scroll.rs

  1use crate::Vim;
  2use editor::{
  3    DisplayPoint, Editor, EditorSettings,
  4    display_map::{DisplayRow, ToDisplayPoint},
  5    scroll::ScrollAmount,
  6};
  7use gpui::{Context, Window, actions};
  8use language::Bias;
  9use settings::Settings;
 10
 11actions!(
 12    vim,
 13    [LineUp, LineDown, ScrollUp, ScrollDown, PageUp, PageDown]
 14);
 15
 16pub fn register(editor: &mut Editor, cx: &mut Context<Vim>) {
 17    Vim::action(editor, cx, |vim, _: &LineDown, window, cx| {
 18        vim.scroll(false, window, cx, |c| ScrollAmount::Line(c.unwrap_or(1.)))
 19    });
 20    Vim::action(editor, cx, |vim, _: &LineUp, window, cx| {
 21        vim.scroll(false, window, cx, |c| ScrollAmount::Line(-c.unwrap_or(1.)))
 22    });
 23    Vim::action(editor, cx, |vim, _: &PageDown, window, cx| {
 24        vim.scroll(false, window, cx, |c| ScrollAmount::Page(c.unwrap_or(1.)))
 25    });
 26    Vim::action(editor, cx, |vim, _: &PageUp, window, cx| {
 27        vim.scroll(false, window, cx, |c| ScrollAmount::Page(-c.unwrap_or(1.)))
 28    });
 29    Vim::action(editor, cx, |vim, _: &ScrollDown, window, cx| {
 30        vim.scroll(true, window, cx, |c| {
 31            if let Some(c) = c {
 32                ScrollAmount::Line(c)
 33            } else {
 34                ScrollAmount::Page(0.5)
 35            }
 36        })
 37    });
 38    Vim::action(editor, cx, |vim, _: &ScrollUp, window, cx| {
 39        vim.scroll(true, window, cx, |c| {
 40            if let Some(c) = c {
 41                ScrollAmount::Line(-c)
 42            } else {
 43                ScrollAmount::Page(-0.5)
 44            }
 45        })
 46    });
 47}
 48
 49impl Vim {
 50    fn scroll(
 51        &mut self,
 52        move_cursor: bool,
 53        window: &mut Window,
 54        cx: &mut Context<Self>,
 55        by: fn(c: Option<f32>) -> ScrollAmount,
 56    ) {
 57        let amount = by(Vim::take_count(cx).map(|c| c as f32));
 58        self.update_editor(window, cx, |_, editor, window, cx| {
 59            scroll_editor(editor, move_cursor, &amount, window, cx)
 60        });
 61    }
 62}
 63
 64fn scroll_editor(
 65    editor: &mut Editor,
 66    preserve_cursor_position: bool,
 67    amount: &ScrollAmount,
 68    window: &mut Window,
 69    cx: &mut Context<Editor>,
 70) {
 71    let should_move_cursor = editor.newest_selection_on_screen(cx).is_eq();
 72    let old_top_anchor = editor.scroll_manager.anchor().anchor;
 73
 74    if editor.scroll_hover(amount, window, cx) {
 75        return;
 76    }
 77
 78    let full_page_up = amount.is_full_page() && amount.direction().is_upwards();
 79    let amount = match (amount.is_full_page(), editor.visible_line_count()) {
 80        (true, Some(visible_line_count)) => {
 81            if amount.direction().is_upwards() {
 82                ScrollAmount::Line(amount.lines(visible_line_count) + 1.0)
 83            } else {
 84                ScrollAmount::Line(amount.lines(visible_line_count) - 1.0)
 85            }
 86        }
 87        _ => amount.clone(),
 88    };
 89
 90    editor.scroll_screen(&amount, window, cx);
 91    if !should_move_cursor {
 92        return;
 93    }
 94
 95    let Some(visible_line_count) = editor.visible_line_count() else {
 96        return;
 97    };
 98
 99    let top_anchor = editor.scroll_manager.anchor().anchor;
100    let vertical_scroll_margin = EditorSettings::get_global(cx).vertical_scroll_margin;
101
102    editor.change_selections(None, window, cx, |s| {
103        s.move_with(|map, selection| {
104            let mut head = selection.head();
105            let top = top_anchor.to_display_point(map);
106            let starting_column = head.column();
107
108            let vertical_scroll_margin =
109                (vertical_scroll_margin as u32).min(visible_line_count as u32 / 2);
110
111            if preserve_cursor_position {
112                let old_top = old_top_anchor.to_display_point(map);
113                let new_row = if old_top.row() == top.row() {
114                    DisplayRow(
115                        head.row()
116                            .0
117                            .saturating_add_signed(amount.lines(visible_line_count) as i32),
118                    )
119                } else {
120                    DisplayRow(top.row().0 + selection.head().row().0 - old_top.row().0)
121                };
122                head = map.clip_point(DisplayPoint::new(new_row, head.column()), Bias::Left)
123            }
124
125            let min_row = if top.row().0 == 0 {
126                DisplayRow(0)
127            } else {
128                DisplayRow(top.row().0 + vertical_scroll_margin)
129            };
130
131            let max_visible_row = top.row().0.saturating_add(
132                (visible_line_count as u32).saturating_sub(1 + vertical_scroll_margin),
133            );
134            let max_row = DisplayRow(map.max_point().row().0.max(max_visible_row));
135
136            let new_row = if full_page_up {
137                // Special-casing ctrl-b/page-up, which is special-cased by Vim, it seems
138                // to always put the cursor on the last line of the page, even if the cursor
139                // was before that.
140                DisplayRow(max_visible_row)
141            } else if head.row() < min_row {
142                min_row
143            } else if head.row() > max_row {
144                max_row
145            } else {
146                head.row()
147            };
148            let new_head = map.clip_point(DisplayPoint::new(new_row, starting_column), Bias::Left);
149
150            if selection.is_empty() {
151                selection.collapse_to(new_head, selection.goal)
152            } else {
153                selection.set_head(new_head, selection.goal)
154            };
155        })
156    });
157}
158
159#[cfg(test)]
160mod test {
161    use crate::{
162        state::Mode,
163        test::{NeovimBackedTestContext, VimTestContext},
164    };
165    use editor::{EditorSettings, ScrollBeyondLastLine};
166    use gpui::{AppContext as _, point, px, size};
167    use indoc::indoc;
168    use language::Point;
169    use settings::SettingsStore;
170
171    pub fn sample_text(rows: usize, cols: usize, start_char: char) -> String {
172        let mut text = String::new();
173        for row in 0..rows {
174            let c: char = (start_char as u32 + row as u32) as u8 as char;
175            let mut line = c.to_string().repeat(cols);
176            if row < rows - 1 {
177                line.push('\n');
178            }
179            text += &line;
180        }
181        text
182    }
183
184    #[gpui::test]
185    async fn test_scroll(cx: &mut gpui::TestAppContext) {
186        let mut cx = VimTestContext::new(cx, true).await;
187
188        let (line_height, visible_line_count) = cx.editor(|editor, window, _cx| {
189            (
190                editor
191                    .style()
192                    .unwrap()
193                    .text
194                    .line_height_in_pixels(window.rem_size()),
195                editor.visible_line_count().unwrap(),
196            )
197        });
198
199        let window = cx.window;
200        let margin = cx
201            .update_window(window, |_, window, _cx| {
202                window.viewport_size().height - line_height * visible_line_count
203            })
204            .unwrap();
205        cx.simulate_window_resize(
206            cx.window,
207            size(px(1000.), margin + 8. * line_height - px(1.0)),
208        );
209
210        cx.set_state(
211            indoc!(
212                "ˇone
213                two
214                three
215                four
216                five
217                six
218                seven
219                eight
220                nine
221                ten
222                eleven
223                twelve
224            "
225            ),
226            Mode::Normal,
227        );
228
229        cx.update_editor(|editor, window, cx| {
230            assert_eq!(editor.snapshot(window, cx).scroll_position(), point(0., 0.))
231        });
232        cx.simulate_keystrokes("ctrl-e");
233        cx.update_editor(|editor, window, cx| {
234            assert_eq!(editor.snapshot(window, cx).scroll_position(), point(0., 1.))
235        });
236        cx.simulate_keystrokes("2 ctrl-e");
237        cx.update_editor(|editor, window, cx| {
238            assert_eq!(editor.snapshot(window, cx).scroll_position(), point(0., 3.))
239        });
240        cx.simulate_keystrokes("ctrl-y");
241        cx.update_editor(|editor, window, cx| {
242            assert_eq!(editor.snapshot(window, cx).scroll_position(), point(0., 2.))
243        });
244
245        // does not select in normal mode
246        cx.simulate_keystrokes("g g");
247        cx.update_editor(|editor, window, cx| {
248            assert_eq!(editor.snapshot(window, cx).scroll_position(), point(0., 0.))
249        });
250        cx.simulate_keystrokes("ctrl-d");
251        cx.update_editor(|editor, window, cx| {
252            assert_eq!(
253                editor.snapshot(window, cx).scroll_position(),
254                point(0., 3.0)
255            );
256            assert_eq!(
257                editor.selections.newest(cx).range(),
258                Point::new(6, 0)..Point::new(6, 0)
259            )
260        });
261
262        // does select in visual mode
263        cx.simulate_keystrokes("g g");
264        cx.update_editor(|editor, window, cx| {
265            assert_eq!(editor.snapshot(window, cx).scroll_position(), point(0., 0.))
266        });
267        cx.simulate_keystrokes("v ctrl-d");
268        cx.update_editor(|editor, window, cx| {
269            assert_eq!(
270                editor.snapshot(window, cx).scroll_position(),
271                point(0., 3.0)
272            );
273            assert_eq!(
274                editor.selections.newest(cx).range(),
275                Point::new(0, 0)..Point::new(6, 1)
276            )
277        });
278    }
279
280    #[gpui::test]
281    async fn test_ctrl_d_u(cx: &mut gpui::TestAppContext) {
282        let mut cx = NeovimBackedTestContext::new(cx).await;
283
284        cx.set_scroll_height(10).await;
285
286        let content = "ˇ".to_owned() + &sample_text(26, 2, 'a');
287        cx.set_shared_state(&content).await;
288
289        // skip over the scrolloff at the top
290        // test ctrl-d
291        cx.simulate_shared_keystrokes("4 j ctrl-d").await;
292        cx.shared_state().await.assert_matches();
293        cx.simulate_shared_keystrokes("ctrl-d").await;
294        cx.shared_state().await.assert_matches();
295        cx.simulate_shared_keystrokes("g g ctrl-d").await;
296        cx.shared_state().await.assert_matches();
297
298        // test ctrl-u
299        cx.simulate_shared_keystrokes("ctrl-u").await;
300        cx.shared_state().await.assert_matches();
301        cx.simulate_shared_keystrokes("ctrl-d ctrl-d 4 j ctrl-u ctrl-u")
302            .await;
303        cx.shared_state().await.assert_matches();
304
305        // test returning to top
306        cx.simulate_shared_keystrokes("g g ctrl-d ctrl-u ctrl-u")
307            .await;
308        cx.shared_state().await.assert_matches();
309    }
310
311    #[gpui::test]
312    async fn test_ctrl_f_b(cx: &mut gpui::TestAppContext) {
313        let mut cx = NeovimBackedTestContext::new(cx).await;
314
315        let visible_lines = 10;
316        cx.set_scroll_height(visible_lines).await;
317
318        // First test without vertical scroll margin
319        cx.neovim.set_option(&format!("scrolloff={}", 0)).await;
320        cx.update_global(|store: &mut SettingsStore, cx| {
321            store.update_user_settings::<EditorSettings>(cx, |s| {
322                s.vertical_scroll_margin = Some(0.0)
323            });
324        });
325
326        let content = "ˇ".to_owned() + &sample_text(26, 2, 'a');
327        cx.set_shared_state(&content).await;
328
329        // scroll down: ctrl-f
330        cx.simulate_shared_keystrokes("ctrl-f").await;
331        cx.shared_state().await.assert_matches();
332
333        cx.simulate_shared_keystrokes("ctrl-f").await;
334        cx.shared_state().await.assert_matches();
335
336        // scroll up: ctrl-b
337        cx.simulate_shared_keystrokes("ctrl-b").await;
338        cx.shared_state().await.assert_matches();
339
340        cx.simulate_shared_keystrokes("ctrl-b").await;
341        cx.shared_state().await.assert_matches();
342
343        // Now go back to start of file, and test with vertical scroll margin
344        cx.simulate_shared_keystrokes("g g").await;
345        cx.shared_state().await.assert_matches();
346
347        cx.neovim.set_option(&format!("scrolloff={}", 3)).await;
348        cx.update_global(|store: &mut SettingsStore, cx| {
349            store.update_user_settings::<EditorSettings>(cx, |s| {
350                s.vertical_scroll_margin = Some(3.0)
351            });
352        });
353
354        // scroll down: ctrl-f
355        cx.simulate_shared_keystrokes("ctrl-f").await;
356        cx.shared_state().await.assert_matches();
357
358        cx.simulate_shared_keystrokes("ctrl-f").await;
359        cx.shared_state().await.assert_matches();
360
361        // scroll up: ctrl-b
362        cx.simulate_shared_keystrokes("ctrl-b").await;
363        cx.shared_state().await.assert_matches();
364
365        cx.simulate_shared_keystrokes("ctrl-b").await;
366        cx.shared_state().await.assert_matches();
367    }
368
369    #[gpui::test]
370    async fn test_scroll_beyond_last_line(cx: &mut gpui::TestAppContext) {
371        let mut cx = NeovimBackedTestContext::new(cx).await;
372
373        cx.set_scroll_height(10).await;
374        cx.neovim.set_option(&format!("scrolloff={}", 0)).await;
375
376        let content = "ˇ".to_owned() + &sample_text(26, 2, 'a');
377        cx.set_shared_state(&content).await;
378
379        cx.update_global(|store: &mut SettingsStore, cx| {
380            store.update_user_settings::<EditorSettings>(cx, |s| {
381                s.scroll_beyond_last_line = Some(ScrollBeyondLastLine::Off)
382            });
383        });
384
385        // ctrl-d can reach the end and the cursor stays in the first column
386        cx.simulate_shared_keystrokes("shift-g k").await;
387        cx.shared_state().await.assert_matches();
388        cx.simulate_shared_keystrokes("ctrl-d").await;
389        cx.shared_state().await.assert_matches();
390
391        // ctrl-u from the last line
392        cx.simulate_shared_keystrokes("shift-g").await;
393        cx.shared_state().await.assert_matches();
394        cx.simulate_shared_keystrokes("ctrl-u").await;
395        cx.shared_state().await.assert_matches();
396    }
397}