Make vertical selection movement work properly.

This commit is contained in:
Nathan Vegdahl 2021-07-05 18:58:33 -07:00
parent 28d2d68804
commit 6e15c9b874
3 changed files with 60 additions and 24 deletions

View file

@ -159,6 +159,13 @@ pub fn line_end_char_index(slice: &RopeSlice, line: usize) -> usize {
.unwrap_or(0)
}
/// Fetches line `line_idx` from the passed rope slice, sans any line ending.
pub fn line_without_line_ending<'a>(slice: &'a RopeSlice, line_idx: usize) -> RopeSlice<'a> {
let start = slice.line_to_char(line_idx);
let end = line_end_char_index(slice, line_idx);
slice.slice(start..end)
}
/// Returns the char index of the end of the given RopeSlice, not including
/// any final line ending.
pub fn rope_end_without_line_ending(slice: &RopeSlice) -> usize {

View file

@ -7,9 +7,9 @@ use crate::{
coords_at_pos,
graphemes::{
next_grapheme_boundary, nth_next_grapheme_boundary, nth_prev_grapheme_boundary,
prev_grapheme_boundary,
prev_grapheme_boundary, RopeGraphemes,
},
line_ending::get_line_ending,
line_ending::line_without_line_ending,
pos_at_coords, Position, Range, RopeSlice,
};
@ -95,36 +95,61 @@ pub fn move_vertically(
count: usize,
behaviour: Movement,
) -> Range {
let Position { row, col } = coords_at_pos(slice, range.head);
// Shift back one grapheme if needed, to account for
// the cursor being visually 1-width.
let pos = if range.head > range.anchor {
prev_grapheme_boundary(slice, range.head)
} else {
range.head
};
// Compute the current position's 2d coordinates.
let Position { row, col } = coords_at_pos(slice, pos);
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),
slice.len_lines().saturating_sub(1),
),
// Compute the new position.
let new_pos = {
let new_row = if dir == Direction::Backward {
row.saturating_sub(count)
} else {
(row + count).min(slice.len_lines().saturating_sub(1))
};
let max_col = RopeGraphemes::new(line_without_line_ending(&slice, new_row)).count();
let new_col = col.max(horiz as usize).min(max_col);
pos_at_coords(slice, Position::new(new_row, new_col))
};
// Length of the line sans line-ending.
let new_line_len = {
let line = slice.line(new_line);
line.len_chars() - get_line_ending(&line).map(|le| le.len_chars()).unwrap_or(0)
};
// Compute the new range according to the type of movement.
match behaviour {
Movement::Move => Range {
anchor: new_pos,
head: new_pos,
horiz: Some(horiz),
},
let new_col = std::cmp::min(horiz as usize, new_line_len);
Movement::Extend => {
let new_head = if new_pos >= range.anchor {
next_grapheme_boundary(slice, new_pos)
} else {
new_pos
};
let pos = pos_at_coords(slice, Position::new(new_line, new_col));
let new_anchor = if range.anchor <= range.head && range.anchor > new_head {
next_grapheme_boundary(slice, range.anchor)
} else if range.anchor > range.head && range.anchor < new_head {
prev_grapheme_boundary(slice, range.anchor)
} else {
range.anchor
};
let anchor = match behaviour {
Movement::Extend => range.anchor,
Movement::Move => pos,
};
let mut range = Range::new(anchor, pos);
range.horiz = Some(horiz);
range
Range {
anchor: new_anchor,
head: new_head,
horiz: Some(horiz),
}
}
}
}
pub fn move_next_word_start(slice: RopeSlice, range: Range, count: usize) -> Range {

View file

@ -53,6 +53,8 @@ impl From<Position> for tree_sitter::Point {
}
/// Convert a character index to (line, column) coordinates.
pub fn coords_at_pos(text: RopeSlice, pos: usize) -> Position {
// TODO: this isn't correct. This needs to work in terms of
// visual horizontal position, not graphemes.
let line = text.char_to_line(pos);
let line_start = text.line_to_char(line);
let col = RopeGraphemes::new(text.slice(line_start..pos)).count();
@ -61,6 +63,8 @@ pub fn coords_at_pos(text: RopeSlice, pos: usize) -> Position {
/// Convert (line, column) coordinates to a character index.
pub fn pos_at_coords(text: RopeSlice, coords: Position) -> usize {
// TODO: this isn't correct. This needs to work in terms of
// visual horizontal position, not graphemes.
let Position { row, col } = coords;
let line_start = text.line_to_char(row);
// line_start + col