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