Files
oak-gpui/zed/src/editor/display_map/tab_map.rs
T

440 lines
13 KiB
Rust

use parking_lot::Mutex;
use super::fold_map::{
Chunks as InputChunks, Edit as InputEdit, HighlightedChunks as InputHighlightedChunks,
OutputOffset as InputOffset, OutputPoint as InputPoint, Snapshot as InputSnapshot,
};
use crate::{editor::rope, settings::StyleId, util::Bias};
use std::{
mem,
ops::{Add, AddAssign, Range},
};
pub struct TabMap(Mutex<Snapshot>);
impl TabMap {
pub fn new(input: InputSnapshot, tab_size: usize) -> Self {
Self(Mutex::new(Snapshot { input, tab_size }))
}
pub fn sync(
&self,
snapshot: InputSnapshot,
input_edits: Vec<InputEdit>,
) -> (Snapshot, Vec<Edit>) {
let mut old_snapshot = self.0.lock();
let new_snapshot = Snapshot {
input: snapshot,
tab_size: old_snapshot.tab_size,
};
let mut output_edits = Vec::with_capacity(input_edits.len());
for input_edit in input_edits {
let old_start = input_edit.old_bytes.start.to_point(&old_snapshot.input);
let old_end = input_edit.old_bytes.end.to_point(&old_snapshot.input);
let new_start = input_edit.new_bytes.start.to_point(&new_snapshot.input);
let new_end = input_edit.new_bytes.end.to_point(&new_snapshot.input);
output_edits.push(Edit {
old_lines: old_snapshot.to_output_point(old_start)
..old_snapshot.to_output_point(old_end),
new_lines: new_snapshot.to_output_point(new_start)
..new_snapshot.to_output_point(new_end),
});
}
*old_snapshot = new_snapshot;
(old_snapshot.clone(), output_edits)
}
}
#[derive(Clone)]
pub struct Snapshot {
input: InputSnapshot,
tab_size: usize,
}
impl Snapshot {
pub fn text_summary(&self) -> TextSummary {
// TODO: expand tabs on first and last line, ignoring the longest row.
let summary = self.input.text_summary();
TextSummary {
lines: summary.lines,
first_line_chars: summary.first_line_chars,
last_line_chars: summary.last_line_chars,
longest_row: summary.longest_row,
longest_row_chars: summary.longest_row_chars,
}
}
pub fn text_summary_for_range(&self, range: Range<OutputPoint>) -> TextSummary {
// TODO: expand tabs on first and last line, ignoring the longest row.
let start = self.to_input_point(range.start, Bias::Left).0;
let end = self.to_input_point(range.end, Bias::Right).0;
let summary = self.input.text_summary_for_range(start..end);
TextSummary {
lines: summary.lines,
first_line_chars: summary.first_line_chars,
last_line_chars: summary.last_line_chars,
longest_row: summary.longest_row,
longest_row_chars: summary.longest_row_chars,
}
}
pub fn version(&self) -> usize {
self.input.version
}
pub fn chunks_at(&self, point: OutputPoint) -> Chunks {
let (point, expanded_char_column, to_next_stop) = self.to_input_point(point, Bias::Left);
let fold_chunks = self.input.chunks_at(self.input.to_output_offset(point));
Chunks {
fold_chunks,
column: expanded_char_column,
tab_size: self.tab_size,
chunk: &SPACES[0..to_next_stop],
skip_leading_tab: to_next_stop > 0,
}
}
pub fn highlighted_chunks_for_rows(&mut self, rows: Range<u32>) -> HighlightedChunks {
let start = self.input.to_output_offset(InputPoint::new(rows.start, 0));
let end = self
.input
.to_output_offset(InputPoint::new(rows.end, 0).min(self.input.max_point()));
HighlightedChunks {
input_chunks: self.input.highlighted_chunks(start..end),
column: 0,
tab_size: self.tab_size,
chunk: "",
style_id: Default::default(),
}
}
#[cfg(test)]
pub fn text(&self) -> String {
self.chunks_at(Default::default()).collect()
}
pub fn len(&self) -> OutputOffset {
self.to_output_offset(self.input.len())
}
pub fn line_len(&self, row: u32) -> u32 {
self.to_output_point(InputPoint::new(row, self.input.line_len(row)))
.column()
}
pub fn longest_row(&self) -> u32 {
// TODO: Account for tab expansion.
self.input.longest_row()
}
pub fn max_point(&self) -> OutputPoint {
self.to_output_point(self.input.max_point())
}
pub fn clip_point(&self, point: OutputPoint, bias: Bias) -> OutputPoint {
self.to_output_point(
self.input
.clip_point(self.to_input_point(point, bias).0, bias),
)
}
pub fn to_output_offset(&self, input_offset: InputOffset) -> OutputOffset {
let input_point = input_offset.to_point(&self.input);
let input_row_start_offset = self
.input
.to_output_offset(InputPoint::new(input_point.row(), 0));
let output_point = self.to_output_point(input_point);
OutputOffset(input_row_start_offset.0 + output_point.column() as usize)
}
pub fn to_output_point(&self, input: InputPoint) -> OutputPoint {
let chars = self.input.chars_at(InputPoint::new(input.row(), 0));
let expanded = Self::expand_tabs(chars, input.column() as usize, self.tab_size);
OutputPoint::new(input.row(), expanded as u32)
}
pub fn to_input_point(&self, output: OutputPoint, bias: Bias) -> (InputPoint, usize, usize) {
let chars = self.input.chars_at(InputPoint::new(output.row(), 0));
let expanded = output.column() as usize;
let (collapsed, expanded_char_column, to_next_stop) =
Self::collapse_tabs(chars, expanded, bias, self.tab_size);
(
InputPoint::new(output.row(), collapsed as u32),
expanded_char_column,
to_next_stop,
)
}
fn expand_tabs(chars: impl Iterator<Item = char>, column: usize, tab_size: usize) -> usize {
let mut expanded_chars = 0;
let mut expanded_bytes = 0;
let mut collapsed_bytes = 0;
for c in chars {
if collapsed_bytes == column {
break;
}
if c == '\t' {
let tab_len = tab_size - expanded_chars % tab_size;
expanded_bytes += tab_len;
expanded_chars += tab_len;
} else {
expanded_bytes += c.len_utf8();
expanded_chars += 1;
}
collapsed_bytes += c.len_utf8();
}
expanded_bytes
}
fn collapse_tabs(
mut chars: impl Iterator<Item = char>,
column: usize,
bias: Bias,
tab_size: usize,
) -> (usize, usize, usize) {
let mut expanded_bytes = 0;
let mut expanded_chars = 0;
let mut collapsed_bytes = 0;
while let Some(c) = chars.next() {
if expanded_bytes >= column {
break;
}
if c == '\t' {
let tab_len = tab_size - (expanded_chars % tab_size);
expanded_chars += tab_len;
expanded_bytes += tab_len;
if expanded_bytes > column {
expanded_chars -= expanded_bytes - column;
return match bias {
Bias::Left => (collapsed_bytes, expanded_chars, expanded_bytes - column),
Bias::Right => (collapsed_bytes + 1, expanded_chars, 0),
};
}
} else {
expanded_chars += 1;
expanded_bytes += c.len_utf8();
}
if expanded_bytes > column && matches!(bias, Bias::Left) {
expanded_chars -= 1;
break;
}
collapsed_bytes += c.len_utf8();
}
(collapsed_bytes, expanded_chars, 0)
}
}
#[derive(Copy, Clone, Debug, PartialEq, Eq)]
pub struct OutputOffset(pub usize);
#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq)]
pub struct OutputPoint(pub super::Point);
impl OutputPoint {
pub fn new(row: u32, column: u32) -> Self {
Self(super::Point::new(row, column))
}
pub fn zero() -> Self {
Self::new(0, 0)
}
pub fn row(self) -> u32 {
self.0.row
}
pub fn column(self) -> u32 {
self.0.column
}
pub fn row_mut(&mut self) -> &mut u32 {
&mut self.0.row
}
pub fn column_mut(&mut self) -> &mut u32 {
&mut self.0.column
}
}
impl AddAssign<Self> for OutputPoint {
fn add_assign(&mut self, rhs: Self) {
self.0 += &rhs.0;
}
}
impl Add<Self> for OutputPoint {
type Output = OutputPoint;
fn add(self, other: Self) -> Self::Output {
Self(self.0 + other.0)
}
}
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct Edit {
pub old_lines: Range<OutputPoint>,
pub new_lines: Range<OutputPoint>,
}
#[derive(Clone, Debug, Default, Eq, PartialEq)]
pub struct TextSummary {
pub lines: super::Point,
pub first_line_chars: u32,
pub last_line_chars: u32,
pub longest_row: u32,
pub longest_row_chars: u32,
}
impl<'a> From<&'a str> for TextSummary {
fn from(text: &'a str) -> Self {
let sum = rope::TextSummary::from(text);
TextSummary {
lines: sum.lines,
first_line_chars: sum.first_line_chars,
last_line_chars: sum.last_line_chars,
longest_row: sum.longest_row,
longest_row_chars: sum.longest_row_chars,
}
}
}
impl<'a> std::ops::AddAssign<&'a Self> for TextSummary {
fn add_assign(&mut self, other: &'a Self) {
let joined_chars = self.last_line_chars + other.first_line_chars;
if joined_chars > self.longest_row_chars {
self.longest_row = self.lines.row;
self.longest_row_chars = joined_chars;
}
if other.longest_row_chars > self.longest_row_chars {
self.longest_row = self.lines.row + other.longest_row;
self.longest_row_chars = other.longest_row_chars;
}
if self.lines.row == 0 {
self.first_line_chars += other.first_line_chars;
}
if other.lines.row == 0 {
self.last_line_chars += other.first_line_chars;
} else {
self.last_line_chars = other.last_line_chars;
}
self.lines += &other.lines;
}
}
// Handles a tab width <= 16
const SPACES: &'static str = " ";
pub struct Chunks<'a> {
fold_chunks: InputChunks<'a>,
chunk: &'a str,
column: usize,
tab_size: usize,
skip_leading_tab: bool,
}
impl<'a> Iterator for Chunks<'a> {
type Item = &'a str;
fn next(&mut self) -> Option<Self::Item> {
if self.chunk.is_empty() {
if let Some(chunk) = self.fold_chunks.next() {
self.chunk = chunk;
if self.skip_leading_tab {
self.chunk = &self.chunk[1..];
self.skip_leading_tab = false;
}
} else {
return None;
}
}
for (ix, c) in self.chunk.char_indices() {
match c {
'\t' => {
if ix > 0 {
let (prefix, suffix) = self.chunk.split_at(ix);
self.chunk = suffix;
return Some(prefix);
} else {
self.chunk = &self.chunk[1..];
let len = self.tab_size - self.column % self.tab_size;
self.column += len;
return Some(&SPACES[0..len]);
}
}
'\n' => self.column = 0,
_ => self.column += 1,
}
}
let result = Some(self.chunk);
self.chunk = "";
result
}
}
pub struct HighlightedChunks<'a> {
input_chunks: InputHighlightedChunks<'a>,
chunk: &'a str,
style_id: StyleId,
column: usize,
tab_size: usize,
}
impl<'a> Iterator for HighlightedChunks<'a> {
type Item = (&'a str, StyleId);
fn next(&mut self) -> Option<Self::Item> {
if self.chunk.is_empty() {
if let Some((chunk, style_id)) = self.input_chunks.next() {
self.chunk = chunk;
self.style_id = style_id;
} else {
return None;
}
}
for (ix, c) in self.chunk.char_indices() {
match c {
'\t' => {
if ix > 0 {
let (prefix, suffix) = self.chunk.split_at(ix);
self.chunk = suffix;
return Some((prefix, self.style_id));
} else {
self.chunk = &self.chunk[1..];
let len = self.tab_size - self.column % self.tab_size;
self.column += len;
return Some((&SPACES[0..len], self.style_id));
}
}
'\n' => self.column = 0,
_ => self.column += 1,
}
}
Some((mem::take(&mut self.chunk), mem::take(&mut self.style_id)))
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_expand_tabs() {
assert_eq!(Snapshot::expand_tabs("\t".chars(), 0, 4), 0);
assert_eq!(Snapshot::expand_tabs("\t".chars(), 1, 4), 4);
assert_eq!(Snapshot::expand_tabs("\ta".chars(), 2, 4), 5);
}
}