1//! Movement module contains helper functions for calculating intended position
2//! in editor given a given motion (e.g. it handles converting a "move left" command into coordinates in editor). It is exposed mostly for use by vim crate.
3
4use super::{Bias, DisplayPoint, DisplaySnapshot, SelectionGoal, ToDisplayPoint};
5use crate::{
6 DisplayRow, EditorStyle, ToOffset, ToPoint,
7 scroll::{ScrollAnchor, ScrollOffset},
8};
9use gpui::{Pixels, WindowTextSystem};
10use language::{CharClassifier, Point};
11use multi_buffer::{MultiBufferRow, MultiBufferSnapshot};
12use serde::Deserialize;
13use workspace::searchable::Direction;
14
15use std::{ops::Range, sync::Arc};
16
17/// Defines search strategy for items in `movement` module.
18/// `FindRange::SingeLine` only looks for a match on a single line at a time, whereas
19/// `FindRange::MultiLine` keeps going until the end of a string.
20#[derive(Clone, Copy, Debug, PartialEq, Eq, Deserialize)]
21pub enum FindRange {
22 SingleLine,
23 MultiLine,
24}
25
26/// TextLayoutDetails encompasses everything we need to move vertically
27/// taking into account variable width characters.
28pub struct TextLayoutDetails {
29 pub(crate) text_system: Arc<WindowTextSystem>,
30 pub(crate) editor_style: EditorStyle,
31 pub(crate) rem_size: Pixels,
32 pub scroll_anchor: ScrollAnchor,
33 pub visible_rows: Option<f64>,
34 pub vertical_scroll_margin: ScrollOffset,
35}
36
37/// Returns a column to the left of the current point, wrapping
38/// to the previous line if that point is at the start of line.
39pub fn left(map: &DisplaySnapshot, mut point: DisplayPoint) -> DisplayPoint {
40 if point.column() > 0 {
41 *point.column_mut() -= 1;
42 } else if point.row().0 > 0 {
43 *point.row_mut() -= 1;
44 *point.column_mut() = map.line_len(point.row());
45 }
46 map.clip_point(point, Bias::Left)
47}
48
49/// Returns a column to the left of the current point, doing nothing if
50/// that point is already at the start of line.
51pub fn saturating_left(map: &DisplaySnapshot, mut point: DisplayPoint) -> DisplayPoint {
52 if point.column() > 0 {
53 *point.column_mut() -= 1;
54 } else if point.column() == 0 {
55 // If the current sofr_wrap mode is used, the column corresponding to the display is 0,
56 // which does not necessarily mean that the actual beginning of a paragraph
57 if map.display_point_to_fold_point(point, Bias::Left).column() > 0 {
58 return left(map, point);
59 }
60 }
61 map.clip_point(point, Bias::Left)
62}
63
64/// Returns a column to the right of the current point, wrapping
65/// to the next line if that point is at the end of line.
66pub fn right(map: &DisplaySnapshot, mut point: DisplayPoint) -> DisplayPoint {
67 if point.column() < map.line_len(point.row()) {
68 *point.column_mut() += 1;
69 } else if point.row() < map.max_point().row() {
70 *point.row_mut() += 1;
71 *point.column_mut() = 0;
72 }
73 map.clip_point(point, Bias::Right)
74}
75
76/// Returns a column to the right of the current point, not performing any wrapping
77/// if that point is already at the end of line.
78pub fn saturating_right(map: &DisplaySnapshot, mut point: DisplayPoint) -> DisplayPoint {
79 *point.column_mut() += 1;
80 map.clip_point(point, Bias::Right)
81}
82
83/// Returns a display point for the preceding displayed line (which might be a soft-wrapped line).
84pub fn up(
85 map: &DisplaySnapshot,
86 start: DisplayPoint,
87 goal: SelectionGoal,
88 preserve_column_at_start: bool,
89 text_layout_details: &TextLayoutDetails,
90) -> (DisplayPoint, SelectionGoal) {
91 up_by_rows(
92 map,
93 start,
94 1,
95 goal,
96 preserve_column_at_start,
97 text_layout_details,
98 )
99}
100
101/// Returns a display point for the next displayed line (which might be a soft-wrapped line).
102pub fn down(
103 map: &DisplaySnapshot,
104 start: DisplayPoint,
105 goal: SelectionGoal,
106 preserve_column_at_end: bool,
107 text_layout_details: &TextLayoutDetails,
108) -> (DisplayPoint, SelectionGoal) {
109 down_by_rows(
110 map,
111 start,
112 1,
113 goal,
114 preserve_column_at_end,
115 text_layout_details,
116 )
117}
118
119pub(crate) fn up_by_rows(
120 map: &DisplaySnapshot,
121 start: DisplayPoint,
122 row_count: u32,
123 goal: SelectionGoal,
124 preserve_column_at_start: bool,
125 text_layout_details: &TextLayoutDetails,
126) -> (DisplayPoint, SelectionGoal) {
127 let goal_x = match goal {
128 SelectionGoal::HorizontalPosition(x) => x.into(),
129 SelectionGoal::WrappedHorizontalPosition((_, x)) => x.into(),
130 SelectionGoal::HorizontalRange { end, .. } => end.into(),
131 _ => map.x_for_display_point(start, text_layout_details),
132 };
133
134 let prev_row = DisplayRow(start.row().0.saturating_sub(row_count));
135 let mut point = map.clip_point(
136 DisplayPoint::new(prev_row, map.line_len(prev_row)),
137 Bias::Left,
138 );
139 if point.row() < start.row() {
140 *point.column_mut() = map.display_column_for_x(point.row(), goal_x, text_layout_details)
141 } else if preserve_column_at_start {
142 return (start, goal);
143 } else {
144 point = DisplayPoint::new(DisplayRow(0), 0);
145 }
146
147 let mut clipped_point = map.clip_point(point, Bias::Left);
148 if clipped_point.row() < point.row() {
149 clipped_point = map.clip_point(point, Bias::Right);
150 }
151 (
152 clipped_point,
153 SelectionGoal::HorizontalPosition(goal_x.into()),
154 )
155}
156
157pub(crate) fn down_by_rows(
158 map: &DisplaySnapshot,
159 start: DisplayPoint,
160 row_count: u32,
161 goal: SelectionGoal,
162 preserve_column_at_end: bool,
163 text_layout_details: &TextLayoutDetails,
164) -> (DisplayPoint, SelectionGoal) {
165 let goal_x = match goal {
166 SelectionGoal::HorizontalPosition(x) => x.into(),
167 SelectionGoal::WrappedHorizontalPosition((_, x)) => x.into(),
168 SelectionGoal::HorizontalRange { end, .. } => end.into(),
169 _ => map.x_for_display_point(start, text_layout_details),
170 };
171
172 let new_row = DisplayRow(start.row().0 + row_count);
173 let mut point = map.clip_point(DisplayPoint::new(new_row, 0), Bias::Right);
174 if point.row() > start.row() {
175 *point.column_mut() = map.display_column_for_x(point.row(), goal_x, text_layout_details)
176 } else if preserve_column_at_end {
177 return (start, goal);
178 } else {
179 point = map.max_point();
180 }
181
182 let mut clipped_point = map.clip_point(point, Bias::Right);
183 if clipped_point.row() > point.row() {
184 clipped_point = map.clip_point(point, Bias::Left);
185 }
186 (
187 clipped_point,
188 SelectionGoal::HorizontalPosition(goal_x.into()),
189 )
190}
191
192/// Returns a position of the start of line.
193/// If `stop_at_soft_boundaries` is true, the returned position is that of the
194/// displayed line (e.g. it could actually be in the middle of a text line if that line is soft-wrapped).
195/// Otherwise it's always going to be the start of a logical line.
196pub fn line_beginning(
197 map: &DisplaySnapshot,
198 display_point: DisplayPoint,
199 stop_at_soft_boundaries: bool,
200) -> DisplayPoint {
201 let point = display_point.to_point(map);
202 let soft_line_start = map.clip_point(DisplayPoint::new(display_point.row(), 0), Bias::Right);
203 let line_start = map.prev_line_boundary(point).1;
204
205 if stop_at_soft_boundaries && display_point != soft_line_start {
206 soft_line_start
207 } else {
208 line_start
209 }
210}
211
212/// Returns the last indented position on a given line.
213/// If `stop_at_soft_boundaries` is true, the returned [`DisplayPoint`] is that of a
214/// displayed line (e.g. if there's soft wrap it's gonna be returned),
215/// otherwise it's always going to be a start of a logical line.
216pub fn indented_line_beginning(
217 map: &DisplaySnapshot,
218 display_point: DisplayPoint,
219 stop_at_soft_boundaries: bool,
220 stop_at_indent: bool,
221) -> DisplayPoint {
222 let point = display_point.to_point(map);
223 let soft_line_start = map.clip_point(DisplayPoint::new(display_point.row(), 0), Bias::Right);
224 let indent_start = Point::new(
225 point.row,
226 map.buffer_snapshot()
227 .indent_size_for_line(MultiBufferRow(point.row))
228 .len,
229 )
230 .to_display_point(map);
231 let line_start = map.prev_line_boundary(point).1;
232
233 if stop_at_soft_boundaries && soft_line_start > indent_start && display_point != soft_line_start
234 {
235 soft_line_start
236 } else if stop_at_indent && (display_point > indent_start || display_point == line_start) {
237 indent_start
238 } else {
239 line_start
240 }
241}
242
243/// Returns a position of the end of line.
244///
245/// If `stop_at_soft_boundaries` is true, the returned position is that of the
246/// displayed line (e.g. it could actually be in the middle of a text line if that line is soft-wrapped).
247/// Otherwise it's always going to be the end of a logical line.
248pub fn line_end(
249 map: &DisplaySnapshot,
250 display_point: DisplayPoint,
251 stop_at_soft_boundaries: bool,
252) -> DisplayPoint {
253 let soft_line_end = map.clip_point(
254 DisplayPoint::new(display_point.row(), map.line_len(display_point.row())),
255 Bias::Left,
256 );
257 if stop_at_soft_boundaries && display_point != soft_line_end {
258 soft_line_end
259 } else {
260 map.next_line_boundary(display_point.to_point(map)).1
261 }
262}
263
264/// Returns a position of the previous word boundary, where a word character is defined as either
265/// uppercase letter, lowercase letter, '_' character or language-specific word character (like '-' in CSS).
266pub fn previous_word_start(map: &DisplaySnapshot, point: DisplayPoint) -> DisplayPoint {
267 let raw_point = point.to_point(map);
268 let classifier = map.buffer_snapshot().char_classifier_at(raw_point);
269
270 let mut is_first_iteration = true;
271 find_preceding_boundary_display_point(map, point, FindRange::MultiLine, |left, right| {
272 // Make alt-left skip punctuation to respect VSCode behaviour. For example: hello.| goes to |hello.
273 if is_first_iteration
274 && classifier.is_punctuation(right)
275 && !classifier.is_punctuation(left)
276 && left != '\n'
277 {
278 is_first_iteration = false;
279 return false;
280 }
281 is_first_iteration = false;
282
283 (classifier.kind(left) != classifier.kind(right) && !classifier.is_whitespace(right))
284 || left == '\n'
285 })
286}
287
288/// Returns a position of the previous word boundary, where a word character is defined as either
289/// uppercase letter, lowercase letter, '_' character, language-specific word character (like '-' in CSS) or newline.
290pub fn previous_word_start_or_newline(map: &DisplaySnapshot, point: DisplayPoint) -> DisplayPoint {
291 let raw_point = point.to_point(map);
292 let classifier = map.buffer_snapshot().char_classifier_at(raw_point);
293
294 find_preceding_boundary_display_point(map, point, FindRange::MultiLine, |left, right| {
295 (classifier.kind(left) != classifier.kind(right) && !classifier.is_whitespace(right))
296 || left == '\n'
297 || right == '\n'
298 })
299}
300
301/// Text movements are too greedy, making deletions too greedy too.
302/// Makes deletions more ergonomic by potentially reducing the deletion range based on its text contents:
303/// * whitespace sequences with length >= 2 stop the deletion after removal (despite movement jumping over the word behind the whitespaces)
304/// * brackets stop the deletion after removal (despite movement currently not accounting for these and jumping over)
305pub fn adjust_greedy_deletion(
306 map: &DisplaySnapshot,
307 delete_from: DisplayPoint,
308 delete_until: DisplayPoint,
309 ignore_brackets: bool,
310) -> DisplayPoint {
311 if delete_from == delete_until {
312 return delete_until;
313 }
314 let is_backward = delete_from > delete_until;
315 let delete_range = if is_backward {
316 map.display_point_to_point(delete_until, Bias::Left)
317 .to_offset(map.buffer_snapshot())
318 ..map
319 .display_point_to_point(delete_from, Bias::Right)
320 .to_offset(map.buffer_snapshot())
321 } else {
322 map.display_point_to_point(delete_from, Bias::Left)
323 .to_offset(map.buffer_snapshot())
324 ..map
325 .display_point_to_point(delete_until, Bias::Right)
326 .to_offset(map.buffer_snapshot())
327 };
328
329 let trimmed_delete_range = if ignore_brackets {
330 delete_range
331 } else {
332 let brackets_in_delete_range = map
333 .buffer_snapshot()
334 .bracket_ranges(delete_range.clone())
335 .into_iter()
336 .flatten()
337 .flat_map(|(left_bracket, right_bracket)| {
338 [
339 left_bracket.start,
340 left_bracket.end,
341 right_bracket.start,
342 right_bracket.end,
343 ]
344 })
345 .filter(|&bracket| delete_range.start < bracket && bracket < delete_range.end);
346 let closest_bracket = if is_backward {
347 brackets_in_delete_range.max()
348 } else {
349 brackets_in_delete_range.min()
350 };
351
352 if is_backward {
353 closest_bracket.unwrap_or(delete_range.start)..delete_range.end
354 } else {
355 delete_range.start..closest_bracket.unwrap_or(delete_range.end)
356 }
357 };
358
359 let mut whitespace_sequences = Vec::new();
360 let mut current_offset = trimmed_delete_range.start;
361 let mut whitespace_sequence_length = 0;
362 let mut whitespace_sequence_start = 0;
363 for ch in map
364 .buffer_snapshot()
365 .text_for_range(trimmed_delete_range.clone())
366 .flat_map(str::chars)
367 {
368 if ch.is_whitespace() {
369 if whitespace_sequence_length == 0 {
370 whitespace_sequence_start = current_offset;
371 }
372 whitespace_sequence_length += 1;
373 } else {
374 if whitespace_sequence_length >= 2 {
375 whitespace_sequences.push((whitespace_sequence_start, current_offset));
376 }
377 whitespace_sequence_start = 0;
378 whitespace_sequence_length = 0;
379 }
380 current_offset += ch.len_utf8();
381 }
382 if whitespace_sequence_length >= 2 {
383 whitespace_sequences.push((whitespace_sequence_start, current_offset));
384 }
385
386 let closest_whitespace_end = if is_backward {
387 whitespace_sequences.last().map(|&(start, _)| start)
388 } else {
389 whitespace_sequences.first().map(|&(_, end)| end)
390 };
391
392 closest_whitespace_end
393 .unwrap_or_else(|| {
394 if is_backward {
395 trimmed_delete_range.start
396 } else {
397 trimmed_delete_range.end
398 }
399 })
400 .to_display_point(map)
401}
402
403/// Returns a position of the previous subword boundary, where a subword is defined as a run of
404/// word characters of the same "subkind" - where subcharacter kinds are '_' character,
405/// lowerspace characters and uppercase characters.
406pub fn previous_subword_start(map: &DisplaySnapshot, point: DisplayPoint) -> DisplayPoint {
407 let raw_point = point.to_point(map);
408 let classifier = map.buffer_snapshot().char_classifier_at(raw_point);
409
410 find_preceding_boundary_display_point(map, point, FindRange::MultiLine, |left, right| {
411 is_subword_start(left, right, &classifier) || left == '\n'
412 })
413}
414
415pub fn is_subword_start(left: char, right: char, classifier: &CharClassifier) -> bool {
416 let is_word_start = classifier.kind(left) != classifier.kind(right) && !right.is_whitespace();
417 let is_subword_start = classifier.is_word('-') && left == '-' && right != '-'
418 || left == '_' && right != '_'
419 || left.is_lowercase() && right.is_uppercase();
420 is_word_start || is_subword_start
421}
422
423/// Returns a position of the next word boundary, where a word character is defined as either
424/// uppercase letter, lowercase letter, '_' character or language-specific word character (like '-' in CSS).
425pub fn next_word_end(map: &DisplaySnapshot, point: DisplayPoint) -> DisplayPoint {
426 let raw_point = point.to_point(map);
427 let classifier = map.buffer_snapshot().char_classifier_at(raw_point);
428 let mut is_first_iteration = true;
429 find_boundary(map, point, FindRange::MultiLine, |left, right| {
430 // Make alt-right skip punctuation to respect VSCode behaviour. For example: |.hello goes to .hello|
431 if is_first_iteration
432 && classifier.is_punctuation(left)
433 && !classifier.is_punctuation(right)
434 && right != '\n'
435 {
436 is_first_iteration = false;
437 return false;
438 }
439 is_first_iteration = false;
440
441 (classifier.kind(left) != classifier.kind(right) && !classifier.is_whitespace(left))
442 || right == '\n'
443 })
444}
445
446/// Returns a position of the next word boundary, where a word character is defined as either
447/// uppercase letter, lowercase letter, '_' character, language-specific word character (like '-' in CSS) or newline.
448pub fn next_word_end_or_newline(map: &DisplaySnapshot, point: DisplayPoint) -> DisplayPoint {
449 let raw_point = point.to_point(map);
450 let classifier = map.buffer_snapshot().char_classifier_at(raw_point);
451
452 let mut on_starting_row = true;
453 find_boundary(map, point, FindRange::MultiLine, |left, right| {
454 if left == '\n' {
455 on_starting_row = false;
456 }
457 (classifier.kind(left) != classifier.kind(right)
458 && ((on_starting_row && !left.is_whitespace())
459 || (!on_starting_row && !right.is_whitespace())))
460 || right == '\n'
461 })
462}
463
464/// Returns a position of the next subword boundary, where a subword is defined as a run of
465/// word characters of the same "subkind" - where subcharacter kinds are '_' character,
466/// lowerspace characters and uppercase characters.
467pub fn next_subword_end(map: &DisplaySnapshot, point: DisplayPoint) -> DisplayPoint {
468 let raw_point = point.to_point(map);
469 let classifier = map.buffer_snapshot().char_classifier_at(raw_point);
470
471 find_boundary(map, point, FindRange::MultiLine, |left, right| {
472 is_subword_end(left, right, &classifier) || right == '\n'
473 })
474}
475
476pub fn is_subword_end(left: char, right: char, classifier: &CharClassifier) -> bool {
477 let is_word_end =
478 (classifier.kind(left) != classifier.kind(right)) && !classifier.is_whitespace(left);
479 let is_subword_end = classifier.is_word('-') && left != '-' && right == '-'
480 || left != '_' && right == '_'
481 || left.is_lowercase() && right.is_uppercase();
482 is_word_end || is_subword_end
483}
484
485/// Returns a position of the start of the current paragraph, where a paragraph
486/// is defined as a run of non-blank lines.
487pub fn start_of_paragraph(
488 map: &DisplaySnapshot,
489 display_point: DisplayPoint,
490 mut count: usize,
491) -> DisplayPoint {
492 let point = display_point.to_point(map);
493 if point.row == 0 {
494 return DisplayPoint::zero();
495 }
496
497 let mut found_non_blank_line = false;
498 for row in (0..point.row + 1).rev() {
499 let blank = map.buffer_snapshot().is_line_blank(MultiBufferRow(row));
500 if found_non_blank_line && blank {
501 if count <= 1 {
502 return Point::new(row, 0).to_display_point(map);
503 }
504 count -= 1;
505 found_non_blank_line = false;
506 }
507
508 found_non_blank_line |= !blank;
509 }
510
511 DisplayPoint::zero()
512}
513
514/// Returns a position of the end of the current paragraph, where a paragraph
515/// is defined as a run of non-blank lines.
516pub fn end_of_paragraph(
517 map: &DisplaySnapshot,
518 display_point: DisplayPoint,
519 mut count: usize,
520) -> DisplayPoint {
521 let point = display_point.to_point(map);
522 if point.row == map.buffer_snapshot().max_row().0 {
523 return map.max_point();
524 }
525
526 let mut found_non_blank_line = false;
527 for row in point.row..=map.buffer_snapshot().max_row().0 {
528 let blank = map.buffer_snapshot().is_line_blank(MultiBufferRow(row));
529 if found_non_blank_line && blank {
530 if count <= 1 {
531 return Point::new(row, 0).to_display_point(map);
532 }
533 count -= 1;
534 found_non_blank_line = false;
535 }
536
537 found_non_blank_line |= !blank;
538 }
539
540 map.max_point()
541}
542
543pub fn start_of_excerpt(
544 map: &DisplaySnapshot,
545 display_point: DisplayPoint,
546 direction: Direction,
547) -> DisplayPoint {
548 let point = map.display_point_to_point(display_point, Bias::Left);
549 let Some(excerpt) = map.buffer_snapshot().excerpt_containing(point..point) else {
550 return display_point;
551 };
552 match direction {
553 Direction::Prev => {
554 let mut start = excerpt.start_anchor().to_display_point(map);
555 if start >= display_point && start.row() > DisplayRow(0) {
556 let Some(excerpt) = map.buffer_snapshot().excerpt_before(excerpt.id()) else {
557 return display_point;
558 };
559 start = excerpt.start_anchor().to_display_point(map);
560 }
561 start
562 }
563 Direction::Next => {
564 let mut end = excerpt.end_anchor().to_display_point(map);
565 *end.row_mut() += 1;
566 map.clip_point(end, Bias::Right)
567 }
568 }
569}
570
571pub fn end_of_excerpt(
572 map: &DisplaySnapshot,
573 display_point: DisplayPoint,
574 direction: Direction,
575) -> DisplayPoint {
576 let point = map.display_point_to_point(display_point, Bias::Left);
577 let Some(excerpt) = map.buffer_snapshot().excerpt_containing(point..point) else {
578 return display_point;
579 };
580 match direction {
581 Direction::Prev => {
582 let mut start = excerpt.start_anchor().to_display_point(map);
583 if start.row() > DisplayRow(0) {
584 *start.row_mut() -= 1;
585 }
586 start = map.clip_point(start, Bias::Left);
587 *start.column_mut() = 0;
588 start
589 }
590 Direction::Next => {
591 let mut end = excerpt.end_anchor().to_display_point(map);
592 *end.column_mut() = 0;
593 if end <= display_point {
594 *end.row_mut() += 1;
595 let point_end = map.display_point_to_point(end, Bias::Right);
596 let Some(excerpt) = map
597 .buffer_snapshot()
598 .excerpt_containing(point_end..point_end)
599 else {
600 return display_point;
601 };
602 end = excerpt.end_anchor().to_display_point(map);
603 *end.column_mut() = 0;
604 }
605 end
606 }
607 }
608}
609
610/// Scans for a boundary preceding the given start point `from` until a boundary is found,
611/// indicated by the given predicate returning true.
612/// The predicate is called with the character to the left and right of the candidate boundary location.
613/// If FindRange::SingleLine is specified and no boundary is found before the start of the current line, the start of the current line will be returned.
614pub fn find_preceding_boundary_point(
615 buffer_snapshot: &MultiBufferSnapshot,
616 from: Point,
617 find_range: FindRange,
618 mut is_boundary: impl FnMut(char, char) -> bool,
619) -> Point {
620 let mut prev_ch = None;
621 let mut offset = from.to_offset(buffer_snapshot);
622
623 for ch in buffer_snapshot.reversed_chars_at(offset) {
624 if find_range == FindRange::SingleLine && ch == '\n' {
625 break;
626 }
627 if let Some(prev_ch) = prev_ch
628 && is_boundary(ch, prev_ch)
629 {
630 break;
631 }
632
633 offset -= ch.len_utf8();
634 prev_ch = Some(ch);
635 }
636
637 offset.to_point(buffer_snapshot)
638}
639
640/// Scans for a boundary preceding the given start point `from` until a boundary is found,
641/// indicated by the given predicate returning true.
642/// The predicate is called with the character to the left and right of the candidate boundary location.
643/// If FindRange::SingleLine is specified and no boundary is found before the start of the current line, the start of the current line will be returned.
644pub fn find_preceding_boundary_display_point(
645 map: &DisplaySnapshot,
646 from: DisplayPoint,
647 find_range: FindRange,
648 is_boundary: impl FnMut(char, char) -> bool,
649) -> DisplayPoint {
650 let result = find_preceding_boundary_point(
651 map.buffer_snapshot(),
652 from.to_point(map),
653 find_range,
654 is_boundary,
655 );
656 map.clip_point(result.to_display_point(map), Bias::Left)
657}
658
659/// Scans for a boundary following the given start point until a boundary is found, indicated by the
660/// given predicate returning true. The predicate is called with the character to the left and right
661/// of the candidate boundary location, and will be called with `\n` characters indicating the start
662/// or end of a line. The function supports optionally returning the point just before the boundary
663/// is found via return_point_before_boundary.
664pub fn find_boundary_point(
665 map: &DisplaySnapshot,
666 from: DisplayPoint,
667 find_range: FindRange,
668 mut is_boundary: impl FnMut(char, char) -> bool,
669 return_point_before_boundary: bool,
670) -> DisplayPoint {
671 let mut offset = from.to_offset(map, Bias::Right);
672 let mut prev_offset = offset;
673 let mut prev_ch = None;
674
675 for ch in map.buffer_snapshot().chars_at(offset) {
676 if find_range == FindRange::SingleLine && ch == '\n' {
677 break;
678 }
679 if let Some(prev_ch) = prev_ch
680 && is_boundary(prev_ch, ch)
681 {
682 if return_point_before_boundary {
683 return map.clip_point(prev_offset.to_display_point(map), Bias::Right);
684 } else {
685 break;
686 }
687 }
688 prev_offset = offset;
689 offset += ch.len_utf8();
690 prev_ch = Some(ch);
691 }
692 map.clip_point(offset.to_display_point(map), Bias::Right)
693}
694
695pub fn find_preceding_boundary_trail(
696 map: &DisplaySnapshot,
697 head: DisplayPoint,
698 mut is_boundary: impl FnMut(char, char) -> bool,
699) -> (Option<DisplayPoint>, DisplayPoint) {
700 let mut offset = head.to_offset(map, Bias::Left);
701 let mut trail_offset = None;
702
703 let mut prev_ch = map.buffer_snapshot().chars_at(offset).next();
704 let mut forward = map.buffer_snapshot().reversed_chars_at(offset).peekable();
705
706 // Skip newlines
707 while let Some(&ch) = forward.peek() {
708 if ch == '\n' {
709 prev_ch = forward.next();
710 offset -= ch.len_utf8();
711 trail_offset = Some(offset);
712 } else {
713 break;
714 }
715 }
716
717 // Find the boundary
718 let start_offset = offset;
719 for ch in forward {
720 if let Some(prev_ch) = prev_ch
721 && is_boundary(prev_ch, ch)
722 {
723 if start_offset == offset {
724 trail_offset = Some(offset);
725 } else {
726 break;
727 }
728 }
729 offset -= ch.len_utf8();
730 prev_ch = Some(ch);
731 }
732
733 let trail = trail_offset
734 .map(|trail_offset: usize| map.clip_point(trail_offset.to_display_point(map), Bias::Left));
735
736 (
737 trail,
738 map.clip_point(offset.to_display_point(map), Bias::Left),
739 )
740}
741
742/// Finds the location of a boundary
743pub fn find_boundary_trail(
744 map: &DisplaySnapshot,
745 head: DisplayPoint,
746 mut is_boundary: impl FnMut(char, char) -> bool,
747) -> (Option<DisplayPoint>, DisplayPoint) {
748 let mut offset = head.to_offset(map, Bias::Right);
749 let mut trail_offset = None;
750
751 let mut prev_ch = map.buffer_snapshot().reversed_chars_at(offset).next();
752 let mut forward = map.buffer_snapshot().chars_at(offset).peekable();
753
754 // Skip newlines
755 while let Some(&ch) = forward.peek() {
756 if ch == '\n' {
757 prev_ch = forward.next();
758 offset += ch.len_utf8();
759 trail_offset = Some(offset);
760 } else {
761 break;
762 }
763 }
764
765 // Find the boundary
766 let start_offset = offset;
767 for ch in forward {
768 if let Some(prev_ch) = prev_ch
769 && is_boundary(prev_ch, ch)
770 {
771 if start_offset == offset {
772 trail_offset = Some(offset);
773 } else {
774 break;
775 }
776 }
777 offset += ch.len_utf8();
778 prev_ch = Some(ch);
779 }
780
781 let trail = trail_offset
782 .map(|trail_offset: usize| map.clip_point(trail_offset.to_display_point(map), Bias::Right));
783
784 (
785 trail,
786 map.clip_point(offset.to_display_point(map), Bias::Right),
787 )
788}
789
790pub fn find_boundary(
791 map: &DisplaySnapshot,
792 from: DisplayPoint,
793 find_range: FindRange,
794 is_boundary: impl FnMut(char, char) -> bool,
795) -> DisplayPoint {
796 find_boundary_point(map, from, find_range, is_boundary, false)
797}
798
799pub fn find_boundary_exclusive(
800 map: &DisplaySnapshot,
801 from: DisplayPoint,
802 find_range: FindRange,
803 is_boundary: impl FnMut(char, char) -> bool,
804) -> DisplayPoint {
805 find_boundary_point(map, from, find_range, is_boundary, true)
806}
807
808/// Returns an iterator over the characters following a given offset in the [`DisplaySnapshot`].
809/// The returned value also contains a range of the start/end of a returned character in
810/// the [`DisplaySnapshot`]. The offsets are relative to the start of a buffer.
811pub fn chars_after(
812 map: &DisplaySnapshot,
813 mut offset: usize,
814) -> impl Iterator<Item = (char, Range<usize>)> + '_ {
815 map.buffer_snapshot().chars_at(offset).map(move |ch| {
816 let before = offset;
817 offset += ch.len_utf8();
818 (ch, before..offset)
819 })
820}
821
822/// Returns a reverse iterator over the characters following a given offset in the [`DisplaySnapshot`].
823/// The returned value also contains a range of the start/end of a returned character in
824/// the [`DisplaySnapshot`]. The offsets are relative to the start of a buffer.
825pub fn chars_before(
826 map: &DisplaySnapshot,
827 mut offset: usize,
828) -> impl Iterator<Item = (char, Range<usize>)> + '_ {
829 map.buffer_snapshot()
830 .reversed_chars_at(offset)
831 .map(move |ch| {
832 let after = offset;
833 offset -= ch.len_utf8();
834 (ch, offset..after)
835 })
836}
837
838/// Returns a list of lines (represented as a [`DisplayPoint`] range) contained
839/// within a passed range.
840///
841/// The line ranges are **always* going to be in bounds of a requested range, which means that
842/// the first and the last lines might not necessarily represent the
843/// full range of a logical line (as their `.start`/`.end` values are clipped to those of a passed in range).
844pub fn split_display_range_by_lines(
845 map: &DisplaySnapshot,
846 range: Range<DisplayPoint>,
847) -> Vec<Range<DisplayPoint>> {
848 let mut result = Vec::new();
849
850 let mut start = range.start;
851 // Loop over all the covered rows until the one containing the range end
852 for row in range.start.row().0..range.end.row().0 {
853 let row_end_column = map.line_len(DisplayRow(row));
854 let end = map.clip_point(
855 DisplayPoint::new(DisplayRow(row), row_end_column),
856 Bias::Left,
857 );
858 if start != end {
859 result.push(start..end);
860 }
861 start = map.clip_point(DisplayPoint::new(DisplayRow(row + 1), 0), Bias::Left);
862 }
863
864 // Add the final range from the start of the last end to the original range end.
865 result.push(start..range.end);
866
867 result
868}
869
870#[cfg(test)]
871mod tests {
872 use super::*;
873 use crate::{
874 Buffer, DisplayMap, DisplayRow, ExcerptRange, FoldPlaceholder, MultiBuffer,
875 inlays::Inlay,
876 test::{editor_test_context::EditorTestContext, marked_display_snapshot},
877 };
878 use gpui::{AppContext as _, font, px};
879 use language::Capability;
880 use project::{Project, project_settings::DiagnosticSeverity};
881 use rope::Rope;
882 use settings::SettingsStore;
883 use util::post_inc;
884
885 #[gpui::test]
886 fn test_previous_word_start(cx: &mut gpui::App) {
887 init_test(cx);
888
889 fn assert(marked_text: &str, cx: &mut gpui::App) {
890 let (snapshot, display_points) = marked_display_snapshot(marked_text, cx);
891 let actual = previous_word_start(&snapshot, display_points[1]);
892 let expected = display_points[0];
893 if actual != expected {
894 eprintln!(
895 "previous_word_start mismatch for '{}': actual={:?}, expected={:?}",
896 marked_text, actual, expected
897 );
898 }
899 assert_eq!(actual, expected);
900 }
901
902 assert("\nˇ ˇlorem", cx);
903 assert("ˇ\nˇ lorem", cx);
904 assert(" ˇloremˇ", cx);
905 assert("ˇ ˇlorem", cx);
906 assert(" ˇlorˇem", cx);
907 assert("\nlorem\nˇ ˇipsum", cx);
908 assert("\n\nˇ\nˇ", cx);
909 assert(" ˇlorem ˇipsum", cx);
910 assert("ˇlorem-ˇipsum", cx);
911 assert("loremˇ-#$@ˇipsum", cx);
912 assert("ˇlorem_ˇipsum", cx);
913 assert(" ˇdefγˇ", cx);
914 assert(" ˇbcΔˇ", cx);
915 // Test punctuation skipping behavior
916 assert("ˇhello.ˇ", cx);
917 assert("helloˇ...ˇ", cx);
918 assert("helloˇ.---..ˇtest", cx);
919 assert("test ˇ.--ˇtest", cx);
920 assert("oneˇ,;:!?ˇtwo", cx);
921 }
922
923 #[gpui::test]
924 fn test_previous_subword_start(cx: &mut gpui::App) {
925 init_test(cx);
926
927 fn assert(marked_text: &str, cx: &mut gpui::App) {
928 let (snapshot, display_points) = marked_display_snapshot(marked_text, cx);
929 assert_eq!(
930 previous_subword_start(&snapshot, display_points[1]),
931 display_points[0]
932 );
933 }
934
935 // Subword boundaries are respected
936 assert("lorem_ˇipˇsum", cx);
937 assert("lorem_ˇipsumˇ", cx);
938 assert("ˇlorem_ˇipsum", cx);
939 assert("lorem_ˇipsum_ˇdolor", cx);
940 assert("loremˇIpˇsum", cx);
941 assert("loremˇIpsumˇ", cx);
942
943 // Word boundaries are still respected
944 assert("\nˇ ˇlorem", cx);
945 assert(" ˇloremˇ", cx);
946 assert(" ˇlorˇem", cx);
947 assert("\nlorem\nˇ ˇipsum", cx);
948 assert("\n\nˇ\nˇ", cx);
949 assert(" ˇlorem ˇipsum", cx);
950 assert("loremˇ-ˇipsum", cx);
951 assert("loremˇ-#$@ˇipsum", cx);
952 assert(" ˇdefγˇ", cx);
953 assert(" bcˇΔˇ", cx);
954 assert(" ˇbcδˇ", cx);
955 assert(" abˇ——ˇcd", cx);
956 }
957
958 #[gpui::test]
959 fn test_find_preceding_boundary(cx: &mut gpui::App) {
960 init_test(cx);
961
962 fn assert(
963 marked_text: &str,
964 cx: &mut gpui::App,
965 is_boundary: impl FnMut(char, char) -> bool,
966 ) {
967 let (snapshot, display_points) = marked_display_snapshot(marked_text, cx);
968 assert_eq!(
969 find_preceding_boundary_display_point(
970 &snapshot,
971 display_points[1],
972 FindRange::MultiLine,
973 is_boundary
974 ),
975 display_points[0]
976 );
977 }
978
979 assert("abcˇdef\ngh\nijˇk", cx, |left, right| {
980 left == 'c' && right == 'd'
981 });
982 assert("abcdef\nˇgh\nijˇk", cx, |left, right| {
983 left == '\n' && right == 'g'
984 });
985 let mut line_count = 0;
986 assert("abcdef\nˇgh\nijˇk", cx, |left, _| {
987 if left == '\n' {
988 line_count += 1;
989 line_count == 2
990 } else {
991 false
992 }
993 });
994 }
995
996 #[gpui::test]
997 fn test_find_preceding_boundary_with_inlays(cx: &mut gpui::App) {
998 init_test(cx);
999
1000 let input_text = "abcdefghijklmnopqrstuvwxys";
1001 let font = font("Helvetica");
1002 let font_size = px(14.0);
1003 let buffer = MultiBuffer::build_simple(input_text, cx);
1004 let buffer_snapshot = buffer.read(cx).snapshot(cx);
1005
1006 let display_map = cx.new(|cx| {
1007 DisplayMap::new(
1008 buffer,
1009 font,
1010 font_size,
1011 None,
1012 1,
1013 1,
1014 FoldPlaceholder::test(),
1015 DiagnosticSeverity::Warning,
1016 cx,
1017 )
1018 });
1019
1020 // add all kinds of inlays between two word boundaries: we should be able to cross them all, when looking for another boundary
1021 let mut id = 0;
1022 let inlays = (0..buffer_snapshot.len())
1023 .flat_map(|offset| {
1024 [
1025 Inlay::edit_prediction(
1026 post_inc(&mut id),
1027 buffer_snapshot.anchor_before(offset),
1028 Rope::from_str_small("test"),
1029 ),
1030 Inlay::edit_prediction(
1031 post_inc(&mut id),
1032 buffer_snapshot.anchor_after(offset),
1033 Rope::from_str_small("test"),
1034 ),
1035 Inlay::mock_hint(
1036 post_inc(&mut id),
1037 buffer_snapshot.anchor_before(offset),
1038 Rope::from_str_small("test"),
1039 ),
1040 Inlay::mock_hint(
1041 post_inc(&mut id),
1042 buffer_snapshot.anchor_after(offset),
1043 Rope::from_str_small("test"),
1044 ),
1045 ]
1046 })
1047 .collect();
1048 let snapshot = display_map.update(cx, |map, cx| {
1049 map.splice_inlays(&[], inlays, cx);
1050 map.snapshot(cx)
1051 });
1052
1053 assert_eq!(
1054 find_preceding_boundary_display_point(
1055 &snapshot,
1056 buffer_snapshot.len().to_display_point(&snapshot),
1057 FindRange::MultiLine,
1058 |left, _| left == 'e',
1059 ),
1060 snapshot
1061 .buffer_snapshot()
1062 .offset_to_point(5)
1063 .to_display_point(&snapshot),
1064 "Should not stop at inlays when looking for boundaries"
1065 );
1066 }
1067
1068 #[gpui::test]
1069 fn test_next_word_end(cx: &mut gpui::App) {
1070 init_test(cx);
1071
1072 fn assert(marked_text: &str, cx: &mut gpui::App) {
1073 let (snapshot, display_points) = marked_display_snapshot(marked_text, cx);
1074 let actual = next_word_end(&snapshot, display_points[0]);
1075 let expected = display_points[1];
1076 if actual != expected {
1077 eprintln!(
1078 "next_word_end mismatch for '{}': actual={:?}, expected={:?}",
1079 marked_text, actual, expected
1080 );
1081 }
1082 assert_eq!(actual, expected);
1083 }
1084
1085 assert("\nˇ loremˇ", cx);
1086 assert(" ˇloremˇ", cx);
1087 assert(" lorˇemˇ", cx);
1088 assert(" loremˇ ˇ\nipsum\n", cx);
1089 assert("\nˇ\nˇ\n\n", cx);
1090 assert("loremˇ ipsumˇ ", cx);
1091 assert("loremˇ-ipsumˇ", cx);
1092 assert("loremˇ#$@-ˇipsum", cx);
1093 assert("loremˇ_ipsumˇ", cx);
1094 assert(" ˇbcΔˇ", cx);
1095 assert(" abˇ——ˇcd", cx);
1096 // Test punctuation skipping behavior
1097 assert("ˇ.helloˇ", cx);
1098 assert("display_pointsˇ[0ˇ]", cx);
1099 assert("ˇ...ˇhello", cx);
1100 assert("helloˇ.---..ˇtest", cx);
1101 assert("testˇ.--ˇ test", cx);
1102 assert("oneˇ,;:!?ˇtwo", cx);
1103 }
1104
1105 #[gpui::test]
1106 fn test_next_subword_end(cx: &mut gpui::App) {
1107 init_test(cx);
1108
1109 fn assert(marked_text: &str, cx: &mut gpui::App) {
1110 let (snapshot, display_points) = marked_display_snapshot(marked_text, cx);
1111 assert_eq!(
1112 next_subword_end(&snapshot, display_points[0]),
1113 display_points[1]
1114 );
1115 }
1116
1117 // Subword boundaries are respected
1118 assert("loˇremˇ_ipsum", cx);
1119 assert("ˇloremˇ_ipsum", cx);
1120 assert("loremˇ_ipsumˇ", cx);
1121 assert("loremˇ_ipsumˇ_dolor", cx);
1122 assert("loˇremˇIpsum", cx);
1123 assert("loremˇIpsumˇDolor", cx);
1124
1125 // Word boundaries are still respected
1126 assert("\nˇ loremˇ", cx);
1127 assert(" ˇloremˇ", cx);
1128 assert(" lorˇemˇ", cx);
1129 assert(" loremˇ ˇ\nipsum\n", cx);
1130 assert("\nˇ\nˇ\n\n", cx);
1131 assert("loremˇ ipsumˇ ", cx);
1132 assert("loremˇ-ˇipsum", cx);
1133 assert("loremˇ#$@-ˇipsum", cx);
1134 assert("loremˇ_ipsumˇ", cx);
1135 assert(" ˇbcˇΔ", cx);
1136 assert(" abˇ——ˇcd", cx);
1137 }
1138
1139 #[gpui::test]
1140 fn test_find_boundary(cx: &mut gpui::App) {
1141 init_test(cx);
1142
1143 fn assert(
1144 marked_text: &str,
1145 cx: &mut gpui::App,
1146 is_boundary: impl FnMut(char, char) -> bool,
1147 ) {
1148 let (snapshot, display_points) = marked_display_snapshot(marked_text, cx);
1149 assert_eq!(
1150 find_boundary(
1151 &snapshot,
1152 display_points[0],
1153 FindRange::MultiLine,
1154 is_boundary,
1155 ),
1156 display_points[1]
1157 );
1158 }
1159
1160 assert("abcˇdef\ngh\nijˇk", cx, |left, right| {
1161 left == 'j' && right == 'k'
1162 });
1163 assert("abˇcdef\ngh\nˇijk", cx, |left, right| {
1164 left == '\n' && right == 'i'
1165 });
1166 let mut line_count = 0;
1167 assert("abcˇdef\ngh\nˇijk", cx, |left, _| {
1168 if left == '\n' {
1169 line_count += 1;
1170 line_count == 2
1171 } else {
1172 false
1173 }
1174 });
1175 }
1176
1177 #[gpui::test]
1178 async fn test_move_up_and_down_with_excerpts(cx: &mut gpui::TestAppContext) {
1179 cx.update(|cx| {
1180 init_test(cx);
1181 });
1182
1183 let mut cx = EditorTestContext::new(cx).await;
1184 let editor = cx.editor.clone();
1185 let window = cx.window;
1186 _ = cx.update_window(window, |_, window, cx| {
1187 let text_layout_details = editor.read(cx).text_layout_details(window);
1188
1189 let font = font("Helvetica");
1190
1191 let buffer = cx.new(|cx| Buffer::local("abc\ndefg\nhijkl\nmn", cx));
1192 let multibuffer = cx.new(|cx| {
1193 let mut multibuffer = MultiBuffer::new(Capability::ReadWrite);
1194 multibuffer.push_excerpts(
1195 buffer.clone(),
1196 [
1197 ExcerptRange::new(Point::new(0, 0)..Point::new(1, 4)),
1198 ExcerptRange::new(Point::new(2, 0)..Point::new(3, 2)),
1199 ],
1200 cx,
1201 );
1202 multibuffer
1203 });
1204 let display_map = cx.new(|cx| {
1205 DisplayMap::new(
1206 multibuffer,
1207 font,
1208 px(14.0),
1209 None,
1210 0,
1211 1,
1212 FoldPlaceholder::test(),
1213 DiagnosticSeverity::Warning,
1214 cx,
1215 )
1216 });
1217 let snapshot = display_map.update(cx, |map, cx| map.snapshot(cx));
1218
1219 assert_eq!(snapshot.text(), "abc\ndefg\n\nhijkl\nmn");
1220
1221 let col_2_x = snapshot
1222 .x_for_display_point(DisplayPoint::new(DisplayRow(0), 2), &text_layout_details);
1223
1224 // Can't move up into the first excerpt's header
1225 assert_eq!(
1226 up(
1227 &snapshot,
1228 DisplayPoint::new(DisplayRow(0), 2),
1229 SelectionGoal::HorizontalPosition(f64::from(col_2_x)),
1230 false,
1231 &text_layout_details
1232 ),
1233 (
1234 DisplayPoint::new(DisplayRow(0), 0),
1235 SelectionGoal::HorizontalPosition(f64::from(col_2_x)),
1236 ),
1237 );
1238 assert_eq!(
1239 up(
1240 &snapshot,
1241 DisplayPoint::new(DisplayRow(0), 0),
1242 SelectionGoal::None,
1243 false,
1244 &text_layout_details
1245 ),
1246 (
1247 DisplayPoint::new(DisplayRow(0), 0),
1248 SelectionGoal::HorizontalPosition(0.0),
1249 ),
1250 );
1251
1252 let col_4_x = snapshot
1253 .x_for_display_point(DisplayPoint::new(DisplayRow(1), 4), &text_layout_details);
1254
1255 // Move up and down within first excerpt
1256 assert_eq!(
1257 up(
1258 &snapshot,
1259 DisplayPoint::new(DisplayRow(1), 4),
1260 SelectionGoal::HorizontalPosition(col_4_x.into()),
1261 false,
1262 &text_layout_details
1263 ),
1264 (
1265 DisplayPoint::new(DisplayRow(0), 3),
1266 SelectionGoal::HorizontalPosition(col_4_x.into())
1267 ),
1268 );
1269 assert_eq!(
1270 down(
1271 &snapshot,
1272 DisplayPoint::new(DisplayRow(0), 3),
1273 SelectionGoal::HorizontalPosition(col_4_x.into()),
1274 false,
1275 &text_layout_details
1276 ),
1277 (
1278 DisplayPoint::new(DisplayRow(1), 4),
1279 SelectionGoal::HorizontalPosition(col_4_x.into())
1280 ),
1281 );
1282
1283 let col_5_x = snapshot
1284 .x_for_display_point(DisplayPoint::new(DisplayRow(3), 5), &text_layout_details);
1285
1286 // Move up and down across second excerpt's header
1287 assert_eq!(
1288 up(
1289 &snapshot,
1290 DisplayPoint::new(DisplayRow(3), 5),
1291 SelectionGoal::HorizontalPosition(col_5_x.into()),
1292 false,
1293 &text_layout_details
1294 ),
1295 (
1296 DisplayPoint::new(DisplayRow(1), 4),
1297 SelectionGoal::HorizontalPosition(col_5_x.into())
1298 ),
1299 );
1300 assert_eq!(
1301 down(
1302 &snapshot,
1303 DisplayPoint::new(DisplayRow(1), 4),
1304 SelectionGoal::HorizontalPosition(col_5_x.into()),
1305 false,
1306 &text_layout_details
1307 ),
1308 (
1309 DisplayPoint::new(DisplayRow(3), 5),
1310 SelectionGoal::HorizontalPosition(col_5_x.into())
1311 ),
1312 );
1313
1314 let max_point_x = snapshot
1315 .x_for_display_point(DisplayPoint::new(DisplayRow(4), 2), &text_layout_details);
1316
1317 // Can't move down off the end, and attempting to do so leaves the selection goal unchanged
1318 assert_eq!(
1319 down(
1320 &snapshot,
1321 DisplayPoint::new(DisplayRow(4), 0),
1322 SelectionGoal::HorizontalPosition(0.0),
1323 false,
1324 &text_layout_details
1325 ),
1326 (
1327 DisplayPoint::new(DisplayRow(4), 2),
1328 SelectionGoal::HorizontalPosition(0.0)
1329 ),
1330 );
1331 assert_eq!(
1332 down(
1333 &snapshot,
1334 DisplayPoint::new(DisplayRow(4), 2),
1335 SelectionGoal::HorizontalPosition(max_point_x.into()),
1336 false,
1337 &text_layout_details
1338 ),
1339 (
1340 DisplayPoint::new(DisplayRow(4), 2),
1341 SelectionGoal::HorizontalPosition(max_point_x.into())
1342 ),
1343 );
1344 });
1345 }
1346
1347 fn init_test(cx: &mut gpui::App) {
1348 let settings_store = SettingsStore::test(cx);
1349 cx.set_global(settings_store);
1350 workspace::init_settings(cx);
1351 theme::init(theme::LoadThemes::JustBase, cx);
1352 language::init(cx);
1353 crate::init(cx);
1354 Project::init_settings(cx);
1355 }
1356}