selections_collection.rs

  1use std::{
  2    cell::Ref,
  3    iter, mem,
  4    ops::{Deref, DerefMut, Range, Sub},
  5    sync::Arc,
  6};
  7
  8use collections::HashMap;
  9use gpui::{AppContext, ModelHandle};
 10use itertools::Itertools;
 11use language::{Bias, Point, Selection, SelectionGoal, TextDimension, ToPoint};
 12use util::post_inc;
 13
 14use crate::{
 15    display_map::{DisplayMap, DisplaySnapshot, ToDisplayPoint},
 16    movement::TextLayoutDetails,
 17    Anchor, DisplayPoint, ExcerptId, MultiBuffer, MultiBufferSnapshot, SelectMode, ToOffset,
 18};
 19
 20#[derive(Debug, Clone)]
 21pub struct PendingSelection {
 22    pub selection: Selection<Anchor>,
 23    pub mode: SelectMode,
 24}
 25
 26#[derive(Debug, Clone)]
 27pub struct SelectionsCollection {
 28    display_map: ModelHandle<DisplayMap>,
 29    buffer: ModelHandle<MultiBuffer>,
 30    pub next_selection_id: usize,
 31    pub line_mode: bool,
 32    disjoint: Arc<[Selection<Anchor>]>,
 33    pending: Option<PendingSelection>,
 34}
 35
 36impl SelectionsCollection {
 37    pub fn new(display_map: ModelHandle<DisplayMap>, buffer: ModelHandle<MultiBuffer>) -> Self {
 38        Self {
 39            display_map,
 40            buffer,
 41            next_selection_id: 1,
 42            line_mode: false,
 43            disjoint: Arc::from([]),
 44            pending: Some(PendingSelection {
 45                selection: Selection {
 46                    id: 0,
 47                    start: Anchor::min(),
 48                    end: Anchor::min(),
 49                    reversed: false,
 50                    goal: SelectionGoal::None,
 51                },
 52                mode: SelectMode::Character,
 53            }),
 54        }
 55    }
 56
 57    pub fn display_map(&self, cx: &mut AppContext) -> DisplaySnapshot {
 58        self.display_map.update(cx, |map, cx| map.snapshot(cx))
 59    }
 60
 61    fn buffer<'a>(&self, cx: &'a AppContext) -> Ref<'a, MultiBufferSnapshot> {
 62        self.buffer.read(cx).read(cx)
 63    }
 64
 65    pub fn clone_state(&mut self, other: &SelectionsCollection) {
 66        self.next_selection_id = other.next_selection_id;
 67        self.line_mode = other.line_mode;
 68        self.disjoint = other.disjoint.clone();
 69        self.pending = other.pending.clone();
 70    }
 71
 72    pub fn count(&self) -> usize {
 73        let mut count = self.disjoint.len();
 74        if self.pending.is_some() {
 75            count += 1;
 76        }
 77        count
 78    }
 79
 80    /// The non-pending, non-overlapping selections. There could still be a pending
 81    /// selection that overlaps these if the mouse is being dragged, etc. Returned as
 82    /// selections over Anchors.
 83    pub fn disjoint_anchors(&self) -> Arc<[Selection<Anchor>]> {
 84        self.disjoint.clone()
 85    }
 86
 87    pub fn pending_anchor(&self) -> Option<Selection<Anchor>> {
 88        self.pending
 89            .as_ref()
 90            .map(|pending| pending.selection.clone())
 91    }
 92
 93    pub fn pending<D: TextDimension + Ord + Sub<D, Output = D>>(
 94        &self,
 95        cx: &AppContext,
 96    ) -> Option<Selection<D>> {
 97        self.pending_anchor()
 98            .as_ref()
 99            .map(|pending| pending.map(|p| p.summary::<D>(&self.buffer(cx))))
100    }
101
102    pub fn pending_mode(&self) -> Option<SelectMode> {
103        self.pending.as_ref().map(|pending| pending.mode.clone())
104    }
105
106    pub fn all<'a, D>(&self, cx: &AppContext) -> Vec<Selection<D>>
107    where
108        D: 'a + TextDimension + Ord + Sub<D, Output = D> + std::fmt::Debug,
109    {
110        let disjoint_anchors = &self.disjoint;
111        let mut disjoint =
112            resolve_multiple::<D, _>(disjoint_anchors.iter(), &self.buffer(cx)).peekable();
113
114        let mut pending_opt = self.pending::<D>(cx);
115
116        iter::from_fn(move || {
117            if let Some(pending) = pending_opt.as_mut() {
118                while let Some(next_selection) = disjoint.peek() {
119                    if pending.start <= next_selection.end && pending.end >= next_selection.start {
120                        let next_selection = disjoint.next().unwrap();
121                        if next_selection.start < pending.start {
122                            pending.start = next_selection.start;
123                        }
124                        if next_selection.end > pending.end {
125                            pending.end = next_selection.end;
126                        }
127                    } else if next_selection.end < pending.start {
128                        return disjoint.next();
129                    } else {
130                        break;
131                    }
132                }
133
134                pending_opt.take()
135            } else {
136                disjoint.next()
137            }
138        })
139        .collect()
140    }
141
142    /// Returns all of the selections, adjusted to take into account the selection line_mode
143    pub fn all_adjusted(&self, cx: &mut AppContext) -> Vec<Selection<Point>> {
144        let mut selections = self.all::<Point>(cx);
145        if self.line_mode {
146            let map = self.display_map(cx);
147            for selection in &mut selections {
148                let new_range = map.expand_to_line(selection.range());
149                selection.start = new_range.start;
150                selection.end = new_range.end;
151            }
152        }
153        selections
154    }
155
156    pub fn all_adjusted_display(
157        &self,
158        cx: &mut AppContext,
159    ) -> (DisplaySnapshot, Vec<Selection<DisplayPoint>>) {
160        if self.line_mode {
161            let selections = self.all::<Point>(cx);
162            let map = self.display_map(cx);
163            let result = selections
164                .into_iter()
165                .map(|mut selection| {
166                    let new_range = map.expand_to_line(selection.range());
167                    selection.start = new_range.start;
168                    selection.end = new_range.end;
169                    selection.map(|point| point.to_display_point(&map))
170                })
171                .collect();
172            (map, result)
173        } else {
174            self.all_display(cx)
175        }
176    }
177
178    pub fn disjoint_in_range<'a, D>(
179        &self,
180        range: Range<Anchor>,
181        cx: &AppContext,
182    ) -> Vec<Selection<D>>
183    where
184        D: 'a + TextDimension + Ord + Sub<D, Output = D> + std::fmt::Debug,
185    {
186        let buffer = self.buffer(cx);
187        let start_ix = match self
188            .disjoint
189            .binary_search_by(|probe| probe.end.cmp(&range.start, &buffer))
190        {
191            Ok(ix) | Err(ix) => ix,
192        };
193        let end_ix = match self
194            .disjoint
195            .binary_search_by(|probe| probe.start.cmp(&range.end, &buffer))
196        {
197            Ok(ix) => ix + 1,
198            Err(ix) => ix,
199        };
200        resolve_multiple(&self.disjoint[start_ix..end_ix], &buffer).collect()
201    }
202
203    pub fn all_display(
204        &self,
205        cx: &mut AppContext,
206    ) -> (DisplaySnapshot, Vec<Selection<DisplayPoint>>) {
207        let display_map = self.display_map(cx);
208        let selections = self
209            .all::<Point>(cx)
210            .into_iter()
211            .map(|selection| selection.map(|point| point.to_display_point(&display_map)))
212            .collect();
213        (display_map, selections)
214    }
215
216    pub fn newest_anchor(&self) -> &Selection<Anchor> {
217        self.pending
218            .as_ref()
219            .map(|s| &s.selection)
220            .or_else(|| self.disjoint.iter().max_by_key(|s| s.id))
221            .unwrap()
222    }
223
224    pub fn newest<D: TextDimension + Ord + Sub<D, Output = D>>(
225        &self,
226        cx: &AppContext,
227    ) -> Selection<D> {
228        resolve(self.newest_anchor(), &self.buffer(cx))
229    }
230
231    pub fn newest_display(&self, cx: &mut AppContext) -> Selection<DisplayPoint> {
232        let display_map = self.display_map(cx);
233        let selection = self
234            .newest_anchor()
235            .map(|point| point.to_display_point(&display_map));
236        selection
237    }
238
239    pub fn oldest_anchor(&self) -> &Selection<Anchor> {
240        self.disjoint
241            .iter()
242            .min_by_key(|s| s.id)
243            .or_else(|| self.pending.as_ref().map(|p| &p.selection))
244            .unwrap()
245    }
246
247    pub fn oldest<D: TextDimension + Ord + Sub<D, Output = D>>(
248        &self,
249        cx: &AppContext,
250    ) -> Selection<D> {
251        resolve(self.oldest_anchor(), &self.buffer(cx))
252    }
253
254    pub fn first_anchor(&self) -> Selection<Anchor> {
255        self.disjoint[0].clone()
256    }
257
258    pub fn first<D: TextDimension + Ord + Sub<D, Output = D>>(
259        &self,
260        cx: &AppContext,
261    ) -> Selection<D> {
262        self.all(cx).first().unwrap().clone()
263    }
264
265    pub fn last<D: TextDimension + Ord + Sub<D, Output = D>>(
266        &self,
267        cx: &AppContext,
268    ) -> Selection<D> {
269        self.all(cx).last().unwrap().clone()
270    }
271
272    #[cfg(any(test, feature = "test-support"))]
273    pub fn ranges<D: TextDimension + Ord + Sub<D, Output = D> + std::fmt::Debug>(
274        &self,
275        cx: &AppContext,
276    ) -> Vec<Range<D>> {
277        self.all::<D>(cx)
278            .iter()
279            .map(|s| {
280                if s.reversed {
281                    s.end.clone()..s.start.clone()
282                } else {
283                    s.start.clone()..s.end.clone()
284                }
285            })
286            .collect()
287    }
288
289    #[cfg(any(test, feature = "test-support"))]
290    pub fn display_ranges(&self, cx: &mut AppContext) -> Vec<Range<DisplayPoint>> {
291        let display_map = self.display_map(cx);
292        self.disjoint_anchors()
293            .iter()
294            .chain(self.pending_anchor().as_ref())
295            .map(|s| {
296                if s.reversed {
297                    s.end.to_display_point(&display_map)..s.start.to_display_point(&display_map)
298                } else {
299                    s.start.to_display_point(&display_map)..s.end.to_display_point(&display_map)
300                }
301            })
302            .collect()
303    }
304
305    pub fn build_columnar_selection(
306        &mut self,
307        display_map: &DisplaySnapshot,
308        row: u32,
309        positions: &Range<f32>,
310        reversed: bool,
311        text_layout_details: &TextLayoutDetails,
312    ) -> Option<Selection<Point>> {
313        let is_empty = positions.start == positions.end;
314        let line_len = display_map.line_len(row);
315
316        let start_col = display_map.column_for_x(row, positions.start, text_layout_details);
317        if start_col < line_len || (is_empty && start_col == line_len) {
318            let start = DisplayPoint::new(row, start_col);
319            let end_col = display_map.column_for_x(row, positions.end, text_layout_details);
320            let end = DisplayPoint::new(row, end_col);
321
322            Some(Selection {
323                id: post_inc(&mut self.next_selection_id),
324                start: start.to_point(display_map),
325                end: end.to_point(display_map),
326                reversed,
327                goal: SelectionGoal::HorizontalRange {
328                    start: positions.start,
329                    end: positions.end,
330                },
331            })
332        } else {
333            None
334        }
335    }
336
337    pub(crate) fn change_with<R>(
338        &mut self,
339        cx: &mut AppContext,
340        change: impl FnOnce(&mut MutableSelectionsCollection) -> R,
341    ) -> (bool, R) {
342        let mut mutable_collection = MutableSelectionsCollection {
343            collection: self,
344            selections_changed: false,
345            cx,
346        };
347
348        let result = change(&mut mutable_collection);
349        assert!(
350            !mutable_collection.disjoint.is_empty() || mutable_collection.pending.is_some(),
351            "There must be at least one selection"
352        );
353        (mutable_collection.selections_changed, result)
354    }
355}
356
357pub struct MutableSelectionsCollection<'a> {
358    collection: &'a mut SelectionsCollection,
359    selections_changed: bool,
360    cx: &'a mut AppContext,
361}
362
363impl<'a> MutableSelectionsCollection<'a> {
364    pub fn display_map(&mut self) -> DisplaySnapshot {
365        self.collection.display_map(self.cx)
366    }
367
368    fn buffer(&self) -> Ref<MultiBufferSnapshot> {
369        self.collection.buffer(self.cx)
370    }
371
372    pub fn clear_disjoint(&mut self) {
373        self.collection.disjoint = Arc::from([]);
374    }
375
376    pub fn delete(&mut self, selection_id: usize) {
377        let mut changed = false;
378        self.collection.disjoint = self
379            .disjoint
380            .iter()
381            .filter(|selection| {
382                let found = selection.id == selection_id;
383                changed |= found;
384                !found
385            })
386            .cloned()
387            .collect();
388
389        self.selections_changed |= changed;
390    }
391
392    pub fn clear_pending(&mut self) {
393        if self.collection.pending.is_some() {
394            self.collection.pending = None;
395            self.selections_changed = true;
396        }
397    }
398
399    pub fn set_pending_anchor_range(&mut self, range: Range<Anchor>, mode: SelectMode) {
400        self.collection.pending = Some(PendingSelection {
401            selection: Selection {
402                id: post_inc(&mut self.collection.next_selection_id),
403                start: range.start,
404                end: range.end,
405                reversed: false,
406                goal: SelectionGoal::None,
407            },
408            mode,
409        });
410        self.selections_changed = true;
411    }
412
413    pub fn set_pending_display_range(&mut self, range: Range<DisplayPoint>, mode: SelectMode) {
414        let (start, end, reversed) = {
415            let display_map = self.display_map();
416            let buffer = self.buffer();
417            let mut start = range.start;
418            let mut end = range.end;
419            let reversed = if start > end {
420                mem::swap(&mut start, &mut end);
421                true
422            } else {
423                false
424            };
425
426            let end_bias = if end > start { Bias::Left } else { Bias::Right };
427            (
428                buffer.anchor_before(start.to_point(&display_map)),
429                buffer.anchor_at(end.to_point(&display_map), end_bias),
430                reversed,
431            )
432        };
433
434        let new_pending = PendingSelection {
435            selection: Selection {
436                id: post_inc(&mut self.collection.next_selection_id),
437                start,
438                end,
439                reversed,
440                goal: SelectionGoal::None,
441            },
442            mode,
443        };
444
445        self.collection.pending = Some(new_pending);
446        self.selections_changed = true;
447    }
448
449    pub fn set_pending(&mut self, selection: Selection<Anchor>, mode: SelectMode) {
450        self.collection.pending = Some(PendingSelection { selection, mode });
451        self.selections_changed = true;
452    }
453
454    pub fn try_cancel(&mut self) -> bool {
455        if let Some(pending) = self.collection.pending.take() {
456            if self.disjoint.is_empty() {
457                self.collection.disjoint = Arc::from([pending.selection]);
458            }
459            self.selections_changed = true;
460            return true;
461        }
462
463        let mut oldest = self.oldest_anchor().clone();
464        if self.count() > 1 {
465            self.collection.disjoint = Arc::from([oldest]);
466            self.selections_changed = true;
467            return true;
468        }
469
470        if !oldest.start.cmp(&oldest.end, &self.buffer()).is_eq() {
471            let head = oldest.head();
472            oldest.start = head.clone();
473            oldest.end = head;
474            self.collection.disjoint = Arc::from([oldest]);
475            self.selections_changed = true;
476            return true;
477        }
478
479        false
480    }
481
482    pub fn insert_range<T>(&mut self, range: Range<T>)
483    where
484        T: 'a + ToOffset + ToPoint + TextDimension + Ord + Sub<T, Output = T> + std::marker::Copy,
485    {
486        let mut selections = self.all(self.cx);
487        let mut start = range.start.to_offset(&self.buffer());
488        let mut end = range.end.to_offset(&self.buffer());
489        let reversed = if start > end {
490            mem::swap(&mut start, &mut end);
491            true
492        } else {
493            false
494        };
495        selections.push(Selection {
496            id: post_inc(&mut self.collection.next_selection_id),
497            start,
498            end,
499            reversed,
500            goal: SelectionGoal::None,
501        });
502        self.select(selections);
503    }
504
505    pub fn select<T>(&mut self, mut selections: Vec<Selection<T>>)
506    where
507        T: ToOffset + ToPoint + Ord + std::marker::Copy + std::fmt::Debug,
508    {
509        let buffer = self.buffer.read(self.cx).snapshot(self.cx);
510        selections.sort_unstable_by_key(|s| s.start);
511        // Merge overlapping selections.
512        let mut i = 1;
513        while i < selections.len() {
514            if selections[i - 1].end >= selections[i].start {
515                let removed = selections.remove(i);
516                if removed.start < selections[i - 1].start {
517                    selections[i - 1].start = removed.start;
518                }
519                if removed.end > selections[i - 1].end {
520                    selections[i - 1].end = removed.end;
521                }
522            } else {
523                i += 1;
524            }
525        }
526
527        self.collection.disjoint = Arc::from_iter(selections.into_iter().map(|selection| {
528            let end_bias = if selection.end > selection.start {
529                Bias::Left
530            } else {
531                Bias::Right
532            };
533            Selection {
534                id: selection.id,
535                start: buffer.anchor_after(selection.start),
536                end: buffer.anchor_at(selection.end, end_bias),
537                reversed: selection.reversed,
538                goal: selection.goal,
539            }
540        }));
541
542        self.collection.pending = None;
543        self.selections_changed = true;
544    }
545
546    pub fn select_anchors(&mut self, selections: Vec<Selection<Anchor>>) {
547        let buffer = self.buffer.read(self.cx).snapshot(self.cx);
548        let resolved_selections =
549            resolve_multiple::<usize, _>(&selections, &buffer).collect::<Vec<_>>();
550        self.select(resolved_selections);
551    }
552
553    pub fn select_ranges<I, T>(&mut self, ranges: I)
554    where
555        I: IntoIterator<Item = Range<T>>,
556        T: ToOffset,
557    {
558        let buffer = self.buffer.read(self.cx).snapshot(self.cx);
559        let ranges = ranges
560            .into_iter()
561            .map(|range| range.start.to_offset(&buffer)..range.end.to_offset(&buffer));
562        self.select_offset_ranges(ranges);
563    }
564
565    fn select_offset_ranges<I>(&mut self, ranges: I)
566    where
567        I: IntoIterator<Item = Range<usize>>,
568    {
569        let selections = ranges
570            .into_iter()
571            .map(|range| {
572                let mut start = range.start;
573                let mut end = range.end;
574                let reversed = if start > end {
575                    mem::swap(&mut start, &mut end);
576                    true
577                } else {
578                    false
579                };
580                Selection {
581                    id: post_inc(&mut self.collection.next_selection_id),
582                    start,
583                    end,
584                    reversed,
585                    goal: SelectionGoal::None,
586                }
587            })
588            .collect::<Vec<_>>();
589
590        self.select(selections)
591    }
592
593    pub fn select_anchor_ranges<I: IntoIterator<Item = Range<Anchor>>>(&mut self, ranges: I) {
594        let buffer = self.buffer.read(self.cx).snapshot(self.cx);
595        let selections = ranges
596            .into_iter()
597            .map(|range| {
598                let mut start = range.start;
599                let mut end = range.end;
600                let reversed = if start.cmp(&end, &buffer).is_gt() {
601                    mem::swap(&mut start, &mut end);
602                    true
603                } else {
604                    false
605                };
606                Selection {
607                    id: post_inc(&mut self.collection.next_selection_id),
608                    start,
609                    end,
610                    reversed,
611                    goal: SelectionGoal::None,
612                }
613            })
614            .collect::<Vec<_>>();
615
616        self.select_anchors(selections)
617    }
618
619    pub fn new_selection_id(&mut self) -> usize {
620        post_inc(&mut self.next_selection_id)
621    }
622
623    pub fn select_display_ranges<T>(&mut self, ranges: T)
624    where
625        T: IntoIterator<Item = Range<DisplayPoint>>,
626    {
627        let display_map = self.display_map();
628        let selections = ranges
629            .into_iter()
630            .map(|range| {
631                let mut start = range.start;
632                let mut end = range.end;
633                let reversed = if start > end {
634                    mem::swap(&mut start, &mut end);
635                    true
636                } else {
637                    false
638                };
639                Selection {
640                    id: post_inc(&mut self.collection.next_selection_id),
641                    start: start.to_point(&display_map),
642                    end: end.to_point(&display_map),
643                    reversed,
644                    goal: SelectionGoal::None,
645                }
646            })
647            .collect();
648        self.select(selections);
649    }
650
651    pub fn move_with(
652        &mut self,
653        mut move_selection: impl FnMut(&DisplaySnapshot, &mut Selection<DisplayPoint>),
654    ) {
655        let mut changed = false;
656        let display_map = self.display_map();
657        let selections = self
658            .all::<Point>(self.cx)
659            .into_iter()
660            .map(|selection| {
661                let mut moved_selection =
662                    selection.map(|point| point.to_display_point(&display_map));
663                move_selection(&display_map, &mut moved_selection);
664                let moved_selection =
665                    moved_selection.map(|display_point| display_point.to_point(&display_map));
666                if selection != moved_selection {
667                    changed = true;
668                }
669                moved_selection
670            })
671            .collect();
672
673        if changed {
674            self.select(selections)
675        }
676    }
677
678    pub fn move_offsets_with(
679        &mut self,
680        mut move_selection: impl FnMut(&MultiBufferSnapshot, &mut Selection<usize>),
681    ) {
682        let mut changed = false;
683        let snapshot = self.buffer().clone();
684        let selections = self
685            .all::<usize>(self.cx)
686            .into_iter()
687            .map(|selection| {
688                let mut moved_selection = selection.clone();
689                move_selection(&snapshot, &mut moved_selection);
690                if selection != moved_selection {
691                    changed = true;
692                }
693                moved_selection
694            })
695            .collect();
696        drop(snapshot);
697
698        if changed {
699            self.select(selections)
700        }
701    }
702
703    pub fn move_heads_with(
704        &mut self,
705        mut update_head: impl FnMut(
706            &DisplaySnapshot,
707            DisplayPoint,
708            SelectionGoal,
709        ) -> (DisplayPoint, SelectionGoal),
710    ) {
711        self.move_with(|map, selection| {
712            let (new_head, new_goal) = update_head(map, selection.head(), selection.goal);
713            selection.set_head(new_head, new_goal);
714        });
715    }
716
717    pub fn move_cursors_with(
718        &mut self,
719        mut update_cursor_position: impl FnMut(
720            &DisplaySnapshot,
721            DisplayPoint,
722            SelectionGoal,
723        ) -> (DisplayPoint, SelectionGoal),
724    ) {
725        self.move_with(|map, selection| {
726            let (cursor, new_goal) = update_cursor_position(map, selection.head(), selection.goal);
727            selection.collapse_to(cursor, new_goal)
728        });
729    }
730
731    pub fn maybe_move_cursors_with(
732        &mut self,
733        mut update_cursor_position: impl FnMut(
734            &DisplaySnapshot,
735            DisplayPoint,
736            SelectionGoal,
737        ) -> Option<(DisplayPoint, SelectionGoal)>,
738    ) {
739        self.move_cursors_with(|map, point, goal| {
740            update_cursor_position(map, point, goal).unwrap_or((point, goal))
741        })
742    }
743
744    pub fn replace_cursors_with(
745        &mut self,
746        mut find_replacement_cursors: impl FnMut(&DisplaySnapshot) -> Vec<DisplayPoint>,
747    ) {
748        let display_map = self.display_map();
749        let new_selections = find_replacement_cursors(&display_map)
750            .into_iter()
751            .map(|cursor| {
752                let cursor_point = cursor.to_point(&display_map);
753                Selection {
754                    id: post_inc(&mut self.collection.next_selection_id),
755                    start: cursor_point,
756                    end: cursor_point,
757                    reversed: false,
758                    goal: SelectionGoal::None,
759                }
760            })
761            .collect();
762        self.select(new_selections);
763    }
764
765    /// Compute new ranges for any selections that were located in excerpts that have
766    /// since been removed.
767    ///
768    /// Returns a `HashMap` indicating which selections whose former head position
769    /// was no longer present. The keys of the map are selection ids. The values are
770    /// the id of the new excerpt where the head of the selection has been moved.
771    pub fn refresh(&mut self) -> HashMap<usize, ExcerptId> {
772        let mut pending = self.collection.pending.take();
773        let mut selections_with_lost_position = HashMap::default();
774
775        let anchors_with_status = {
776            let buffer = self.buffer();
777            let disjoint_anchors = self
778                .disjoint
779                .iter()
780                .flat_map(|selection| [&selection.start, &selection.end]);
781            buffer.refresh_anchors(disjoint_anchors)
782        };
783        let adjusted_disjoint: Vec<_> = anchors_with_status
784            .chunks(2)
785            .map(|selection_anchors| {
786                let (anchor_ix, start, kept_start) = selection_anchors[0].clone();
787                let (_, end, kept_end) = selection_anchors[1].clone();
788                let selection = &self.disjoint[anchor_ix / 2];
789                let kept_head = if selection.reversed {
790                    kept_start
791                } else {
792                    kept_end
793                };
794                if !kept_head {
795                    selections_with_lost_position.insert(selection.id, selection.head().excerpt_id);
796                }
797
798                Selection {
799                    id: selection.id,
800                    start,
801                    end,
802                    reversed: selection.reversed,
803                    goal: selection.goal,
804                }
805            })
806            .collect();
807
808        if !adjusted_disjoint.is_empty() {
809            let resolved_selections =
810                resolve_multiple(adjusted_disjoint.iter(), &self.buffer()).collect();
811            self.select::<usize>(resolved_selections);
812        }
813
814        if let Some(pending) = pending.as_mut() {
815            let buffer = self.buffer();
816            let anchors =
817                buffer.refresh_anchors([&pending.selection.start, &pending.selection.end]);
818            let (_, start, kept_start) = anchors[0].clone();
819            let (_, end, kept_end) = anchors[1].clone();
820            let kept_head = if pending.selection.reversed {
821                kept_start
822            } else {
823                kept_end
824            };
825            if !kept_head {
826                selections_with_lost_position
827                    .insert(pending.selection.id, pending.selection.head().excerpt_id);
828            }
829
830            pending.selection.start = start;
831            pending.selection.end = end;
832        }
833        self.collection.pending = pending;
834        self.selections_changed = true;
835
836        selections_with_lost_position
837    }
838}
839
840impl<'a> Deref for MutableSelectionsCollection<'a> {
841    type Target = SelectionsCollection;
842    fn deref(&self) -> &Self::Target {
843        self.collection
844    }
845}
846
847impl<'a> DerefMut for MutableSelectionsCollection<'a> {
848    fn deref_mut(&mut self) -> &mut Self::Target {
849        self.collection
850    }
851}
852
853// Panics if passed selections are not in order
854pub fn resolve_multiple<'a, D, I>(
855    selections: I,
856    snapshot: &MultiBufferSnapshot,
857) -> impl 'a + Iterator<Item = Selection<D>>
858where
859    D: TextDimension + Ord + Sub<D, Output = D> + std::fmt::Debug,
860    I: 'a + IntoIterator<Item = &'a Selection<Anchor>>,
861{
862    let (to_summarize, selections) = selections.into_iter().tee();
863    let mut summaries = snapshot
864        .summaries_for_anchors::<D, _>(
865            to_summarize
866                .flat_map(|s| [&s.start, &s.end])
867                .collect::<Vec<_>>(),
868        )
869        .into_iter();
870    selections.map(move |s| Selection {
871        id: s.id,
872        start: summaries.next().unwrap(),
873        end: summaries.next().unwrap(),
874        reversed: s.reversed,
875        goal: s.goal,
876    })
877}
878
879fn resolve<D: TextDimension + Ord + Sub<D, Output = D>>(
880    selection: &Selection<Anchor>,
881    buffer: &MultiBufferSnapshot,
882) -> Selection<D> {
883    selection.map(|p| p.summary::<D>(buffer))
884}