summaryrefslogtreecommitdiff
path: root/helix-term/src/ui/menu.rs
blob: 893c75e73590ef891bb6be93ed964c8fd58e57ae (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
use crate::compositor::{Component, Compositor, Context, EventResult};
use crossterm::event::{Event, KeyCode, KeyEvent, KeyModifiers};
use tui::{
    buffer::Buffer as Surface,
    layout::Rect,
    style::{Color, Style},
    widgets::Table,
};

pub use tui::widgets::{Cell, Row};

use std::borrow::Cow;

use fuzzy_matcher::skim::SkimMatcherV2 as Matcher;
use fuzzy_matcher::FuzzyMatcher;

use helix_core::Position;
use helix_view::Editor;

pub trait Item {
    // TODO: sort_text
    fn filter_text(&self) -> &str;

    fn label(&self) -> &str;
    fn row(&self) -> Row;
}

pub struct Menu<T: Item> {
    options: Vec<T>,

    cursor: Option<usize>,

    matcher: Box<Matcher>,
    /// (index, score)
    matches: Vec<(usize, i64)>,

    callback_fn: Box<dyn Fn(&mut Editor, Option<&T>, MenuEvent)>,

    scroll: usize,
    size: (u16, u16),
}

impl<T: Item> Menu<T> {
    // TODO: it's like a slimmed down picker, share code? (picker = menu + prompt with different
    // rendering)
    pub fn new(
        options: Vec<T>,
        callback_fn: impl Fn(&mut Editor, Option<&T>, MenuEvent) + 'static,
    ) -> Self {
        let mut menu = Self {
            options,
            matcher: Box::new(Matcher::default()),
            matches: Vec::new(),
            cursor: None,
            callback_fn: Box::new(callback_fn),
            scroll: 0,
            size: (0, 0),
        };

        // TODO: scoring on empty input should just use a fastpath
        menu.score("");

        menu
    }

    pub fn score(&mut self, pattern: &str) {
        // need to borrow via pattern match otherwise it complains about simultaneous borrow
        let Self {
            ref mut options,
            ref mut matcher,
            ref mut matches,
            ..
        } = *self;

        // reuse the matches allocation
        matches.clear();
        matches.extend(
            self.options
                .iter()
                .enumerate()
                .filter_map(|(index, option)| {
                    let text = option.filter_text();
                    // TODO: using fuzzy_indices could give us the char idx for match highlighting
                    matcher
                        .fuzzy_match(&text, pattern)
                        .map(|score| (index, score))
                }),
        );
        matches.sort_unstable_by_key(|(_, score)| -score);

        // reset cursor position
        self.cursor = None;
        self.scroll = 0;
    }

    pub fn move_up(&mut self) {
        // TODO: wrap around to end
        let pos = self.cursor.map_or(0, |i| i.saturating_sub(1)) % self.options.len();
        self.cursor = Some(pos);
        self.adjust_scroll();
    }

    pub fn move_down(&mut self) {
        let pos = self.cursor.map_or(0, |i| i + 1) % self.options.len();
        self.cursor = Some(pos);
        self.adjust_scroll();
    }

    fn adjust_scroll(&mut self) {
        let win_height = self.size.1 as usize;
        if let Some(cursor) = self.cursor {
            let mut scroll = self.scroll;
            if cursor > (win_height + scroll).saturating_sub(1) {
                // scroll down
                scroll += cursor - (win_height + scroll).saturating_sub(1)
            } else if cursor < scroll {
                // scroll up
                scroll = cursor
            }
            self.scroll = scroll;
        }
    }

    pub fn selection(&self) -> Option<&T> {
        self.cursor.and_then(|cursor| {
            self.matches
                .get(cursor)
                .map(|(index, _score)| &self.options[*index])
        })
    }

    pub fn is_empty(&self) -> bool {
        self.matches.is_empty()
    }

    pub fn len(&self) -> usize {
        self.matches.len()
    }
}

use super::PromptEvent as MenuEvent;

impl<T: Item + 'static> Component for Menu<T> {
    fn handle_event(&mut self, event: Event, cx: &mut Context) -> EventResult {
        let event = match event {
            Event::Key(event) => event,
            _ => return EventResult::Ignored,
        };

        let close_fn = EventResult::Consumed(Some(Box::new(|compositor: &mut Compositor| {
            // remove the layer
            compositor.pop();
        })));

        match event {
            // esc or ctrl-c aborts the completion and closes the menu
            KeyEvent {
                code: KeyCode::Esc, ..
            }
            | KeyEvent {
                code: KeyCode::Char('c'),
                modifiers: KeyModifiers::CONTROL,
            } => {
                (self.callback_fn)(cx.editor, self.selection(), MenuEvent::Abort);
                return close_fn;
            }
            // arrow up/ctrl-p/shift-tab prev completion choice (including updating the doc)
            KeyEvent {
                code: KeyCode::Tab,
                modifiers: KeyModifiers::SHIFT,
            }
            | KeyEvent {
                code: KeyCode::Up, ..
            }
            | KeyEvent {
                code: KeyCode::Char('p'),
                modifiers: KeyModifiers::CONTROL,
            } => {
                self.move_up();
                (self.callback_fn)(cx.editor, self.selection(), MenuEvent::Update);
                return EventResult::Consumed(None);
            }
            // arrow down/ctrl-n/tab advances completion choice (including updating the doc)
            KeyEvent {
                code: KeyCode::Tab,
                modifiers: KeyModifiers::NONE,
            }
            | KeyEvent {
                code: KeyCode::Down,
                ..
            }
            | KeyEvent {
                code: KeyCode::Char('n'),
                modifiers: KeyModifiers::CONTROL,
            } => {
                self.move_down();
                (self.callback_fn)(cx.editor, self.selection(), MenuEvent::Update);
                return EventResult::Consumed(None);
            }
            KeyEvent {
                code: KeyCode::Enter,
                ..
            } => {
                if let Some(selection) = self.selection() {
                    (self.callback_fn)(cx.editor, Some(selection), MenuEvent::Validate);
                }
                return close_fn;
            }
            // KeyEvent {
            //     code: KeyCode::Char(c),
            //     modifiers: KeyModifiers::NONE,
            // } => {
            //     self.insert_char(c);
            //     (self.callback_fn)(cx.editor, &self.line, MenuEvent::Update);
            // }

            // / -> edit_filter?
            //
            // enter confirms the match and closes the menu
            // typing filters the menu
            // if we run out of options the menu closes itself
            _ => (),
        }
        // for some events, we want to process them but send ignore, specifically all input except
        // tab/enter/ctrl-k or whatever will confirm the selection/ ctrl-n/ctrl-p for scroll.
        // EventResult::Consumed(None)
        EventResult::Ignored
    }

    fn required_size(&mut self, viewport: (u16, u16)) -> Option<(u16, u16)> {
        let width = std::cmp::min(30, viewport.0);

        const MAX: usize = 5;
        let height = std::cmp::min(self.options.len(), MAX);
        let height = std::cmp::min(height, viewport.1 as usize);

        self.size = (width as u16, height as u16);

        // adjust scroll offsets if size changed
        self.adjust_scroll();

        Some(self.size)
    }

    fn render(&self, area: Rect, surface: &mut Surface, cx: &mut Context) {
        let style = cx.editor.theme.get("ui.text");
        let selected = Style::default().fg(Color::Rgb(255, 255, 255));

        let scroll = self.scroll;

        let options: Vec<_> = self
            .matches
            .iter()
            .map(|(index, _score)| {
                // (index, self.options.get(*index).unwrap()) // get_unchecked
                &self.options[*index] // get_unchecked
            })
            .collect();

        let len = options.len();

        let win_height = area.height as usize;

        const fn div_ceil(a: usize, b: usize) -> usize {
            (a + b - 1) / a
        }

        let scroll_height = std::cmp::min(div_ceil(win_height.pow(2), len), win_height as usize);

        let scroll_line = (win_height - scroll_height) * scroll
            / std::cmp::max(1, len.saturating_sub(win_height));

        use tui::layout::Constraint;
        let rows = options.iter().map(|option| option.row());
        let table = Table::new(rows)
            .style(style)
            .highlight_style(selected)
            .column_spacing(1)
            .widths(&[Constraint::Percentage(50), Constraint::Percentage(50)]);

        use tui::widgets::TableState;

        table.render_table(
            area,
            surface,
            &mut TableState {
                offset: scroll,
                selected: self.cursor,
            },
        );

        for (i, option) in (scroll..(scroll + win_height).min(len)).enumerate() {
            let is_marked = i >= scroll_line && i < scroll_line + scroll_height;

            if is_marked {
                let cell = surface.get_mut(area.x + area.width - 2, area.y + i as u16);
                cell.set_symbol("▐ ");
                cell.set_style(selected);
                // cell.set_style(if is_marked { selected } else { style });
            }
        }
    }
}