movement.rs

  1use super::{Bias, DisplayPoint, DisplaySnapshot, SelectionGoal, ToDisplayPoint};
  2use crate::{char_kind, CharKind, ToPoint};
  3use language::Point;
  4use std::ops::Range;
  5
  6pub fn left(map: &DisplaySnapshot, mut point: DisplayPoint) -> DisplayPoint {
  7    if point.column() > 0 {
  8        *point.column_mut() -= 1;
  9    } else if point.row() > 0 {
 10        *point.row_mut() -= 1;
 11        *point.column_mut() = map.line_len(point.row());
 12    }
 13    map.clip_point(point, Bias::Left)
 14}
 15
 16pub fn right(map: &DisplaySnapshot, mut point: DisplayPoint) -> DisplayPoint {
 17    let max_column = map.line_len(point.row());
 18    if point.column() < max_column {
 19        *point.column_mut() += 1;
 20    } else if point.row() < map.max_point().row() {
 21        *point.row_mut() += 1;
 22        *point.column_mut() = 0;
 23    }
 24    map.clip_point(point, Bias::Right)
 25}
 26
 27pub fn up(
 28    map: &DisplaySnapshot,
 29    start: DisplayPoint,
 30    goal: SelectionGoal,
 31    preserve_column_at_start: bool,
 32) -> (DisplayPoint, SelectionGoal) {
 33    up_by_rows(map, start, 1, goal, preserve_column_at_start)
 34}
 35
 36pub fn down(
 37    map: &DisplaySnapshot,
 38    start: DisplayPoint,
 39    goal: SelectionGoal,
 40    preserve_column_at_end: bool,
 41) -> (DisplayPoint, SelectionGoal) {
 42    down_by_rows(map, start, 1, goal, preserve_column_at_end)
 43}
 44
 45pub fn up_by_rows(
 46    map: &DisplaySnapshot,
 47    start: DisplayPoint,
 48    row_count: u32,
 49    goal: SelectionGoal,
 50    preserve_column_at_start: bool,
 51) -> (DisplayPoint, SelectionGoal) {
 52    let mut goal_column = if let SelectionGoal::Column(column) = goal {
 53        column
 54    } else {
 55        map.column_to_chars(start.row(), start.column())
 56    };
 57
 58    let prev_row = start.row().saturating_sub(row_count);
 59    let mut point = map.clip_point(
 60        DisplayPoint::new(prev_row, map.line_len(prev_row)),
 61        Bias::Left,
 62    );
 63    if point.row() < start.row() {
 64        *point.column_mut() = map.column_from_chars(point.row(), goal_column);
 65    } else if preserve_column_at_start {
 66        return (start, goal);
 67    } else {
 68        point = DisplayPoint::new(0, 0);
 69        goal_column = 0;
 70    }
 71
 72    let clip_bias = if point.column() == map.line_len(point.row()) {
 73        Bias::Left
 74    } else {
 75        Bias::Right
 76    };
 77
 78    (
 79        map.clip_point(point, clip_bias),
 80        SelectionGoal::Column(goal_column),
 81    )
 82}
 83
 84pub fn down_by_rows(
 85    map: &DisplaySnapshot,
 86    start: DisplayPoint,
 87    row_count: u32,
 88    goal: SelectionGoal,
 89    preserve_column_at_end: bool,
 90) -> (DisplayPoint, SelectionGoal) {
 91    let mut goal_column = if let SelectionGoal::Column(column) = goal {
 92        column
 93    } else {
 94        map.column_to_chars(start.row(), start.column())
 95    };
 96
 97    let new_row = start.row() + row_count;
 98    let mut point = map.clip_point(DisplayPoint::new(new_row, 0), Bias::Right);
 99    if point.row() > start.row() {
100        *point.column_mut() = map.column_from_chars(point.row(), goal_column);
101    } else if preserve_column_at_end {
102        return (start, goal);
103    } else {
104        point = map.max_point();
105        goal_column = map.column_to_chars(point.row(), point.column())
106    }
107
108    let clip_bias = if point.column() == map.line_len(point.row()) {
109        Bias::Left
110    } else {
111        Bias::Right
112    };
113
114    (
115        map.clip_point(point, clip_bias),
116        SelectionGoal::Column(goal_column),
117    )
118}
119
120pub fn line_beginning(
121    map: &DisplaySnapshot,
122    display_point: DisplayPoint,
123    stop_at_soft_boundaries: bool,
124) -> DisplayPoint {
125    let point = display_point.to_point(map);
126    let soft_line_start = map.clip_point(DisplayPoint::new(display_point.row(), 0), Bias::Right);
127    let line_start = map.prev_line_boundary(point).1;
128
129    if stop_at_soft_boundaries && display_point != soft_line_start {
130        soft_line_start
131    } else {
132        line_start
133    }
134}
135
136pub fn indented_line_beginning(
137    map: &DisplaySnapshot,
138    display_point: DisplayPoint,
139    stop_at_soft_boundaries: bool,
140) -> DisplayPoint {
141    let point = display_point.to_point(map);
142    let soft_line_start = map.clip_point(DisplayPoint::new(display_point.row(), 0), Bias::Right);
143    let indent_start = Point::new(
144        point.row,
145        map.buffer_snapshot.indent_size_for_line(point.row).len,
146    )
147    .to_display_point(map);
148    let line_start = map.prev_line_boundary(point).1;
149
150    if stop_at_soft_boundaries && soft_line_start > indent_start && display_point != soft_line_start
151    {
152        soft_line_start
153    } else if stop_at_soft_boundaries && display_point != indent_start {
154        indent_start
155    } else {
156        line_start
157    }
158}
159
160pub fn line_end(
161    map: &DisplaySnapshot,
162    display_point: DisplayPoint,
163    stop_at_soft_boundaries: bool,
164) -> DisplayPoint {
165    let soft_line_end = map.clip_point(
166        DisplayPoint::new(display_point.row(), map.line_len(display_point.row())),
167        Bias::Left,
168    );
169    if stop_at_soft_boundaries && display_point != soft_line_end {
170        soft_line_end
171    } else {
172        map.next_line_boundary(display_point.to_point(map)).1
173    }
174}
175
176pub fn previous_word_start(map: &DisplaySnapshot, point: DisplayPoint) -> DisplayPoint {
177    find_preceding_boundary(map, point, |left, right| {
178        (char_kind(left) != char_kind(right) && !right.is_whitespace()) || left == '\n'
179    })
180}
181
182pub fn previous_subword_start(map: &DisplaySnapshot, point: DisplayPoint) -> DisplayPoint {
183    find_preceding_boundary(map, point, |left, right| {
184        let is_word_start = char_kind(left) != char_kind(right) && !right.is_whitespace();
185        let is_subword_start =
186            left == '_' && right != '_' || left.is_lowercase() && right.is_uppercase();
187        is_word_start || is_subword_start || left == '\n'
188    })
189}
190
191pub fn next_word_end(map: &DisplaySnapshot, point: DisplayPoint) -> DisplayPoint {
192    find_boundary(map, point, |left, right| {
193        (char_kind(left) != char_kind(right) && !left.is_whitespace()) || right == '\n'
194    })
195}
196
197pub fn next_subword_end(map: &DisplaySnapshot, point: DisplayPoint) -> DisplayPoint {
198    find_boundary(map, point, |left, right| {
199        let is_word_end = (char_kind(left) != char_kind(right)) && !left.is_whitespace();
200        let is_subword_end =
201            left != '_' && right == '_' || left.is_lowercase() && right.is_uppercase();
202        is_word_end || is_subword_end || right == '\n'
203    })
204}
205
206/// Scans for a boundary preceding the given start point `from` until a boundary is found, indicated by the
207/// given predicate returning true. The predicate is called with the character to the left and right
208/// of the candidate boundary location, and will be called with `\n` characters indicating the start
209/// or end of a line.
210pub fn find_preceding_boundary(
211    map: &DisplaySnapshot,
212    from: DisplayPoint,
213    mut is_boundary: impl FnMut(char, char) -> bool,
214) -> DisplayPoint {
215    let mut start_column = 0;
216    let mut soft_wrap_row = from.row() + 1;
217
218    let mut prev = None;
219    for (ch, point) in map.reverse_chars_at(from) {
220        // Recompute soft_wrap_indent if the row has changed
221        if point.row() != soft_wrap_row {
222            soft_wrap_row = point.row();
223
224            if point.row() == 0 {
225                start_column = 0;
226            } else if let Some(indent) = map.soft_wrap_indent(point.row() - 1) {
227                start_column = indent;
228            }
229        }
230
231        // If the current point is in the soft_wrap, skip comparing it
232        if point.column() < start_column {
233            continue;
234        }
235
236        if let Some((prev_ch, prev_point)) = prev {
237            if is_boundary(ch, prev_ch) {
238                return prev_point;
239            }
240        }
241
242        prev = Some((ch, point));
243    }
244    DisplayPoint::zero()
245}
246
247/// Scans for a boundary preceding the given start point `from` until a boundary is found, indicated by the
248/// given predicate returning true. The predicate is called with the character to the left and right
249/// of the candidate boundary location, and will be called with `\n` characters indicating the start
250/// or end of a line. If no boundary is found, the start of the line is returned.
251pub fn find_preceding_boundary_in_line(
252    map: &DisplaySnapshot,
253    from: DisplayPoint,
254    mut is_boundary: impl FnMut(char, char) -> bool,
255) -> DisplayPoint {
256    let mut start_column = 0;
257    if from.row() > 0 {
258        if let Some(indent) = map.soft_wrap_indent(from.row() - 1) {
259            start_column = indent;
260        }
261    }
262
263    let mut prev = None;
264    for (ch, point) in map.reverse_chars_at(from) {
265        if let Some((prev_ch, prev_point)) = prev {
266            if is_boundary(ch, prev_ch) {
267                return prev_point;
268            }
269        }
270
271        if ch == '\n' || point.column() < start_column {
272            break;
273        }
274
275        prev = Some((ch, point));
276    }
277
278    prev.map(|(_, point)| point).unwrap_or(from)
279}
280
281/// Scans for a boundary following the given start point until a boundary is found, indicated by the
282/// given predicate returning true. The predicate is called with the character to the left and right
283/// of the candidate boundary location, and will be called with `\n` characters indicating the start
284/// or end of a line.
285pub fn find_boundary(
286    map: &DisplaySnapshot,
287    from: DisplayPoint,
288    mut is_boundary: impl FnMut(char, char) -> bool,
289) -> DisplayPoint {
290    let mut prev_ch = None;
291    for (ch, point) in map.chars_at(from) {
292        if let Some(prev_ch) = prev_ch {
293            if is_boundary(prev_ch, ch) {
294                return map.clip_point(point, Bias::Right);
295            }
296        }
297
298        prev_ch = Some(ch);
299    }
300    map.clip_point(map.max_point(), Bias::Right)
301}
302
303/// Scans for a boundary following the given start point until a boundary is found, indicated by the
304/// given predicate returning true. The predicate is called with the character to the left and right
305/// of the candidate boundary location, and will be called with `\n` characters indicating the start
306/// or end of a line. If no boundary is found, the end of the line is returned
307pub fn find_boundary_in_line(
308    map: &DisplaySnapshot,
309    from: DisplayPoint,
310    mut is_boundary: impl FnMut(char, char) -> bool,
311) -> DisplayPoint {
312    let mut prev = None;
313    for (ch, point) in map.chars_at(from) {
314        if let Some((prev_ch, _)) = prev {
315            if is_boundary(prev_ch, ch) {
316                return map.clip_point(point, Bias::Right);
317            }
318        }
319
320        prev = Some((ch, point));
321
322        if ch == '\n' {
323            break;
324        }
325    }
326
327    // Return the last position checked so that we give a point right before the newline or eof.
328    map.clip_point(prev.map(|(_, point)| point).unwrap_or(from), Bias::Right)
329}
330
331pub fn is_inside_word(map: &DisplaySnapshot, point: DisplayPoint) -> bool {
332    let ix = map.clip_point(point, Bias::Left).to_offset(map, Bias::Left);
333    let text = &map.buffer_snapshot;
334    let next_char_kind = text.chars_at(ix).next().map(char_kind);
335    let prev_char_kind = text.reversed_chars_at(ix).next().map(char_kind);
336    prev_char_kind.zip(next_char_kind) == Some((CharKind::Word, CharKind::Word))
337}
338
339pub fn surrounding_word(map: &DisplaySnapshot, position: DisplayPoint) -> Range<DisplayPoint> {
340    let position = map
341        .clip_point(position, Bias::Left)
342        .to_offset(map, Bias::Left);
343    let (range, _) = map.buffer_snapshot.surrounding_word(position);
344    let start = range
345        .start
346        .to_point(&map.buffer_snapshot)
347        .to_display_point(map);
348    let end = range
349        .end
350        .to_point(&map.buffer_snapshot)
351        .to_display_point(map);
352    start..end
353}
354
355#[cfg(test)]
356mod tests {
357    use super::*;
358    use crate::{test::marked_display_snapshot, Buffer, DisplayMap, ExcerptRange, MultiBuffer};
359    use settings::Settings;
360
361    #[gpui::test]
362    fn test_previous_word_start(cx: &mut gpui::MutableAppContext) {
363        cx.set_global(Settings::test(cx));
364        fn assert(marked_text: &str, cx: &mut gpui::MutableAppContext) {
365            let (snapshot, display_points) = marked_display_snapshot(marked_text, cx);
366            assert_eq!(
367                previous_word_start(&snapshot, display_points[1]),
368                display_points[0]
369            );
370        }
371
372        assert("\nˇ   ˇlorem", cx);
373        assert("ˇ\nˇ   lorem", cx);
374        assert("    ˇloremˇ", cx);
375        assert("ˇ    ˇlorem", cx);
376        assert("    ˇlorˇem", cx);
377        assert("\nlorem\nˇ   ˇipsum", cx);
378        assert("\n\nˇ\nˇ", cx);
379        assert("    ˇlorem  ˇipsum", cx);
380        assert("loremˇ-ˇipsum", cx);
381        assert("loremˇ-#$@ˇipsum", cx);
382        assert("ˇlorem_ˇipsum", cx);
383        assert(" ˇdefγˇ", cx);
384        assert(" ˇbcΔˇ", cx);
385        assert(" abˇ——ˇcd", cx);
386    }
387
388    #[gpui::test]
389    fn test_previous_subword_start(cx: &mut gpui::MutableAppContext) {
390        cx.set_global(Settings::test(cx));
391        fn assert(marked_text: &str, cx: &mut gpui::MutableAppContext) {
392            let (snapshot, display_points) = marked_display_snapshot(marked_text, cx);
393            assert_eq!(
394                previous_subword_start(&snapshot, display_points[1]),
395                display_points[0]
396            );
397        }
398
399        // Subword boundaries are respected
400        assert("lorem_ˇipˇsum", cx);
401        assert("lorem_ˇipsumˇ", cx);
402        assert("ˇlorem_ˇipsum", cx);
403        assert("lorem_ˇipsum_ˇdolor", cx);
404        assert("loremˇIpˇsum", cx);
405        assert("loremˇIpsumˇ", cx);
406
407        // Word boundaries are still respected
408        assert("\nˇ   ˇlorem", cx);
409        assert("    ˇloremˇ", cx);
410        assert("    ˇlorˇem", cx);
411        assert("\nlorem\nˇ   ˇipsum", cx);
412        assert("\n\nˇ\nˇ", cx);
413        assert("    ˇlorem  ˇipsum", cx);
414        assert("loremˇ-ˇipsum", cx);
415        assert("loremˇ-#$@ˇipsum", cx);
416        assert(" ˇdefγˇ", cx);
417        assert(" bcˇΔˇ", cx);
418        assert(" ˇbcδˇ", cx);
419        assert(" abˇ——ˇcd", cx);
420    }
421
422    #[gpui::test]
423    fn test_find_preceding_boundary(cx: &mut gpui::MutableAppContext) {
424        cx.set_global(Settings::test(cx));
425        fn assert(
426            marked_text: &str,
427            cx: &mut gpui::MutableAppContext,
428            is_boundary: impl FnMut(char, char) -> bool,
429        ) {
430            let (snapshot, display_points) = marked_display_snapshot(marked_text, cx);
431            assert_eq!(
432                find_preceding_boundary(&snapshot, display_points[1], is_boundary),
433                display_points[0]
434            );
435        }
436
437        assert("abcˇdef\ngh\nijˇk", cx, |left, right| {
438            left == 'c' && right == 'd'
439        });
440        assert("abcdef\nˇgh\nijˇk", cx, |left, right| {
441            left == '\n' && right == 'g'
442        });
443        let mut line_count = 0;
444        assert("abcdef\nˇgh\nijˇk", cx, |left, _| {
445            if left == '\n' {
446                line_count += 1;
447                line_count == 2
448            } else {
449                false
450            }
451        });
452    }
453
454    #[gpui::test]
455    fn test_next_word_end(cx: &mut gpui::MutableAppContext) {
456        cx.set_global(Settings::test(cx));
457        fn assert(marked_text: &str, cx: &mut gpui::MutableAppContext) {
458            let (snapshot, display_points) = marked_display_snapshot(marked_text, cx);
459            assert_eq!(
460                next_word_end(&snapshot, display_points[0]),
461                display_points[1]
462            );
463        }
464
465        assert("\nˇ   loremˇ", cx);
466        assert("    ˇloremˇ", cx);
467        assert("    lorˇemˇ", cx);
468        assert("    loremˇ    ˇ\nipsum\n", cx);
469        assert("\nˇ\nˇ\n\n", cx);
470        assert("loremˇ    ipsumˇ   ", cx);
471        assert("loremˇ-ˇipsum", cx);
472        assert("loremˇ#$@-ˇipsum", cx);
473        assert("loremˇ_ipsumˇ", cx);
474        assert(" ˇbcΔˇ", cx);
475        assert(" abˇ——ˇcd", cx);
476    }
477
478    #[gpui::test]
479    fn test_next_subword_end(cx: &mut gpui::MutableAppContext) {
480        cx.set_global(Settings::test(cx));
481        fn assert(marked_text: &str, cx: &mut gpui::MutableAppContext) {
482            let (snapshot, display_points) = marked_display_snapshot(marked_text, cx);
483            assert_eq!(
484                next_subword_end(&snapshot, display_points[0]),
485                display_points[1]
486            );
487        }
488
489        // Subword boundaries are respected
490        assert("loˇremˇ_ipsum", cx);
491        assert("ˇloremˇ_ipsum", cx);
492        assert("loremˇ_ipsumˇ", cx);
493        assert("loremˇ_ipsumˇ_dolor", cx);
494        assert("loˇremˇIpsum", cx);
495        assert("loremˇIpsumˇDolor", cx);
496
497        // Word boundaries are still respected
498        assert("\nˇ   loremˇ", cx);
499        assert("    ˇloremˇ", cx);
500        assert("    lorˇemˇ", cx);
501        assert("    loremˇ    ˇ\nipsum\n", cx);
502        assert("\nˇ\nˇ\n\n", cx);
503        assert("loremˇ    ipsumˇ   ", cx);
504        assert("loremˇ-ˇipsum", cx);
505        assert("loremˇ#$@-ˇipsum", cx);
506        assert("loremˇ_ipsumˇ", cx);
507        assert(" ˇbcˇΔ", cx);
508        assert(" abˇ——ˇcd", cx);
509    }
510
511    #[gpui::test]
512    fn test_find_boundary(cx: &mut gpui::MutableAppContext) {
513        cx.set_global(Settings::test(cx));
514        fn assert(
515            marked_text: &str,
516            cx: &mut gpui::MutableAppContext,
517            is_boundary: impl FnMut(char, char) -> bool,
518        ) {
519            let (snapshot, display_points) = marked_display_snapshot(marked_text, cx);
520            assert_eq!(
521                find_boundary(&snapshot, display_points[0], is_boundary),
522                display_points[1]
523            );
524        }
525
526        assert("abcˇdef\ngh\nijˇk", cx, |left, right| {
527            left == 'j' && right == 'k'
528        });
529        assert("abˇcdef\ngh\nˇijk", cx, |left, right| {
530            left == '\n' && right == 'i'
531        });
532        let mut line_count = 0;
533        assert("abcˇdef\ngh\nˇijk", cx, |left, _| {
534            if left == '\n' {
535                line_count += 1;
536                line_count == 2
537            } else {
538                false
539            }
540        });
541    }
542
543    #[gpui::test]
544    fn test_surrounding_word(cx: &mut gpui::MutableAppContext) {
545        cx.set_global(Settings::test(cx));
546        fn assert(marked_text: &str, cx: &mut gpui::MutableAppContext) {
547            let (snapshot, display_points) = marked_display_snapshot(marked_text, cx);
548            assert_eq!(
549                surrounding_word(&snapshot, display_points[1]),
550                display_points[0]..display_points[2]
551            );
552        }
553
554        assert("ˇˇloremˇ  ipsum", cx);
555        assert("ˇloˇremˇ  ipsum", cx);
556        assert("ˇloremˇˇ  ipsum", cx);
557        assert("loremˇ ˇ  ˇipsum", cx);
558        assert("lorem\nˇˇˇ\nipsum", cx);
559        assert("lorem\nˇˇipsumˇ", cx);
560        assert("lorem,ˇˇ ˇipsum", cx);
561        assert("ˇloremˇˇ, ipsum", cx);
562    }
563
564    #[gpui::test]
565    fn test_move_up_and_down_with_excerpts(cx: &mut gpui::MutableAppContext) {
566        cx.set_global(Settings::test(cx));
567        let family_id = cx.font_cache().load_family(&["Helvetica"]).unwrap();
568        let font_id = cx
569            .font_cache()
570            .select_font(family_id, &Default::default())
571            .unwrap();
572
573        let buffer = cx.add_model(|cx| Buffer::new(0, "abc\ndefg\nhijkl\nmn", cx));
574        let multibuffer = cx.add_model(|cx| {
575            let mut multibuffer = MultiBuffer::new(0);
576            multibuffer.push_excerpts(
577                buffer.clone(),
578                [
579                    ExcerptRange {
580                        context: Point::new(0, 0)..Point::new(1, 4),
581                        primary: None,
582                    },
583                    ExcerptRange {
584                        context: Point::new(2, 0)..Point::new(3, 2),
585                        primary: None,
586                    },
587                ],
588                cx,
589            );
590            multibuffer
591        });
592        let display_map =
593            cx.add_model(|cx| DisplayMap::new(multibuffer, font_id, 14.0, None, 2, 2, cx));
594        let snapshot = display_map.update(cx, |map, cx| map.snapshot(cx));
595
596        assert_eq!(snapshot.text(), "\n\nabc\ndefg\n\n\nhijkl\nmn");
597
598        // Can't move up into the first excerpt's header
599        assert_eq!(
600            up(
601                &snapshot,
602                DisplayPoint::new(2, 2),
603                SelectionGoal::Column(2),
604                false
605            ),
606            (DisplayPoint::new(2, 0), SelectionGoal::Column(0)),
607        );
608        assert_eq!(
609            up(
610                &snapshot,
611                DisplayPoint::new(2, 0),
612                SelectionGoal::None,
613                false
614            ),
615            (DisplayPoint::new(2, 0), SelectionGoal::Column(0)),
616        );
617
618        // Move up and down within first excerpt
619        assert_eq!(
620            up(
621                &snapshot,
622                DisplayPoint::new(3, 4),
623                SelectionGoal::Column(4),
624                false
625            ),
626            (DisplayPoint::new(2, 3), SelectionGoal::Column(4)),
627        );
628        assert_eq!(
629            down(
630                &snapshot,
631                DisplayPoint::new(2, 3),
632                SelectionGoal::Column(4),
633                false
634            ),
635            (DisplayPoint::new(3, 4), SelectionGoal::Column(4)),
636        );
637
638        // Move up and down across second excerpt's header
639        assert_eq!(
640            up(
641                &snapshot,
642                DisplayPoint::new(6, 5),
643                SelectionGoal::Column(5),
644                false
645            ),
646            (DisplayPoint::new(3, 4), SelectionGoal::Column(5)),
647        );
648        assert_eq!(
649            down(
650                &snapshot,
651                DisplayPoint::new(3, 4),
652                SelectionGoal::Column(5),
653                false
654            ),
655            (DisplayPoint::new(6, 5), SelectionGoal::Column(5)),
656        );
657
658        // Can't move down off the end
659        assert_eq!(
660            down(
661                &snapshot,
662                DisplayPoint::new(7, 0),
663                SelectionGoal::Column(0),
664                false
665            ),
666            (DisplayPoint::new(7, 2), SelectionGoal::Column(2)),
667        );
668        assert_eq!(
669            down(
670                &snapshot,
671                DisplayPoint::new(7, 2),
672                SelectionGoal::Column(2),
673                false
674            ),
675            (DisplayPoint::new(7, 2), SelectionGoal::Column(2)),
676        );
677    }
678}