scroll.rs

  1pub mod actions;
  2pub mod autoscroll;
  3pub mod scroll_amount;
  4
  5use crate::{
  6    display_map::{DisplaySnapshot, ToDisplayPoint},
  7    hover_popover::hide_hover,
  8    persistence::DB,
  9    Anchor, DisplayPoint, Editor, EditorMode, Event, InlayHintRefreshReason, MultiBufferSnapshot,
 10    ToPoint,
 11};
 12use gpui::{point, px, AppContext, Entity, Pixels, Styled, Task, ViewContext};
 13use language::{Bias, Point};
 14use std::{
 15    cmp::Ordering,
 16    time::{Duration, Instant},
 17};
 18use util::ResultExt;
 19use workspace::{ItemId, WorkspaceId};
 20
 21use self::{
 22    autoscroll::{Autoscroll, AutoscrollStrategy},
 23    scroll_amount::ScrollAmount,
 24};
 25
 26pub const SCROLL_EVENT_SEPARATION: Duration = Duration::from_millis(28);
 27pub const VERTICAL_SCROLL_MARGIN: f32 = 3.;
 28const SCROLLBAR_SHOW_INTERVAL: Duration = Duration::from_secs(1);
 29
 30#[derive(Default)]
 31pub struct ScrollbarAutoHide(pub bool);
 32
 33#[derive(Clone, Copy, Debug, PartialEq)]
 34pub struct ScrollAnchor {
 35    pub offset: gpui::Point<f32>,
 36    pub anchor: Anchor,
 37}
 38
 39impl ScrollAnchor {
 40    fn new() -> Self {
 41        Self {
 42            offset: gpui::Point::default(),
 43            anchor: Anchor::min(),
 44        }
 45    }
 46
 47    pub fn scroll_position(&self, snapshot: &DisplaySnapshot) -> gpui::Point<f32> {
 48        let mut scroll_position = self.offset;
 49        if self.anchor != Anchor::min() {
 50            let scroll_top = self.anchor.to_display_point(snapshot).row() as f32;
 51            scroll_position.y = scroll_top + scroll_position.y;
 52        } else {
 53            scroll_position.y = 0.;
 54        }
 55        scroll_position
 56    }
 57
 58    pub fn top_row(&self, buffer: &MultiBufferSnapshot) -> u32 {
 59        self.anchor.to_point(buffer).row
 60    }
 61}
 62
 63#[derive(Copy, Clone, PartialEq, Eq, Debug)]
 64pub enum Axis {
 65    Vertical,
 66    Horizontal,
 67}
 68
 69#[derive(Clone, Copy, Debug)]
 70pub struct OngoingScroll {
 71    last_event: Instant,
 72    axis: Option<Axis>,
 73}
 74
 75impl OngoingScroll {
 76    fn new() -> Self {
 77        Self {
 78            last_event: Instant::now() - SCROLL_EVENT_SEPARATION,
 79            axis: None,
 80        }
 81    }
 82
 83    pub fn filter(&self, delta: &mut gpui::Point<Pixels>) -> Option<Axis> {
 84        const UNLOCK_PERCENT: f32 = 1.9;
 85        const UNLOCK_LOWER_BOUND: Pixels = px(6.);
 86        let mut axis = self.axis;
 87
 88        let x = delta.x.abs();
 89        let y = delta.y.abs();
 90        let duration = Instant::now().duration_since(self.last_event);
 91        if duration > SCROLL_EVENT_SEPARATION {
 92            //New ongoing scroll will start, determine axis
 93            axis = if x <= y {
 94                Some(Axis::Vertical)
 95            } else {
 96                Some(Axis::Horizontal)
 97            };
 98        } else if x.max(y) >= UNLOCK_LOWER_BOUND {
 99            //Check if the current ongoing will need to unlock
100            match axis {
101                Some(Axis::Vertical) => {
102                    if x > y && x >= y * UNLOCK_PERCENT {
103                        axis = None;
104                    }
105                }
106
107                Some(Axis::Horizontal) => {
108                    if y > x && y >= x * UNLOCK_PERCENT {
109                        axis = None;
110                    }
111                }
112
113                None => {}
114            }
115        }
116
117        match axis {
118            Some(Axis::Vertical) => {
119                *delta = point(px(0.), delta.y);
120            }
121            Some(Axis::Horizontal) => {
122                *delta = point(delta.x, px(0.));
123            }
124            None => {}
125        }
126
127        axis
128    }
129}
130
131pub struct ScrollManager {
132    vertical_scroll_margin: f32,
133    anchor: ScrollAnchor,
134    ongoing: OngoingScroll,
135    autoscroll_request: Option<(Autoscroll, bool)>,
136    last_autoscroll: Option<(gpui::Point<f32>, f32, f32, AutoscrollStrategy)>,
137    show_scrollbars: bool,
138    hide_scrollbar_task: Option<Task<()>>,
139    visible_line_count: Option<f32>,
140}
141
142impl ScrollManager {
143    pub fn new() -> Self {
144        ScrollManager {
145            vertical_scroll_margin: VERTICAL_SCROLL_MARGIN,
146            anchor: ScrollAnchor::new(),
147            ongoing: OngoingScroll::new(),
148            autoscroll_request: None,
149            show_scrollbars: true,
150            hide_scrollbar_task: None,
151            last_autoscroll: None,
152            visible_line_count: None,
153        }
154    }
155
156    pub fn clone_state(&mut self, other: &Self) {
157        self.anchor = other.anchor;
158        self.ongoing = other.ongoing;
159    }
160
161    pub fn anchor(&self) -> ScrollAnchor {
162        self.anchor
163    }
164
165    pub fn ongoing_scroll(&self) -> OngoingScroll {
166        self.ongoing
167    }
168
169    pub fn update_ongoing_scroll(&mut self, axis: Option<Axis>) {
170        self.ongoing.last_event = Instant::now();
171        self.ongoing.axis = axis;
172    }
173
174    pub fn scroll_position(&self, snapshot: &DisplaySnapshot) -> gpui::Point<f32> {
175        self.anchor.scroll_position(snapshot)
176    }
177
178    fn set_scroll_position(
179        &mut self,
180        scroll_position: gpui::Point<f32>,
181        map: &DisplaySnapshot,
182        local: bool,
183        autoscroll: bool,
184        workspace_id: Option<i64>,
185        cx: &mut ViewContext<Editor>,
186    ) {
187        let (new_anchor, top_row) = if scroll_position.y <= 0. {
188            (
189                ScrollAnchor {
190                    anchor: Anchor::min(),
191                    offset: scroll_position.max(&gpui::Point::default()),
192                },
193                0,
194            )
195        } else {
196            let scroll_top_buffer_point =
197                DisplayPoint::new(scroll_position.y as u32, 0).to_point(&map);
198            let top_anchor = map
199                .buffer_snapshot
200                .anchor_at(scroll_top_buffer_point, Bias::Right);
201
202            (
203                ScrollAnchor {
204                    anchor: top_anchor,
205                    offset: point(
206                        scroll_position.x,
207                        scroll_position.y - top_anchor.to_display_point(&map).row() as f32,
208                    ),
209                },
210                scroll_top_buffer_point.row,
211            )
212        };
213
214        self.set_anchor(new_anchor, top_row, local, autoscroll, workspace_id, cx);
215    }
216
217    fn set_anchor(
218        &mut self,
219        anchor: ScrollAnchor,
220        top_row: u32,
221        local: bool,
222        autoscroll: bool,
223        workspace_id: Option<i64>,
224        cx: &mut ViewContext<Editor>,
225    ) {
226        self.anchor = anchor;
227        cx.emit(Event::ScrollPositionChanged { local, autoscroll });
228        self.show_scrollbar(cx);
229        self.autoscroll_request.take();
230        if let Some(workspace_id) = workspace_id {
231            let item_id = cx.view().entity_id().as_u64() as ItemId;
232
233            cx.foreground_executor()
234                .spawn(async move {
235                    DB.save_scroll_position(
236                        item_id,
237                        workspace_id,
238                        top_row,
239                        anchor.offset.x,
240                        anchor.offset.y,
241                    )
242                    .await
243                    .log_err()
244                })
245                .detach()
246        }
247        cx.notify();
248    }
249
250    pub fn show_scrollbar(&mut self, cx: &mut ViewContext<Editor>) {
251        if !self.show_scrollbars {
252            self.show_scrollbars = true;
253            cx.notify();
254        }
255
256        if cx.default_global::<ScrollbarAutoHide>().0 {
257            self.hide_scrollbar_task = Some(cx.spawn(|editor, mut cx| async move {
258                cx.background_executor()
259                    .timer(SCROLLBAR_SHOW_INTERVAL)
260                    .await;
261                editor
262                    .update(&mut cx, |editor, cx| {
263                        editor.scroll_manager.show_scrollbars = false;
264                        cx.notify();
265                    })
266                    .log_err();
267            }));
268        } else {
269            self.hide_scrollbar_task = None;
270        }
271    }
272
273    pub fn scrollbars_visible(&self) -> bool {
274        self.show_scrollbars
275    }
276
277    pub fn has_autoscroll_request(&self) -> bool {
278        self.autoscroll_request.is_some()
279    }
280
281    pub fn clamp_scroll_left(&mut self, max: f32) -> bool {
282        if max < self.anchor.offset.x {
283            self.anchor.offset.x = max;
284            true
285        } else {
286            false
287        }
288    }
289}
290
291// todo!()
292impl Editor {
293    //     pub fn vertical_scroll_margin(&mut self) -> usize {
294    //         self.scroll_manager.vertical_scroll_margin as usize
295    //     }
296
297    //     pub fn set_vertical_scroll_margin(&mut self, margin_rows: usize, cx: &mut ViewContext<Self>) {
298    //         self.scroll_manager.vertical_scroll_margin = margin_rows as f32;
299    //         cx.notify();
300    //     }
301
302    pub fn visible_line_count(&self) -> Option<f32> {
303        self.scroll_manager.visible_line_count
304    }
305
306    pub(crate) fn set_visible_line_count(&mut self, lines: f32, cx: &mut ViewContext<Self>) {
307        let opened_first_time = self.scroll_manager.visible_line_count.is_none();
308        self.scroll_manager.visible_line_count = Some(lines);
309        if opened_first_time {
310            cx.spawn(|editor, mut cx| async move {
311                editor
312                    .update(&mut cx, |editor, cx| {
313                        editor.refresh_inlay_hints(InlayHintRefreshReason::NewLinesShown, cx)
314                    })
315                    .ok()
316            })
317            .detach()
318        }
319    }
320
321    pub fn set_scroll_position(
322        &mut self,
323        scroll_position: gpui::Point<f32>,
324        cx: &mut ViewContext<Self>,
325    ) {
326        self.set_scroll_position_internal(scroll_position, true, false, cx);
327    }
328
329    pub(crate) fn set_scroll_position_internal(
330        &mut self,
331        scroll_position: gpui::Point<f32>,
332        local: bool,
333        autoscroll: bool,
334        cx: &mut ViewContext<Self>,
335    ) {
336        let map = self.display_map.update(cx, |map, cx| map.snapshot(cx));
337
338        hide_hover(self, cx);
339        let workspace_id = self.workspace.as_ref().map(|workspace| workspace.1);
340        self.scroll_manager.set_scroll_position(
341            scroll_position,
342            &map,
343            local,
344            autoscroll,
345            workspace_id,
346            cx,
347        );
348
349        self.refresh_inlay_hints(InlayHintRefreshReason::NewLinesShown, cx);
350    }
351
352    pub fn scroll_position(&self, cx: &mut ViewContext<Self>) -> gpui::Point<Pixels> {
353        let display_map = self.display_map.update(cx, |map, cx| map.snapshot(cx));
354        // todo!() Should `self.scroll_manager.anchor.scroll_position()` return `Pixels`?
355        // self.scroll_manager.anchor.scroll_position(&display_map)
356        todo!()
357    }
358
359    pub fn set_scroll_anchor(&mut self, scroll_anchor: ScrollAnchor, cx: &mut ViewContext<Self>) {
360        hide_hover(self, cx);
361        let workspace_id = self.workspace.as_ref().map(|workspace| workspace.1);
362        let top_row = scroll_anchor
363            .anchor
364            .to_point(&self.buffer().read(cx).snapshot(cx))
365            .row;
366        self.scroll_manager
367            .set_anchor(scroll_anchor, top_row, true, false, workspace_id, cx);
368    }
369
370    pub(crate) fn set_scroll_anchor_remote(
371        &mut self,
372        scroll_anchor: ScrollAnchor,
373        cx: &mut ViewContext<Self>,
374    ) {
375        hide_hover(self, cx);
376        let workspace_id = self.workspace.as_ref().map(|workspace| workspace.1);
377        let top_row = scroll_anchor
378            .anchor
379            .to_point(&self.buffer().read(cx).snapshot(cx))
380            .row;
381        self.scroll_manager
382            .set_anchor(scroll_anchor, top_row, false, false, workspace_id, cx);
383    }
384
385    //     pub fn scroll_screen(&mut self, amount: &ScrollAmount, cx: &mut ViewContext<Self>) {
386    //         if matches!(self.mode, EditorMode::SingleLine) {
387    //             cx.propagate_action();
388    //             return;
389    //         }
390
391    //         if self.take_rename(true, cx).is_some() {
392    //             return;
393    //         }
394
395    //         let cur_position = self.scroll_position(cx);
396    //         let new_pos = cur_position + point(0., amount.lines(self));
397    //         self.set_scroll_position(new_pos, cx);
398    //     }
399
400    //     /// Returns an ordering. The newest selection is:
401    //     ///     Ordering::Equal => on screen
402    //     ///     Ordering::Less => above the screen
403    //     ///     Ordering::Greater => below the screen
404    //     pub fn newest_selection_on_screen(&self, cx: &mut AppContext) -> Ordering {
405    //         let snapshot = self.display_map.update(cx, |map, cx| map.snapshot(cx));
406    //         let newest_head = self
407    //             .selections
408    //             .newest_anchor()
409    //             .head()
410    //             .to_display_point(&snapshot);
411    //         let screen_top = self
412    //             .scroll_manager
413    //             .anchor
414    //             .anchor
415    //             .to_display_point(&snapshot);
416
417    //         if screen_top > newest_head {
418    //             return Ordering::Less;
419    //         }
420
421    //         if let Some(visible_lines) = self.visible_line_count() {
422    //             if newest_head.row() < screen_top.row() + visible_lines as u32 {
423    //                 return Ordering::Equal;
424    //             }
425    //         }
426
427    //         Ordering::Greater
428    //     }
429
430    pub fn read_scroll_position_from_db(
431        &mut self,
432        item_id: usize,
433        workspace_id: WorkspaceId,
434        cx: &mut ViewContext<Editor>,
435    ) {
436        let scroll_position = DB.get_scroll_position(item_id, workspace_id);
437        if let Ok(Some((top_row, x, y))) = scroll_position {
438            let top_anchor = self
439                .buffer()
440                .read(cx)
441                .snapshot(cx)
442                .anchor_at(Point::new(top_row as u32, 0), Bias::Left);
443            let scroll_anchor = ScrollAnchor {
444                offset: gpui::Point::new(x, y),
445                anchor: top_anchor,
446            };
447            self.set_scroll_anchor(scroll_anchor, cx);
448        }
449    }
450}