip(Some(line))
+        }) {
             // FIXME: last line will not be highlighted because of a -1 in View::last_line
-            let mut view = view.clone();
+            let mut view = View::new(doc.id());
+            view.id = if doc.selections().contains_key(&self._preview_view_id) {
+                self._preview_view_id // doc from cache
+            } else {
+                // Any view will do since we do not depend on doc selections for highlighting
+                *doc.selections().keys().next().unwrap() // doc from editor
+            };
+            view.first_col = 0;
+            // align to middle
+            view.first_line = line.saturating_sub(inner.height as usize / 2);
             view.area = inner;
             EditorView::render_doc(
                 doc,
                 &view,
                 inner,
                 surface,
                 &cx.editor.theme,
-                true, // is_focused
+                false, // is_focused
                 &cx.editor.syn_loader,
             );
+            // highlight the line
+            for x in inner.left()..inner.right() {
+                surface
+                    .get_mut(x, inner.y + line.saturating_sub(view.first_line) as u16)
+                    .set_style(cx.editor.theme.get("ui.selection.primary"));
+            }
         }
     }
 

helix-view/src/document.rs

@@ -431,15 +431,16 @@ impl Document {
     // TODO: async fn?
     /// Create a new document from `path`. Encoding is auto-detected, but it can be manually
     /// overwritten with the `encoding` parameter.
-    pub fn open(
-        path: PathBuf,
+    pub fn open<P: AsRef<Path>>(
+        path: P,
         encoding: Option<&'static encoding_rs::Encoding>,
         theme: Option<&Theme>,
         config_loader: Option<&syntax::Loader>,
     ) -> Result<Self, Error> {
+        let path = path.as_ref();
         let (rope, encoding) = if path.exists() {
             let mut file =
-                std::fs::File::open(&path).context(format!("unable to open {:?}", path))?;
+                std::fs::File::open(path).context(format!("unable to open {:?}", path))?;
             from_reader(&mut file, encoding)?
         } else {
             let encoding = encoding.unwrap_or(encoding_rs::UTF_8);
@@ -449,7 +450,7 @@ impl Document {
         let mut doc = Self::from(rope, Some(encoding));
 
         // set the path and try detecting the language
-        doc.set_path(&path)?;
+        doc.set_path(path)?;
         if let Some(loader) = config_loader {
             doc.detect_language(theme, loader);
         }

helix-view/src/editor.rs

@@ -7,7 +7,11 @@ use crate::{
 };
 
 use futures_util::future;
-use std::{path::PathBuf, sync::Arc, time::Duration};
+use std::{
+    path::{Path, PathBuf},
+    sync::Arc,
+    time::Duration,
+};
 
 use slotmap::SlotMap;
 
@@ -286,6 +290,11 @@ impl Editor {
         self.documents.iter_mut().map(|(_id, doc)| doc)
     }
 
+    pub fn document_by_path<P: AsRef<Path>>(&self, path: P) -> Option<&Document> {
+        self.documents()
+            .find(|doc| doc.path().map(|p| p == path.as_ref()).unwrap_or(false))
+    }
+
     // pub fn current_document(&self) -> Document {
     //     let id = self.view().doc;
     //     let doc = &mut editor.documents[id];