scroll.rs

  1use crate::Vim;
  2use editor::{
  3    display_map::{DisplayRow, ToDisplayPoint},
  4    scroll::ScrollAmount,
  5    DisplayPoint, Editor, EditorSettings,
  6};
  7use gpui::{actions, ViewContext};
  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 ViewContext<Vim>) {
 17    Vim::action(editor, cx, |vim, _: &LineDown, cx| {
 18        vim.scroll(false, cx, |c| ScrollAmount::Line(c.unwrap_or(1.)))
 19    });
 20    Vim::action(editor, cx, |vim, _: &LineUp, cx| {
 21        vim.scroll(false, cx, |c| ScrollAmount::Line(-c.unwrap_or(1.)))
 22    });
 23    Vim::action(editor, cx, |vim, _: &PageDown, cx| {
 24        vim.scroll(false, cx, |c| ScrollAmount::Page(c.unwrap_or(1.)))
 25    });
 26    Vim::action(editor, cx, |vim, _: &PageUp, cx| {
 27        vim.scroll(false, cx, |c| ScrollAmount::Page(-c.unwrap_or(1.)))
 28    });
 29    Vim::action(editor, cx, |vim, _: &ScrollDown, cx| {
 30        vim.scroll(true, 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, cx| {
 39        vim.scroll(true, 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        cx: &mut ViewContext<Self>,
 54        by: fn(c: Option<f32>) -> ScrollAmount,
 55    ) {
 56        let amount = by(self.take_count(cx).map(|c| c as f32));
 57        self.update_editor(cx, |_, editor, cx| {
 58            scroll_editor(editor, move_cursor, &amount, cx)
 59        });
 60    }
 61}
 62
 63fn scroll_editor(
 64    editor: &mut Editor,
 65    preserve_cursor_position: bool,
 66    amount: &ScrollAmount,
 67    cx: &mut ViewContext<Editor>,
 68) {
 69    let should_move_cursor = editor.newest_selection_on_screen(cx).is_eq();
 70    let old_top_anchor = editor.scroll_manager.anchor().anchor;
 71
 72    if editor.scroll_hover(amount, cx) {
 73        return;
 74    }
 75
 76    editor.scroll_screen(amount, cx);
 77    if !should_move_cursor {
 78        return;
 79    }
 80
 81    let visible_line_count = if let Some(visible_line_count) = editor.visible_line_count() {
 82        visible_line_count
 83    } else {
 84        return;
 85    };
 86
 87    let top_anchor = editor.scroll_manager.anchor().anchor;
 88    let vertical_scroll_margin = EditorSettings::get_global(cx).vertical_scroll_margin;
 89
 90    editor.change_selections(None, cx, |s| {
 91        s.move_with(|map, selection| {
 92            let mut head = selection.head();
 93            let top = top_anchor.to_display_point(map);
 94            let starting_column = head.column();
 95
 96            let vertical_scroll_margin =
 97                (vertical_scroll_margin as u32).min(visible_line_count as u32 / 2);
 98
 99            if preserve_cursor_position {
100                let old_top = old_top_anchor.to_display_point(map);
101                let new_row = if old_top.row() == top.row() {
102                    DisplayRow(
103                        head.row()
104                            .0
105                            .saturating_add_signed(amount.lines(visible_line_count) as i32),
106                    )
107                } else {
108                    DisplayRow(top.row().0 + selection.head().row().0 - old_top.row().0)
109                };
110                head = map.clip_point(DisplayPoint::new(new_row, head.column()), Bias::Left)
111            }
112
113            let min_row = if top.row().0 == 0 {
114                DisplayRow(0)
115            } else {
116                DisplayRow(top.row().0 + vertical_scroll_margin)
117            };
118            let max_row = DisplayRow(map.max_point().row().0.max(top.row().0.saturating_add(
119                (visible_line_count as u32).saturating_sub(1 + vertical_scroll_margin),
120            )));
121
122            let new_row = if head.row() < min_row {
123                min_row
124            } else if head.row() > max_row {
125                max_row
126            } else {
127                head.row()
128            };
129            let new_head = map.clip_point(DisplayPoint::new(new_row, starting_column), Bias::Left);
130
131            if selection.is_empty() {
132                selection.collapse_to(new_head, selection.goal)
133            } else {
134                selection.set_head(new_head, selection.goal)
135            };
136        })
137    });
138}
139
140#[cfg(test)]
141mod test {
142    use crate::{
143        state::Mode,
144        test::{NeovimBackedTestContext, VimTestContext},
145    };
146    use editor::{EditorSettings, ScrollBeyondLastLine};
147    use gpui::{point, px, size, Context};
148    use indoc::indoc;
149    use language::Point;
150    use settings::SettingsStore;
151
152    pub fn sample_text(rows: usize, cols: usize, start_char: char) -> String {
153        let mut text = String::new();
154        for row in 0..rows {
155            let c: char = (start_char as u32 + row as u32) as u8 as char;
156            let mut line = c.to_string().repeat(cols);
157            if row < rows - 1 {
158                line.push('\n');
159            }
160            text += &line;
161        }
162        text
163    }
164
165    #[gpui::test]
166    async fn test_scroll(cx: &mut gpui::TestAppContext) {
167        let mut cx = VimTestContext::new(cx, true).await;
168
169        let (line_height, visible_line_count) = cx.editor(|editor, cx| {
170            (
171                editor
172                    .style()
173                    .unwrap()
174                    .text
175                    .line_height_in_pixels(cx.rem_size()),
176                editor.visible_line_count().unwrap(),
177            )
178        });
179
180        let window = cx.window;
181        let margin = cx
182            .update_window(window, |_, cx| {
183                cx.viewport_size().height - line_height * visible_line_count
184            })
185            .unwrap();
186        cx.simulate_window_resize(
187            cx.window,
188            size(px(1000.), margin + 8. * line_height - px(1.0)),
189        );
190
191        cx.set_state(
192            indoc!(
193                "Λ‡one
194                two
195                three
196                four
197                five
198                six
199                seven
200                eight
201                nine
202                ten
203                eleven
204                twelve
205            "
206            ),
207            Mode::Normal,
208        );
209
210        cx.update_editor(|editor, cx| {
211            assert_eq!(editor.snapshot(cx).scroll_position(), point(0., 0.))
212        });
213        cx.simulate_keystrokes("ctrl-e");
214        cx.update_editor(|editor, cx| {
215            assert_eq!(editor.snapshot(cx).scroll_position(), point(0., 1.))
216        });
217        cx.simulate_keystrokes("2 ctrl-e");
218        cx.update_editor(|editor, cx| {
219            assert_eq!(editor.snapshot(cx).scroll_position(), point(0., 3.))
220        });
221        cx.simulate_keystrokes("ctrl-y");
222        cx.update_editor(|editor, cx| {
223            assert_eq!(editor.snapshot(cx).scroll_position(), point(0., 2.))
224        });
225
226        // does not select in normal mode
227        cx.simulate_keystrokes("g g");
228        cx.update_editor(|editor, cx| {
229            assert_eq!(editor.snapshot(cx).scroll_position(), point(0., 0.))
230        });
231        cx.simulate_keystrokes("ctrl-d");
232        cx.update_editor(|editor, cx| {
233            assert_eq!(editor.snapshot(cx).scroll_position(), point(0., 3.0));
234            assert_eq!(
235                editor.selections.newest(cx).range(),
236                Point::new(6, 0)..Point::new(6, 0)
237            )
238        });
239
240        // does select in visual mode
241        cx.simulate_keystrokes("g g");
242        cx.update_editor(|editor, cx| {
243            assert_eq!(editor.snapshot(cx).scroll_position(), point(0., 0.))
244        });
245        cx.simulate_keystrokes("v ctrl-d");
246        cx.update_editor(|editor, cx| {
247            assert_eq!(editor.snapshot(cx).scroll_position(), point(0., 3.0));
248            assert_eq!(
249                editor.selections.newest(cx).range(),
250                Point::new(0, 0)..Point::new(6, 1)
251            )
252        });
253    }
254    #[gpui::test]
255    async fn test_ctrl_d_u(cx: &mut gpui::TestAppContext) {
256        let mut cx = NeovimBackedTestContext::new(cx).await;
257
258        cx.set_scroll_height(10).await;
259
260        let content = "Λ‡".to_owned() + &sample_text(26, 2, 'a');
261        cx.set_shared_state(&content).await;
262
263        // skip over the scrolloff at the top
264        // test ctrl-d
265        cx.simulate_shared_keystrokes("4 j ctrl-d").await;
266        cx.shared_state().await.assert_matches();
267        cx.simulate_shared_keystrokes("ctrl-d").await;
268        cx.shared_state().await.assert_matches();
269        cx.simulate_shared_keystrokes("g g ctrl-d").await;
270        cx.shared_state().await.assert_matches();
271
272        // test ctrl-u
273        cx.simulate_shared_keystrokes("ctrl-u").await;
274        cx.shared_state().await.assert_matches();
275        cx.simulate_shared_keystrokes("ctrl-d ctrl-d 4 j ctrl-u ctrl-u")
276            .await;
277        cx.shared_state().await.assert_matches();
278
279        // test returning to top
280        cx.simulate_shared_keystrokes("g g ctrl-d ctrl-u ctrl-u")
281            .await;
282        cx.shared_state().await.assert_matches();
283    }
284
285    #[gpui::test]
286    async fn test_scroll_beyond_last_line(cx: &mut gpui::TestAppContext) {
287        let mut cx = NeovimBackedTestContext::new(cx).await;
288
289        cx.set_scroll_height(10).await;
290        cx.neovim.set_option(&format!("scrolloff={}", 0)).await;
291
292        let content = "Λ‡".to_owned() + &sample_text(26, 2, 'a');
293        cx.set_shared_state(&content).await;
294
295        cx.update_global(|store: &mut SettingsStore, cx| {
296            store.update_user_settings::<EditorSettings>(cx, |s| {
297                s.scroll_beyond_last_line = Some(ScrollBeyondLastLine::Off)
298            });
299        });
300
301        // ctrl-d can reach the end and the cursor stays in the first column
302        cx.simulate_shared_keystrokes("shift-g k").await;
303        cx.shared_state().await.assert_matches();
304        cx.simulate_shared_keystrokes("ctrl-d").await;
305        cx.shared_state().await.assert_matches();
306
307        // ctrl-u from the last line
308        cx.simulate_shared_keystrokes("shift-g").await;
309        cx.shared_state().await.assert_matches();
310        cx.simulate_shared_keystrokes("ctrl-u").await;
311        cx.shared_state().await.assert_matches();
312    }
313}