Scroll cursor and page together (neovim-like scrolling) (#8015)

* neovim like scroll function

* clear line annotations outside of move_vertically/_visual

* add nvim scroll function to commands

* assign nvim-scroll to C-d and C-u (half page scrolls)

* dont remove backspace and space mapping

* move non-softwrap logic to seperate function, call this in nvim-scroll fn

* Revert "move non-softwrap logic to seperate function, call this in nvim-scroll fn"

This reverts commit e4905729c3.

* Revert "clear line annotations outside of move_vertically/_visual"

This reverts commit 1df3fefe55.

* add TODO for when inline diagnostics gets merged

* move nvim-scroll logic into scroll(), dont respect scrolloff

* run cargo fmt

* run cargo clippy

* update documenation for Ctrl-d and Ctrl-u remap

book/src/keymap.md

@@ -53,8 +53,8 @@ ### Movement
 | `End`                 | Move to the end of the line                        | `goto_line_end`             |
 | `Ctrl-b`, `PageUp`    | Move page up                                       | `page_up`                   |
 | `Ctrl-f`, `PageDown`  | Move page down                                     | `page_down`                 |
-| `Ctrl-u`              | Move half page up                                  | `half_page_up`              |
-| `Ctrl-d`              | Move half page down                                | `half_page_down`            |
+| `Ctrl-u`              | Move cursor and page half page up                  | `page_cursor_half_up`       |
+| `Ctrl-d`              | Move cursor and page half page down                | `page_cursor_half_down`     |
 | `Ctrl-i`              | Jump forward on the jumplist                       | `jump_forward`              |
 | `Ctrl-o`              | Jump backward on the jumplist                      | `jump_backward`             |
 | `Ctrl-s`              | Save the current selection to the jumplist         | `save_selection`            |
@@ -182,18 +182,18 @@ #### View mode
 useful when you're simply looking over text and not actively editing it.
 
 
-| Key                  | Description                                               | Command             |
-| -----                | -----------                                               | -------             |
-| `z`, `c`             | Vertically center the line                                | `align_view_center` |
-| `t`                  | Align the line to the top of the screen                   | `align_view_top`    |
-| `b`                  | Align the line to the bottom of the screen                | `align_view_bottom` |
-| `m`                  | Align the line to the middle of the screen (horizontally) | `align_view_middle` |
-| `j`, `down`          | Scroll the view downwards                                 | `scroll_down`       |
-| `k`, `up`            | Scroll the view upwards                                   | `scroll_up`         |
-| `Ctrl-f`, `PageDown` | Move page down                                            | `page_down`         |
-| `Ctrl-b`, `PageUp`   | Move page up                                              | `page_up`           |
-| `Ctrl-d`             | Move half page down                                       | `half_page_down`    |
-| `Ctrl-u`             | Move half page up                                         | `half_page_up`      |
+| Key                  | Description                                               | Command                 |
+| -----                | -----------                                               | -------                 |
+| `z`, `c`             | Vertically center the line                                | `align_view_center`     |
+| `t`                  | Align the line to the top of the screen                   | `align_view_top`        |
+| `b`                  | Align the line to the bottom of the screen                | `align_view_bottom`     |
+| `m`                  | Align the line to the middle of the screen (horizontally) | `align_view_middle`     |
+| `j`, `down`          | Scroll the view downwards                                 | `scroll_down`           |
+| `k`, `up`            | Scroll the view upwards                                   | `scroll_up`             |
+| `Ctrl-f`, `PageDown` | Move page down                                            | `page_down`             |
+| `Ctrl-b`, `PageUp`   | Move page up                                              | `page_up`               |
+| `Ctrl-u`             | Move cursor and page half page up                         | `page_cursor_half_up`   |
+| `Ctrl-d`             | Move cursor and page half page down                       | `page_cursor_half_down` |
 
 #### Goto mode
 

helix-term/src/commands.rs

@@ -277,6 +277,10 @@ pub fn doc(&self) -> &str {
         page_down, "Move page down",
         half_page_up, "Move half page up",
         half_page_down, "Move half page down",
+        page_cursor_up, "Move page and cursor up",
+        page_cursor_down, "Move page and cursor down",
+        page_cursor_half_up, "Move page and cursor half up",
+        page_cursor_half_down, "Move page and cursor half down",
         select_all, "Select whole document",
         select_regex, "Select all regex matches inside selections",
         split_selection, "Split selections on regex matches",
@@ -1608,7 +1612,7 @@ fn switch_to_lowercase(cx: &mut Context) {
     });
 }
 
-pub fn scroll(cx: &mut Context, offset: usize, direction: Direction) {
+pub fn scroll(cx: &mut Context, offset: usize, direction: Direction, sync_cursor: bool) {
     use Direction::*;
     let config = cx.editor.config();
     let (view, doc) = current!(cx.editor);
@@ -1628,7 +1632,7 @@ pub fn scroll(cx: &mut Context, offset: usize, direction: Direction) {
     let doc_text = doc.text().slice(..);
     let viewport = view.inner_area(doc);
     let text_fmt = doc.text_format(viewport.width, None);
-    let annotations = view.text_annotations(doc, None);
+    let mut annotations = view.text_annotations(doc, None);
     (view.offset.anchor, view.offset.vertical_offset) = char_idx_at_visual_offset(
         doc_text,
         view.offset.anchor,
@@ -1638,6 +1642,30 @@ pub fn scroll(cx: &mut Context, offset: usize, direction: Direction) {
         &annotations,
     );
 
+    if sync_cursor {
+        let movement = match cx.editor.mode {
+            Mode::Select => Movement::Extend,
+            _ => Movement::Move,
+        };
+        // TODO: When inline diagnostics gets merged- 1. move_vertically_visual removes
+        // line annotations/diagnostics so the cursor may jump further than the view.
+        // 2. If the cursor lands on a complete line of virtual text, the cursor will
+        // jump a different distance than the view.
+        let selection = doc.selection(view.id).clone().transform(|range| {
+            move_vertically_visual(
+                doc_text,
+                range,
+                direction,
+                offset.unsigned_abs(),
+                movement,
+                &text_fmt,
+                &mut annotations,
+            )
+        });
+        doc.set_selection(view.id, selection);
+        return;
+    }
+
     let mut head;
     match direction {
         Forward => {
@@ -1688,25 +1716,49 @@ pub fn scroll(cx: &mut Context, offset: usize, direction: Direction) {
 fn page_up(cx: &mut Context) {
     let view = view!(cx.editor);
     let offset = view.inner_height();
-    scroll(cx, offset, Direction::Backward);
+    scroll(cx, offset, Direction::Backward, false);
 }
 
 fn page_down(cx: &mut Context) {
     let view = view!(cx.editor);
     let offset = view.inner_height();
-    scroll(cx, offset, Direction::Forward);
+    scroll(cx, offset, Direction::Forward, false);
 }
 
 fn half_page_up(cx: &mut Context) {
     let view = view!(cx.editor);
     let offset = view.inner_height() / 2;
-    scroll(cx, offset, Direction::Backward);
+    scroll(cx, offset, Direction::Backward, false);
 }
 
 fn half_page_down(cx: &mut Context) {
     let view = view!(cx.editor);
     let offset = view.inner_height() / 2;
-    scroll(cx, offset, Direction::Forward);
+    scroll(cx, offset, Direction::Forward, false);
+}
+
+fn page_cursor_up(cx: &mut Context) {
+    let view = view!(cx.editor);
+    let offset = view.inner_height();
+    scroll(cx, offset, Direction::Backward, true);
+}
+
+fn page_cursor_down(cx: &mut Context) {
+    let view = view!(cx.editor);
+    let offset = view.inner_height();
+    scroll(cx, offset, Direction::Forward, true);
+}
+
+fn page_cursor_half_up(cx: &mut Context) {
+    let view = view!(cx.editor);
+    let offset = view.inner_height() / 2;
+    scroll(cx, offset, Direction::Backward, true);
+}
+
+fn page_cursor_half_down(cx: &mut Context) {
+    let view = view!(cx.editor);
+    let offset = view.inner_height() / 2;
+    scroll(cx, offset, Direction::Forward, true);
 }
 
 #[allow(deprecated)]
@@ -4856,11 +4908,11 @@ fn align_view_middle(cx: &mut Context) {
 }
 
 fn scroll_up(cx: &mut Context) {
-    scroll(cx, cx.count(), Direction::Backward);
+    scroll(cx, cx.count(), Direction::Backward, false);
 }
 
 fn scroll_down(cx: &mut Context) {
-    scroll(cx, cx.count(), Direction::Forward);
+    scroll(cx, cx.count(), Direction::Forward, false);
 }
 
 fn goto_ts_object_impl(cx: &mut Context, object: &'static str, direction: Direction) {

helix-term/src/keymap/default.rs

@@ -178,8 +178,8 @@ pub fn default() -> HashMap<Mode, KeyTrie> {
         "esc" => normal_mode,
         "C-b" | "pageup" => page_up,
         "C-f" | "pagedown" => page_down,
-        "C-u" => half_page_up,
-        "C-d" => half_page_down,
+        "C-u" => page_cursor_half_up,
+        "C-d" => page_cursor_half_down,
 
         "C-w" => { "Window"
             "C-w" | "w" => rotate_view,
@@ -287,8 +287,8 @@ pub fn default() -> HashMap<Mode, KeyTrie> {
             "j" | "down" => scroll_down,
             "C-b" | "pageup" => page_up,
             "C-f" | "pagedown" => page_down,
-            "C-u" | "backspace" => half_page_up,
-            "C-d" | "space" => half_page_down,
+            "C-u" | "backspace" => page_cursor_half_up,
+            "C-d" | "space" => page_cursor_half_down,
 
             "/" => search,
             "?" => rsearch,
@@ -304,8 +304,8 @@ pub fn default() -> HashMap<Mode, KeyTrie> {
             "j" | "down" => scroll_down,
             "C-b" | "pageup" => page_up,
             "C-f" | "pagedown" => page_down,
-            "C-u" | "backspace" => half_page_up,
-            "C-d" | "space" => half_page_down,
+            "C-u" | "backspace" => page_cursor_half_up,
+            "C-d" | "space" => page_cursor_half_down,
 
             "/" => search,
             "?" => rsearch,

helix-term/src/ui/editor.rs

@@ -1156,7 +1156,7 @@ fn handle_mouse_event(
                 }
 
                 let offset = config.scroll_lines.unsigned_abs();
-                commands::scroll(cxt, offset, direction);
+                commands::scroll(cxt, offset, direction, false);
 
                 cxt.editor.tree.focus = current_view;
                 cxt.editor.ensure_cursor_in_view(current_view);