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 target_top = selections
117 .first()
118 .unwrap()
119 .head()
120 .to_display_point(&display_map)
121 .row()
122 .as_f32();
123 target_bottom = selections
124 .last()
125 .unwrap()
126 .head()
127 .to_display_point(&display_map)
128 .row()
129 .next_row()
130 .as_f32();
131
132 let selections_fit = target_bottom - target_top <= visible_lines;
133 if autoscroll == Autoscroll::newest()
134 || (autoscroll == Autoscroll::fit() && !selections_fit)
135 {
136 let newest_selection_top = selections
137 .iter()
138 .max_by_key(|s| s.id)
139 .unwrap()
140 .head()
141 .to_display_point(&display_map)
142 .row()
143 .as_f32();
144 target_top = newest_selection_top;
145 target_bottom = newest_selection_top + 1.;
146 }
147 }
148
149 let margin = if matches!(self.mode, EditorMode::AutoHeight { .. }) {
150 0.
151 } else {
152 ((visible_lines - (target_bottom - target_top)) / 2.0).floor()
153 };
154
155 let strategy = match autoscroll {
156 Autoscroll::Strategy(strategy) => strategy,
157 Autoscroll::Next => {
158 let last_autoscroll = &self.scroll_manager.last_autoscroll;
159 if let Some(last_autoscroll) = last_autoscroll {
160 if self.scroll_manager.anchor.offset == last_autoscroll.0
161 && target_top == last_autoscroll.1
162 && target_bottom == last_autoscroll.2
163 {
164 last_autoscroll.3.next()
165 } else {
166 AutoscrollStrategy::default()
167 }
168 } else {
169 AutoscrollStrategy::default()
170 }
171 }
172 };
173
174 match strategy {
175 AutoscrollStrategy::Fit | AutoscrollStrategy::Newest => {
176 let margin = margin.min(self.scroll_manager.vertical_scroll_margin);
177 let target_top = (target_top - margin).max(0.0);
178 let target_bottom = target_bottom + margin;
179 let start_row = scroll_position.y;
180 let end_row = start_row + visible_lines;
181
182 let needs_scroll_up = target_top < start_row;
183 let needs_scroll_down = target_bottom >= end_row;
184
185 if needs_scroll_up && !needs_scroll_down {
186 scroll_position.y = target_top;
187 self.set_scroll_position_internal(scroll_position, local, true, window, cx);
188 }
189 if !needs_scroll_up && needs_scroll_down {
190 scroll_position.y = target_bottom - visible_lines;
191 self.set_scroll_position_internal(scroll_position, local, true, window, cx);
192 }
193 }
194 AutoscrollStrategy::Center => {
195 scroll_position.y = (target_top - margin).max(0.0);
196 self.set_scroll_position_internal(scroll_position, local, true, window, cx);
197 }
198 AutoscrollStrategy::Focused => {
199 let margin = margin.min(self.scroll_manager.vertical_scroll_margin);
200 scroll_position.y = (target_top - margin).max(0.0);
201 self.set_scroll_position_internal(scroll_position, local, true, window, cx);
202 }
203 AutoscrollStrategy::Top => {
204 scroll_position.y = (target_top).max(0.0);
205 self.set_scroll_position_internal(scroll_position, local, true, window, cx);
206 }
207 AutoscrollStrategy::Bottom => {
208 scroll_position.y = (target_bottom - visible_lines).max(0.0);
209 self.set_scroll_position_internal(scroll_position, local, true, window, cx);
210 }
211 AutoscrollStrategy::TopRelative(lines) => {
212 scroll_position.y = target_top - lines as f32;
213 self.set_scroll_position_internal(scroll_position, local, true, window, cx);
214 }
215 }
216
217 self.scroll_manager.last_autoscroll = Some((
218 self.scroll_manager.anchor.offset,
219 target_top,
220 target_bottom,
221 strategy,
222 ));
223
224 true
225 }
226
227 pub(crate) fn autoscroll_horizontally(
228 &mut self,
229 start_row: DisplayRow,
230 viewport_width: Pixels,
231 scroll_width: Pixels,
232 max_glyph_width: Pixels,
233 layouts: &[LineWithInvisibles],
234 cx: &mut Context<Self>,
235 ) -> bool {
236 let display_map = self.display_map.update(cx, |map, cx| map.snapshot(cx));
237 let selections = self.selections.all::<Point>(cx);
238
239 let mut target_left;
240 let mut target_right;
241
242 if self
243 .highlighted_display_row_for_autoscroll(&display_map)
244 .is_none()
245 {
246 target_left = px(f32::INFINITY);
247 target_right = px(0.);
248 for selection in selections {
249 let head = selection.head().to_display_point(&display_map);
250 if head.row() >= start_row
251 && head.row() < DisplayRow(start_row.0 + layouts.len() as u32)
252 {
253 let start_column = head.column().saturating_sub(3);
254 let end_column = cmp::min(display_map.line_len(head.row()), head.column() + 3);
255 target_left = target_left.min(
256 layouts[head.row().minus(start_row) as usize]
257 .x_for_index(start_column as usize),
258 );
259 target_right = target_right.max(
260 layouts[head.row().minus(start_row) as usize]
261 .x_for_index(end_column as usize)
262 + max_glyph_width,
263 );
264 }
265 }
266 } else {
267 target_left = px(0.);
268 target_right = px(0.);
269 }
270
271 target_right = target_right.min(scroll_width);
272
273 if target_right - target_left > viewport_width {
274 return false;
275 }
276
277 let scroll_left = self.scroll_manager.anchor.offset.x * max_glyph_width;
278 let scroll_right = scroll_left + viewport_width;
279
280 if target_left < scroll_left {
281 self.scroll_manager.anchor.offset.x = target_left / max_glyph_width;
282 true
283 } else if target_right > scroll_right {
284 self.scroll_manager.anchor.offset.x = (target_right - viewport_width) / max_glyph_width;
285 true
286 } else {
287 false
288 }
289 }
290
291 pub fn request_autoscroll(&mut self, autoscroll: Autoscroll, cx: &mut Context<Self>) {
292 self.scroll_manager.autoscroll_request = Some((autoscroll, true));
293 cx.notify();
294 }
295
296 pub(crate) fn request_autoscroll_remotely(
297 &mut self,
298 autoscroll: Autoscroll,
299 cx: &mut Context<Self>,
300 ) {
301 self.scroll_manager.autoscroll_request = Some((autoscroll, false));
302 cx.notify();
303 }
304}