Add preview for scratch buffers in buffer picker (#3454)

2 files changed, 82 insertions, 49 deletions

diff --git a/helix-term/src/ui/mod.rs b/helix-term/src/ui/mod.rs
index cca9e9bf..3416b319 100644
--- a/helix-term/src/ui/mod.rs
+++ b/helix-term/src/ui/mod.rs
@@ -230,7 +230,7 @@ pub fn file_picker(root: PathBuf, config: &helix_view::editor::Config) -> FilePi
                 cx.editor.set_error(err);
             }
         },
-        |_editor, path| Some((path.clone(), None)),
+        |_editor, path| Some((path.clone().into(), None)),
     )
 }
 
diff --git a/helix-term/src/ui/picker.rs b/helix-term/src/ui/picker.rs
index 54911924..5e9ca3d8 100644
--- a/helix-term/src/ui/picker.rs
+++ b/helix-term/src/ui/picker.rs
@@ -12,18 +12,14 @@ use fuzzy_matcher::skim::SkimMatcherV2 as Matcher;
 use tui::widgets::Widget;
 
 use std::{cmp::Ordering, time::Instant};
-use std::{
-    collections::HashMap,
-    io::Read,
-    path::{Path, PathBuf},
-};
+use std::{collections::HashMap, io::Read, path::PathBuf};
 
 use crate::ui::{Prompt, PromptEvent};
 use helix_core::{movement::Direction, Position};
 use helix_view::{
     editor::Action,
     graphics::{CursorKind, Margin, Modifier, Rect},
-    Document, Editor,
+    Document, DocumentId, Editor,
 };
 
 use super::menu::Item;
@@ -32,8 +28,36 @@ 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;
 
+#[derive(PartialEq, Eq, Hash)]
+pub enum PathOrId {
+    Id(DocumentId),
+    Path(PathBuf),
+}
+
+impl PathOrId {
+    fn get_canonicalized(self) -> std::io::Result<Self> {
+        use PathOrId::*;
+        Ok(match self {
+            Path(path) => Path(helix_core::path::get_canonicalized_path(&path)?),
+            Id(id) => Id(id),
+        })
+    }
+}
+
+impl From<PathBuf> for PathOrId {
+    fn from(v: PathBuf) -> Self {
+        Self::Path(v)
+    }
+}
+
+impl From<DocumentId> for PathOrId {
+    fn from(v: DocumentId) -> Self {
+        Self::Id(v)
+    }
+}
+
 /// File path and range of lines (used to align and highlight lines)
-pub type FileLocation = (PathBuf, Option<(usize, usize)>);
+pub type FileLocation = (PathOrId, Option<(usize, usize)>);
 
 pub struct FilePicker<T: Item> {
     picker: Picker<T>,
@@ -112,62 +136,71 @@ impl<T: Item> FilePicker<T> {
         self.picker
             .selection()
             .and_then(|current| (self.file_fn)(editor, current))
-            .and_then(|(path, line)| {
-                helix_core::path::get_canonicalized_path(&path)
-                    .ok()
-                    .zip(Some(line))
-            })
+            .and_then(|(path_or_id, line)| path_or_id.get_canonicalized().ok().zip(Some(line)))
     }
 
     /// Get (cached) preview for a given path. If a document corresponding
     /// to the path is already open in the editor, it is used instead.
     fn get_preview<'picker, 'editor>(
         &'picker mut self,
-        path: &Path,
+        path_or_id: PathOrId,
         editor: &'editor Editor,
     ) -> Preview<'picker, 'editor> {
-        if let Some(doc) = editor.document_by_path(path) {
-            return Preview::EditorDocument(doc);
-        }
+        match path_or_id {
+            PathOrId::Path(path) => {
+                let path = &path;
+                if let Some(doc) = editor.document_by_path(path) {
+                    return Preview::EditorDocument(doc);
+                }
 
-        if self.preview_cache.contains_key(path) {
-            return Preview::Cached(&self.preview_cache[path]);
-        }
+                if self.preview_cache.contains_key(path) {
+                    return Preview::Cached(&self.preview_cache[path]);
+                }
 
-        let data = std::fs::File::open(path).and_then(|file| {
-            let metadata = file.metadata()?;
-            // Read up to 1kb to detect the content type
-            let n = file.take(1024).read_to_end(&mut self.read_buffer)?;
-            let content_type = content_inspector::inspect(&self.read_buffer[..n]);
-            self.read_buffer.clear();
-            Ok((metadata, content_type))
-        });
-        let preview = data
-            .map(
-                |(metadata, content_type)| match (metadata.len(), content_type) {
-                    (_, content_inspector::ContentType::BINARY) => CachedPreview::Binary,
-                    (size, _) if size > MAX_FILE_SIZE_FOR_PREVIEW => CachedPreview::LargeFile,
-                    _ => {
-                        // TODO: enable syntax highlighting; blocked by async rendering
-                        Document::open(path, None, None)
-                            .map(|doc| CachedPreview::Document(Box::new(doc)))
-                            .unwrap_or(CachedPreview::NotFound)
-                    }
-                },
-            )
-            .unwrap_or(CachedPreview::NotFound);
-        self.preview_cache.insert(path.to_owned(), preview);
-        Preview::Cached(&self.preview_cache[path])
+                let data = std::fs::File::open(path).and_then(|file| {
+                    let metadata = file.metadata()?;
+                    // Read up to 1kb to detect the content type
+                    let n = file.take(1024).read_to_end(&mut self.read_buffer)?;
+                    let content_type = content_inspector::inspect(&self.read_buffer[..n]);
+                    self.read_buffer.clear();
+                    Ok((metadata, content_type))
+                });
+                let preview = data
+                    .map(
+                        |(metadata, content_type)| match (metadata.len(), content_type) {
+                            (_, content_inspector::ContentType::BINARY) => CachedPreview::Binary,
+                            (size, _) if size > MAX_FILE_SIZE_FOR_PREVIEW => {
+                                CachedPreview::LargeFile
+                            }
+                            _ => {
+                                // TODO: enable syntax highlighting; blocked by async rendering
+                                Document::open(path, None, None)
+                                    .map(|doc| CachedPreview::Document(Box::new(doc)))
+                                    .unwrap_or(CachedPreview::NotFound)
+                            }
+                        },
+                    )
+                    .unwrap_or(CachedPreview::NotFound);
+                self.preview_cache.insert(path.to_owned(), preview);
+                Preview::Cached(&self.preview_cache[path])
+            }
+            PathOrId::Id(id) => {
+                let doc = editor.documents.get(&id).unwrap();
+                Preview::EditorDocument(doc)
+            }
+        }
     }
 
     fn handle_idle_timeout(&mut self, cx: &mut Context) -> EventResult {
         // Try to find a document in the cache
         let doc = self
             .current_file(cx.editor)
-            .and_then(|(path, _range)| self.preview_cache.get_mut(&path))
-            .and_then(|cache| match cache {
-                CachedPreview::Document(doc) => Some(doc),
-                _ => None,
+            .and_then(|(path, _range)| match path {
+                PathOrId::Id(doc_id) => Some(doc_mut!(cx.editor, &doc_id)),
+                PathOrId::Path(path) => match self.preview_cache.get_mut(&path) {
+                    Some(CachedPreview::Document(doc)) => Some(doc),
+                    _ => None,
+                },
             });
 
         // Then attempt to highlight it if it has no language set
@@ -224,7 +257,7 @@ impl<T: Item + 'static> Component for FilePicker<T> {
         block.render(preview_area, surface);
 
         if let Some((path, range)) = self.current_file(cx.editor) {
-            let preview = self.get_preview(&path, cx.editor);
+            let preview = self.get_preview(path, cx.editor);
             let doc = match preview.document() {
                 Some(doc) => doc,
                 None => {