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