1use std::{cmp, f32};
2
3use gpui::{px, Bounds, Pixels, ViewContext};
4use language::Point;
5
6use crate::{display_map::ToDisplayPoint, Editor, EditorMode, LineWithInvisibles};
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 neweset cursor is near the top
31 /// (offset by vertical_scroll_margin)
32 pub fn focused() -> Self {
33 Self::Strategy(AutoscrollStrategy::Focused)
34 }
35 /// Scrolls so that the newest cursor is roughly an n-th line from the top.
36 pub fn top_relative(n: usize) -> Self {
37 Self::Strategy(AutoscrollStrategy::TopRelative(n))
38 }
39}
40
41#[derive(PartialEq, Eq, Default, Clone, Copy)]
42pub enum AutoscrollStrategy {
43 Fit,
44 Newest,
45 #[default]
46 Center,
47 Focused,
48 Top,
49 Bottom,
50 TopRelative(usize),
51}
52
53impl AutoscrollStrategy {
54 fn next(&self) -> Self {
55 match self {
56 AutoscrollStrategy::Center => AutoscrollStrategy::Top,
57 AutoscrollStrategy::Top => AutoscrollStrategy::Bottom,
58 _ => AutoscrollStrategy::Center,
59 }
60 }
61}
62
63impl Editor {
64 pub fn autoscroll_requested(&self) -> bool {
65 self.scroll_manager.autoscroll_requested()
66 }
67
68 pub fn autoscroll_vertically(
69 &mut self,
70 bounds: Bounds<Pixels>,
71 line_height: Pixels,
72 cx: &mut ViewContext<Editor>,
73 ) -> bool {
74 let viewport_height = bounds.size.height;
75 let visible_lines = viewport_height / line_height;
76 let display_map = self.display_map.update(cx, |map, cx| map.snapshot(cx));
77 let mut scroll_position = self.scroll_manager.scroll_position(&display_map);
78 let original_y = scroll_position.y;
79 if let Some(last_bounds) = self.expect_bounds_change.take() {
80 if scroll_position.y != 0. {
81 scroll_position.y += (bounds.top() - last_bounds.top()) / line_height;
82 if scroll_position.y < 0. {
83 scroll_position.y = 0.;
84 }
85 }
86 }
87 let max_scroll_top = if matches!(self.mode, EditorMode::AutoHeight { .. }) {
88 (display_map.max_point().row() as f32 - visible_lines + 1.).max(0.)
89 } else {
90 display_map.max_point().row() as f32
91 };
92 if scroll_position.y > max_scroll_top {
93 scroll_position.y = max_scroll_top;
94 }
95
96 if original_y != scroll_position.y {
97 self.set_scroll_position(scroll_position, cx);
98 }
99
100 let Some((autoscroll, local)) = self.scroll_manager.autoscroll_request.take() else {
101 return false;
102 };
103
104 let mut target_top;
105 let mut target_bottom;
106 if let Some(first_highlighted_row) = &self.highlighted_display_rows(cx).first_entry() {
107 target_top = *first_highlighted_row.key() as f32;
108 target_bottom = target_top + 1.;
109 } else {
110 let selections = self.selections.all::<Point>(cx);
111 target_top = selections
112 .first()
113 .unwrap()
114 .head()
115 .to_display_point(&display_map)
116 .row() as f32;
117 target_bottom = selections
118 .last()
119 .unwrap()
120 .head()
121 .to_display_point(&display_map)
122 .row() as f32
123 + 1.0;
124
125 // If the selections can't all fit on screen, scroll to the newest.
126 if autoscroll == Autoscroll::newest()
127 || autoscroll == Autoscroll::fit() && target_bottom - target_top > visible_lines
128 {
129 let newest_selection_top = selections
130 .iter()
131 .max_by_key(|s| s.id)
132 .unwrap()
133 .head()
134 .to_display_point(&display_map)
135 .row() as f32;
136 target_top = newest_selection_top;
137 target_bottom = newest_selection_top + 1.;
138 }
139 }
140
141 let margin = if matches!(self.mode, EditorMode::AutoHeight { .. }) {
142 0.
143 } else {
144 ((visible_lines - (target_bottom - target_top)) / 2.0).floor()
145 };
146
147 let strategy = match autoscroll {
148 Autoscroll::Strategy(strategy) => strategy,
149 Autoscroll::Next => {
150 let last_autoscroll = &self.scroll_manager.last_autoscroll;
151 if let Some(last_autoscroll) = last_autoscroll {
152 if self.scroll_manager.anchor.offset == last_autoscroll.0
153 && target_top == last_autoscroll.1
154 && target_bottom == last_autoscroll.2
155 {
156 last_autoscroll.3.next()
157 } else {
158 AutoscrollStrategy::default()
159 }
160 } else {
161 AutoscrollStrategy::default()
162 }
163 }
164 };
165
166 match strategy {
167 AutoscrollStrategy::Fit | AutoscrollStrategy::Newest => {
168 let margin = margin.min(self.scroll_manager.vertical_scroll_margin);
169 let target_top = (target_top - margin).max(0.0);
170 let target_bottom = target_bottom + margin;
171 let start_row = scroll_position.y;
172 let end_row = start_row + visible_lines;
173
174 let needs_scroll_up = target_top < start_row;
175 let needs_scroll_down = target_bottom >= end_row;
176
177 if needs_scroll_up && !needs_scroll_down {
178 scroll_position.y = target_top;
179 self.set_scroll_position_internal(scroll_position, local, true, cx);
180 }
181 if !needs_scroll_up && needs_scroll_down {
182 scroll_position.y = target_bottom - visible_lines;
183 self.set_scroll_position_internal(scroll_position, local, true, cx);
184 }
185 }
186 AutoscrollStrategy::Center => {
187 scroll_position.y = (target_top - margin).max(0.0);
188 self.set_scroll_position_internal(scroll_position, local, true, cx);
189 }
190 AutoscrollStrategy::Focused => {
191 scroll_position.y =
192 (target_top - self.scroll_manager.vertical_scroll_margin).max(0.0);
193 self.set_scroll_position_internal(scroll_position, local, true, cx);
194 }
195 AutoscrollStrategy::Top => {
196 scroll_position.y = (target_top).max(0.0);
197 self.set_scroll_position_internal(scroll_position, local, true, cx);
198 }
199 AutoscrollStrategy::Bottom => {
200 scroll_position.y = (target_bottom - visible_lines).max(0.0);
201 self.set_scroll_position_internal(scroll_position, local, true, cx);
202 }
203 AutoscrollStrategy::TopRelative(lines) => {
204 scroll_position.y = target_top - lines as f32;
205 self.set_scroll_position_internal(scroll_position, local, true, cx);
206 }
207 }
208
209 self.scroll_manager.last_autoscroll = Some((
210 self.scroll_manager.anchor.offset,
211 target_top,
212 target_bottom,
213 strategy,
214 ));
215
216 true
217 }
218
219 pub(crate) fn autoscroll_horizontally(
220 &mut self,
221 start_row: u32,
222 viewport_width: Pixels,
223 scroll_width: Pixels,
224 max_glyph_width: Pixels,
225 layouts: &[LineWithInvisibles],
226 cx: &mut ViewContext<Self>,
227 ) -> bool {
228 let display_map = self.display_map.update(cx, |map, cx| map.snapshot(cx));
229 let selections = self.selections.all::<Point>(cx);
230
231 let mut target_left;
232 let mut target_right;
233
234 if self.highlighted_rows.is_empty() {
235 target_left = px(f32::INFINITY);
236 target_right = px(0.);
237 for selection in selections {
238 let head = selection.head().to_display_point(&display_map);
239 if head.row() >= start_row && head.row() < start_row + layouts.len() as u32 {
240 let start_column = head.column().saturating_sub(3);
241 let end_column = cmp::min(display_map.line_len(head.row()), head.column() + 3);
242 target_left = target_left.min(
243 layouts[(head.row() - start_row) as usize]
244 .line
245 .x_for_index(start_column as usize),
246 );
247 target_right = target_right.max(
248 layouts[(head.row() - start_row) as usize]
249 .line
250 .x_for_index(end_column as usize)
251 + max_glyph_width,
252 );
253 }
254 }
255 } else {
256 target_left = px(0.);
257 target_right = px(0.);
258 }
259
260 target_right = target_right.min(scroll_width);
261
262 if target_right - target_left > viewport_width {
263 return false;
264 }
265
266 let scroll_left = self.scroll_manager.anchor.offset.x * max_glyph_width;
267 let scroll_right = scroll_left + viewport_width;
268
269 if target_left < scroll_left {
270 self.scroll_manager.anchor.offset.x = target_left / max_glyph_width;
271 true
272 } else if target_right > scroll_right {
273 self.scroll_manager.anchor.offset.x = (target_right - viewport_width) / max_glyph_width;
274 true
275 } else {
276 false
277 }
278 }
279
280 pub fn request_autoscroll(&mut self, autoscroll: Autoscroll, cx: &mut ViewContext<Self>) {
281 self.scroll_manager.autoscroll_request = Some((autoscroll, true));
282 cx.notify();
283 }
284
285 pub(crate) fn request_autoscroll_remotely(
286 &mut self,
287 autoscroll: Autoscroll,
288 cx: &mut ViewContext<Self>,
289 ) {
290 self.scroll_manager.autoscroll_request = Some((autoscroll, false));
291 cx.notify();
292 }
293}