1use crate::{
2 display_map::ToDisplayPoint, DisplayRow, Editor, EditorMode, LineWithInvisibles, RowExt,
3};
4use gpui::{px, Bounds, Context, Pixels, Window};
5use language::Point;
6use std::{cmp, f32};
7
8#[derive(PartialEq, Eq, Clone, Copy)]
9pub enum Autoscroll {
10 Next,
11 Strategy(AutoscrollStrategy),
12}
13
14impl Autoscroll {
15 /// scrolls the minimal amount to (try) and fit all cursors onscreen
16 pub fn fit() -> Self {
17 Self::Strategy(AutoscrollStrategy::Fit)
18 }
19
20 /// scrolls the minimal amount to fit the newest cursor
21 pub fn newest() -> Self {
22 Self::Strategy(AutoscrollStrategy::Newest)
23 }
24
25 /// scrolls so the newest cursor is vertically centered
26 pub fn center() -> Self {
27 Self::Strategy(AutoscrollStrategy::Center)
28 }
29
30 /// scrolls so the newest cursor is near the top
31 /// (offset by vertical_scroll_margin)
32 pub fn focused() -> Self {
33 Self::Strategy(AutoscrollStrategy::Focused)
34 }
35
36 /// Scrolls so that the newest cursor is roughly an n-th line from the top.
37 pub fn top_relative(n: usize) -> Self {
38 Self::Strategy(AutoscrollStrategy::TopRelative(n))
39 }
40
41 /// Scrolls so that the newest cursor is at the bottom.
42 pub fn bottom() -> Self {
43 Self::Strategy(AutoscrollStrategy::Bottom)
44 }
45}
46
47#[derive(PartialEq, Eq, Default, Clone, Copy)]
48pub enum AutoscrollStrategy {
49 Fit,
50 Newest,
51 #[default]
52 Center,
53 Focused,
54 Top,
55 Bottom,
56 TopRelative(usize),
57}
58
59impl AutoscrollStrategy {
60 fn next(&self) -> Self {
61 match self {
62 AutoscrollStrategy::Center => AutoscrollStrategy::Top,
63 AutoscrollStrategy::Top => AutoscrollStrategy::Bottom,
64 _ => AutoscrollStrategy::Center,
65 }
66 }
67}
68
69impl Editor {
70 pub fn autoscroll_request(&self) -> Option<Autoscroll> {
71 self.scroll_manager.autoscroll_request()
72 }
73
74 pub fn autoscroll_vertically(
75 &mut self,
76 bounds: Bounds<Pixels>,
77 line_height: Pixels,
78 max_scroll_top: f32,
79 window: &mut Window,
80 cx: &mut Context<Editor>,
81 ) -> bool {
82 let viewport_height = bounds.size.height;
83 let visible_lines = viewport_height / line_height;
84 let display_map = self.display_map.update(cx, |map, cx| map.snapshot(cx));
85 let mut scroll_position = self.scroll_manager.scroll_position(&display_map);
86 let original_y = scroll_position.y;
87 if let Some(last_bounds) = self.expect_bounds_change.take() {
88 if scroll_position.y != 0. {
89 scroll_position.y += (bounds.top() - last_bounds.top()) / line_height;
90 if scroll_position.y < 0. {
91 scroll_position.y = 0.;
92 }
93 }
94 }
95 if scroll_position.y > max_scroll_top {
96 scroll_position.y = max_scroll_top;
97 }
98
99 if original_y != scroll_position.y {
100 self.set_scroll_position(scroll_position, window, cx);
101 }
102
103 let Some((autoscroll, local)) = self.scroll_manager.autoscroll_request.take() else {
104 return false;
105 };
106
107 let mut target_top;
108 let mut target_bottom;
109 if let Some(first_highlighted_row) =
110 self.highlighted_display_row_for_autoscroll(&display_map)
111 {
112 target_top = first_highlighted_row.as_f32();
113 target_bottom = target_top + 1.;
114 } else {
115 let selections = self.selections.all::<Point>(cx);
116
117 target_top = selections
118 .first()
119 .unwrap()
120 .head()
121 .to_display_point(&display_map)
122 .row()
123 .as_f32();
124 target_bottom = selections
125 .last()
126 .unwrap()
127 .head()
128 .to_display_point(&display_map)
129 .row()
130 .next_row()
131 .as_f32();
132
133 let selections_fit = target_bottom - target_top <= visible_lines;
134 if autoscroll == Autoscroll::newest()
135 || (autoscroll == Autoscroll::fit() && !selections_fit)
136 {
137 let newest_selection_top = selections
138 .iter()
139 .max_by_key(|s| s.id)
140 .unwrap()
141 .head()
142 .to_display_point(&display_map)
143 .row()
144 .as_f32();
145 target_top = newest_selection_top;
146 target_bottom = newest_selection_top + 1.;
147 }
148 }
149
150 let margin = if matches!(self.mode, EditorMode::AutoHeight { .. }) {
151 0.
152 } else {
153 ((visible_lines - (target_bottom - target_top)) / 2.0).floor()
154 };
155
156 let strategy = match autoscroll {
157 Autoscroll::Strategy(strategy) => strategy,
158 Autoscroll::Next => {
159 let last_autoscroll = &self.scroll_manager.last_autoscroll;
160 if let Some(last_autoscroll) = last_autoscroll {
161 if self.scroll_manager.anchor.offset == last_autoscroll.0
162 && target_top == last_autoscroll.1
163 && target_bottom == last_autoscroll.2
164 {
165 last_autoscroll.3.next()
166 } else {
167 AutoscrollStrategy::default()
168 }
169 } else {
170 AutoscrollStrategy::default()
171 }
172 }
173 };
174
175 match strategy {
176 AutoscrollStrategy::Fit | AutoscrollStrategy::Newest => {
177 let margin = margin.min(self.scroll_manager.vertical_scroll_margin);
178 let target_top = (target_top - margin).max(0.0);
179 let target_bottom = target_bottom + margin;
180 let start_row = scroll_position.y;
181 let end_row = start_row + visible_lines;
182
183 let needs_scroll_up = target_top < start_row;
184 let needs_scroll_down = target_bottom >= end_row;
185
186 if needs_scroll_up && !needs_scroll_down {
187 scroll_position.y = target_top;
188 self.set_scroll_position_internal(scroll_position, local, true, window, cx);
189 }
190 if !needs_scroll_up && needs_scroll_down {
191 scroll_position.y = target_bottom - visible_lines;
192 self.set_scroll_position_internal(scroll_position, local, true, window, cx);
193 }
194 }
195 AutoscrollStrategy::Center => {
196 scroll_position.y = (target_top - margin).max(0.0);
197 self.set_scroll_position_internal(scroll_position, local, true, window, cx);
198 }
199 AutoscrollStrategy::Focused => {
200 let margin = margin.min(self.scroll_manager.vertical_scroll_margin);
201 scroll_position.y = (target_top - margin).max(0.0);
202 self.set_scroll_position_internal(scroll_position, local, true, window, cx);
203 }
204 AutoscrollStrategy::Top => {
205 scroll_position.y = (target_top).max(0.0);
206 self.set_scroll_position_internal(scroll_position, local, true, window, cx);
207 }
208 AutoscrollStrategy::Bottom => {
209 scroll_position.y = (target_bottom - visible_lines).max(0.0);
210 self.set_scroll_position_internal(scroll_position, local, true, window, cx);
211 }
212 AutoscrollStrategy::TopRelative(lines) => {
213 scroll_position.y = target_top - lines as f32;
214 self.set_scroll_position_internal(scroll_position, local, true, window, cx);
215 }
216 }
217
218 self.scroll_manager.last_autoscroll = Some((
219 self.scroll_manager.anchor.offset,
220 target_top,
221 target_bottom,
222 strategy,
223 ));
224
225 true
226 }
227
228 pub(crate) fn autoscroll_horizontally(
229 &mut self,
230 start_row: DisplayRow,
231 viewport_width: Pixels,
232 scroll_width: Pixels,
233 max_glyph_width: Pixels,
234 layouts: &[LineWithInvisibles],
235 cx: &mut Context<Self>,
236 ) -> bool {
237 let display_map = self.display_map.update(cx, |map, cx| map.snapshot(cx));
238 let selections = self.selections.all::<Point>(cx);
239
240 let mut target_left;
241 let mut target_right;
242
243 if self
244 .highlighted_display_row_for_autoscroll(&display_map)
245 .is_none()
246 {
247 target_left = px(f32::INFINITY);
248 target_right = px(0.);
249 for selection in selections {
250 let head = selection.head().to_display_point(&display_map);
251 if head.row() >= start_row
252 && head.row() < DisplayRow(start_row.0 + layouts.len() as u32)
253 {
254 let start_column = head.column().saturating_sub(3);
255 let end_column = cmp::min(display_map.line_len(head.row()), head.column() + 3);
256 target_left = target_left.min(
257 layouts[head.row().minus(start_row) as usize]
258 .x_for_index(start_column as usize),
259 );
260 target_right = target_right.max(
261 layouts[head.row().minus(start_row) as usize]
262 .x_for_index(end_column as usize)
263 + max_glyph_width,
264 );
265 }
266 }
267 } else {
268 target_left = px(0.);
269 target_right = px(0.);
270 }
271
272 target_right = target_right.min(scroll_width);
273
274 if target_right - target_left > viewport_width {
275 return false;
276 }
277
278 let scroll_left = self.scroll_manager.anchor.offset.x * max_glyph_width;
279 let scroll_right = scroll_left + viewport_width;
280
281 if target_left < scroll_left {
282 self.scroll_manager.anchor.offset.x = target_left / max_glyph_width;
283 true
284 } else if target_right > scroll_right {
285 self.scroll_manager.anchor.offset.x = (target_right - viewport_width) / max_glyph_width;
286 true
287 } else {
288 false
289 }
290 }
291
292 pub fn request_autoscroll(&mut self, autoscroll: Autoscroll, cx: &mut Context<Self>) {
293 self.scroll_manager.autoscroll_request = Some((autoscroll, true));
294 cx.notify();
295 }
296
297 pub(crate) fn request_autoscroll_remotely(
298 &mut self,
299 autoscroll: Autoscroll,
300 cx: &mut Context<Self>,
301 ) {
302 self.scroll_manager.autoscroll_request = Some((autoscroll, false));
303 cx.notify();
304 }
305}