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.exit_temporary_normal(window, cx);
 60        self.update_editor(window, cx, |_, editor, window, cx| {
 61            scroll_editor(editor, move_cursor, &amount, window, cx)
 62        });
 63    }
 64}
 65
 66fn scroll_editor(
 67    editor: &mut Editor,
 68    preserve_cursor_position: bool,
 69    amount: &ScrollAmount,
 70    window: &mut Window,
 71    cx: &mut Context<Editor>,
 72) {
 73    let should_move_cursor = editor.newest_selection_on_screen(cx).is_eq();
 74    let old_top_anchor = editor.scroll_manager.anchor().anchor;
 75
 76    if editor.scroll_hover(amount, window, cx) {
 77        return;
 78    }
 79
 80    let full_page_up = amount.is_full_page() && amount.direction().is_upwards();
 81    let amount = match (amount.is_full_page(), editor.visible_line_count()) {
 82        (true, Some(visible_line_count)) => {
 83            if amount.direction().is_upwards() {
 84                ScrollAmount::Line(amount.lines(visible_line_count) + 1.0)
 85            } else {
 86                ScrollAmount::Line(amount.lines(visible_line_count) - 1.0)
 87            }
 88        }
 89        _ => amount.clone(),
 90    };
 91
 92    editor.scroll_screen(&amount, window, cx);
 93    if !should_move_cursor {
 94        return;
 95    }
 96
 97    let Some(visible_line_count) = editor.visible_line_count() else {
 98        return;
 99    };
100
101    let top_anchor = editor.scroll_manager.anchor().anchor;
102    let vertical_scroll_margin = EditorSettings::get_global(cx).vertical_scroll_margin;
103
104    editor.change_selections(None, window, cx, |s| {
105        s.move_with(|map, selection| {
106            let mut head = selection.head();
107            let top = top_anchor.to_display_point(map);
108            let starting_column = head.column();
109
110            let vertical_scroll_margin =
111                (vertical_scroll_margin as u32).min(visible_line_count as u32 / 2);
112
113            if preserve_cursor_position {
114                let old_top = old_top_anchor.to_display_point(map);
115                let new_row = if old_top.row() == top.row() {
116                    DisplayRow(
117                        head.row()
118                            .0
119                            .saturating_add_signed(amount.lines(visible_line_count) as i32),
120                    )
121                } else {
122                    DisplayRow(top.row().0 + selection.head().row().0 - old_top.row().0)
123                };
124                head = map.clip_point(DisplayPoint::new(new_row, head.column()), Bias::Left)
125            }
126
127            let min_row = if top.row().0 == 0 {
128                DisplayRow(0)
129            } else {
130                DisplayRow(top.row().0 + vertical_scroll_margin)
131            };
132
133            let max_visible_row = top.row().0.saturating_add(
134                (visible_line_count as u32).saturating_sub(1 + vertical_scroll_margin),
135            );
136            // scroll off the end.
137            let max_row = if top.row().0 + visible_line_count as u32 >= map.max_point().row().0 {
138                map.max_point().row()
139            } else {
140                DisplayRow(
141                    (top.row().0 + visible_line_count as u32)
142                        .saturating_sub(1 + vertical_scroll_margin),
143                )
144            };
145
146            let new_row = if full_page_up {
147                // Special-casing ctrl-b/page-up, which is special-cased by Vim, it seems
148                // to always put the cursor on the last line of the page, even if the cursor
149                // was before that.
150                DisplayRow(max_visible_row)
151            } else if head.row() < min_row {
152                min_row
153            } else if head.row() > max_row {
154                max_row
155            } else {
156                head.row()
157            };
158            let new_head = map.clip_point(DisplayPoint::new(new_row, starting_column), Bias::Left);
159
160            if selection.is_empty() {
161                selection.collapse_to(new_head, selection.goal)
162            } else {
163                selection.set_head(new_head, selection.goal)
164            };
165        })
166    });
167}
168
169#[cfg(test)]
170mod test {
171    use crate::{
172        state::Mode,
173        test::{NeovimBackedTestContext, VimTestContext},
174    };
175    use editor::{EditorSettings, ScrollBeyondLastLine};
176    use gpui::{AppContext as _, point, px, size};
177    use indoc::indoc;
178    use language::Point;
179    use settings::SettingsStore;
180
181    pub fn sample_text(rows: usize, cols: usize, start_char: char) -> String {
182        let mut text = String::new();
183        for row in 0..rows {
184            let c: char = (start_char as u32 + row as u32) as u8 as char;
185            let mut line = c.to_string().repeat(cols);
186            if row < rows - 1 {
187                line.push('\n');
188            }
189            text += &line;
190        }
191        text
192    }
193
194    #[gpui::test]
195    async fn test_scroll(cx: &mut gpui::TestAppContext) {
196        let mut cx = VimTestContext::new(cx, true).await;
197
198        let (line_height, visible_line_count) = cx.editor(|editor, window, _cx| {
199            (
200                editor
201                    .style()
202                    .unwrap()
203                    .text
204                    .line_height_in_pixels(window.rem_size()),
205                editor.visible_line_count().unwrap(),
206            )
207        });
208
209        let window = cx.window;
210        let margin = cx
211            .update_window(window, |_, window, _cx| {
212                window.viewport_size().height - line_height * visible_line_count
213            })
214            .unwrap();
215        cx.simulate_window_resize(
216            cx.window,
217            size(px(1000.), margin + 8. * line_height - px(1.0)),
218        );
219
220        cx.set_state(
221            indoc!(
222                "ˇone
223                two
224                three
225                four
226                five
227                six
228                seven
229                eight
230                nine
231                ten
232                eleven
233                twelve
234            "
235            ),
236            Mode::Normal,
237        );
238
239        cx.update_editor(|editor, window, cx| {
240            assert_eq!(editor.snapshot(window, cx).scroll_position(), point(0., 0.))
241        });
242        cx.simulate_keystrokes("ctrl-e");
243        cx.update_editor(|editor, window, cx| {
244            assert_eq!(editor.snapshot(window, cx).scroll_position(), point(0., 1.))
245        });
246        cx.simulate_keystrokes("2 ctrl-e");
247        cx.update_editor(|editor, window, cx| {
248            assert_eq!(editor.snapshot(window, cx).scroll_position(), point(0., 3.))
249        });
250        cx.simulate_keystrokes("ctrl-y");
251        cx.update_editor(|editor, window, cx| {
252            assert_eq!(editor.snapshot(window, cx).scroll_position(), point(0., 2.))
253        });
254
255        // does not select in normal mode
256        cx.simulate_keystrokes("g g");
257        cx.update_editor(|editor, window, cx| {
258            assert_eq!(editor.snapshot(window, cx).scroll_position(), point(0., 0.))
259        });
260        cx.simulate_keystrokes("ctrl-d");
261        cx.update_editor(|editor, window, cx| {
262            assert_eq!(
263                editor.snapshot(window, cx).scroll_position(),
264                point(0., 3.0)
265            );
266            assert_eq!(
267                editor.selections.newest(cx).range(),
268                Point::new(6, 0)..Point::new(6, 0)
269            )
270        });
271
272        // does select in visual mode
273        cx.simulate_keystrokes("g g");
274        cx.update_editor(|editor, window, cx| {
275            assert_eq!(editor.snapshot(window, cx).scroll_position(), point(0., 0.))
276        });
277        cx.simulate_keystrokes("v ctrl-d");
278        cx.update_editor(|editor, window, cx| {
279            assert_eq!(
280                editor.snapshot(window, cx).scroll_position(),
281                point(0., 3.0)
282            );
283            assert_eq!(
284                editor.selections.newest(cx).range(),
285                Point::new(0, 0)..Point::new(6, 1)
286            )
287        });
288    }
289
290    #[gpui::test]
291    async fn test_ctrl_d_u(cx: &mut gpui::TestAppContext) {
292        let mut cx = NeovimBackedTestContext::new(cx).await;
293
294        cx.set_scroll_height(10).await;
295
296        let content = "ˇ".to_owned() + &sample_text(26, 2, 'a');
297        cx.set_shared_state(&content).await;
298
299        // skip over the scrolloff at the top
300        // test ctrl-d
301        cx.simulate_shared_keystrokes("4 j ctrl-d").await;
302        cx.shared_state().await.assert_matches();
303        cx.simulate_shared_keystrokes("ctrl-d").await;
304        cx.shared_state().await.assert_matches();
305        cx.simulate_shared_keystrokes("g g ctrl-d").await;
306        cx.shared_state().await.assert_matches();
307
308        // test ctrl-u
309        cx.simulate_shared_keystrokes("ctrl-u").await;
310        cx.shared_state().await.assert_matches();
311        cx.simulate_shared_keystrokes("ctrl-d ctrl-d 4 j ctrl-u ctrl-u")
312            .await;
313        cx.shared_state().await.assert_matches();
314
315        // test returning to top
316        cx.simulate_shared_keystrokes("g g ctrl-d ctrl-u ctrl-u")
317            .await;
318        cx.shared_state().await.assert_matches();
319    }
320
321    #[gpui::test]
322    async fn test_ctrl_f_b(cx: &mut gpui::TestAppContext) {
323        let mut cx = NeovimBackedTestContext::new(cx).await;
324
325        let visible_lines = 10;
326        cx.set_scroll_height(visible_lines).await;
327
328        // First test without vertical scroll margin
329        cx.neovim.set_option(&format!("scrolloff={}", 0)).await;
330        cx.update_global(|store: &mut SettingsStore, cx| {
331            store.update_user_settings::<EditorSettings>(cx, |s| {
332                s.vertical_scroll_margin = Some(0.0)
333            });
334        });
335
336        let content = "ˇ".to_owned() + &sample_text(26, 2, 'a');
337        cx.set_shared_state(&content).await;
338
339        // scroll down: ctrl-f
340        cx.simulate_shared_keystrokes("ctrl-f").await;
341        cx.shared_state().await.assert_matches();
342
343        cx.simulate_shared_keystrokes("ctrl-f").await;
344        cx.shared_state().await.assert_matches();
345
346        // scroll up: ctrl-b
347        cx.simulate_shared_keystrokes("ctrl-b").await;
348        cx.shared_state().await.assert_matches();
349
350        cx.simulate_shared_keystrokes("ctrl-b").await;
351        cx.shared_state().await.assert_matches();
352
353        // Now go back to start of file, and test with vertical scroll margin
354        cx.simulate_shared_keystrokes("g g").await;
355        cx.shared_state().await.assert_matches();
356
357        cx.neovim.set_option(&format!("scrolloff={}", 3)).await;
358        cx.update_global(|store: &mut SettingsStore, cx| {
359            store.update_user_settings::<EditorSettings>(cx, |s| {
360                s.vertical_scroll_margin = Some(3.0)
361            });
362        });
363
364        // scroll down: ctrl-f
365        cx.simulate_shared_keystrokes("ctrl-f").await;
366        cx.shared_state().await.assert_matches();
367
368        cx.simulate_shared_keystrokes("ctrl-f").await;
369        cx.shared_state().await.assert_matches();
370
371        // scroll up: ctrl-b
372        cx.simulate_shared_keystrokes("ctrl-b").await;
373        cx.shared_state().await.assert_matches();
374
375        cx.simulate_shared_keystrokes("ctrl-b").await;
376        cx.shared_state().await.assert_matches();
377    }
378
379    #[gpui::test]
380    async fn test_scroll_beyond_last_line(cx: &mut gpui::TestAppContext) {
381        let mut cx = NeovimBackedTestContext::new(cx).await;
382
383        cx.set_scroll_height(10).await;
384
385        let content = "ˇ".to_owned() + &sample_text(26, 2, 'a');
386        cx.set_shared_state(&content).await;
387
388        cx.update_global(|store: &mut SettingsStore, cx| {
389            store.update_user_settings::<EditorSettings>(cx, |s| {
390                s.scroll_beyond_last_line = Some(ScrollBeyondLastLine::Off);
391                // s.vertical_scroll_margin = Some(0.);
392            });
393        });
394
395        // ctrl-d can reach the end and the cursor stays in the first column
396        cx.simulate_shared_keystrokes("shift-g k").await;
397        cx.shared_state().await.assert_matches();
398        cx.simulate_shared_keystrokes("ctrl-d").await;
399        cx.shared_state().await.assert_matches();
400
401        // ctrl-u from the last line
402        cx.simulate_shared_keystrokes("shift-g").await;
403        cx.shared_state().await.assert_matches();
404        cx.simulate_shared_keystrokes("ctrl-u").await;
405        cx.shared_state().await.assert_matches();
406    }
407
408    #[gpui::test]
409    async fn test_ctrl_y_e(cx: &mut gpui::TestAppContext) {
410        let mut cx = NeovimBackedTestContext::new(cx).await;
411
412        cx.set_scroll_height(10).await;
413
414        let content = "ˇ".to_owned() + &sample_text(26, 2, 'a');
415        cx.set_shared_state(&content).await;
416
417        for _ in 0..8 {
418            cx.simulate_shared_keystrokes("ctrl-e").await;
419            cx.shared_state().await.assert_matches();
420        }
421
422        for _ in 0..8 {
423            cx.simulate_shared_keystrokes("ctrl-y").await;
424            cx.shared_state().await.assert_matches();
425        }
426    }
427}