scroll.rs

  1use crate::Vim;
  2use editor::{
  3    display_map::ToDisplayPoint,
  4    scroll::{scroll_amount::ScrollAmount, VERTICAL_SCROLL_MARGIN},
  5    DisplayPoint, Editor,
  6};
  7use gpui::{actions, AppContext, ViewContext};
  8use language::Bias;
  9use workspace::Workspace;
 10
 11actions!(
 12    vim,
 13    [LineUp, LineDown, ScrollUp, ScrollDown, PageUp, PageDown,]
 14);
 15
 16pub fn init(cx: &mut AppContext) {
 17    cx.add_action(|_: &mut Workspace, _: &LineDown, cx| {
 18        scroll(cx, |c| ScrollAmount::Line(c.unwrap_or(1.)))
 19    });
 20    cx.add_action(|_: &mut Workspace, _: &LineUp, cx| {
 21        scroll(cx, |c| ScrollAmount::Line(-c.unwrap_or(1.)))
 22    });
 23    cx.add_action(|_: &mut Workspace, _: &PageDown, cx| {
 24        scroll(cx, |c| ScrollAmount::Page(c.unwrap_or(1.)))
 25    });
 26    cx.add_action(|_: &mut Workspace, _: &PageUp, cx| {
 27        scroll(cx, |c| ScrollAmount::Page(-c.unwrap_or(1.)))
 28    });
 29    cx.add_action(|_: &mut Workspace, _: &ScrollDown, cx| {
 30        scroll(cx, |c| {
 31            if let Some(c) = c {
 32                ScrollAmount::Line(c)
 33            } else {
 34                ScrollAmount::Page(0.5)
 35            }
 36        })
 37    });
 38    cx.add_action(|_: &mut Workspace, _: &ScrollUp, cx| {
 39        scroll(cx, |c| {
 40            if let Some(c) = c {
 41                ScrollAmount::Line(-c)
 42            } else {
 43                ScrollAmount::Page(-0.5)
 44            }
 45        })
 46    });
 47}
 48
 49fn scroll(cx: &mut ViewContext<Workspace>, by: fn(c: Option<f32>) -> ScrollAmount) {
 50    Vim::update(cx, |vim, cx| {
 51        let amount = by(vim.pop_number_operator(cx).map(|c| c as f32));
 52        vim.update_active_editor(cx, |editor, cx| scroll_editor(editor, &amount, cx));
 53    })
 54}
 55
 56fn scroll_editor(editor: &mut Editor, amount: &ScrollAmount, cx: &mut ViewContext<Editor>) {
 57    let should_move_cursor = editor.newest_selection_on_screen(cx).is_eq();
 58
 59    editor.scroll_screen(amount, cx);
 60    if should_move_cursor {
 61        let visible_rows = if let Some(visible_rows) = editor.visible_line_count() {
 62            visible_rows as u32
 63        } else {
 64            return;
 65        };
 66
 67        let top_anchor = editor.scroll_manager.anchor().anchor;
 68
 69        editor.change_selections(None, cx, |s| {
 70            s.move_heads_with(|map, head, goal| {
 71                let top = top_anchor.to_display_point(map);
 72                let min_row = top.row() + VERTICAL_SCROLL_MARGIN as u32;
 73                let max_row = top.row() + visible_rows - VERTICAL_SCROLL_MARGIN as u32 - 1;
 74
 75                let new_head = if head.row() < min_row {
 76                    map.clip_point(DisplayPoint::new(min_row, head.column()), Bias::Left)
 77                } else if head.row() > max_row {
 78                    map.clip_point(DisplayPoint::new(max_row, head.column()), Bias::Left)
 79                } else {
 80                    head
 81                };
 82                (new_head, goal)
 83            })
 84        });
 85    }
 86}
 87
 88#[cfg(test)]
 89mod test {
 90    use crate::{state::Mode, test::VimTestContext};
 91    use gpui::geometry::vector::vec2f;
 92    use indoc::indoc;
 93
 94    #[gpui::test]
 95    async fn test_scroll(cx: &mut gpui::TestAppContext) {
 96        let mut cx = VimTestContext::new(cx, true).await;
 97
 98        cx.set_state(indoc! {"ˇa\nb\nc\nd\ne\n"}, Mode::Normal);
 99
100        cx.update_editor(|editor, cx| {
101            assert_eq!(editor.snapshot(cx).scroll_position(), vec2f(0., 0.))
102        });
103        cx.simulate_keystrokes(["ctrl-e"]);
104        cx.update_editor(|editor, cx| {
105            assert_eq!(editor.snapshot(cx).scroll_position(), vec2f(0., 1.))
106        });
107        cx.simulate_keystrokes(["2", "ctrl-e"]);
108        cx.update_editor(|editor, cx| {
109            assert_eq!(editor.snapshot(cx).scroll_position(), vec2f(0., 3.))
110        });
111        cx.simulate_keystrokes(["ctrl-y"]);
112        cx.update_editor(|editor, cx| {
113            assert_eq!(editor.snapshot(cx).scroll_position(), vec2f(0., 2.))
114        });
115    }
116}