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;
 10use workspace::Workspace;
 11
 12actions!(
 13    vim,
 14    [LineUp, LineDown, ScrollUp, ScrollDown, PageUp, PageDown]
 15);
 16
 17pub fn register(workspace: &mut Workspace, _: &mut ViewContext<Workspace>) {
 18    workspace.register_action(|_: &mut Workspace, _: &LineDown, cx| {
 19        scroll(cx, false, |c| ScrollAmount::Line(c.unwrap_or(1.)))
 20    });
 21    workspace.register_action(|_: &mut Workspace, _: &LineUp, cx| {
 22        scroll(cx, false, |c| ScrollAmount::Line(-c.unwrap_or(1.)))
 23    });
 24    workspace.register_action(|_: &mut Workspace, _: &PageDown, cx| {
 25        scroll(cx, false, |c| ScrollAmount::Page(c.unwrap_or(1.)))
 26    });
 27    workspace.register_action(|_: &mut Workspace, _: &PageUp, cx| {
 28        scroll(cx, false, |c| ScrollAmount::Page(-c.unwrap_or(1.)))
 29    });
 30    workspace.register_action(|_: &mut Workspace, _: &ScrollDown, cx| {
 31        scroll(cx, true, |c| {
 32            if let Some(c) = c {
 33                ScrollAmount::Line(c)
 34            } else {
 35                ScrollAmount::Page(0.5)
 36            }
 37        })
 38    });
 39    workspace.register_action(|_: &mut Workspace, _: &ScrollUp, cx| {
 40        scroll(cx, true, |c| {
 41            if let Some(c) = c {
 42                ScrollAmount::Line(-c)
 43            } else {
 44                ScrollAmount::Page(-0.5)
 45            }
 46        })
 47    });
 48}
 49
 50fn scroll(
 51    cx: &mut ViewContext<Workspace>,
 52    move_cursor: bool,
 53    by: fn(c: Option<f32>) -> ScrollAmount,
 54) {
 55    Vim::update(cx, |vim, cx| {
 56        let amount = by(vim.take_count(cx).map(|c| c as f32));
 57        vim.update_active_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
 95            let vertical_scroll_margin =
 96                (vertical_scroll_margin as u32).min(visible_line_count as u32 / 2);
 97
 98            if preserve_cursor_position {
 99                let old_top = old_top_anchor.to_display_point(map);
100                let new_row = if old_top.row() == top.row() {
101                    DisplayRow(
102                        top.row()
103                            .0
104                            .saturating_add_signed(amount.lines(visible_line_count) as i32),
105                    )
106                } else {
107                    DisplayRow(top.row().0 + selection.head().row().0 - old_top.row().0)
108                };
109                head = map.clip_point(DisplayPoint::new(new_row, head.column()), Bias::Left)
110            }
111            let min_row = if top.row().0 == 0 {
112                DisplayRow(0)
113            } else {
114                DisplayRow(top.row().0 + vertical_scroll_margin)
115            };
116            let max_row = DisplayRow(
117                top.row().0
118                    + (visible_line_count as u32)
119                        .saturating_sub(vertical_scroll_margin)
120                        .saturating_sub(1),
121            );
122
123            let new_head = if head.row() < min_row {
124                map.clip_point(DisplayPoint::new(min_row, head.column()), Bias::Left)
125            } else if head.row() > max_row {
126                map.clip_point(DisplayPoint::new(max_row, head.column()), Bias::Left)
127            } else {
128                head
129            };
130            if selection.is_empty() {
131                selection.collapse_to(new_head, selection.goal)
132            } else {
133                selection.set_head(new_head, selection.goal)
134            };
135        })
136    });
137}
138
139#[cfg(test)]
140mod test {
141    use crate::{
142        state::Mode,
143        test::{NeovimBackedTestContext, VimTestContext},
144    };
145    use gpui::{point, px, size, Context};
146    use indoc::indoc;
147    use language::Point;
148
149    #[gpui::test]
150    async fn test_scroll(cx: &mut gpui::TestAppContext) {
151        let mut cx = VimTestContext::new(cx, true).await;
152
153        let (line_height, visible_line_count) = cx.editor(|editor, cx| {
154            (
155                editor
156                    .style()
157                    .unwrap()
158                    .text
159                    .line_height_in_pixels(cx.rem_size()),
160                editor.visible_line_count().unwrap(),
161            )
162        });
163
164        let window = cx.window;
165        let margin = cx
166            .update_window(window, |_, cx| {
167                cx.viewport_size().height - line_height * visible_line_count
168            })
169            .unwrap();
170        cx.simulate_window_resize(
171            cx.window,
172            size(px(1000.), margin + 8. * line_height - px(1.0)),
173        );
174
175        cx.set_state(
176            indoc!(
177                "Λ‡one
178                two
179                three
180                four
181                five
182                six
183                seven
184                eight
185                nine
186                ten
187                eleven
188                twelve
189            "
190            ),
191            Mode::Normal,
192        );
193
194        cx.update_editor(|editor, cx| {
195            assert_eq!(editor.snapshot(cx).scroll_position(), point(0., 0.))
196        });
197        cx.simulate_keystrokes("ctrl-e");
198        cx.update_editor(|editor, cx| {
199            assert_eq!(editor.snapshot(cx).scroll_position(), point(0., 1.))
200        });
201        cx.simulate_keystrokes("2 ctrl-e");
202        cx.update_editor(|editor, cx| {
203            assert_eq!(editor.snapshot(cx).scroll_position(), point(0., 3.))
204        });
205        cx.simulate_keystrokes("ctrl-y");
206        cx.update_editor(|editor, cx| {
207            assert_eq!(editor.snapshot(cx).scroll_position(), point(0., 2.))
208        });
209
210        // does not select in normal mode
211        cx.simulate_keystrokes("g g");
212        cx.update_editor(|editor, cx| {
213            assert_eq!(editor.snapshot(cx).scroll_position(), point(0., 0.))
214        });
215        cx.simulate_keystrokes("ctrl-d");
216        cx.update_editor(|editor, cx| {
217            assert_eq!(editor.snapshot(cx).scroll_position(), point(0., 3.0));
218            assert_eq!(
219                editor.selections.newest(cx).range(),
220                Point::new(6, 0)..Point::new(6, 0)
221            )
222        });
223
224        // does select in visual mode
225        cx.simulate_keystrokes("g g");
226        cx.update_editor(|editor, cx| {
227            assert_eq!(editor.snapshot(cx).scroll_position(), point(0., 0.))
228        });
229        cx.simulate_keystrokes("v ctrl-d");
230        cx.update_editor(|editor, cx| {
231            assert_eq!(editor.snapshot(cx).scroll_position(), point(0., 3.0));
232            assert_eq!(
233                editor.selections.newest(cx).range(),
234                Point::new(0, 0)..Point::new(6, 1)
235            )
236        });
237    }
238    #[gpui::test]
239    async fn test_ctrl_d_u(cx: &mut gpui::TestAppContext) {
240        let mut cx = NeovimBackedTestContext::new(cx).await;
241
242        cx.set_scroll_height(10).await;
243
244        pub fn sample_text(rows: usize, cols: usize, start_char: char) -> String {
245            let mut text = String::new();
246            for row in 0..rows {
247                let c: char = (start_char as u32 + row as u32) as u8 as char;
248                let mut line = c.to_string().repeat(cols);
249                if row < rows - 1 {
250                    line.push('\n');
251                }
252                text += &line;
253            }
254            text
255        }
256        let content = "Λ‡".to_owned() + &sample_text(26, 2, 'a');
257        cx.set_shared_state(&content).await;
258
259        // skip over the scrolloff at the top
260        // test ctrl-d
261        cx.simulate_shared_keystrokes("4 j ctrl-d").await;
262        cx.shared_state().await.assert_matches();
263        cx.simulate_shared_keystrokes("ctrl-d").await;
264        cx.shared_state().await.assert_matches();
265        cx.simulate_shared_keystrokes("g g ctrl-d").await;
266        cx.shared_state().await.assert_matches();
267
268        // test ctrl-u
269        cx.simulate_shared_keystrokes("ctrl-u").await;
270        cx.shared_state().await.assert_matches();
271        cx.simulate_shared_keystrokes("ctrl-d ctrl-d 4 j ctrl-u ctrl-u")
272            .await;
273        cx.shared_state().await.assert_matches();
274
275        // test returning to top
276        cx.simulate_shared_keystrokes("g g ctrl-d ctrl-u ctrl-u")
277            .await;
278        cx.shared_state().await.assert_matches();
279    }
280}