aboutsummaryrefslogtreecommitdiff
path: root/helix-view/src/commands.rs
blob: 9a6d2e5d70643ba8c64bab20594b746eade21e01 (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
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
use helix_core::{
    graphemes,
    regex::Regex,
    selection,
    state::{Direction, Granularity, Mode, State},
    ChangeSet, Range, Selection, Tendril, Transaction,
};
use once_cell::sync::Lazy;

use crate::view::View;

/// A command is a function that takes the current state and a count, and does a side-effect on the
/// state (usually by creating and applying a transaction).
pub type Command = fn(view: &mut View, count: usize);

const PADDING: usize = 5;

pub fn move_char_left(view: &mut View, count: usize) {
    // TODO: use a transaction
    let selection = view
        .state
        .move_selection(Direction::Backward, Granularity::Character, count);
    view.state.selection = selection;
}

pub fn move_char_right(view: &mut View, count: usize) {
    // TODO: use a transaction
    view.state.selection =
        view.state
            .move_selection(Direction::Forward, Granularity::Character, count);
}

pub fn move_line_up(view: &mut View, count: usize) {
    // TODO: use a transaction
    view.state.selection = view
        .state
        .move_selection(Direction::Backward, Granularity::Line, count);
}

pub fn move_line_down(view: &mut View, count: usize) {
    // TODO: use a transaction
    view.state.selection = view
        .state
        .move_selection(Direction::Forward, Granularity::Line, count);
}

pub fn move_line_end(view: &mut View, _count: usize) {
    // TODO: use a transaction
    let lines = selection_lines(&view.state);

    let positions = lines
        .into_iter()
        .map(|index| {
            // adjust all positions to the end of the line.

            // Line end is pos at the start of next line - 1
            // subtract another 1 because the line ends with \n
            view.state.doc.line_to_char(index + 1).saturating_sub(2)
        })
        .map(|pos| Range::new(pos, pos));

    let selection = Selection::new(positions.collect(), 0);

    let transaction = Transaction::new(&mut view.state).with_selection(selection);

    transaction.apply(&mut view.state);
}

pub fn move_line_start(view: &mut View, _count: usize) {
    let lines = selection_lines(&view.state);

    let positions = lines
        .into_iter()
        .map(|index| {
            // adjust all positions to the start of the line.
            view.state.doc.line_to_char(index)
        })
        .map(|pos| Range::new(pos, pos));

    let selection = Selection::new(positions.collect(), 0);

    let transaction = Transaction::new(&mut view.state).with_selection(selection);

    transaction.apply(&mut view.state);
}

pub fn move_next_word_start(view: &mut View, count: usize) {
    let pos = view.state.move_pos(
        view.state.selection.cursor(),
        Direction::Forward,
        Granularity::Word,
        count,
    );

    // TODO: use a transaction
    view.state.selection = Selection::single(pos, pos);
}

pub fn move_prev_word_start(view: &mut View, count: usize) {
    let pos = view.state.move_pos(
        view.state.selection.cursor(),
        Direction::Backward,
        Granularity::Word,
        count,
    );

    // TODO: use a transaction
    view.state.selection = Selection::single(pos, pos);
}

pub fn move_next_word_end(view: &mut View, count: usize) {
    let pos = State::move_next_word_end(
        &view.state.doc().slice(..),
        view.state.selection.cursor(),
        count,
    );

    // TODO: use a transaction
    view.state.selection = Selection::single(pos, pos);
}

pub fn move_file_start(view: &mut View, _count: usize) {
    // TODO: use a transaction
    view.state.selection = Selection::single(0, 0);

    view.state.mode = Mode::Normal;
}

pub fn move_file_end(view: &mut View, _count: usize) {
    // TODO: use a transaction
    let text = &view.state.doc;
    let last_line = text.line_to_char(text.len_lines().saturating_sub(2));
    view.state.selection = Selection::single(last_line, last_line);

    view.state.mode = Mode::Normal;
}

pub fn check_cursor_in_view(view: &mut View) -> bool {
    let cursor = view.state.selection().cursor();
    let line = view.state.doc().char_to_line(cursor);
    let document_end = view.first_line + view.size.1.saturating_sub(1) as usize;

    if (line > document_end.saturating_sub(PADDING)) | (line < view.first_line + PADDING) {
        return false;
    }
    true
}

pub fn page_up(view: &mut View, _count: usize) {
    if view.first_line < PADDING {
        return;
    }

    view.first_line = view.first_line.saturating_sub(view.size.1 as usize);

    if !check_cursor_in_view(view) {
        let text = view.state.doc();
        let pos = text.line_to_char(view.last_line().saturating_sub(PADDING));
        view.state.selection = Selection::single(pos, pos);
    }
}

pub fn page_down(view: &mut View, _count: usize) {
    view.first_line += view.size.1 as usize + PADDING;

    if view.first_line < view.state.doc().len_lines() {
        let text = view.state.doc();
        let pos = text.line_to_char(view.first_line as usize);
        view.state.selection = Selection::single(pos, pos);
    }
}

pub fn half_page_up(view: &mut View, _count: usize) {
    if view.first_line < PADDING {
        return;
    }

    view.first_line = view.first_line.saturating_sub(view.size.1 as usize / 2);

    if !check_cursor_in_view(view) {
        let text = &view.state.doc;
        let pos = text.line_to_char(view.last_line() - PADDING);
        view.state.selection = Selection::single(pos, pos);
    }
}

pub fn half_page_down(view: &mut View, _count: usize) {
    let lines = view.state.doc().len_lines();
    if view.first_line < lines.saturating_sub(view.size.1 as usize) {
        view.first_line += view.size.1 as usize / 2;
    }
    if !check_cursor_in_view(view) {
        let text = view.state.doc();
        let pos = text.line_to_char(view.first_line as usize);
        view.state.selection = Selection::single(pos, pos);
    }
}
// avoid select by default by having a visual mode switch that makes movements into selects

pub fn extend_char_left(view: &mut View, count: usize) {
    // TODO: use a transaction
    let selection = view
        .state
        .extend_selection(Direction::Backward, Granularity::Character, count);
    view.state.selection = selection;
}

pub fn extend_char_right(view: &mut View, count: usize) {
    // TODO: use a transaction
    view.state.selection =
        view.state
            .extend_selection(Direction::Forward, Granularity::Character, count);
}

pub fn extend_line_up(view: &mut View, count: usize) {
    // TODO: use a transaction
    view.state.selection =
        view.state
            .extend_selection(Direction::Backward, Granularity::Line, count);
}

pub fn extend_line_down(view: &mut View, count: usize) {
    // TODO: use a transaction
    view.state.selection =
        view.state
            .extend_selection(Direction::Forward, Granularity::Line, count);
}

pub fn split_selection_on_newline(view: &mut View, _count: usize) {
    let text = &view.state.doc.slice(..);
    // only compile the regex once
    #[allow(clippy::trivial_regex)]
    static REGEX: Lazy<Regex> = Lazy::new(|| Regex::new(r"\n").unwrap());
    // TODO: use a transaction
    view.state.selection = selection::split_on_matches(text, view.state.selection(), &REGEX)
}

pub fn delete_selection(view: &mut View, _count: usize) {
    let transaction =
        Transaction::change_by_selection(&view.state, |range| (range.from(), range.to(), None));
    transaction.apply(&mut view.state);
}

pub fn change_selection(view: &mut View, count: usize) {
    delete_selection(view, count);
    insert_mode(view, count);
}

pub fn collapse_selection(view: &mut View, _count: usize) {
    view.state.selection = view
        .state
        .selection
        .transform(|range| Range::new(range.head, range.head))
}

fn enter_insert_mode(view: &mut View) {
    view.state.mode = Mode::Insert;

    // HAXX
    view.state.changes = Some(ChangeSet::new(view.state.doc()));
    view.state.old_state = Some((view.state.doc().clone(), view.state.selection.clone()));
}
// inserts at the start of each selection
pub fn insert_mode(view: &mut View, _count: usize) {
    enter_insert_mode(view);

    view.state.selection = view
        .state
        .selection
        .transform(|range| Range::new(range.to(), range.from()))
}

// inserts at the end of each selection
pub fn append_mode(view: &mut View, _count: usize) {
    enter_insert_mode(view);
    view.state.restore_cursor = true;

    // TODO: as transaction
    let text = &view.state.doc.slice(..);
    view.state.selection = view.state.selection.transform(|range| {
        // TODO: to() + next char
        Range::new(
            range.from(),
            graphemes::next_grapheme_boundary(text, range.to()),
        )
    })
}

// TODO: I, A, o and O can share a lot of the primitives.

// calculate line numbers for each selection range
fn selection_lines(state: &State) -> Vec<usize> {
    let mut lines = state
        .selection
        .ranges()
        .iter()
        .map(|range| state.doc.char_to_line(range.head))
        .collect::<Vec<_>>();

    lines.sort_unstable(); // sorting by usize so _unstable is preferred
    lines.dedup();

    lines
}

// I inserts at the start of each line with a selection
pub fn prepend_to_line(view: &mut View, count: usize) {
    enter_insert_mode(view);

    move_line_start(view, count);
}

// A inserts at the end of each line with a selection
pub fn append_to_line(view: &mut View, count: usize) {
    enter_insert_mode(view);

    move_line_end(view, count);
}

// o inserts a new line after each line with a selection
pub fn open_below(view: &mut View, _count: usize) {
    enter_insert_mode(view);

    let lines = selection_lines(&view.state);

    let positions: Vec<_> = lines
        .into_iter()
        .map(|index| {
            // adjust all positions to the end of the line/start of the next one.
            view.state.doc.line_to_char(index + 1)
        })
        .collect();

    let changes = positions.iter().copied().map(|index|
        // generate changes
        (index, index, Some(Tendril::from_char('\n'))));

    // TODO: count actually inserts "n" new lines and starts editing on all of them.
    // TODO: append "count" newlines and modify cursors to those lines

    let selection = Selection::new(
        positions
            .iter()
            .copied()
            .map(|pos| Range::new(pos, pos))
            .collect(),
        0,
    );

    let transaction = Transaction::change(&view.state, changes).with_selection(selection);

    transaction.apply(&mut view.state);
    // TODO: need to store into history if successful
}

// O inserts a new line before each line with a selection

pub fn normal_mode(view: &mut View, _count: usize) {
    view.state.mode = Mode::Normal;

    if let Some(changes) = view.state.changes.take() {
        // Instead of doing this messy merge we could always commit, and based on transaction
        // annotations either add a new layer or compose into the previous one.
        let transaction = Transaction::from(changes).with_selection(view.state.selection().clone());
        let (doc, selection) = view.state.old_state.take().unwrap();
        let mut old_state = State::new(doc);
        old_state.selection = selection;

        // TODO: take transaction by value?
        view.history.commit_revision(&transaction, &old_state);
    }

    // if leaving append mode, move cursor back by 1
    if view.state.restore_cursor {
        let text = &view.state.doc.slice(..);
        view.state.selection = view.state.selection.transform(|range| {
            Range::new(
                range.from(),
                graphemes::prev_grapheme_boundary(text, range.to()),
            )
        });

        view.state.restore_cursor = false;
    }
}

pub fn goto_mode(view: &mut View, _count: usize) {
    view.state.mode = Mode::Goto;
}

// TODO: insert means add text just before cursor, on exit we should be on the last letter.
pub fn insert_char(view: &mut View, c: char) {
    let c = Tendril::from_char(c);
    let transaction = Transaction::insert(&view.state, c);

    transaction.apply(&mut view.state);
    // TODO: need to store into history if successful
}

pub fn insert_tab(view: &mut View, _count: usize) {
    insert_char(view, '\t');
}

pub fn insert_newline(view: &mut View, _count: usize) {
    insert_char(view, '\n');
}

// TODO: handle indent-aware delete
pub fn delete_char_backward(view: &mut View, count: usize) {
    let text = &view.state.doc.slice(..);
    let transaction = Transaction::change_by_selection(&view.state, |range| {
        (
            graphemes::nth_prev_grapheme_boundary(text, range.head, count),
            range.head,
            None,
        )
    });
    transaction.apply(&mut view.state);
    // TODO: need to store into history if successful
}

pub fn delete_char_forward(view: &mut View, count: usize) {
    let text = &view.state.doc.slice(..);
    let transaction = Transaction::change_by_selection(&view.state, |range| {
        (
            range.head,
            graphemes::nth_next_grapheme_boundary(text, range.head, count),
            None,
        )
    });
    transaction.apply(&mut view.state);
    // TODO: need to store into history if successful
}

// Undo / Redo

pub fn undo(view: &mut View, _count: usize) {
    view.history.undo(&mut view.state);

    // TODO: each command should simply return a Option<transaction>, then the higher level handles storing it?
}

pub fn redo(view: &mut View, _count: usize) {
    view.history.redo(&mut view.state);
}