Show file preview in split pane in fuzzy finder (#534)

* Add preview pane for fuzzy finder

* Fix picker preview lag by caching

* Add picker preview for document symbols

* Cache picker preview per document instead of view

* Use line instead of range for preview doc

* Add picker preview for buffer picker

* Fix render bug and refactor picker

* Refactor picker preview rendering

* Split picker and preview and compose

The current selected item is cloned on every event, which is
undesirable

* Refactor out clones in previewed picker

* Retrieve doc from editor if possible in filepicker

* Disable syntax highlight for picker preview

Files already loaded in memory have syntax highlighting enabled

* Ignore directory symlinks in file picker

* Cleanup unnecessary pubs and derives

* Remove unnecessary highlight from file picker

* Reorganize buffer rendering

* Use normal picker for code actions

* Remove unnecessary generics and trait impls

* Remove prepare_for_render and make render mutable

* Skip picker preview if screen small, less padding

1 files changed, 11 insertions, 2 deletions

diff --git a/helix-view/src/editor.rs b/helix-view/src/editor.rs
index 9b7f8429..413b7913 100644
--- a/helix-view/src/editor.rs
+++ b/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;
 
@@ -222,7 +226,7 @@ impl Editor {
         let id = if let Some(id) = id {
             id
         } else {
-            let mut doc = Document::open(path, None, Some(&self.theme), Some(&self.syn_loader))?;
+            let mut doc = Document::open(&path, None, Some(&self.theme), Some(&self.syn_loader))?;
 
             // try to find a language server based on the language name
             let language_server = doc
@@ -316,6 +320,11 @@ 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];