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author | Blaž Hrastnik | 2021-03-18 06:07:02 +0000 |
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committer | Blaž Hrastnik | 2021-03-18 06:07:02 +0000 |
commit | c331721565a00850849e0a99fd325ae281bfb800 (patch) | |
tree | 9645238dc5900e77426e44ecbd4d9e47250d3a1d /helix-core/src/movement.rs | |
parent | 8ba1e15d296fd3350332d8fa372c4c7703024a67 (diff) |
Finish hiding doc.state / State as an implementation detail.
Diffstat (limited to 'helix-core/src/movement.rs')
-rw-r--r-- | helix-core/src/movement.rs | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/helix-core/src/movement.rs b/helix-core/src/movement.rs index 57abc498..88d6df0a 100644 --- a/helix-core/src/movement.rs +++ b/helix-core/src/movement.rs @@ -1,6 +1,66 @@ use crate::graphemes::{nth_next_grapheme_boundary, nth_prev_grapheme_boundary, RopeGraphemes}; use crate::{coords_at_pos, pos_at_coords, ChangeSet, Position, Range, Rope, RopeSlice, Selection}; +#[derive(Copy, Clone, PartialEq, Eq)] +pub enum Direction { + Forward, + Backward, +} + +pub fn move_horizontally( + text: RopeSlice, + range: Range, + dir: Direction, + count: usize, + extend: bool, +) -> Range { + let pos = range.head; + let line = text.char_to_line(pos); + // TODO: we can optimize clamping by passing in RopeSlice limited to current line. that way + // we stop calculating past start/end of line. + let pos = match dir { + Direction::Backward => { + let start = text.line_to_char(line); + nth_prev_grapheme_boundary(text, pos, count).max(start) + } + Direction::Forward => { + // Line end is pos at the start of next line - 1 + // subtract another 1 because the line ends with \n + let end = text.line_to_char(line + 1).saturating_sub(2); + nth_next_grapheme_boundary(text, pos, count).min(end) + } + }; + Range::new(if extend { range.anchor } else { pos }, pos) +} + +pub fn move_vertically( + text: RopeSlice, + range: Range, + dir: Direction, + count: usize, + extend: bool, +) -> Range { + let Position { row, col } = coords_at_pos(text, range.head); + + let horiz = range.horiz.unwrap_or(col as u32); + + let new_line = match dir { + Direction::Backward => row.saturating_sub(count), + Direction::Forward => std::cmp::min(row.saturating_add(count), text.len_lines() - 1), + }; + + // convert to 0-indexed, subtract another 1 because len_chars() counts \n + let new_line_len = text.line(new_line).len_chars().saturating_sub(2); + + let new_col = std::cmp::min(horiz as usize, new_line_len); + + let pos = pos_at_coords(text, Position::new(new_line, new_col)); + + let mut range = Range::new(if extend { range.anchor } else { pos }, pos); + range.horiz = Some(horiz); + range +} + pub fn move_next_word_start(slice: RopeSlice, mut pos: usize, count: usize) -> usize { for _ in 0..count { if pos + 1 == slice.len_chars() { @@ -155,3 +215,24 @@ where *pos = pos.saturating_sub(1); } } + +#[cfg(test)] +mod test { + use super::*; + + #[test] + fn test_vertical_move() { + let text = Rope::from("abcd\nefg\nwrs"); + let slice = text.slice(..); + let pos = pos_at_coords(slice, (0, 4).into()); + + let range = Range::new(pos, pos); + assert_eq!( + coords_at_pos( + slice, + move_vertically(slice, range, Direction::Forward, 1, false).head + ), + (1, 2).into() + ); + } +} |