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        Vim::take_forced_motion(cx);
 59        self.update_editor(window, cx, |_, editor, window, cx| {
 60            scroll_editor(editor, move_cursor, &amount, window, cx)
 61        });
 62    }
 63}
 64
 65fn scroll_editor(
 66    editor: &mut Editor,
 67    preserve_cursor_position: bool,
 68    amount: &ScrollAmount,
 69    window: &mut Window,
 70    cx: &mut Context<Editor>,
 71) {
 72    let should_move_cursor = editor.newest_selection_on_screen(cx).is_eq();
 73    let old_top_anchor = editor.scroll_manager.anchor().anchor;
 74
 75    if editor.scroll_hover(amount, window, cx) {
 76        return;
 77    }
 78
 79    let full_page_up = amount.is_full_page() && amount.direction().is_upwards();
 80    let amount = match (amount.is_full_page(), editor.visible_line_count()) {
 81        (true, Some(visible_line_count)) => {
 82            if amount.direction().is_upwards() {
 83                ScrollAmount::Line(amount.lines(visible_line_count) + 1.0)
 84            } else {
 85                ScrollAmount::Line(amount.lines(visible_line_count) - 1.0)
 86            }
 87        }
 88        _ => amount.clone(),
 89    };
 90
 91    editor.scroll_screen(&amount, window, cx);
 92    if !should_move_cursor {
 93        return;
 94    }
 95
 96    let Some(visible_line_count) = editor.visible_line_count() else {
 97        return;
 98    };
 99
100    let top_anchor = editor.scroll_manager.anchor().anchor;
101    let vertical_scroll_margin = EditorSettings::get_global(cx).vertical_scroll_margin;
102
103    editor.change_selections(None, window, cx, |s| {
104        s.move_with(|map, selection| {
105            let mut head = selection.head();
106            let top = top_anchor.to_display_point(map);
107            let starting_column = head.column();
108
109            let vertical_scroll_margin =
110                (vertical_scroll_margin as u32).min(visible_line_count as u32 / 2);
111
112            if preserve_cursor_position {
113                let old_top = old_top_anchor.to_display_point(map);
114                let new_row = if old_top.row() == top.row() {
115                    DisplayRow(
116                        head.row()
117                            .0
118                            .saturating_add_signed(amount.lines(visible_line_count) as i32),
119                    )
120                } else {
121                    DisplayRow(top.row().0 + selection.head().row().0 - old_top.row().0)
122                };
123                head = map.clip_point(DisplayPoint::new(new_row, head.column()), Bias::Left)
124            }
125
126            let min_row = if top.row().0 == 0 {
127                DisplayRow(0)
128            } else {
129                DisplayRow(top.row().0 + vertical_scroll_margin)
130            };
131
132            let max_visible_row = top.row().0.saturating_add(
133                (visible_line_count as u32).saturating_sub(1 + vertical_scroll_margin),
134            );
135            // scroll off the end.
136            let max_row = if top.row().0 + visible_line_count as u32 >= map.max_point().row().0 {
137                map.max_point().row()
138            } else {
139                DisplayRow(
140                    (top.row().0 + visible_line_count as u32)
141                        .saturating_sub(1 + vertical_scroll_margin),
142                )
143            };
144
145            let new_row = if full_page_up {
146                // Special-casing ctrl-b/page-up, which is special-cased by Vim, it seems
147                // to always put the cursor on the last line of the page, even if the cursor
148                // was before that.
149                DisplayRow(max_visible_row)
150            } else if head.row() < min_row {
151                min_row
152            } else if head.row() > max_row {
153                max_row
154            } else {
155                head.row()
156            };
157            let new_head = map.clip_point(DisplayPoint::new(new_row, starting_column), Bias::Left);
158
159            if selection.is_empty() {
160                selection.collapse_to(new_head, selection.goal)
161            } else {
162                selection.set_head(new_head, selection.goal)
163            };
164        })
165    });
166}
167
168#[cfg(test)]
169mod test {
170    use crate::{
171        state::Mode,
172        test::{NeovimBackedTestContext, VimTestContext},
173    };
174    use editor::{EditorSettings, ScrollBeyondLastLine};
175    use gpui::{AppContext as _, point, px, size};
176    use indoc::indoc;
177    use language::Point;
178    use settings::SettingsStore;
179
180    pub fn sample_text(rows: usize, cols: usize, start_char: char) -> String {
181        let mut text = String::new();
182        for row in 0..rows {
183            let c: char = (start_char as u32 + row as u32) as u8 as char;
184            let mut line = c.to_string().repeat(cols);
185            if row < rows - 1 {
186                line.push('\n');
187            }
188            text += &line;
189        }
190        text
191    }
192
193    #[gpui::test]
194    async fn test_scroll(cx: &mut gpui::TestAppContext) {
195        let mut cx = VimTestContext::new(cx, true).await;
196
197        let (line_height, visible_line_count) = cx.editor(|editor, window, _cx| {
198            (
199                editor
200                    .style()
201                    .unwrap()
202                    .text
203                    .line_height_in_pixels(window.rem_size()),
204                editor.visible_line_count().unwrap(),
205            )
206        });
207
208        let window = cx.window;
209        let margin = cx
210            .update_window(window, |_, window, _cx| {
211                window.viewport_size().height - line_height * visible_line_count
212            })
213            .unwrap();
214        cx.simulate_window_resize(
215            cx.window,
216            size(px(1000.), margin + 8. * line_height - px(1.0)),
217        );
218
219        cx.set_state(
220            indoc!(
221                "ˇone
222                two
223                three
224                four
225                five
226                six
227                seven
228                eight
229                nine
230                ten
231                eleven
232                twelve
233            "
234            ),
235            Mode::Normal,
236        );
237
238        cx.update_editor(|editor, window, cx| {
239            assert_eq!(editor.snapshot(window, cx).scroll_position(), point(0., 0.))
240        });
241        cx.simulate_keystrokes("ctrl-e");
242        cx.update_editor(|editor, window, cx| {
243            assert_eq!(editor.snapshot(window, cx).scroll_position(), point(0., 1.))
244        });
245        cx.simulate_keystrokes("2 ctrl-e");
246        cx.update_editor(|editor, window, cx| {
247            assert_eq!(editor.snapshot(window, cx).scroll_position(), point(0., 3.))
248        });
249        cx.simulate_keystrokes("ctrl-y");
250        cx.update_editor(|editor, window, cx| {
251            assert_eq!(editor.snapshot(window, cx).scroll_position(), point(0., 2.))
252        });
253
254        // does not select in normal mode
255        cx.simulate_keystrokes("g g");
256        cx.update_editor(|editor, window, cx| {
257            assert_eq!(editor.snapshot(window, cx).scroll_position(), point(0., 0.))
258        });
259        cx.simulate_keystrokes("ctrl-d");
260        cx.update_editor(|editor, window, cx| {
261            assert_eq!(
262                editor.snapshot(window, cx).scroll_position(),
263                point(0., 3.0)
264            );
265            assert_eq!(
266                editor.selections.newest(cx).range(),
267                Point::new(6, 0)..Point::new(6, 0)
268            )
269        });
270
271        // does select in visual mode
272        cx.simulate_keystrokes("g g");
273        cx.update_editor(|editor, window, cx| {
274            assert_eq!(editor.snapshot(window, cx).scroll_position(), point(0., 0.))
275        });
276        cx.simulate_keystrokes("v ctrl-d");
277        cx.update_editor(|editor, window, cx| {
278            assert_eq!(
279                editor.snapshot(window, cx).scroll_position(),
280                point(0., 3.0)
281            );
282            assert_eq!(
283                editor.selections.newest(cx).range(),
284                Point::new(0, 0)..Point::new(6, 1)
285            )
286        });
287    }
288
289    #[gpui::test]
290    async fn test_ctrl_d_u(cx: &mut gpui::TestAppContext) {
291        let mut cx = NeovimBackedTestContext::new(cx).await;
292
293        cx.set_scroll_height(10).await;
294
295        let content = "ˇ".to_owned() + &sample_text(26, 2, 'a');
296        cx.set_shared_state(&content).await;
297
298        // skip over the scrolloff at the top
299        // test ctrl-d
300        cx.simulate_shared_keystrokes("4 j ctrl-d").await;
301        cx.shared_state().await.assert_matches();
302        cx.simulate_shared_keystrokes("ctrl-d").await;
303        cx.shared_state().await.assert_matches();
304        cx.simulate_shared_keystrokes("g g ctrl-d").await;
305        cx.shared_state().await.assert_matches();
306
307        // test ctrl-u
308        cx.simulate_shared_keystrokes("ctrl-u").await;
309        cx.shared_state().await.assert_matches();
310        cx.simulate_shared_keystrokes("ctrl-d ctrl-d 4 j ctrl-u ctrl-u")
311            .await;
312        cx.shared_state().await.assert_matches();
313
314        // test returning to top
315        cx.simulate_shared_keystrokes("g g ctrl-d ctrl-u ctrl-u")
316            .await;
317        cx.shared_state().await.assert_matches();
318    }
319
320    #[gpui::test]
321    async fn test_ctrl_f_b(cx: &mut gpui::TestAppContext) {
322        let mut cx = NeovimBackedTestContext::new(cx).await;
323
324        let visible_lines = 10;
325        cx.set_scroll_height(visible_lines).await;
326
327        // First test without vertical scroll margin
328        cx.neovim.set_option(&format!("scrolloff={}", 0)).await;
329        cx.update_global(|store: &mut SettingsStore, cx| {
330            store.update_user_settings::<EditorSettings>(cx, |s| {
331                s.vertical_scroll_margin = Some(0.0)
332            });
333        });
334
335        let content = "ˇ".to_owned() + &sample_text(26, 2, 'a');
336        cx.set_shared_state(&content).await;
337
338        // scroll down: ctrl-f
339        cx.simulate_shared_keystrokes("ctrl-f").await;
340        cx.shared_state().await.assert_matches();
341
342        cx.simulate_shared_keystrokes("ctrl-f").await;
343        cx.shared_state().await.assert_matches();
344
345        // scroll up: ctrl-b
346        cx.simulate_shared_keystrokes("ctrl-b").await;
347        cx.shared_state().await.assert_matches();
348
349        cx.simulate_shared_keystrokes("ctrl-b").await;
350        cx.shared_state().await.assert_matches();
351
352        // Now go back to start of file, and test with vertical scroll margin
353        cx.simulate_shared_keystrokes("g g").await;
354        cx.shared_state().await.assert_matches();
355
356        cx.neovim.set_option(&format!("scrolloff={}", 3)).await;
357        cx.update_global(|store: &mut SettingsStore, cx| {
358            store.update_user_settings::<EditorSettings>(cx, |s| {
359                s.vertical_scroll_margin = Some(3.0)
360            });
361        });
362
363        // scroll down: ctrl-f
364        cx.simulate_shared_keystrokes("ctrl-f").await;
365        cx.shared_state().await.assert_matches();
366
367        cx.simulate_shared_keystrokes("ctrl-f").await;
368        cx.shared_state().await.assert_matches();
369
370        // scroll up: ctrl-b
371        cx.simulate_shared_keystrokes("ctrl-b").await;
372        cx.shared_state().await.assert_matches();
373
374        cx.simulate_shared_keystrokes("ctrl-b").await;
375        cx.shared_state().await.assert_matches();
376    }
377
378    #[gpui::test]
379    async fn test_scroll_beyond_last_line(cx: &mut gpui::TestAppContext) {
380        let mut cx = NeovimBackedTestContext::new(cx).await;
381
382        cx.set_scroll_height(10).await;
383
384        let content = "ˇ".to_owned() + &sample_text(26, 2, 'a');
385        cx.set_shared_state(&content).await;
386
387        cx.update_global(|store: &mut SettingsStore, cx| {
388            store.update_user_settings::<EditorSettings>(cx, |s| {
389                s.scroll_beyond_last_line = Some(ScrollBeyondLastLine::Off);
390                // s.vertical_scroll_margin = Some(0.);
391            });
392        });
393
394        // ctrl-d can reach the end and the cursor stays in the first column
395        cx.simulate_shared_keystrokes("shift-g k").await;
396        cx.shared_state().await.assert_matches();
397        cx.simulate_shared_keystrokes("ctrl-d").await;
398        cx.shared_state().await.assert_matches();
399
400        // ctrl-u from the last line
401        cx.simulate_shared_keystrokes("shift-g").await;
402        cx.shared_state().await.assert_matches();
403        cx.simulate_shared_keystrokes("ctrl-u").await;
404        cx.shared_state().await.assert_matches();
405    }
406
407    #[gpui::test]
408    async fn test_ctrl_y_e(cx: &mut gpui::TestAppContext) {
409        let mut cx = NeovimBackedTestContext::new(cx).await;
410
411        cx.set_scroll_height(10).await;
412
413        let content = "ˇ".to_owned() + &sample_text(26, 2, 'a');
414        cx.set_shared_state(&content).await;
415
416        for _ in 0..8 {
417            cx.simulate_shared_keystrokes("ctrl-e").await;
418            cx.shared_state().await.assert_matches();
419        }
420
421        for _ in 0..8 {
422            cx.simulate_shared_keystrokes("ctrl-y").await;
423            cx.shared_state().await.assert_matches();
424        }
425    }
426}