scroll.rs

  1mod actions;
  2pub(crate) mod autoscroll;
  3pub(crate) mod scroll_amount;
  4
  5use crate::editor_settings::ScrollBeyondLastLine;
  6use crate::{
  7    Anchor, DisplayPoint, DisplayRow, Editor, EditorEvent, EditorMode, EditorSettings,
  8    InlayHintRefreshReason, MultiBufferSnapshot, RowExt, ToPoint,
  9    display_map::{DisplaySnapshot, ToDisplayPoint},
 10    hover_popover::hide_hover,
 11    persistence::DB,
 12};
 13pub use autoscroll::{Autoscroll, AutoscrollStrategy};
 14use core::fmt::Debug;
 15use gpui::{App, Axis, Context, Global, Pixels, Task, Window, point, px};
 16use language::{Bias, Point};
 17pub use scroll_amount::ScrollAmount;
 18use settings::Settings;
 19use std::{
 20    cmp::Ordering,
 21    time::{Duration, Instant},
 22};
 23use util::ResultExt;
 24use workspace::{ItemId, WorkspaceId};
 25
 26pub const SCROLL_EVENT_SEPARATION: Duration = Duration::from_millis(28);
 27const SCROLLBAR_SHOW_INTERVAL: Duration = Duration::from_secs(1);
 28
 29#[derive(Default)]
 30pub struct ScrollbarAutoHide(pub bool);
 31
 32impl Global for ScrollbarAutoHide {}
 33
 34#[derive(Clone, Copy, Debug, PartialEq)]
 35pub struct ScrollAnchor {
 36    pub offset: gpui::Point<f32>,
 37    pub anchor: Anchor,
 38}
 39
 40impl ScrollAnchor {
 41    pub(super) fn new() -> Self {
 42        Self {
 43            offset: gpui::Point::default(),
 44            anchor: Anchor::min(),
 45        }
 46    }
 47
 48    pub fn scroll_position(&self, snapshot: &DisplaySnapshot) -> gpui::Point<f32> {
 49        let mut scroll_position = self.offset;
 50        if self.anchor == Anchor::min() {
 51            scroll_position.y = 0.;
 52        } else {
 53            let scroll_top = self.anchor.to_display_point(snapshot).row().as_f32();
 54            scroll_position.y += scroll_top;
 55        }
 56        scroll_position
 57    }
 58
 59    pub fn top_row(&self, buffer: &MultiBufferSnapshot) -> u32 {
 60        self.anchor.to_point(buffer).row
 61    }
 62}
 63
 64#[derive(Clone, Copy, Debug)]
 65pub struct OngoingScroll {
 66    last_event: Instant,
 67    axis: Option<Axis>,
 68}
 69
 70impl OngoingScroll {
 71    fn new() -> Self {
 72        Self {
 73            last_event: Instant::now() - SCROLL_EVENT_SEPARATION,
 74            axis: None,
 75        }
 76    }
 77
 78    pub fn filter(&self, delta: &mut gpui::Point<Pixels>) -> Option<Axis> {
 79        const UNLOCK_PERCENT: f32 = 1.9;
 80        const UNLOCK_LOWER_BOUND: Pixels = px(6.);
 81        let mut axis = self.axis;
 82
 83        let x = delta.x.abs();
 84        let y = delta.y.abs();
 85        let duration = Instant::now().duration_since(self.last_event);
 86        if duration > SCROLL_EVENT_SEPARATION {
 87            //New ongoing scroll will start, determine axis
 88            axis = if x <= y {
 89                Some(Axis::Vertical)
 90            } else {
 91                Some(Axis::Horizontal)
 92            };
 93        } else if x.max(y) >= UNLOCK_LOWER_BOUND {
 94            //Check if the current ongoing will need to unlock
 95            match axis {
 96                Some(Axis::Vertical) => {
 97                    if x > y && x >= y * UNLOCK_PERCENT {
 98                        axis = None;
 99                    }
100                }
101
102                Some(Axis::Horizontal) => {
103                    if y > x && y >= x * UNLOCK_PERCENT {
104                        axis = None;
105                    }
106                }
107
108                None => {}
109            }
110        }
111
112        match axis {
113            Some(Axis::Vertical) => {
114                *delta = point(px(0.), delta.y);
115            }
116            Some(Axis::Horizontal) => {
117                *delta = point(delta.x, px(0.));
118            }
119            None => {}
120        }
121
122        axis
123    }
124}
125
126#[derive(Copy, Clone, PartialEq, Eq)]
127pub enum ScrollbarThumbState {
128    Idle,
129    Hovered,
130    Dragging,
131}
132
133#[derive(PartialEq, Eq)]
134pub struct ActiveScrollbarState {
135    axis: Axis,
136    thumb_state: ScrollbarThumbState,
137}
138
139impl ActiveScrollbarState {
140    pub fn new(axis: Axis, thumb_state: ScrollbarThumbState) -> Self {
141        ActiveScrollbarState { axis, thumb_state }
142    }
143
144    pub fn thumb_state_for_axis(&self, axis: Axis) -> Option<ScrollbarThumbState> {
145        (self.axis == axis).then_some(self.thumb_state)
146    }
147}
148
149pub struct ScrollManager {
150    pub(crate) vertical_scroll_margin: f32,
151    anchor: ScrollAnchor,
152    ongoing: OngoingScroll,
153    autoscroll_request: Option<(Autoscroll, bool)>,
154    last_autoscroll: Option<(gpui::Point<f32>, f32, f32, AutoscrollStrategy)>,
155    show_scrollbars: bool,
156    hide_scrollbar_task: Option<Task<()>>,
157    active_scrollbar: Option<ActiveScrollbarState>,
158    visible_line_count: Option<f32>,
159    forbid_vertical_scroll: bool,
160    dragging_minimap: bool,
161    show_minimap_thumb: bool,
162}
163
164impl ScrollManager {
165    pub fn new(cx: &mut App) -> Self {
166        ScrollManager {
167            vertical_scroll_margin: EditorSettings::get_global(cx).vertical_scroll_margin,
168            anchor: ScrollAnchor::new(),
169            ongoing: OngoingScroll::new(),
170            autoscroll_request: None,
171            show_scrollbars: true,
172            hide_scrollbar_task: None,
173            active_scrollbar: None,
174            last_autoscroll: None,
175            visible_line_count: None,
176            forbid_vertical_scroll: false,
177            dragging_minimap: false,
178            show_minimap_thumb: false,
179        }
180    }
181
182    pub fn clone_state(&mut self, other: &Self) {
183        self.anchor = other.anchor;
184        self.ongoing = other.ongoing;
185    }
186
187    pub fn anchor(&self) -> ScrollAnchor {
188        self.anchor
189    }
190
191    pub fn ongoing_scroll(&self) -> OngoingScroll {
192        self.ongoing
193    }
194
195    pub fn update_ongoing_scroll(&mut self, axis: Option<Axis>) {
196        self.ongoing.last_event = Instant::now();
197        self.ongoing.axis = axis;
198    }
199
200    pub fn scroll_position(&self, snapshot: &DisplaySnapshot) -> gpui::Point<f32> {
201        self.anchor.scroll_position(snapshot)
202    }
203
204    fn set_scroll_position(
205        &mut self,
206        scroll_position: gpui::Point<f32>,
207        map: &DisplaySnapshot,
208        local: bool,
209        autoscroll: bool,
210        workspace_id: Option<WorkspaceId>,
211        window: &mut Window,
212        cx: &mut Context<Editor>,
213    ) {
214        let (new_anchor, top_row) = if scroll_position.y <= 0. {
215            (
216                ScrollAnchor {
217                    anchor: Anchor::min(),
218                    offset: scroll_position.max(&gpui::Point::default()),
219                },
220                0,
221            )
222        } else {
223            let scroll_top = scroll_position.y;
224            let scroll_top = match EditorSettings::get_global(cx).scroll_beyond_last_line {
225                ScrollBeyondLastLine::OnePage => scroll_top,
226                ScrollBeyondLastLine::Off => {
227                    if let Some(height_in_lines) = self.visible_line_count {
228                        let max_row = map.max_point().row().0 as f32;
229                        scroll_top.min(max_row - height_in_lines + 1.).max(0.)
230                    } else {
231                        scroll_top
232                    }
233                }
234                ScrollBeyondLastLine::VerticalScrollMargin => {
235                    if let Some(height_in_lines) = self.visible_line_count {
236                        let max_row = map.max_point().row().0 as f32;
237                        scroll_top
238                            .min(max_row - height_in_lines + 1. + self.vertical_scroll_margin)
239                            .max(0.)
240                    } else {
241                        scroll_top
242                    }
243                }
244            };
245
246            let scroll_top_buffer_point =
247                DisplayPoint::new(DisplayRow(scroll_top as u32), 0).to_point(map);
248            let top_anchor = map
249                .buffer_snapshot
250                .anchor_at(scroll_top_buffer_point, Bias::Right);
251
252            (
253                ScrollAnchor {
254                    anchor: top_anchor,
255                    offset: point(
256                        scroll_position.x.max(0.),
257                        scroll_top - top_anchor.to_display_point(map).row().as_f32(),
258                    ),
259                },
260                scroll_top_buffer_point.row,
261            )
262        };
263
264        self.set_anchor(
265            new_anchor,
266            top_row,
267            local,
268            autoscroll,
269            workspace_id,
270            window,
271            cx,
272        );
273    }
274
275    fn set_anchor(
276        &mut self,
277        anchor: ScrollAnchor,
278        top_row: u32,
279        local: bool,
280        autoscroll: bool,
281        workspace_id: Option<WorkspaceId>,
282        window: &mut Window,
283        cx: &mut Context<Editor>,
284    ) {
285        let adjusted_anchor = if self.forbid_vertical_scroll {
286            ScrollAnchor {
287                offset: gpui::Point::new(anchor.offset.x, self.anchor.offset.y),
288                anchor: self.anchor.anchor,
289            }
290        } else {
291            anchor
292        };
293
294        self.anchor = adjusted_anchor;
295        cx.emit(EditorEvent::ScrollPositionChanged { local, autoscroll });
296        self.show_scrollbars(window, cx);
297        self.autoscroll_request.take();
298        if let Some(workspace_id) = workspace_id {
299            let item_id = cx.entity().entity_id().as_u64() as ItemId;
300
301            cx.foreground_executor()
302                .spawn(async move {
303                    log::debug!(
304                        "Saving scroll position for item {item_id:?} in workspace {workspace_id:?}"
305                    );
306                    DB.save_scroll_position(
307                        item_id,
308                        workspace_id,
309                        top_row,
310                        anchor.offset.x,
311                        anchor.offset.y,
312                    )
313                    .await
314                    .log_err()
315                })
316                .detach()
317        }
318        cx.notify();
319    }
320
321    pub fn show_scrollbars(&mut self, window: &mut Window, cx: &mut Context<Editor>) {
322        if !self.show_scrollbars {
323            self.show_scrollbars = true;
324            cx.notify();
325        }
326
327        if cx.default_global::<ScrollbarAutoHide>().0 {
328            self.hide_scrollbar_task = Some(cx.spawn_in(window, async move |editor, cx| {
329                cx.background_executor()
330                    .timer(SCROLLBAR_SHOW_INTERVAL)
331                    .await;
332                editor
333                    .update(cx, |editor, cx| {
334                        editor.scroll_manager.show_scrollbars = false;
335                        cx.notify();
336                    })
337                    .log_err();
338            }));
339        } else {
340            self.hide_scrollbar_task = None;
341        }
342    }
343
344    pub fn scrollbars_visible(&self) -> bool {
345        self.show_scrollbars
346    }
347
348    pub fn show_minimap_thumb(&mut self, cx: &mut Context<Editor>) {
349        if !self.show_minimap_thumb {
350            self.show_minimap_thumb = true;
351            cx.notify();
352        }
353    }
354
355    pub fn hide_minimap_thumb(&mut self, cx: &mut Context<Editor>) {
356        if self.show_minimap_thumb {
357            self.show_minimap_thumb = false;
358            cx.notify();
359        }
360    }
361
362    pub fn minimap_thumb_visible(&mut self) -> bool {
363        self.show_minimap_thumb
364    }
365
366    pub fn autoscroll_request(&self) -> Option<Autoscroll> {
367        self.autoscroll_request.map(|(autoscroll, _)| autoscroll)
368    }
369
370    pub fn active_scrollbar_state(&self) -> Option<&ActiveScrollbarState> {
371        self.active_scrollbar.as_ref()
372    }
373
374    pub fn dragging_scrollbar_axis(&self) -> Option<Axis> {
375        self.active_scrollbar
376            .as_ref()
377            .map(|scrollbar| scrollbar.axis)
378    }
379
380    pub fn any_scrollbar_dragged(&self) -> bool {
381        self.active_scrollbar
382            .as_ref()
383            .is_some_and(|scrollbar| scrollbar.thumb_state == ScrollbarThumbState::Dragging)
384    }
385
386    pub fn set_hovered_scroll_thumb_axis(&mut self, axis: Axis, cx: &mut Context<Editor>) {
387        self.update_active_scrollbar_state(
388            Some(ActiveScrollbarState::new(
389                axis,
390                ScrollbarThumbState::Hovered,
391            )),
392            cx,
393        );
394    }
395
396    pub fn set_dragged_scroll_thumb_axis(&mut self, axis: Axis, cx: &mut Context<Editor>) {
397        self.update_active_scrollbar_state(
398            Some(ActiveScrollbarState::new(
399                axis,
400                ScrollbarThumbState::Dragging,
401            )),
402            cx,
403        );
404    }
405
406    pub fn reset_scrollbar_state(&mut self, cx: &mut Context<Editor>) {
407        self.update_active_scrollbar_state(None, cx);
408    }
409
410    fn update_active_scrollbar_state(
411        &mut self,
412        new_state: Option<ActiveScrollbarState>,
413        cx: &mut Context<Editor>,
414    ) {
415        if self.active_scrollbar != new_state {
416            self.active_scrollbar = new_state;
417            cx.notify();
418        }
419    }
420
421    pub fn is_dragging_minimap(&self) -> bool {
422        self.dragging_minimap
423    }
424
425    pub fn set_is_dragging_minimap(&mut self, dragging: bool, cx: &mut Context<Editor>) {
426        self.dragging_minimap = dragging;
427        cx.notify();
428    }
429
430    pub fn clamp_scroll_left(&mut self, max: f32) -> bool {
431        if max < self.anchor.offset.x {
432            self.anchor.offset.x = max;
433            true
434        } else {
435            false
436        }
437    }
438
439    pub fn set_forbid_vertical_scroll(&mut self, forbid: bool) {
440        self.forbid_vertical_scroll = forbid;
441    }
442
443    pub fn forbid_vertical_scroll(&self) -> bool {
444        self.forbid_vertical_scroll
445    }
446}
447
448impl Editor {
449    pub fn vertical_scroll_margin(&self) -> usize {
450        self.scroll_manager.vertical_scroll_margin as usize
451    }
452
453    pub fn set_vertical_scroll_margin(&mut self, margin_rows: usize, cx: &mut Context<Self>) {
454        self.scroll_manager.vertical_scroll_margin = margin_rows as f32;
455        cx.notify();
456    }
457
458    pub fn visible_line_count(&self) -> Option<f32> {
459        self.scroll_manager.visible_line_count
460    }
461
462    pub fn visible_row_count(&self) -> Option<u32> {
463        self.visible_line_count()
464            .map(|line_count| line_count as u32 - 1)
465    }
466
467    pub(crate) fn set_visible_line_count(
468        &mut self,
469        lines: f32,
470        window: &mut Window,
471        cx: &mut Context<Self>,
472    ) {
473        let opened_first_time = self.scroll_manager.visible_line_count.is_none();
474        self.scroll_manager.visible_line_count = Some(lines);
475        if opened_first_time {
476            cx.spawn_in(window, async move |editor, cx| {
477                editor
478                    .update(cx, |editor, cx| {
479                        editor.refresh_inlay_hints(InlayHintRefreshReason::NewLinesShown, cx)
480                    })
481                    .ok()
482            })
483            .detach()
484        }
485    }
486
487    pub fn apply_scroll_delta(
488        &mut self,
489        scroll_delta: gpui::Point<f32>,
490        window: &mut Window,
491        cx: &mut Context<Self>,
492    ) {
493        let mut delta = scroll_delta;
494        if self.scroll_manager.forbid_vertical_scroll {
495            delta.y = 0.0;
496        }
497        let display_map = self.display_map.update(cx, |map, cx| map.snapshot(cx));
498        let position = self.scroll_manager.anchor.scroll_position(&display_map) + delta;
499        self.set_scroll_position_taking_display_map(position, true, false, display_map, window, cx);
500    }
501
502    pub fn set_scroll_position(
503        &mut self,
504        scroll_position: gpui::Point<f32>,
505        window: &mut Window,
506        cx: &mut Context<Self>,
507    ) {
508        let mut position = scroll_position;
509        if self.scroll_manager.forbid_vertical_scroll {
510            let current_position = self.scroll_position(cx);
511            position.y = current_position.y;
512        }
513        self.set_scroll_position_internal(position, true, false, window, cx);
514    }
515
516    /// Scrolls so that `row` is at the top of the editor view.
517    pub fn set_scroll_top_row(
518        &mut self,
519        row: DisplayRow,
520        window: &mut Window,
521        cx: &mut Context<Editor>,
522    ) {
523        let snapshot = self.snapshot(window, cx).display_snapshot;
524        let new_screen_top = DisplayPoint::new(row, 0);
525        let new_screen_top = new_screen_top.to_offset(&snapshot, Bias::Left);
526        let new_anchor = snapshot.buffer_snapshot.anchor_before(new_screen_top);
527
528        self.set_scroll_anchor(
529            ScrollAnchor {
530                anchor: new_anchor,
531                offset: Default::default(),
532            },
533            window,
534            cx,
535        );
536    }
537
538    pub(crate) fn set_scroll_position_internal(
539        &mut self,
540        scroll_position: gpui::Point<f32>,
541        local: bool,
542        autoscroll: bool,
543        window: &mut Window,
544        cx: &mut Context<Self>,
545    ) {
546        let map = self.display_map.update(cx, |map, cx| map.snapshot(cx));
547        self.set_scroll_position_taking_display_map(
548            scroll_position,
549            local,
550            autoscroll,
551            map,
552            window,
553            cx,
554        );
555    }
556
557    fn set_scroll_position_taking_display_map(
558        &mut self,
559        scroll_position: gpui::Point<f32>,
560        local: bool,
561        autoscroll: bool,
562        display_map: DisplaySnapshot,
563        window: &mut Window,
564        cx: &mut Context<Self>,
565    ) {
566        hide_hover(self, cx);
567        let workspace_id = self.workspace.as_ref().and_then(|workspace| workspace.1);
568
569        self.edit_prediction_preview
570            .set_previous_scroll_position(None);
571
572        let adjusted_position = if self.scroll_manager.forbid_vertical_scroll {
573            let current_position = self.scroll_manager.anchor.scroll_position(&display_map);
574            gpui::Point::new(scroll_position.x, current_position.y)
575        } else {
576            scroll_position
577        };
578
579        self.scroll_manager.set_scroll_position(
580            adjusted_position,
581            &display_map,
582            local,
583            autoscroll,
584            workspace_id,
585            window,
586            cx,
587        );
588
589        self.refresh_inlay_hints(InlayHintRefreshReason::NewLinesShown, cx);
590    }
591
592    pub fn scroll_position(&self, cx: &mut Context<Self>) -> gpui::Point<f32> {
593        let display_map = self.display_map.update(cx, |map, cx| map.snapshot(cx));
594        self.scroll_manager.anchor.scroll_position(&display_map)
595    }
596
597    pub fn set_scroll_anchor(
598        &mut self,
599        scroll_anchor: ScrollAnchor,
600        window: &mut Window,
601        cx: &mut Context<Self>,
602    ) {
603        hide_hover(self, cx);
604        let workspace_id = self.workspace.as_ref().and_then(|workspace| workspace.1);
605        let top_row = scroll_anchor
606            .anchor
607            .to_point(&self.buffer().read(cx).snapshot(cx))
608            .row;
609        self.scroll_manager.set_anchor(
610            scroll_anchor,
611            top_row,
612            true,
613            false,
614            workspace_id,
615            window,
616            cx,
617        );
618    }
619
620    pub(crate) fn set_scroll_anchor_remote(
621        &mut self,
622        scroll_anchor: ScrollAnchor,
623        window: &mut Window,
624        cx: &mut Context<Self>,
625    ) {
626        hide_hover(self, cx);
627        let workspace_id = self.workspace.as_ref().and_then(|workspace| workspace.1);
628        let snapshot = &self.buffer().read(cx).snapshot(cx);
629        if !scroll_anchor.anchor.is_valid(snapshot) {
630            log::warn!("Invalid scroll anchor: {:?}", scroll_anchor);
631            return;
632        }
633        let top_row = scroll_anchor.anchor.to_point(snapshot).row;
634        self.scroll_manager.set_anchor(
635            scroll_anchor,
636            top_row,
637            false,
638            false,
639            workspace_id,
640            window,
641            cx,
642        );
643    }
644
645    pub fn scroll_screen(
646        &mut self,
647        amount: &ScrollAmount,
648        window: &mut Window,
649        cx: &mut Context<Self>,
650    ) {
651        if matches!(self.mode, EditorMode::SingleLine { .. }) {
652            cx.propagate();
653            return;
654        }
655
656        if self.take_rename(true, window, cx).is_some() {
657            return;
658        }
659
660        let cur_position = self.scroll_position(cx);
661        let Some(visible_line_count) = self.visible_line_count() else {
662            return;
663        };
664        let new_pos = cur_position + point(0., amount.lines(visible_line_count));
665        self.set_scroll_position(new_pos, window, cx);
666    }
667
668    /// Returns an ordering. The newest selection is:
669    ///     Ordering::Equal => on screen
670    ///     Ordering::Less => above the screen
671    ///     Ordering::Greater => below the screen
672    pub fn newest_selection_on_screen(&self, cx: &mut App) -> Ordering {
673        let snapshot = self.display_map.update(cx, |map, cx| map.snapshot(cx));
674        let newest_head = self
675            .selections
676            .newest_anchor()
677            .head()
678            .to_display_point(&snapshot);
679        let screen_top = self
680            .scroll_manager
681            .anchor
682            .anchor
683            .to_display_point(&snapshot);
684
685        if screen_top > newest_head {
686            return Ordering::Less;
687        }
688
689        if let Some(visible_lines) = self.visible_line_count() {
690            if newest_head.row() <= DisplayRow(screen_top.row().0 + visible_lines as u32) {
691                return Ordering::Equal;
692            }
693        }
694
695        Ordering::Greater
696    }
697
698    pub fn read_scroll_position_from_db(
699        &mut self,
700        item_id: u64,
701        workspace_id: WorkspaceId,
702        window: &mut Window,
703        cx: &mut Context<Editor>,
704    ) {
705        let scroll_position = DB.get_scroll_position(item_id, workspace_id);
706        if let Ok(Some((top_row, x, y))) = scroll_position {
707            let top_anchor = self
708                .buffer()
709                .read(cx)
710                .snapshot(cx)
711                .anchor_at(Point::new(top_row, 0), Bias::Left);
712            let scroll_anchor = ScrollAnchor {
713                offset: gpui::Point::new(x, y),
714                anchor: top_anchor,
715            };
716            self.set_scroll_anchor(scroll_anchor, window, cx);
717        }
718    }
719}