1use crate::{
2 DisplayRow, Editor, EditorMode, LineWithInvisibles, RowExt, SelectionEffects,
3 display_map::ToDisplayPoint,
4 scroll::{ScrollOffset, WasScrolled},
5};
6use gpui::{Bounds, Context, Pixels, Window};
7use language::Point;
8use multi_buffer::{Anchor, ToPoint};
9use std::cmp;
10
11#[derive(Debug, PartialEq, Eq, Clone, Copy)]
12pub enum Autoscroll {
13 Next,
14 Strategy(AutoscrollStrategy, Option<Anchor>),
15}
16
17impl Autoscroll {
18 /// scrolls the minimal amount to (try) and fit all cursors onscreen
19 pub fn fit() -> Self {
20 Self::Strategy(AutoscrollStrategy::Fit, None)
21 }
22
23 /// scrolls the minimal amount to fit the newest cursor
24 pub fn newest() -> Self {
25 Self::Strategy(AutoscrollStrategy::Newest, None)
26 }
27
28 /// scrolls so the newest cursor is vertically centered
29 pub fn center() -> Self {
30 Self::Strategy(AutoscrollStrategy::Center, None)
31 }
32
33 /// scrolls so the newest cursor is near the top
34 /// (offset by vertical_scroll_margin)
35 pub fn focused() -> Self {
36 Self::Strategy(AutoscrollStrategy::Focused, None)
37 }
38
39 /// Scrolls so that the newest cursor is roughly an n-th line from the top.
40 pub fn top_relative(n: usize) -> Self {
41 Self::Strategy(AutoscrollStrategy::TopRelative(n), None)
42 }
43
44 /// Scrolls so that the newest cursor is at the top.
45 pub fn top() -> Self {
46 Self::Strategy(AutoscrollStrategy::Top, None)
47 }
48
49 /// Scrolls so that the newest cursor is roughly an n-th line from the bottom.
50 pub fn bottom_relative(n: usize) -> Self {
51 Self::Strategy(AutoscrollStrategy::BottomRelative(n), None)
52 }
53
54 /// Scrolls so that the newest cursor is at the bottom.
55 pub fn bottom() -> Self {
56 Self::Strategy(AutoscrollStrategy::Bottom, None)
57 }
58
59 /// Applies a given auto-scroll strategy to a given anchor instead of a cursor.
60 /// E.G: Autoscroll::center().for_anchor(...) results in the anchor being at the center of the screen.
61 pub fn for_anchor(self, anchor: Anchor) -> Self {
62 match self {
63 Autoscroll::Next => self,
64 Autoscroll::Strategy(autoscroll_strategy, _) => {
65 Self::Strategy(autoscroll_strategy, Some(anchor))
66 }
67 }
68 }
69}
70
71impl Into<SelectionEffects> for Option<Autoscroll> {
72 fn into(self) -> SelectionEffects {
73 match self {
74 Some(autoscroll) => SelectionEffects::scroll(autoscroll),
75 None => SelectionEffects::no_scroll(),
76 }
77 }
78}
79
80#[derive(Debug, PartialEq, Eq, Default, Clone, Copy)]
81pub enum AutoscrollStrategy {
82 Fit,
83 Newest,
84 #[default]
85 Center,
86 Focused,
87 Top,
88 Bottom,
89 TopRelative(usize),
90 BottomRelative(usize),
91}
92
93impl AutoscrollStrategy {
94 fn next(&self) -> Self {
95 match self {
96 AutoscrollStrategy::Center => AutoscrollStrategy::Top,
97 AutoscrollStrategy::Top => AutoscrollStrategy::Bottom,
98 _ => AutoscrollStrategy::Center,
99 }
100 }
101}
102
103pub(crate) struct NeedsHorizontalAutoscroll(pub(crate) bool);
104
105impl Editor {
106 pub(crate) fn autoscroll_vertically(
107 &mut self,
108 bounds: Bounds<Pixels>,
109 line_height: Pixels,
110 max_scroll_top: ScrollOffset,
111 autoscroll_request: Option<(Autoscroll, bool)>,
112 window: &mut Window,
113 cx: &mut Context<Editor>,
114 ) -> (NeedsHorizontalAutoscroll, WasScrolled) {
115 let viewport_height = bounds.size.height;
116 let visible_lines = ScrollOffset::from(viewport_height / line_height);
117 let display_map = self.display_map.update(cx, |map, cx| map.snapshot(cx));
118 let mut scroll_position = self.scroll_manager.scroll_position(&display_map);
119 let original_y = scroll_position.y;
120 if let Some(last_bounds) = self.expect_bounds_change.take()
121 && scroll_position.y != 0.
122 {
123 scroll_position.y +=
124 ScrollOffset::from((bounds.top() - last_bounds.top()) / line_height);
125 if scroll_position.y < 0. {
126 scroll_position.y = 0.;
127 }
128 }
129 if scroll_position.y > max_scroll_top {
130 scroll_position.y = max_scroll_top;
131 }
132
133 let editor_was_scrolled = if original_y != scroll_position.y {
134 self.set_scroll_position(scroll_position, window, cx)
135 } else {
136 WasScrolled(false)
137 };
138
139 let Some((autoscroll, local)) = autoscroll_request else {
140 return (NeedsHorizontalAutoscroll(false), editor_was_scrolled);
141 };
142
143 let mut target_top;
144 let mut target_bottom;
145 if let Some(first_highlighted_row) =
146 self.highlighted_display_row_for_autoscroll(&display_map)
147 {
148 target_top = first_highlighted_row.as_f64();
149 target_bottom = target_top + 1.;
150 } else {
151 let selections = self.selections.all::<Point>(&display_map);
152
153 target_top = selections
154 .first()
155 .unwrap()
156 .head()
157 .to_display_point(&display_map)
158 .row()
159 .as_f64();
160 target_bottom = selections
161 .last()
162 .unwrap()
163 .head()
164 .to_display_point(&display_map)
165 .row()
166 .next_row()
167 .as_f64();
168
169 let selections_fit = target_bottom - target_top <= visible_lines;
170 if matches!(
171 autoscroll,
172 Autoscroll::Strategy(AutoscrollStrategy::Newest, _)
173 ) || (matches!(autoscroll, Autoscroll::Strategy(AutoscrollStrategy::Fit, _))
174 && !selections_fit)
175 {
176 let newest_selection_top = selections
177 .iter()
178 .max_by_key(|s| s.id)
179 .unwrap()
180 .head()
181 .to_display_point(&display_map)
182 .row()
183 .as_f64();
184 target_top = newest_selection_top;
185 target_bottom = newest_selection_top + 1.;
186 }
187 }
188
189 let style = self.style(cx).clone();
190 let sticky_headers = self.sticky_headers(&style, cx).unwrap_or_default();
191 let visible_sticky_headers = sticky_headers
192 .iter()
193 .filter(|h| {
194 let buffer_snapshot = display_map.buffer_snapshot();
195 let buffer_range =
196 h.range.start.to_point(buffer_snapshot)..h.range.end.to_point(buffer_snapshot);
197
198 buffer_range.contains(&Point::new(target_top as u32, 0))
199 })
200 .count();
201
202 let margin = if matches!(self.mode, EditorMode::AutoHeight { .. }) {
203 0.
204 } else {
205 ((visible_lines - (target_bottom - target_top)) / 2.0).floor()
206 };
207
208 let strategy = match autoscroll {
209 Autoscroll::Strategy(strategy, _) => strategy,
210 Autoscroll::Next => self
211 .scroll_manager
212 .last_autoscroll
213 .as_ref()
214 .filter(|(offset, last_target_top, last_target_bottom, _)| {
215 self.scroll_manager.anchor.offset == *offset
216 && target_top == *last_target_top
217 && target_bottom == *last_target_bottom
218 })
219 .map(|(_, _, _, strategy)| strategy.next())
220 .unwrap_or_default(),
221 };
222 if let Autoscroll::Strategy(_, Some(anchor)) = autoscroll {
223 target_top = anchor.to_display_point(&display_map).row().as_f64();
224 target_bottom = target_top + 1.;
225 }
226
227 let was_autoscrolled = match strategy {
228 AutoscrollStrategy::Fit | AutoscrollStrategy::Newest => {
229 let margin = margin.min(self.scroll_manager.vertical_scroll_margin);
230 let target_top = (target_top - margin - visible_sticky_headers as f64).max(0.0);
231 let target_bottom = target_bottom + margin;
232 let start_row = scroll_position.y;
233 let end_row = start_row + visible_lines;
234
235 let needs_scroll_up = target_top < start_row;
236 let needs_scroll_down = target_bottom >= end_row;
237
238 if needs_scroll_up && !needs_scroll_down {
239 scroll_position.y = target_top;
240 } else if !needs_scroll_up && needs_scroll_down {
241 scroll_position.y = target_bottom - visible_lines;
242 }
243
244 if needs_scroll_up ^ needs_scroll_down {
245 self.set_scroll_position_internal(scroll_position, local, true, window, cx)
246 } else {
247 WasScrolled(false)
248 }
249 }
250 AutoscrollStrategy::Center => {
251 scroll_position.y = (target_top - margin).max(0.0);
252 self.set_scroll_position_internal(scroll_position, local, true, window, cx)
253 }
254 AutoscrollStrategy::Focused => {
255 let margin = margin.min(self.scroll_manager.vertical_scroll_margin);
256 scroll_position.y = (target_top - margin).max(0.0);
257 self.set_scroll_position_internal(scroll_position, local, true, window, cx)
258 }
259 AutoscrollStrategy::Top => {
260 scroll_position.y = (target_top).max(0.0);
261 self.set_scroll_position_internal(scroll_position, local, true, window, cx)
262 }
263 AutoscrollStrategy::Bottom => {
264 scroll_position.y = (target_bottom - visible_lines).max(0.0);
265 self.set_scroll_position_internal(scroll_position, local, true, window, cx)
266 }
267 AutoscrollStrategy::TopRelative(lines) => {
268 scroll_position.y = target_top - lines as ScrollOffset;
269 self.set_scroll_position_internal(scroll_position, local, true, window, cx)
270 }
271 AutoscrollStrategy::BottomRelative(lines) => {
272 scroll_position.y = target_bottom + lines as ScrollOffset;
273 self.set_scroll_position_internal(scroll_position, local, true, window, cx)
274 }
275 };
276
277 self.scroll_manager.last_autoscroll = Some((
278 self.scroll_manager.anchor.offset,
279 target_top,
280 target_bottom,
281 strategy,
282 ));
283
284 let was_scrolled = WasScrolled(editor_was_scrolled.0 || was_autoscrolled.0);
285 (NeedsHorizontalAutoscroll(true), was_scrolled)
286 }
287
288 pub(crate) fn autoscroll_horizontally(
289 &mut self,
290 start_row: DisplayRow,
291 viewport_width: Pixels,
292 scroll_width: Pixels,
293 em_advance: Pixels,
294 layouts: &[LineWithInvisibles],
295 autoscroll_request: Option<(Autoscroll, bool)>,
296 window: &mut Window,
297 cx: &mut Context<Self>,
298 ) -> Option<gpui::Point<ScrollOffset>> {
299 let (_, local) = autoscroll_request?;
300 let em_advance = ScrollOffset::from(em_advance);
301 let viewport_width = ScrollOffset::from(viewport_width);
302 let scroll_width = ScrollOffset::from(scroll_width);
303
304 let display_map = self.display_map.update(cx, |map, cx| map.snapshot(cx));
305 let selections = self.selections.all::<Point>(&display_map);
306 let mut scroll_position = self.scroll_manager.scroll_position(&display_map);
307
308 let mut target_left;
309 let mut target_right: f64;
310
311 if self
312 .highlighted_display_row_for_autoscroll(&display_map)
313 .is_none()
314 {
315 target_left = f64::INFINITY;
316 target_right = 0.;
317 for selection in selections {
318 let head = selection.head().to_display_point(&display_map);
319 if head.row() >= start_row
320 && head.row() < DisplayRow(start_row.0 + layouts.len() as u32)
321 {
322 let start_column = head.column();
323 let end_column = cmp::min(display_map.line_len(head.row()), head.column());
324 target_left = target_left.min(ScrollOffset::from(
325 layouts[head.row().minus(start_row) as usize]
326 .x_for_index(start_column as usize)
327 + self.gutter_dimensions.margin,
328 ));
329 target_right = target_right.max(
330 ScrollOffset::from(
331 layouts[head.row().minus(start_row) as usize]
332 .x_for_index(end_column as usize),
333 ) + em_advance,
334 );
335 }
336 }
337 } else {
338 target_left = 0.;
339 target_right = 0.;
340 }
341
342 target_right = target_right.min(scroll_width);
343
344 if target_right - target_left > viewport_width {
345 return None;
346 }
347
348 let scroll_left = self.scroll_manager.anchor.offset.x * em_advance;
349 let scroll_right = scroll_left + viewport_width;
350
351 let was_scrolled = if target_left < scroll_left {
352 scroll_position.x = target_left / em_advance;
353 self.set_scroll_position_internal(scroll_position, local, true, window, cx)
354 } else if target_right > scroll_right {
355 scroll_position.x = (target_right - viewport_width) / em_advance;
356 self.set_scroll_position_internal(scroll_position, local, true, window, cx)
357 } else {
358 WasScrolled(false)
359 };
360
361 if was_scrolled.0 {
362 Some(scroll_position)
363 } else {
364 None
365 }
366 }
367
368 pub fn request_autoscroll(&mut self, autoscroll: Autoscroll, cx: &mut Context<Self>) {
369 self.scroll_manager.autoscroll_request = Some((autoscroll, true));
370 cx.notify();
371 }
372
373 pub(crate) fn request_autoscroll_remotely(
374 &mut self,
375 autoscroll: Autoscroll,
376 cx: &mut Context<Self>,
377 ) {
378 self.scroll_manager.autoscroll_request = Some((autoscroll, false));
379 cx.notify();
380 }
381}