1use crate::{
2 DisplayRow, Editor, EditorMode, LineWithInvisibles, RowExt, SelectionEffects,
3 display_map::ToDisplayPoint,
4};
5use gpui::{Bounds, Context, Pixels, Window, px};
6use language::Point;
7use multi_buffer::Anchor;
8use std::{cmp, f32};
9
10#[derive(Debug, PartialEq, Eq, Clone, Copy)]
11pub enum Autoscroll {
12 Next,
13 Strategy(AutoscrollStrategy, Option<Anchor>),
14}
15
16impl Autoscroll {
17 /// scrolls the minimal amount to (try) and fit all cursors onscreen
18 pub fn fit() -> Self {
19 Self::Strategy(AutoscrollStrategy::Fit, None)
20 }
21
22 /// scrolls the minimal amount to fit the newest cursor
23 pub fn newest() -> Self {
24 Self::Strategy(AutoscrollStrategy::Newest, None)
25 }
26
27 /// scrolls so the newest cursor is vertically centered
28 pub fn center() -> Self {
29 Self::Strategy(AutoscrollStrategy::Center, None)
30 }
31
32 /// scrolls so the newest cursor is near the top
33 /// (offset by vertical_scroll_margin)
34 pub fn focused() -> Self {
35 Self::Strategy(AutoscrollStrategy::Focused, None)
36 }
37
38 /// Scrolls so that the newest cursor is roughly an n-th line from the top.
39 pub fn top_relative(n: usize) -> Self {
40 Self::Strategy(AutoscrollStrategy::TopRelative(n), None)
41 }
42
43 /// Scrolls so that the newest cursor is at the top.
44 pub fn top() -> Self {
45 Self::Strategy(AutoscrollStrategy::Top, None)
46 }
47
48 /// Scrolls so that the newest cursor is roughly an n-th line from the bottom.
49 pub fn bottom_relative(n: usize) -> Self {
50 Self::Strategy(AutoscrollStrategy::BottomRelative(n), None)
51 }
52
53 /// Scrolls so that the newest cursor is at the bottom.
54 pub fn bottom() -> Self {
55 Self::Strategy(AutoscrollStrategy::Bottom, None)
56 }
57
58 /// Applies a given auto-scroll strategy to a given anchor instead of a cursor.
59 /// E.G: Autoscroll::center().for_anchor(...) results in the anchor being at the center of the screen.
60 pub fn for_anchor(self, anchor: Anchor) -> Self {
61 match self {
62 Autoscroll::Next => self,
63 Autoscroll::Strategy(autoscroll_strategy, _) => {
64 Self::Strategy(autoscroll_strategy, Some(anchor))
65 }
66 }
67 }
68}
69
70impl Into<SelectionEffects> for Option<Autoscroll> {
71 fn into(self) -> SelectionEffects {
72 match self {
73 Some(autoscroll) => SelectionEffects::scroll(autoscroll),
74 None => SelectionEffects::no_scroll(),
75 }
76 }
77}
78
79#[derive(Debug, PartialEq, Eq, Default, Clone, Copy)]
80pub enum AutoscrollStrategy {
81 Fit,
82 Newest,
83 #[default]
84 Center,
85 Focused,
86 Top,
87 Bottom,
88 TopRelative(usize),
89 BottomRelative(usize),
90}
91
92impl AutoscrollStrategy {
93 fn next(&self) -> Self {
94 match self {
95 AutoscrollStrategy::Center => AutoscrollStrategy::Top,
96 AutoscrollStrategy::Top => AutoscrollStrategy::Bottom,
97 _ => AutoscrollStrategy::Center,
98 }
99 }
100}
101
102impl Editor {
103 pub fn autoscroll_request(&self) -> Option<Autoscroll> {
104 self.scroll_manager.autoscroll_request()
105 }
106
107 pub fn autoscroll_vertically(
108 &mut self,
109 bounds: Bounds<Pixels>,
110 line_height: Pixels,
111 max_scroll_top: f32,
112 window: &mut Window,
113 cx: &mut Context<Editor>,
114 ) -> bool {
115 let viewport_height = bounds.size.height;
116 let visible_lines = 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 if scroll_position.y != 0. {
122 scroll_position.y += (bounds.top() - last_bounds.top()) / line_height;
123 if scroll_position.y < 0. {
124 scroll_position.y = 0.;
125 }
126 }
127 }
128 if scroll_position.y > max_scroll_top {
129 scroll_position.y = max_scroll_top;
130 }
131
132 if original_y != scroll_position.y {
133 self.set_scroll_position(scroll_position, window, cx);
134 }
135
136 let Some((autoscroll, local)) = self.scroll_manager.autoscroll_request.take() else {
137 return false;
138 };
139
140 let mut target_top;
141 let mut target_bottom;
142 if let Some(first_highlighted_row) =
143 self.highlighted_display_row_for_autoscroll(&display_map)
144 {
145 target_top = first_highlighted_row.as_f32();
146 target_bottom = target_top + 1.;
147 } else {
148 let selections = self.selections.all::<Point>(cx);
149
150 target_top = selections
151 .first()
152 .unwrap()
153 .head()
154 .to_display_point(&display_map)
155 .row()
156 .as_f32();
157 target_bottom = selections
158 .last()
159 .unwrap()
160 .head()
161 .to_display_point(&display_map)
162 .row()
163 .next_row()
164 .as_f32();
165
166 let selections_fit = target_bottom - target_top <= visible_lines;
167 if matches!(
168 autoscroll,
169 Autoscroll::Strategy(AutoscrollStrategy::Newest, _)
170 ) || (matches!(autoscroll, Autoscroll::Strategy(AutoscrollStrategy::Fit, _))
171 && !selections_fit)
172 {
173 let newest_selection_top = selections
174 .iter()
175 .max_by_key(|s| s.id)
176 .unwrap()
177 .head()
178 .to_display_point(&display_map)
179 .row()
180 .as_f32();
181 target_top = newest_selection_top;
182 target_bottom = newest_selection_top + 1.;
183 }
184 }
185
186 let margin = if matches!(self.mode, EditorMode::AutoHeight { .. }) {
187 0.
188 } else {
189 ((visible_lines - (target_bottom - target_top)) / 2.0).floor()
190 };
191
192 let strategy = match autoscroll {
193 Autoscroll::Strategy(strategy, _) => strategy,
194 Autoscroll::Next => {
195 let last_autoscroll = &self.scroll_manager.last_autoscroll;
196 if let Some(last_autoscroll) = last_autoscroll {
197 if self.scroll_manager.anchor.offset == last_autoscroll.0
198 && target_top == last_autoscroll.1
199 && target_bottom == last_autoscroll.2
200 {
201 last_autoscroll.3.next()
202 } else {
203 AutoscrollStrategy::default()
204 }
205 } else {
206 AutoscrollStrategy::default()
207 }
208 }
209 };
210 if let Autoscroll::Strategy(_, Some(anchor)) = autoscroll {
211 target_top = anchor.to_display_point(&display_map).row().as_f32();
212 target_bottom = target_top + 1.;
213 }
214
215 match strategy {
216 AutoscrollStrategy::Fit | AutoscrollStrategy::Newest => {
217 let margin = margin.min(self.scroll_manager.vertical_scroll_margin);
218 let target_top = (target_top - margin).max(0.0);
219 let target_bottom = target_bottom + margin;
220 let start_row = scroll_position.y;
221 let end_row = start_row + visible_lines;
222
223 let needs_scroll_up = target_top < start_row;
224 let needs_scroll_down = target_bottom >= end_row;
225
226 if needs_scroll_up && !needs_scroll_down {
227 scroll_position.y = target_top;
228 self.set_scroll_position_internal(scroll_position, local, true, window, cx);
229 }
230 if !needs_scroll_up && needs_scroll_down {
231 scroll_position.y = target_bottom - visible_lines;
232 self.set_scroll_position_internal(scroll_position, local, true, window, cx);
233 }
234 }
235 AutoscrollStrategy::Center => {
236 scroll_position.y = (target_top - margin).max(0.0);
237 self.set_scroll_position_internal(scroll_position, local, true, window, cx);
238 }
239 AutoscrollStrategy::Focused => {
240 let margin = margin.min(self.scroll_manager.vertical_scroll_margin);
241 scroll_position.y = (target_top - margin).max(0.0);
242 self.set_scroll_position_internal(scroll_position, local, true, window, cx);
243 }
244 AutoscrollStrategy::Top => {
245 scroll_position.y = (target_top).max(0.0);
246 self.set_scroll_position_internal(scroll_position, local, true, window, cx);
247 }
248 AutoscrollStrategy::Bottom => {
249 scroll_position.y = (target_bottom - visible_lines).max(0.0);
250 self.set_scroll_position_internal(scroll_position, local, true, window, cx);
251 }
252 AutoscrollStrategy::TopRelative(lines) => {
253 scroll_position.y = target_top - lines as f32;
254 self.set_scroll_position_internal(scroll_position, local, true, window, cx);
255 }
256 AutoscrollStrategy::BottomRelative(lines) => {
257 scroll_position.y = target_bottom + lines as f32;
258 self.set_scroll_position_internal(scroll_position, local, true, window, cx);
259 }
260 }
261
262 self.scroll_manager.last_autoscroll = Some((
263 self.scroll_manager.anchor.offset,
264 target_top,
265 target_bottom,
266 strategy,
267 ));
268
269 true
270 }
271
272 pub(crate) fn autoscroll_horizontally(
273 &mut self,
274 start_row: DisplayRow,
275 viewport_width: Pixels,
276 scroll_width: Pixels,
277 em_advance: Pixels,
278 layouts: &[LineWithInvisibles],
279 window: &mut Window,
280 cx: &mut Context<Self>,
281 ) -> bool {
282 let display_map = self.display_map.update(cx, |map, cx| map.snapshot(cx));
283 let selections = self.selections.all::<Point>(cx);
284 let mut scroll_position = self.scroll_manager.scroll_position(&display_map);
285
286 let mut target_left;
287 let mut target_right;
288
289 if self
290 .highlighted_display_row_for_autoscroll(&display_map)
291 .is_none()
292 {
293 target_left = px(f32::INFINITY);
294 target_right = px(0.);
295 for selection in selections {
296 let head = selection.head().to_display_point(&display_map);
297 if head.row() >= start_row
298 && head.row() < DisplayRow(start_row.0 + layouts.len() as u32)
299 {
300 let start_column = head.column();
301 let end_column = cmp::min(display_map.line_len(head.row()), head.column());
302 target_left = target_left.min(
303 layouts[head.row().minus(start_row) as usize]
304 .x_for_index(start_column as usize)
305 + self.gutter_dimensions.margin,
306 );
307 target_right = target_right.max(
308 layouts[head.row().minus(start_row) as usize]
309 .x_for_index(end_column as usize)
310 + em_advance,
311 );
312 }
313 }
314 } else {
315 target_left = px(0.);
316 target_right = px(0.);
317 }
318
319 target_right = target_right.min(scroll_width);
320
321 if target_right - target_left > viewport_width {
322 return false;
323 }
324
325 let scroll_left = self.scroll_manager.anchor.offset.x * em_advance;
326 let scroll_right = scroll_left + viewport_width;
327
328 if target_left < scroll_left {
329 scroll_position.x = target_left / em_advance;
330 self.set_scroll_position_internal(scroll_position, true, true, window, cx);
331 true
332 } else if target_right > scroll_right {
333 scroll_position.x = (target_right - viewport_width) / em_advance;
334 self.set_scroll_position_internal(scroll_position, true, true, window, cx);
335 true
336 } else {
337 false
338 }
339 }
340
341 pub fn request_autoscroll(&mut self, autoscroll: Autoscroll, cx: &mut Context<Self>) {
342 self.scroll_manager.autoscroll_request = Some((autoscroll, true));
343 cx.notify();
344 }
345
346 pub(crate) fn request_autoscroll_remotely(
347 &mut self,
348 autoscroll: Autoscroll,
349 cx: &mut Context<Self>,
350 ) {
351 self.scroll_manager.autoscroll_request = Some((autoscroll, false));
352 cx.notify();
353 }
354}