feat: make `move_vertically` aware of tabs and wide characters (#2620)

* feat: make `move_vertically` aware of tabs and wide characters

* refactor: replace unnecessary checked_sub with comparison

* refactor: leave pos_at_coords unchanged and introduce separate pos_at_visual_coords

* style: include comment to explain `pos_at_visual_coords` breaking condition

* refactor: use `pos_at_visual_coords` in `text_pos_at_screen_coords`

* feat: make `copy_selection_on_line` aware of wide characters

1 files changed, 14 insertions, 12 deletions

diff --git a/helix-term/src/commands.rs b/helix-term/src/commands.rs
index 046351a3..d7937ff5 100644
--- a/helix-term/src/commands.rs
+++ b/helix-term/src/commands.rs
@@ -16,14 +16,14 @@ use helix_core::{
     line_ending::{get_line_ending_of_str, line_end_char_index, str_is_line_ending},
     match_brackets,
     movement::{self, Direction},
-    object, pos_at_coords,
+    object, pos_at_coords, pos_at_visual_coords,
     regex::{self, Regex, RegexBuilder},
     search::{self, CharMatcher},
     selection, shellwords, surround, textobject,
     tree_sitter::Node,
     unicode::width::UnicodeWidthChar,
-    LineEnding, Position, Range, Rope, RopeGraphemes, RopeSlice, Selection, SmallVec, Tendril,
-    Transaction,
+    visual_coords_at_pos, LineEnding, Position, Range, Rope, RopeGraphemes, RopeSlice, Selection,
+    SmallVec, Tendril, Transaction,
 };
 use helix_view::{
     clipboard::ClipboardType,
@@ -511,7 +511,7 @@ fn no_op(_cx: &mut Context) {}
 
 fn move_impl<F>(cx: &mut Context, move_fn: F, dir: Direction, behaviour: Movement)
 where
-    F: Fn(RopeSlice, Range, Direction, usize, Movement) -> Range,
+    F: Fn(RopeSlice, Range, Direction, usize, Movement, usize) -> Range,
 {
     let count = cx.count();
     let (view, doc) = current!(cx.editor);
@@ -520,7 +520,7 @@ where
     let selection = doc
         .selection(view.id)
         .clone()
-        .transform(|range| move_fn(text, range, dir, count, behaviour));
+        .transform(|range| move_fn(text, range, dir, count, behaviour, doc.tab_width()));
     doc.set_selection(view.id, selection);
 }
 
@@ -1412,9 +1412,10 @@ fn copy_selection_on_line(cx: &mut Context, direction: Direction) {
             range.head
         };
 
-        // TODO: this should use visual offsets / pos_at_screen_coords
-        let head_pos = coords_at_pos(text, head);
-        let anchor_pos = coords_at_pos(text, range.anchor);
+        let tab_width = doc.tab_width();
+
+        let head_pos = visual_coords_at_pos(text, head, tab_width);
+        let anchor_pos = visual_coords_at_pos(text, range.anchor, tab_width);
 
         let height = std::cmp::max(head_pos.row, anchor_pos.row)
             - std::cmp::min(head_pos.row, anchor_pos.row)
@@ -1444,12 +1445,13 @@ fn copy_selection_on_line(cx: &mut Context, direction: Direction) {
                 break;
             }
 
-            let anchor = pos_at_coords(text, Position::new(anchor_row, anchor_pos.col), true);
-            let head = pos_at_coords(text, Position::new(head_row, head_pos.col), true);
+            let anchor =
+                pos_at_visual_coords(text, Position::new(anchor_row, anchor_pos.col), tab_width);
+            let head = pos_at_visual_coords(text, Position::new(head_row, head_pos.col), tab_width);
 
             // skip lines that are too short
-            if coords_at_pos(text, anchor).col == anchor_pos.col
-                && coords_at_pos(text, head).col == head_pos.col
+            if visual_coords_at_pos(text, anchor, tab_width).col == anchor_pos.col
+                && visual_coords_at_pos(text, head, tab_width).col == head_pos.col
             {
                 if is_primary {
                     primary_index = ranges.len();