feat(commands): better handling of buffer-close (#1397)

* feat(commands): better handling of buffer-close

Previously, when closing buffer, you would loose cursor position in other docs.
Also, all splits where the buffer was open would be closed.

This PR changes the behavior, if the view has also other buffer
previously viewed it switches back to the last one instead of the view
being closed. As a side effect, since the views are persisted,
 the cursor history is persisted as well.

Fixes: https://github.com/helix-editor/helix/issues/1186

* Adjust buffer close behavior

* Remove closed documents from jump history

* Fix after rebase

2 files changed, 38 insertions, 10 deletions

diff --git a/helix-view/src/editor.rs b/helix-view/src/editor.rs
index 79775c89..38826f4b 100644
--- a/helix-view/src/editor.rs
+++ b/helix-view/src/editor.rs
@@ -667,7 +667,7 @@ impl Editor {
                     view.jumps.push(jump);
                     // Set last accessed doc if it is a different document
                     if doc.id != id {
-                        view.last_accessed_doc = Some(view.doc);
+                        view.add_to_history(view.doc);
                         // Set last modified doc if modified and last modified doc is different
                         if std::mem::take(&mut doc.modified_since_accessed)
                             && view.last_modified_docs[0] != Some(view.doc)
@@ -785,20 +785,41 @@ impl Editor {
             tokio::spawn(language_server.text_document_did_close(doc.identifier()));
         }
 
-        let views_to_close = self
+        enum Action {
+            Close(ViewId),
+            ReplaceDoc(ViewId, DocumentId),
+        }
+
+        let actions: Vec<Action> = self
             .tree
-            .views()
+            .views_mut()
             .filter_map(|(view, _focus)| {
+                // remove the document from jump list of all views
+                view.jumps.remove(&doc_id);
+
                 if view.doc == doc_id {
-                    Some(view.id)
+                    // something was previously open in the view, switch to previous doc
+                    if let Some(prev_doc) = view.docs_access_history.pop() {
+                        Some(Action::ReplaceDoc(view.id, prev_doc))
+                    } else {
+                        // only the document that is being closed was in the view, close it
+                        Some(Action::Close(view.id))
+                    }
                 } else {
                     None
                 }
             })
-            .collect::<Vec<_>>();
+            .collect();
 
-        for view_id in views_to_close {
-            self.close(view_id);
+        for action in actions {
+            match action {
+                Action::Close(view_id) => {
+                    self.close(view_id);
+                }
+                Action::ReplaceDoc(view_id, doc_id) => {
+                    self.replace_document_in_view(view_id, doc_id);
+                }
+            }
         }
 
         self.documents.remove(&doc_id);
diff --git a/helix-view/src/view.rs b/helix-view/src/view.rs
index 7cf88c2e..3450da9b 100644
--- a/helix-view/src/view.rs
+++ b/helix-view/src/view.rs
@@ -72,8 +72,8 @@ pub struct View {
     pub area: Rect,
     pub doc: DocumentId,
     pub jumps: JumpList,
-    /// the last accessed file before the current one
-    pub last_accessed_doc: Option<DocumentId>,
+    // documents accessed from this view from the oldest one to last viewed one
+    pub docs_access_history: Vec<DocumentId>,
     /// the last modified files before the current one
     /// ordered from most frequent to least frequent
     // uses two docs because we want to be able to swap between the
@@ -110,13 +110,20 @@ impl View {
             offset: Position::new(0, 0),
             area: Rect::default(), // will get calculated upon inserting into tree
             jumps: JumpList::new((doc, Selection::point(0))), // TODO: use actual sel
-            last_accessed_doc: None,
+            docs_access_history: Vec::new(),
             last_modified_docs: [None, None],
             object_selections: Vec::new(),
             gutters,
         }
     }
 
+    pub fn add_to_history(&mut self, id: DocumentId) {
+        if let Some(pos) = self.docs_access_history.iter().position(|&doc| doc == id) {
+            self.docs_access_history.remove(pos);
+        }
+        self.docs_access_history.push(id);
+    }
+
     pub fn inner_area(&self) -> Rect {
         // TODO: cache this
         let offset = self