vim: Fix ctrl-u/ctrl-d (#3044)

Conrad Irwin created

- vim: Fix ctrl-d/ctrl-u to match vim (when :set scrolloff=3)

Change summary

crates/editor/src/editor_tests.rs                 |  2 
crates/editor/src/scroll/scroll_amount.rs         | 10 +
crates/vim/src/normal/scroll.rs                   | 88 ++++++++++++++--
crates/vim/src/test/neovim_backed_test_context.rs | 21 +++
crates/vim/test_data/test_ctrl_d_u.json           | 22 ++++
5 files changed, 122 insertions(+), 21 deletions(-)

Detailed changes

crates/editor/src/editor_tests.rs 🔗

@@ -1429,7 +1429,7 @@ async fn test_scroll_page_up_page_down(cx: &mut gpui::TestAppContext) {
         assert_eq!(editor.snapshot(cx).scroll_position(), vec2f(0., 3.));
 
         editor.scroll_screen(&ScrollAmount::Page(-0.5), cx);
-        assert_eq!(editor.snapshot(cx).scroll_position(), vec2f(0., 2.));
+        assert_eq!(editor.snapshot(cx).scroll_position(), vec2f(0., 1.));
         editor.scroll_screen(&ScrollAmount::Page(0.5), cx);
         assert_eq!(editor.snapshot(cx).scroll_position(), vec2f(0., 3.));
     });

crates/editor/src/scroll/scroll_amount.rs 🔗

@@ -15,9 +15,13 @@ impl ScrollAmount {
             Self::Line(count) => *count,
             Self::Page(count) => editor
                 .visible_line_count()
-                // subtract one to leave an anchor line
-                // round towards zero (so page-up and page-down are symmetric)
-                .map(|l| (l * count).trunc() - count.signum())
+                .map(|mut l| {
+                    // for full pages subtract one to leave an anchor line
+                    if count.abs() == 1.0 {
+                        l -= 1.0
+                    }
+                    (l * count).trunc()
+                })
                 .unwrap_or(0.),
         }
     }

crates/vim/src/normal/scroll.rs 🔗

@@ -15,19 +15,19 @@ actions!(
 
 pub fn init(cx: &mut AppContext) {
     cx.add_action(|_: &mut Workspace, _: &LineDown, cx| {
-        scroll(cx, |c| ScrollAmount::Line(c.unwrap_or(1.)))
+        scroll(cx, false, |c| ScrollAmount::Line(c.unwrap_or(1.)))
     });
     cx.add_action(|_: &mut Workspace, _: &LineUp, cx| {
-        scroll(cx, |c| ScrollAmount::Line(-c.unwrap_or(1.)))
+        scroll(cx, false, |c| ScrollAmount::Line(-c.unwrap_or(1.)))
     });
     cx.add_action(|_: &mut Workspace, _: &PageDown, cx| {
-        scroll(cx, |c| ScrollAmount::Page(c.unwrap_or(1.)))
+        scroll(cx, false, |c| ScrollAmount::Page(c.unwrap_or(1.)))
     });
     cx.add_action(|_: &mut Workspace, _: &PageUp, cx| {
-        scroll(cx, |c| ScrollAmount::Page(-c.unwrap_or(1.)))
+        scroll(cx, false, |c| ScrollAmount::Page(-c.unwrap_or(1.)))
     });
     cx.add_action(|_: &mut Workspace, _: &ScrollDown, cx| {
-        scroll(cx, |c| {
+        scroll(cx, true, |c| {
             if let Some(c) = c {
                 ScrollAmount::Line(c)
             } else {
@@ -36,7 +36,7 @@ pub fn init(cx: &mut AppContext) {
         })
     });
     cx.add_action(|_: &mut Workspace, _: &ScrollUp, cx| {
-        scroll(cx, |c| {
+        scroll(cx, true, |c| {
             if let Some(c) = c {
                 ScrollAmount::Line(-c)
             } else {
@@ -46,15 +46,27 @@ pub fn init(cx: &mut AppContext) {
     });
 }
 
-fn scroll(cx: &mut ViewContext<Workspace>, by: fn(c: Option<f32>) -> ScrollAmount) {
+fn scroll(
+    cx: &mut ViewContext<Workspace>,
+    move_cursor: bool,
+    by: fn(c: Option<f32>) -> ScrollAmount,
+) {
     Vim::update(cx, |vim, cx| {
         let amount = by(vim.take_count(cx).map(|c| c as f32));
-        vim.update_active_editor(cx, |editor, cx| scroll_editor(editor, &amount, cx));
+        vim.update_active_editor(cx, |editor, cx| {
+            scroll_editor(editor, move_cursor, &amount, cx)
+        });
     })
 }
 
-fn scroll_editor(editor: &mut Editor, amount: &ScrollAmount, cx: &mut ViewContext<Editor>) {
+fn scroll_editor(
+    editor: &mut Editor,
+    preserve_cursor_position: bool,
+    amount: &ScrollAmount,
+    cx: &mut ViewContext<Editor>,
+) {
     let should_move_cursor = editor.newest_selection_on_screen(cx).is_eq();
+    let old_top_anchor = editor.scroll_manager.anchor().anchor;
 
     editor.scroll_screen(amount, cx);
     if should_move_cursor {
@@ -68,8 +80,14 @@ fn scroll_editor(editor: &mut Editor, amount: &ScrollAmount, cx: &mut ViewContex
 
         editor.change_selections(None, cx, |s| {
             s.move_with(|map, selection| {
-                let head = selection.head();
+                let mut head = selection.head();
                 let top = top_anchor.to_display_point(map);
+
+                if preserve_cursor_position {
+                    let old_top = old_top_anchor.to_display_point(map);
+                    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;
 
@@ -92,7 +110,10 @@ fn scroll_editor(editor: &mut Editor, amount: &ScrollAmount, cx: &mut ViewContex
 
 #[cfg(test)]
 mod test {
-    use crate::{state::Mode, test::VimTestContext};
+    use crate::{
+        state::Mode,
+        test::{NeovimBackedTestContext, VimTestContext},
+    };
     use gpui::geometry::vector::vec2f;
     use indoc::indoc;
     use language::Point;
@@ -148,10 +169,10 @@ mod test {
         });
         cx.simulate_keystrokes(["ctrl-d"]);
         cx.update_editor(|editor, cx| {
-            assert_eq!(editor.snapshot(cx).scroll_position(), vec2f(0., 2.0));
+            assert_eq!(editor.snapshot(cx).scroll_position(), vec2f(0., 3.0));
             assert_eq!(
                 editor.selections.newest(cx).range(),
-                Point::new(5, 0)..Point::new(5, 0)
+                Point::new(6, 0)..Point::new(6, 0)
             )
         });
 
@@ -162,11 +183,48 @@ mod test {
         });
         cx.simulate_keystrokes(["v", "ctrl-d"]);
         cx.update_editor(|editor, cx| {
-            assert_eq!(editor.snapshot(cx).scroll_position(), vec2f(0., 2.0));
+            assert_eq!(editor.snapshot(cx).scroll_position(), vec2f(0., 3.0));
             assert_eq!(
                 editor.selections.newest(cx).range(),
-                Point::new(0, 0)..Point::new(5, 1)
+                Point::new(0, 0)..Point::new(6, 1)
             )
         });
     }
+    #[gpui::test]
+    async fn test_ctrl_d_u(cx: &mut gpui::TestAppContext) {
+        let mut cx = NeovimBackedTestContext::new(cx).await;
+
+        cx.set_scroll_height(10).await;
+
+        pub fn sample_text(rows: usize, cols: usize, start_char: char) -> String {
+            let mut text = String::new();
+            for row in 0..rows {
+                let c: char = (start_char as u32 + row as u32) as u8 as char;
+                let mut line = c.to_string().repeat(cols);
+                if row < rows - 1 {
+                    line.push('\n');
+                }
+                text += &line;
+            }
+            text
+        }
+        let content = "ˇ".to_owned() + &sample_text(26, 2, 'a');
+        cx.set_shared_state(&content).await;
+
+        // skip over the scrolloff at the top
+        // test ctrl-d
+        cx.simulate_shared_keystrokes(["4", "j", "ctrl-d"]).await;
+        cx.assert_state_matches().await;
+        cx.simulate_shared_keystrokes(["ctrl-d"]).await;
+        cx.assert_state_matches().await;
+        cx.simulate_shared_keystrokes(["g", "g", "ctrl-d"]).await;
+        cx.assert_state_matches().await;
+
+        // test ctrl-u
+        cx.simulate_shared_keystrokes(["ctrl-u"]).await;
+        cx.assert_state_matches().await;
+        cx.simulate_shared_keystrokes(["ctrl-d", "ctrl-d", "4", "j", "ctrl-u", "ctrl-u"])
+            .await;
+        cx.assert_state_matches().await;
+    }
 }

crates/vim/src/test/neovim_backed_test_context.rs 🔗

@@ -1,9 +1,10 @@
+use editor::scroll::VERTICAL_SCROLL_MARGIN;
 use indoc::indoc;
 use settings::SettingsStore;
 use std::ops::{Deref, DerefMut, Range};
 
 use collections::{HashMap, HashSet};
-use gpui::ContextHandle;
+use gpui::{geometry::vector::vec2f, ContextHandle};
 use language::{
     language_settings::{AllLanguageSettings, SoftWrap},
     OffsetRangeExt,
@@ -132,7 +133,9 @@ impl<'a> NeovimBackedTestContext<'a> {
             panic!("nvim doesn't support columns < 12")
         }
         self.neovim.set_option("wrap").await;
-        self.neovim.set_option("columns=12").await;
+        self.neovim
+            .set_option(&format!("columns={}", columns))
+            .await;
 
         self.update(|cx| {
             cx.update_global(|settings: &mut SettingsStore, cx| {
@@ -144,6 +147,20 @@ impl<'a> NeovimBackedTestContext<'a> {
         })
     }
 
+    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;
+        // +2 to account for the vim command UI at the bottom.
+        self.neovim.set_option(&format!("lines={}", rows + 2)).await;
+        let window = self.window;
+        let line_height =
+            self.editor(|editor, cx| editor.style(cx).text.line_height(cx.font_cache()));
+
+        window.simulate_resize(vec2f(1000., (rows as f32) * line_height), &mut self.cx);
+    }
+
     pub async fn set_neovim_option(&mut self, option: &str) {
         self.neovim.set_option(option).await;
     }

crates/vim/test_data/test_ctrl_d_u.json 🔗

@@ -0,0 +1,22 @@
+{"SetOption":{"value":"scrolloff=3"}}
+{"SetOption":{"value":"lines=12"}}
+{"Put":{"state":"ˇaa\nbb\ncc\ndd\nee\nff\ngg\nhh\nii\njj\nkk\nll\nmm\nnn\noo\npp\nqq\nrr\nss\ntt\nuu\nvv\nww\nxx\nyy\nzz"}}
+{"Key":"4"}
+{"Key":"j"}
+{"Key":"ctrl-d"}
+{"Get":{"state":"aa\nbb\ncc\ndd\nee\nff\ngg\nhh\nii\nˇjj\nkk\nll\nmm\nnn\noo\npp\nqq\nrr\nss\ntt\nuu\nvv\nww\nxx\nyy\nzz","mode":"Normal"}}
+{"Key":"ctrl-d"}
+{"Get":{"state":"aa\nbb\ncc\ndd\nee\nff\ngg\nhh\nii\njj\nkk\nll\nmm\nnn\nˇoo\npp\nqq\nrr\nss\ntt\nuu\nvv\nww\nxx\nyy\nzz","mode":"Normal"}}
+{"Key":"g"}
+{"Key":"g"}
+{"Key":"ctrl-d"}
+{"Get":{"state":"aa\nbb\ncc\ndd\nee\nff\ngg\nhh\nˇii\njj\nkk\nll\nmm\nnn\noo\npp\nqq\nrr\nss\ntt\nuu\nvv\nww\nxx\nyy\nzz","mode":"Normal"}}
+{"Key":"ctrl-u"}
+{"Get":{"state":"aa\nbb\ncc\nˇdd\nee\nff\ngg\nhh\nii\njj\nkk\nll\nmm\nnn\noo\npp\nqq\nrr\nss\ntt\nuu\nvv\nww\nxx\nyy\nzz","mode":"Normal"}}
+{"Key":"ctrl-d"}
+{"Key":"ctrl-d"}
+{"Key":"4"}
+{"Key":"j"}
+{"Key":"ctrl-u"}
+{"Key":"ctrl-u"}
+{"Get":{"state":"aa\nbb\ncc\ndd\nee\nff\ngg\nˇhh\nii\njj\nkk\nll\nmm\nnn\noo\npp\nqq\nrr\nss\ntt\nuu\nvv\nww\nxx\nyy\nzz","mode":"Normal"}}