From 5aa1db8183891df057bd0630d055d7cdf39bdb65 Mon Sep 17 00:00:00 2001
From: t-monaghan <tomaghan@gmail.com>
Date: Sat, 8 Jul 2023 12:30:01 +1000
Subject: [PATCH 1/2] ViewData struct in style of dead10ck's changes

see https://github.com/helix-editor/helix/commit/599bb29f26d3051cec24ea6c1fcd16ff82199b4e
---
 helix-view/src/document.rs | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/helix-view/src/document.rs b/helix-view/src/document.rs
index b08370f9f371..c2dee6b83476 100644
--- a/helix-view/src/document.rs
+++ b/helix-view/src/document.rs
@@ -34,6 +34,7 @@ use helix_core::{
 };
 
 use crate::editor::{Config, RedrawHandle};
+use crate::view::ViewPosition;
 use crate::{DocumentId, Editor, Theme, View, ViewId};
 
 /// 8kB of buffer space for encoding and decoding `Rope`s.
@@ -131,6 +132,7 @@ pub struct Document {
     pub(crate) id: DocumentId,
     text: Rope,
     selections: HashMap<ViewId, Selection>,
+    view_data: HashMap<ViewId, ViewData>,
 
     /// Inlay hints annotations for the document, by view.
     ///
@@ -263,6 +265,7 @@ impl fmt::Debug for Document {
             .field("selections", &self.selections)
             .field("inlay_hints_oudated", &self.inlay_hints_oudated)
             .field("text_annotations", &self.inlay_hints)
+            .field("view_data", &self.view_data)
             .field("path", &self.path)
             .field("encoding", &self.encoding)
             .field("restore_cursor", &self.restore_cursor)
@@ -654,6 +657,7 @@ impl Document {
             selections: HashMap::default(),
             inlay_hints: HashMap::default(),
             inlay_hints_oudated: false,
+            view_data: Default::default(),
             indent_style: DEFAULT_INDENT,
             line_ending,
             restore_cursor: false,
@@ -1614,6 +1618,14 @@ impl Document {
         &self.selections
     }
 
+    pub fn view_data(&mut self, view_id: ViewId) -> &ViewData {
+        self.view_data.entry(view_id).or_default()
+    }
+
+    pub fn view_data_mut(&mut self, view_id: ViewId) -> &mut ViewData {
+        self.view_data.entry(view_id).or_default()
+    }
+
     pub fn relative_path(&self) -> Option<PathBuf> {
         self.path
             .as_deref()
@@ -1788,6 +1800,11 @@ impl Document {
     }
 }
 
+#[derive(Debug, Default)]
+pub struct ViewData {
+    pub view_position: ViewPosition,
+}
+
 #[derive(Clone, Debug)]
 pub enum FormatterError {
     SpawningFailed {
@@ -1837,6 +1854,7 @@ mod test {
             Arc::new(ArcSwap::new(Arc::new(Config::default()))),
         );
         let view = ViewId::default();
+        doc.ensure_view_init(view);
         doc.set_selection(view, Selection::single(0, 0));
 
         let transaction =
@@ -1875,6 +1893,7 @@ mod test {
             Arc::new(ArcSwap::new(Arc::new(Config::default()))),
         );
         let view = ViewId::default();
+        doc.ensure_view_init(view);
         doc.set_selection(view, Selection::single(5, 5));
 
         // insert

From 411c4e772053445f2e15069cff136c309fe32963 Mon Sep 17 00:00:00 2001
From: t-monaghan <tomaghan@gmail.com>
Date: Sat, 8 Jul 2023 12:43:13 +1000
Subject: [PATCH 2/2] view position updates based on view id

---
 helix-view/src/editor.rs | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/helix-view/src/editor.rs b/helix-view/src/editor.rs
index 630ea5cf987b..3194d345cb88 100644
--- a/helix-view/src/editor.rs
+++ b/helix-view/src/editor.rs
@@ -1,5 +1,4 @@
 use crate::{
-    align_view,
     clipboard::{get_clipboard_provider, ClipboardProvider},
     document::{DocumentSavedEventFuture, DocumentSavedEventResult, Mode, SavePoint},
     graphics::{CursorKind, Rect},
@@ -7,8 +6,7 @@ use crate::{
     input::KeyEvent,
     theme::{self, Theme},
     tree::{self, Tree},
-    view::ViewPosition,
-    Align, Document, DocumentId, View, ViewId,
+    Document, DocumentId, View, ViewId,
 };
 use dap::StackFrame;
 use helix_vcs::DiffProviderRegistry;
@@ -1252,16 +1250,22 @@ impl Editor {
     }
 
     fn replace_document_in_view(&mut self, current_view: ViewId, doc_id: DocumentId) {
+        let scrolloff = self.config().scrolloff;
         let view = self.tree.get_mut(current_view);
+
+        if let Some(old_doc) = self.documents.get_mut(&view.doc) {
+            old_doc.view_data_mut(current_view).view_position = view.offset;
+        }
+
         view.doc = doc_id;
-        view.offset = ViewPosition::default();
 
         let doc = doc_mut!(self, &doc_id);
+        view.offset = doc.view_data(current_view).view_position;
         doc.ensure_view_init(view.id);
         view.sync_changes(doc);
         doc.mark_as_focused();
 
-        align_view(doc, view, Align::Center);
+        view.ensure_cursor_in_view(doc, scrolloff);
     }
 
     pub fn switch(&mut self, id: DocumentId, action: Action) {