vim hml (#7298)

- Add a setting for `vertical_scroll_offset`
- Fix H/M/L in vim with scrolloff



Release Notes:

- Added a settings for `vertical_scroll_offset`
- vim: Fix H/M/L with various values of vertical_scroll_offset

---------

Co-authored-by: Vbhavsar <vbhavsar@gmail.com>
Co-authored-by: fdionisi <code@fdionisi.me>

crates/vim/src/motion.rs

@@ -1044,9 +1044,17 @@ fn window_top(
     map: &DisplaySnapshot,
     point: DisplayPoint,
     text_layout_details: &TextLayoutDetails,
-    times: usize,
+    mut times: usize,
 ) -> (DisplayPoint, SelectionGoal) {
-    let first_visible_line = text_layout_details.anchor.to_display_point(map);
+    let first_visible_line = text_layout_details
+        .scroll_anchor
+        .anchor
+        .to_display_point(map);
+
+    if first_visible_line.row() != 0 && text_layout_details.vertical_scroll_margin as usize > times
+    {
+        times = text_layout_details.vertical_scroll_margin.ceil() as usize;
+    }
 
     if let Some(visible_rows) = text_layout_details.visible_rows {
         let bottom_row = first_visible_line.row() + visible_rows as u32;
@@ -1070,7 +1078,10 @@ fn window_middle(
     text_layout_details: &TextLayoutDetails,
 ) -> (DisplayPoint, SelectionGoal) {
     if let Some(visible_rows) = text_layout_details.visible_rows {
-        let first_visible_line = text_layout_details.anchor.to_display_point(map);
+        let first_visible_line = text_layout_details
+            .scroll_anchor
+            .anchor
+            .to_display_point(map);
         let max_rows = (visible_rows as u32).min(map.max_buffer_row());
         let new_row = first_visible_line.row() + (max_rows.div_euclid(2));
         let new_col = point.column().min(map.line_len(new_row));
@@ -1085,11 +1096,20 @@ fn window_bottom(
     map: &DisplaySnapshot,
     point: DisplayPoint,
     text_layout_details: &TextLayoutDetails,
-    times: usize,
+    mut times: usize,
 ) -> (DisplayPoint, SelectionGoal) {
     if let Some(visible_rows) = text_layout_details.visible_rows {
-        let first_visible_line = text_layout_details.anchor.to_display_point(map);
-        let bottom_row = first_visible_line.row() + (visible_rows) as u32;
+        let first_visible_line = text_layout_details
+            .scroll_anchor
+            .anchor
+            .to_display_point(map);
+        let bottom_row = first_visible_line.row()
+            + (visible_rows + text_layout_details.scroll_anchor.offset.y - 1.).floor() as u32;
+        if bottom_row < map.max_buffer_row()
+            && text_layout_details.vertical_scroll_margin as usize > times
+        {
+            times = text_layout_details.vertical_scroll_margin.ceil() as usize;
+        }
         let bottom_row_capped = bottom_row.min(map.max_buffer_row());
         let new_row = if bottom_row_capped.saturating_sub(times as u32) < first_visible_line.row() {
             first_visible_line.row()

crates/vim/src/normal/scroll.rs

@@ -1,11 +1,10 @@
 use crate::Vim;
 use editor::{
-    display_map::ToDisplayPoint,
-    scroll::{ScrollAmount, VERTICAL_SCROLL_MARGIN},
-    DisplayPoint, Editor,
+    display_map::ToDisplayPoint, scroll::ScrollAmount, DisplayPoint, Editor, EditorSettings,
 };
 use gpui::{actions, ViewContext};
 use language::Bias;
+use settings::Settings;
 use workspace::Workspace;
 
 actions!(
@@ -77,6 +76,7 @@ fn scroll_editor(
         };
 
         let top_anchor = editor.scroll_manager.anchor().anchor;
+        let vertical_scroll_margin = EditorSettings::get_global(cx).vertical_scroll_margin;
 
         editor.change_selections(None, cx, |s| {
             s.move_with(|map, selection| {
@@ -88,8 +88,8 @@ fn scroll_editor(
                     let new_row = top.row() + selection.head().row() - old_top.row();
                     head = map.clip_point(DisplayPoint::new(new_row, head.column()), Bias::Left)
                 }
-                let min_row = top.row() + VERTICAL_SCROLL_MARGIN as u32;
-                let max_row = top.row() + visible_rows - VERTICAL_SCROLL_MARGIN as u32 - 1;
+                let min_row = top.row() + vertical_scroll_margin as u32;
+                let max_row = top.row() + visible_rows - vertical_scroll_margin as u32 - 1;
 
                 let new_head = if head.row() < min_row {
                     map.clip_point(DisplayPoint::new(min_row, head.column()), Bias::Left)

crates/vim/src/test/neovim_backed_test_context.rs

@@ -1,4 +1,4 @@
-use editor::{scroll::VERTICAL_SCROLL_MARGIN, test::editor_test_context::ContextHandle};
+use editor::test::editor_test_context::ContextHandle;
 use gpui::{px, size, Context};
 use indoc::indoc;
 use settings::SettingsStore;
@@ -155,9 +155,7 @@ impl NeovimBackedTestContext {
 
     pub async fn set_scroll_height(&mut self, rows: u32) {
         // match Zed's scrolling behavior
-        self.neovim
-            .set_option(&format!("scrolloff={}", VERTICAL_SCROLL_MARGIN))
-            .await;
+        self.neovim.set_option(&format!("scrolloff={}", 3)).await;
         // +2 to account for the vim command UI at the bottom.
         self.neovim.set_option(&format!("lines={}", rows + 2)).await;
         let (line_height, visible_line_count) = self.editor(|editor, cx| {