cosmic_text/
buffer.rs

1// SPDX-License-Identifier: MIT OR Apache-2.0
2
3#[cfg(not(feature = "std"))]
4use alloc::{string::String, vec::Vec};
5
6use core::{cmp, fmt};
7
8#[cfg(not(feature = "std"))]
9use core_maths::CoreFloat;
10use unicode_segmentation::UnicodeSegmentation;
11
12#[cfg(feature = "swash")]
13use crate::Color;
14
15use crate::{
16    Affinity, Align, Attrs, AttrsList, BidiParagraphs, BorrowedWithFontSystem, BufferLine, Cursor,
17    FontSystem, LayoutCursor, LayoutGlyph, LayoutLine, LineEnding, LineIter, Motion, Scroll,
18    ShapeLine, Shaping, Wrap,
19};
20
21/// A line of visible text for rendering
22#[derive(Debug)]
23pub struct LayoutRun<'a> {
24    /// The index of the original text line
25    pub line_i: usize,
26    /// The original text line
27    pub text: &'a str,
28    /// True if the original paragraph direction is RTL
29    pub rtl: bool,
30    /// The array of layout glyphs to draw
31    pub glyphs: &'a [LayoutGlyph],
32    /// Y offset to baseline of line
33    pub line_y: f32,
34    /// Y offset to top of line
35    pub line_top: f32,
36    /// Y offset to next line
37    pub line_height: f32,
38    /// Width of line
39    pub line_w: f32,
40}
41
42impl LayoutRun<'_> {
43    /// Return the pixel span `Some((x_left, x_width))` of the highlighted area between `cursor_start`
44    /// and `cursor_end` within this run, or None if the cursor range does not intersect this run.
45    /// This may return widths of zero if `cursor_start == cursor_end`, if the run is empty, or if the
46    /// region's left start boundary is the same as the cursor's end boundary or vice versa.
47    #[allow(clippy::missing_panics_doc)]
48    pub fn highlight(&self, cursor_start: Cursor, cursor_end: Cursor) -> Option<(f32, f32)> {
49        let mut x_start = None;
50        let mut x_end = None;
51        let rtl_factor = if self.rtl { 1. } else { 0. };
52        let ltr_factor = 1. - rtl_factor;
53        for glyph in self.glyphs {
54            let cursor = self.cursor_from_glyph_left(glyph);
55            if cursor >= cursor_start && cursor <= cursor_end {
56                if x_start.is_none() {
57                    x_start = Some(glyph.x + glyph.w.mul_add(rtl_factor, 0.0));
58                }
59                x_end = Some(glyph.x + glyph.w.mul_add(rtl_factor, 0.0));
60            }
61            let cursor = self.cursor_from_glyph_right(glyph);
62            if cursor >= cursor_start && cursor <= cursor_end {
63                if x_start.is_none() {
64                    x_start = Some(glyph.x + glyph.w.mul_add(ltr_factor, 0.0));
65                }
66                x_end = Some(glyph.x + glyph.w.mul_add(ltr_factor, 0.0));
67            }
68        }
69        x_start.map(|x_start| {
70            let x_end = x_end.expect("end of cursor not found");
71            let (x_start, x_end) = if x_start < x_end {
72                (x_start, x_end)
73            } else {
74                (x_end, x_start)
75            };
76            (x_start, x_end - x_start)
77        })
78    }
79
80    const fn cursor_from_glyph_left(&self, glyph: &LayoutGlyph) -> Cursor {
81        if self.rtl {
82            Cursor::new_with_affinity(self.line_i, glyph.end, Affinity::Before)
83        } else {
84            Cursor::new_with_affinity(self.line_i, glyph.start, Affinity::After)
85        }
86    }
87
88    const fn cursor_from_glyph_right(&self, glyph: &LayoutGlyph) -> Cursor {
89        if self.rtl {
90            Cursor::new_with_affinity(self.line_i, glyph.start, Affinity::After)
91        } else {
92            Cursor::new_with_affinity(self.line_i, glyph.end, Affinity::Before)
93        }
94    }
95}
96
97/// An iterator of visible text lines, see [`LayoutRun`]
98#[derive(Debug)]
99pub struct LayoutRunIter<'b> {
100    buffer: &'b Buffer,
101    line_i: usize,
102    layout_i: usize,
103    total_height: f32,
104    line_top: f32,
105}
106
107impl<'b> LayoutRunIter<'b> {
108    pub const fn new(buffer: &'b Buffer) -> Self {
109        Self {
110            buffer,
111            line_i: buffer.scroll.line,
112            layout_i: 0,
113            total_height: 0.0,
114            line_top: 0.0,
115        }
116    }
117}
118
119impl<'b> Iterator for LayoutRunIter<'b> {
120    type Item = LayoutRun<'b>;
121
122    fn next(&mut self) -> Option<Self::Item> {
123        while let Some(line) = self.buffer.lines.get(self.line_i) {
124            let shape = line.shape_opt()?;
125            let layout = line.layout_opt()?;
126            while let Some(layout_line) = layout.get(self.layout_i) {
127                self.layout_i += 1;
128
129                let line_height = layout_line
130                    .line_height_opt
131                    .unwrap_or(self.buffer.metrics.line_height);
132                self.total_height += line_height;
133
134                let line_top = self.line_top - self.buffer.scroll.vertical;
135                let glyph_height = layout_line.max_ascent + layout_line.max_descent;
136                let centering_offset = (line_height - glyph_height) / 2.0;
137                let line_y = line_top + centering_offset + layout_line.max_ascent;
138                if let Some(height) = self.buffer.height_opt {
139                    if line_y - layout_line.max_ascent > height {
140                        return None;
141                    }
142                }
143                self.line_top += line_height;
144                if line_y + layout_line.max_descent < 0.0 {
145                    continue;
146                }
147
148                return Some(LayoutRun {
149                    line_i: self.line_i,
150                    text: line.text(),
151                    rtl: shape.rtl,
152                    glyphs: &layout_line.glyphs,
153                    line_y,
154                    line_top,
155                    line_height,
156                    line_w: layout_line.w,
157                });
158            }
159            self.line_i += 1;
160            self.layout_i = 0;
161        }
162
163        None
164    }
165}
166
167/// Metrics of text
168#[derive(Clone, Copy, Debug, Default, PartialEq)]
169pub struct Metrics {
170    /// Font size in pixels
171    pub font_size: f32,
172    /// Line height in pixels
173    pub line_height: f32,
174}
175
176impl Metrics {
177    /// Create metrics with given font size and line height
178    pub const fn new(font_size: f32, line_height: f32) -> Self {
179        Self {
180            font_size,
181            line_height,
182        }
183    }
184
185    /// Create metrics with given font size and calculate line height using relative scale
186    pub fn relative(font_size: f32, line_height_scale: f32) -> Self {
187        Self {
188            font_size,
189            line_height: font_size * line_height_scale,
190        }
191    }
192
193    /// Scale font size and line height
194    pub fn scale(self, scale: f32) -> Self {
195        Self {
196            font_size: self.font_size * scale,
197            line_height: self.line_height * scale,
198        }
199    }
200}
201
202impl fmt::Display for Metrics {
203    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
204        write!(f, "{}px / {}px", self.font_size, self.line_height)
205    }
206}
207
208/// A buffer of text that is shaped and laid out
209#[derive(Debug)]
210pub struct Buffer {
211    /// [`BufferLine`]s (or paragraphs) of text in the buffer
212    pub lines: Vec<BufferLine>,
213    metrics: Metrics,
214    width_opt: Option<f32>,
215    height_opt: Option<f32>,
216    scroll: Scroll,
217    /// True if a redraw is requires. Set to false after processing
218    redraw: bool,
219    wrap: Wrap,
220    monospace_width: Option<f32>,
221    tab_width: u16,
222}
223
224impl Clone for Buffer {
225    fn clone(&self) -> Self {
226        Self {
227            lines: self.lines.clone(),
228            metrics: self.metrics,
229            width_opt: self.width_opt,
230            height_opt: self.height_opt,
231            scroll: self.scroll,
232            redraw: self.redraw,
233            wrap: self.wrap,
234            monospace_width: self.monospace_width,
235            tab_width: self.tab_width,
236        }
237    }
238}
239
240impl Buffer {
241    /// Create an empty [`Buffer`] with the provided [`Metrics`].
242    /// This is useful for initializing a [`Buffer`] without a [`FontSystem`].
243    ///
244    /// You must populate the [`Buffer`] with at least one [`BufferLine`] before shaping and layout,
245    /// for example by calling [`Buffer::set_text`].
246    ///
247    /// If you have a [`FontSystem`] in scope, you should use [`Buffer::new`] instead.
248    ///
249    /// # Panics
250    ///
251    /// Will panic if `metrics.line_height` is zero.
252    pub fn new_empty(metrics: Metrics) -> Self {
253        assert_ne!(metrics.line_height, 0.0, "line height cannot be 0");
254        Self {
255            lines: Vec::new(),
256            metrics,
257            width_opt: None,
258            height_opt: None,
259            scroll: Scroll::default(),
260            redraw: false,
261            wrap: Wrap::WordOrGlyph,
262            monospace_width: None,
263            tab_width: 8,
264        }
265    }
266
267    /// Create a new [`Buffer`] with the provided [`FontSystem`] and [`Metrics`]
268    ///
269    /// # Panics
270    ///
271    /// Will panic if `metrics.line_height` is zero.
272    pub fn new(font_system: &mut FontSystem, metrics: Metrics) -> Self {
273        let mut buffer = Self::new_empty(metrics);
274        buffer.set_text(font_system, "", &Attrs::new(), Shaping::Advanced);
275        buffer
276    }
277
278    /// Mutably borrows the buffer together with an [`FontSystem`] for more convenient methods
279    pub fn borrow_with<'a>(
280        &'a mut self,
281        font_system: &'a mut FontSystem,
282    ) -> BorrowedWithFontSystem<'a, Self> {
283        BorrowedWithFontSystem {
284            inner: self,
285            font_system,
286        }
287    }
288
289    fn relayout(&mut self, font_system: &mut FontSystem) {
290        #[cfg(all(feature = "std", not(target_arch = "wasm32")))]
291        let instant = std::time::Instant::now();
292
293        for line in &mut self.lines {
294            if line.shape_opt().is_some() {
295                line.reset_layout();
296                line.layout(
297                    font_system,
298                    self.metrics.font_size,
299                    self.width_opt,
300                    self.wrap,
301                    self.monospace_width,
302                    self.tab_width,
303                );
304            }
305        }
306
307        self.redraw = true;
308
309        #[cfg(all(feature = "std", not(target_arch = "wasm32")))]
310        log::debug!("relayout: {:?}", instant.elapsed());
311    }
312
313    /// Shape lines until cursor, also scrolling to include cursor in view
314    #[allow(clippy::missing_panics_doc)]
315    pub fn shape_until_cursor(
316        &mut self,
317        font_system: &mut FontSystem,
318        cursor: Cursor,
319        prune: bool,
320    ) {
321        let metrics = self.metrics;
322        let old_scroll = self.scroll;
323
324        let layout_cursor = self
325            .layout_cursor(font_system, cursor)
326            .expect("shape_until_cursor invalid cursor");
327
328        let mut layout_y = 0.0;
329        let mut total_height = {
330            let layout = self
331                .line_layout(font_system, layout_cursor.line)
332                .expect("shape_until_cursor failed to scroll forwards");
333            (0..layout_cursor.layout).for_each(|layout_i| {
334                layout_y += layout[layout_i]
335                    .line_height_opt
336                    .unwrap_or(metrics.line_height);
337            });
338            layout_y
339                + layout[layout_cursor.layout]
340                    .line_height_opt
341                    .unwrap_or(metrics.line_height)
342        };
343
344        if self.scroll.line > layout_cursor.line
345            || (self.scroll.line == layout_cursor.line && self.scroll.vertical > layout_y)
346        {
347            // Adjust scroll backwards if cursor is before it
348            self.scroll.line = layout_cursor.line;
349            self.scroll.vertical = layout_y;
350        } else if let Some(height) = self.height_opt {
351            // Adjust scroll forwards if cursor is after it
352            let mut line_i = layout_cursor.line;
353            if line_i <= self.scroll.line {
354                // This is a single line that may wrap
355                if total_height > height + self.scroll.vertical {
356                    self.scroll.vertical = total_height - height;
357                }
358            } else {
359                while line_i > self.scroll.line {
360                    line_i -= 1;
361                    let layout = self
362                        .line_layout(font_system, line_i)
363                        .expect("shape_until_cursor failed to scroll forwards");
364                    for layout_line in layout {
365                        total_height += layout_line.line_height_opt.unwrap_or(metrics.line_height);
366                    }
367                    if total_height > height + self.scroll.vertical {
368                        self.scroll.line = line_i;
369                        self.scroll.vertical = total_height - height;
370                    }
371                }
372            }
373        }
374
375        if old_scroll != self.scroll {
376            self.redraw = true;
377        }
378
379        self.shape_until_scroll(font_system, prune);
380
381        // Adjust horizontal scroll to include cursor
382        if let Some(layout_cursor) = self.layout_cursor(font_system, cursor) {
383            if let Some(layout_lines) = self.line_layout(font_system, layout_cursor.line) {
384                if let Some(layout_line) = layout_lines.get(layout_cursor.layout) {
385                    let (x_min, x_max) = layout_line
386                        .glyphs
387                        .get(layout_cursor.glyph)
388                        .or_else(|| layout_line.glyphs.last())
389                        .map_or((0.0, 0.0), |glyph| {
390                            //TODO: use code from cursor_glyph_opt?
391                            let x_a = glyph.x;
392                            let x_b = glyph.x + glyph.w;
393                            (x_a.min(x_b), x_a.max(x_b))
394                        });
395                    if x_min < self.scroll.horizontal {
396                        self.scroll.horizontal = x_min;
397                        self.redraw = true;
398                    }
399                    if let Some(width) = self.width_opt {
400                        if x_max > self.scroll.horizontal + width {
401                            self.scroll.horizontal = x_max - width;
402                            self.redraw = true;
403                        }
404                    }
405                }
406            }
407        }
408    }
409
410    /// Shape lines until scroll
411    #[allow(clippy::missing_panics_doc)]
412    pub fn shape_until_scroll(&mut self, font_system: &mut FontSystem, prune: bool) {
413        let metrics = self.metrics;
414        let old_scroll = self.scroll;
415
416        loop {
417            // Adjust scroll.layout to be positive by moving scroll.line backwards
418            while self.scroll.vertical < 0.0 {
419                if self.scroll.line > 0 {
420                    let line_i = self.scroll.line - 1;
421                    if let Some(layout) = self.line_layout(font_system, line_i) {
422                        let mut layout_height = 0.0;
423                        for layout_line in layout {
424                            layout_height +=
425                                layout_line.line_height_opt.unwrap_or(metrics.line_height);
426                        }
427                        self.scroll.line = line_i;
428                        self.scroll.vertical += layout_height;
429                    } else {
430                        // If layout is missing, just assume line height
431                        self.scroll.line = line_i;
432                        self.scroll.vertical += metrics.line_height;
433                    }
434                } else {
435                    self.scroll.vertical = 0.0;
436                    break;
437                }
438            }
439
440            let scroll_start = self.scroll.vertical;
441            let scroll_end = scroll_start + self.height_opt.unwrap_or(f32::INFINITY);
442
443            let mut total_height = 0.0;
444            for line_i in 0..self.lines.len() {
445                if line_i < self.scroll.line {
446                    if prune {
447                        self.lines[line_i].reset_shaping();
448                    }
449                    continue;
450                }
451                if total_height > scroll_end {
452                    if prune {
453                        self.lines[line_i].reset_shaping();
454                        continue;
455                    }
456                    break;
457                }
458
459                let mut layout_height = 0.0;
460                let layout = self
461                    .line_layout(font_system, line_i)
462                    .expect("shape_until_scroll invalid line");
463                for layout_line in layout {
464                    let line_height = layout_line.line_height_opt.unwrap_or(metrics.line_height);
465                    layout_height += line_height;
466                    total_height += line_height;
467                }
468
469                // Adjust scroll.vertical to be smaller by moving scroll.line forwards
470                if line_i == self.scroll.line && layout_height <= self.scroll.vertical {
471                    self.scroll.line += 1;
472                    self.scroll.vertical -= layout_height;
473                }
474            }
475
476            if total_height < scroll_end && self.scroll.line > 0 {
477                // Need to scroll up to stay inside of buffer
478                self.scroll.vertical -= scroll_end - total_height;
479            } else {
480                // Done adjusting scroll
481                break;
482            }
483        }
484
485        if old_scroll != self.scroll {
486            self.redraw = true;
487        }
488    }
489
490    /// Convert a [`Cursor`] to a [`LayoutCursor`]
491    pub fn layout_cursor(
492        &mut self,
493        font_system: &mut FontSystem,
494        cursor: Cursor,
495    ) -> Option<LayoutCursor> {
496        let layout = self.line_layout(font_system, cursor.line)?;
497        for (layout_i, layout_line) in layout.iter().enumerate() {
498            for (glyph_i, glyph) in layout_line.glyphs.iter().enumerate() {
499                let cursor_end =
500                    Cursor::new_with_affinity(cursor.line, glyph.end, Affinity::Before);
501                let cursor_start =
502                    Cursor::new_with_affinity(cursor.line, glyph.start, Affinity::After);
503                let (cursor_left, cursor_right) = if glyph.level.is_ltr() {
504                    (cursor_start, cursor_end)
505                } else {
506                    (cursor_end, cursor_start)
507                };
508                if cursor == cursor_left {
509                    return Some(LayoutCursor::new(cursor.line, layout_i, glyph_i));
510                }
511                if cursor == cursor_right {
512                    return Some(LayoutCursor::new(cursor.line, layout_i, glyph_i + 1));
513                }
514            }
515        }
516
517        // Fall back to start of line
518        //TODO: should this be the end of the line?
519        Some(LayoutCursor::new(cursor.line, 0, 0))
520    }
521
522    /// Shape the provided line index and return the result
523    pub fn line_shape(
524        &mut self,
525        font_system: &mut FontSystem,
526        line_i: usize,
527    ) -> Option<&ShapeLine> {
528        let line = self.lines.get_mut(line_i)?;
529        Some(line.shape(font_system, self.tab_width))
530    }
531
532    /// Lay out the provided line index and return the result
533    pub fn line_layout(
534        &mut self,
535        font_system: &mut FontSystem,
536        line_i: usize,
537    ) -> Option<&[LayoutLine]> {
538        let line = self.lines.get_mut(line_i)?;
539        Some(line.layout(
540            font_system,
541            self.metrics.font_size,
542            self.width_opt,
543            self.wrap,
544            self.monospace_width,
545            self.tab_width,
546        ))
547    }
548
549    /// Get the current [`Metrics`]
550    pub const fn metrics(&self) -> Metrics {
551        self.metrics
552    }
553
554    /// Set the current [`Metrics`]
555    ///
556    /// # Panics
557    ///
558    /// Will panic if `metrics.font_size` is zero.
559    pub fn set_metrics(&mut self, font_system: &mut FontSystem, metrics: Metrics) {
560        self.set_metrics_and_size(font_system, metrics, self.width_opt, self.height_opt);
561    }
562
563    /// Get the current [`Wrap`]
564    pub const fn wrap(&self) -> Wrap {
565        self.wrap
566    }
567
568    /// Set the current [`Wrap`]
569    pub fn set_wrap(&mut self, font_system: &mut FontSystem, wrap: Wrap) {
570        if wrap != self.wrap {
571            self.wrap = wrap;
572            self.relayout(font_system);
573            self.shape_until_scroll(font_system, false);
574        }
575    }
576
577    /// Get the current `monospace_width`
578    pub const fn monospace_width(&self) -> Option<f32> {
579        self.monospace_width
580    }
581
582    /// Set monospace width monospace glyphs should be resized to match. `None` means don't resize
583    pub fn set_monospace_width(
584        &mut self,
585        font_system: &mut FontSystem,
586        monospace_width: Option<f32>,
587    ) {
588        if monospace_width != self.monospace_width {
589            self.monospace_width = monospace_width;
590            self.relayout(font_system);
591            self.shape_until_scroll(font_system, false);
592        }
593    }
594
595    /// Get the current `tab_width`
596    pub const fn tab_width(&self) -> u16 {
597        self.tab_width
598    }
599
600    /// Set tab width (number of spaces between tab stops)
601    pub fn set_tab_width(&mut self, font_system: &mut FontSystem, tab_width: u16) {
602        // A tab width of 0 is not allowed
603        if tab_width == 0 {
604            return;
605        }
606        if tab_width != self.tab_width {
607            self.tab_width = tab_width;
608            // Shaping must be reset when tab width is changed
609            for line in &mut self.lines {
610                if line.shape_opt().is_some() && line.text().contains('\t') {
611                    line.reset_shaping();
612                }
613            }
614            self.redraw = true;
615            self.shape_until_scroll(font_system, false);
616        }
617    }
618
619    /// Get the current buffer dimensions (width, height)
620    pub const fn size(&self) -> (Option<f32>, Option<f32>) {
621        (self.width_opt, self.height_opt)
622    }
623
624    /// Set the current buffer dimensions
625    pub fn set_size(
626        &mut self,
627        font_system: &mut FontSystem,
628        width_opt: Option<f32>,
629        height_opt: Option<f32>,
630    ) {
631        self.set_metrics_and_size(font_system, self.metrics, width_opt, height_opt);
632    }
633
634    /// Set the current [`Metrics`] and buffer dimensions at the same time
635    ///
636    /// # Panics
637    ///
638    /// Will panic if `metrics.font_size` is zero.
639    pub fn set_metrics_and_size(
640        &mut self,
641        font_system: &mut FontSystem,
642        metrics: Metrics,
643        width_opt: Option<f32>,
644        height_opt: Option<f32>,
645    ) {
646        let clamped_width_opt = width_opt.map(|width| width.max(0.0));
647        let clamped_height_opt = height_opt.map(|height| height.max(0.0));
648
649        if metrics != self.metrics
650            || clamped_width_opt != self.width_opt
651            || clamped_height_opt != self.height_opt
652        {
653            assert_ne!(metrics.font_size, 0.0, "font size cannot be 0");
654            self.metrics = metrics;
655            self.width_opt = clamped_width_opt;
656            self.height_opt = clamped_height_opt;
657            self.relayout(font_system);
658            self.shape_until_scroll(font_system, false);
659        }
660    }
661
662    /// Get the current scroll location
663    pub const fn scroll(&self) -> Scroll {
664        self.scroll
665    }
666
667    /// Set the current scroll location
668    pub fn set_scroll(&mut self, scroll: Scroll) {
669        if scroll != self.scroll {
670            self.scroll = scroll;
671            self.redraw = true;
672        }
673    }
674
675    /// Set text of buffer, using provided attributes for each line by default
676    pub fn set_text(
677        &mut self,
678        font_system: &mut FontSystem,
679        text: &str,
680        attrs: &Attrs,
681        shaping: Shaping,
682    ) {
683        self.lines.clear();
684        for (range, ending) in LineIter::new(text) {
685            self.lines.push(BufferLine::new(
686                &text[range],
687                ending,
688                AttrsList::new(attrs),
689                shaping,
690            ));
691        }
692        if self.lines.is_empty() {
693            self.lines.push(BufferLine::new(
694                "",
695                LineEnding::default(),
696                AttrsList::new(attrs),
697                shaping,
698            ));
699        }
700        self.scroll = Scroll::default();
701        self.shape_until_scroll(font_system, false);
702    }
703
704    /// Set text of buffer, using an iterator of styled spans (pairs of text and attributes)
705    ///
706    /// ```
707    /// # use cosmic_text::{Attrs, Buffer, Family, FontSystem, Metrics, Shaping};
708    /// # let mut font_system = FontSystem::new();
709    /// let mut buffer = Buffer::new_empty(Metrics::new(32.0, 44.0));
710    /// let attrs = Attrs::new().family(Family::Serif);
711    /// buffer.set_rich_text(
712    ///     &mut font_system,
713    ///     [
714    ///         ("hello, ", attrs.clone()),
715    ///         ("cosmic\ntext", attrs.clone().family(Family::Monospace)),
716    ///     ],
717    ///     &attrs,
718    ///     Shaping::Advanced,
719    ///     None,
720    /// );
721    /// ```
722    pub fn set_rich_text<'r, 's, I>(
723        &mut self,
724        font_system: &mut FontSystem,
725        spans: I,
726        default_attrs: &Attrs,
727        shaping: Shaping,
728        alignment: Option<Align>,
729    ) where
730        I: IntoIterator<Item = (&'s str, Attrs<'r>)>,
731    {
732        let mut end = 0;
733        // TODO: find a way to cache this string and vec for reuse
734        let (string, spans_data): (String, Vec<_>) = spans
735            .into_iter()
736            .map(|(s, attrs)| {
737                let start = end;
738                end += s.len();
739                (s, (attrs, start..end))
740            })
741            .unzip();
742
743        let mut spans_iter = spans_data.into_iter();
744        let mut maybe_span = spans_iter.next();
745
746        // split the string into lines, as ranges
747        let string_start = string.as_ptr() as usize;
748        let mut lines_iter = BidiParagraphs::new(&string).map(|line: &str| {
749            let start = line.as_ptr() as usize - string_start;
750            let end = start + line.len();
751            start..end
752        });
753        let mut maybe_line = lines_iter.next();
754        //TODO: set this based on information from spans
755        let line_ending = LineEnding::default();
756
757        let mut line_count = 0;
758        let mut attrs_list = self
759            .lines
760            .get_mut(line_count)
761            .map_or_else(|| AttrsList::new(&Attrs::new()), BufferLine::reclaim_attrs)
762            .reset(default_attrs);
763        let mut line_string = self
764            .lines
765            .get_mut(line_count)
766            .map(BufferLine::reclaim_text)
767            .unwrap_or_default();
768
769        loop {
770            let (Some(line_range), Some((attrs, span_range))) = (&maybe_line, &maybe_span) else {
771                // this is reached only if this text is empty
772                if self.lines.len() == line_count {
773                    self.lines.push(BufferLine::empty());
774                }
775                self.lines[line_count].reset_new(
776                    String::new(),
777                    line_ending,
778                    AttrsList::new(default_attrs),
779                    shaping,
780                );
781                line_count += 1;
782                break;
783            };
784
785            // start..end is the intersection of this line and this span
786            let start = line_range.start.max(span_range.start);
787            let end = line_range.end.min(span_range.end);
788            if start < end {
789                let text = &string[start..end];
790                let text_start = line_string.len();
791                line_string.push_str(text);
792                let text_end = line_string.len();
793                // Only add attrs if they don't match the defaults
794                if *attrs != attrs_list.defaults() {
795                    attrs_list.add_span(text_start..text_end, attrs);
796                }
797            }
798
799            // we know that at the end of a line,
800            // span text's end index is always >= line text's end index
801            // so if this span ends before this line ends,
802            // there is another span in this line.
803            // otherwise, we move on to the next line.
804            if span_range.end < line_range.end {
805                maybe_span = spans_iter.next();
806            } else {
807                maybe_line = lines_iter.next();
808                if maybe_line.is_some() {
809                    // finalize this line and start a new line
810                    let next_attrs_list = self
811                        .lines
812                        .get_mut(line_count + 1)
813                        .map_or_else(|| AttrsList::new(&Attrs::new()), BufferLine::reclaim_attrs)
814                        .reset(default_attrs);
815                    let next_line_string = self
816                        .lines
817                        .get_mut(line_count + 1)
818                        .map(BufferLine::reclaim_text)
819                        .unwrap_or_default();
820                    let prev_attrs_list = core::mem::replace(&mut attrs_list, next_attrs_list);
821                    let prev_line_string = core::mem::replace(&mut line_string, next_line_string);
822                    if self.lines.len() == line_count {
823                        self.lines.push(BufferLine::empty());
824                    }
825                    self.lines[line_count].reset_new(
826                        prev_line_string,
827                        line_ending,
828                        prev_attrs_list,
829                        shaping,
830                    );
831                    line_count += 1;
832                } else {
833                    // finalize the final line
834                    if self.lines.len() == line_count {
835                        self.lines.push(BufferLine::empty());
836                    }
837                    self.lines[line_count].reset_new(line_string, line_ending, attrs_list, shaping);
838                    line_count += 1;
839                    break;
840                }
841            }
842        }
843
844        // Discard excess lines now that we have reused as much of the existing allocations as possible.
845        self.lines.truncate(line_count);
846
847        self.lines.iter_mut().for_each(|line| {
848            line.set_align(alignment);
849        });
850
851        self.scroll = Scroll::default();
852
853        self.shape_until_scroll(font_system, false);
854    }
855
856    /// True if a redraw is needed
857    pub const fn redraw(&self) -> bool {
858        self.redraw
859    }
860
861    /// Set redraw needed flag
862    pub fn set_redraw(&mut self, redraw: bool) {
863        self.redraw = redraw;
864    }
865
866    /// Get the visible layout runs for rendering and other tasks
867    pub fn layout_runs(&self) -> LayoutRunIter<'_> {
868        LayoutRunIter::new(self)
869    }
870
871    /// Convert x, y position to Cursor (hit detection)
872    pub fn hit(&self, x: f32, y: f32) -> Option<Cursor> {
873        #[cfg(all(feature = "std", not(target_arch = "wasm32")))]
874        let instant = std::time::Instant::now();
875
876        let mut new_cursor_opt = None;
877
878        let mut runs = self.layout_runs().peekable();
879        let mut first_run = true;
880        while let Some(run) = runs.next() {
881            let line_top = run.line_top;
882            let line_height = run.line_height;
883
884            if first_run && y < line_top {
885                first_run = false;
886                let new_cursor = Cursor::new(run.line_i, 0);
887                new_cursor_opt = Some(new_cursor);
888            } else if y >= line_top && y < line_top + line_height {
889                let mut new_cursor_glyph = run.glyphs.len();
890                let mut new_cursor_char = 0;
891                let mut new_cursor_affinity = Affinity::After;
892
893                let mut first_glyph = true;
894
895                'hit: for (glyph_i, glyph) in run.glyphs.iter().enumerate() {
896                    if first_glyph {
897                        first_glyph = false;
898                        if (run.rtl && x > glyph.x) || (!run.rtl && x < 0.0) {
899                            new_cursor_glyph = 0;
900                            new_cursor_char = 0;
901                        }
902                    }
903                    if x >= glyph.x && x <= glyph.x + glyph.w {
904                        new_cursor_glyph = glyph_i;
905
906                        let cluster = &run.text[glyph.start..glyph.end];
907                        let total = cluster.grapheme_indices(true).count();
908                        let mut egc_x = glyph.x;
909                        let egc_w = glyph.w / (total as f32);
910                        for (egc_i, egc) in cluster.grapheme_indices(true) {
911                            if x >= egc_x && x <= egc_x + egc_w {
912                                new_cursor_char = egc_i;
913
914                                let right_half = x >= egc_x + egc_w / 2.0;
915                                if right_half != glyph.level.is_rtl() {
916                                    // If clicking on last half of glyph, move cursor past glyph
917                                    new_cursor_char += egc.len();
918                                    new_cursor_affinity = Affinity::Before;
919                                }
920                                break 'hit;
921                            }
922                            egc_x += egc_w;
923                        }
924
925                        let right_half = x >= glyph.x + glyph.w / 2.0;
926                        if right_half != glyph.level.is_rtl() {
927                            // If clicking on last half of glyph, move cursor past glyph
928                            new_cursor_char = cluster.len();
929                            new_cursor_affinity = Affinity::Before;
930                        }
931                        break 'hit;
932                    }
933                }
934
935                let mut new_cursor = Cursor::new(run.line_i, 0);
936
937                match run.glyphs.get(new_cursor_glyph) {
938                    Some(glyph) => {
939                        // Position at glyph
940                        new_cursor.index = glyph.start + new_cursor_char;
941                        new_cursor.affinity = new_cursor_affinity;
942                    }
943                    None => {
944                        if let Some(glyph) = run.glyphs.last() {
945                            // Position at end of line
946                            new_cursor.index = glyph.end;
947                            new_cursor.affinity = Affinity::Before;
948                        }
949                    }
950                }
951
952                new_cursor_opt = Some(new_cursor);
953
954                break;
955            } else if runs.peek().is_none() && y > run.line_y {
956                let mut new_cursor = Cursor::new(run.line_i, 0);
957                if let Some(glyph) = run.glyphs.last() {
958                    new_cursor = run.cursor_from_glyph_right(glyph);
959                }
960                new_cursor_opt = Some(new_cursor);
961            }
962        }
963
964        #[cfg(all(feature = "std", not(target_arch = "wasm32")))]
965        log::trace!("click({}, {}): {:?}", x, y, instant.elapsed());
966
967        new_cursor_opt
968    }
969
970    /// Apply a [`Motion`] to a [`Cursor`]
971    pub fn cursor_motion(
972        &mut self,
973        font_system: &mut FontSystem,
974        mut cursor: Cursor,
975        mut cursor_x_opt: Option<i32>,
976        motion: Motion,
977    ) -> Option<(Cursor, Option<i32>)> {
978        match motion {
979            Motion::LayoutCursor(layout_cursor) => {
980                let layout = self.line_layout(font_system, layout_cursor.line)?;
981
982                let layout_line = match layout.get(layout_cursor.layout) {
983                    Some(some) => some,
984                    None => match layout.last() {
985                        Some(some) => some,
986                        None => {
987                            return None;
988                        }
989                    },
990                };
991
992                let (new_index, new_affinity) =
993                    layout_line.glyphs.get(layout_cursor.glyph).map_or_else(
994                        || {
995                            layout_line
996                                .glyphs
997                                .last()
998                                .map_or((0, Affinity::After), |glyph| (glyph.end, Affinity::Before))
999                        },
1000                        |glyph| (glyph.start, Affinity::After),
1001                    );
1002
1003                if cursor.line != layout_cursor.line
1004                    || cursor.index != new_index
1005                    || cursor.affinity != new_affinity
1006                {
1007                    cursor.line = layout_cursor.line;
1008                    cursor.index = new_index;
1009                    cursor.affinity = new_affinity;
1010                }
1011            }
1012            Motion::Previous => {
1013                let line = self.lines.get(cursor.line)?;
1014                if cursor.index > 0 {
1015                    // Find previous character index
1016                    let mut prev_index = 0;
1017                    for (i, _) in line.text().grapheme_indices(true) {
1018                        if i < cursor.index {
1019                            prev_index = i;
1020                        } else {
1021                            break;
1022                        }
1023                    }
1024
1025                    cursor.index = prev_index;
1026                    cursor.affinity = Affinity::After;
1027                } else if cursor.line > 0 {
1028                    cursor.line -= 1;
1029                    cursor.index = self.lines.get(cursor.line)?.text().len();
1030                    cursor.affinity = Affinity::After;
1031                }
1032                cursor_x_opt = None;
1033            }
1034            Motion::Next => {
1035                let line = self.lines.get(cursor.line)?;
1036                if cursor.index < line.text().len() {
1037                    for (i, c) in line.text().grapheme_indices(true) {
1038                        if i == cursor.index {
1039                            cursor.index += c.len();
1040                            cursor.affinity = Affinity::Before;
1041                            break;
1042                        }
1043                    }
1044                } else if cursor.line + 1 < self.lines.len() {
1045                    cursor.line += 1;
1046                    cursor.index = 0;
1047                    cursor.affinity = Affinity::Before;
1048                }
1049                cursor_x_opt = None;
1050            }
1051            Motion::Left => {
1052                let rtl_opt = self
1053                    .line_shape(font_system, cursor.line)
1054                    .map(|shape| shape.rtl);
1055                if let Some(rtl) = rtl_opt {
1056                    if rtl {
1057                        (cursor, cursor_x_opt) =
1058                            self.cursor_motion(font_system, cursor, cursor_x_opt, Motion::Next)?;
1059                    } else {
1060                        (cursor, cursor_x_opt) = self.cursor_motion(
1061                            font_system,
1062                            cursor,
1063                            cursor_x_opt,
1064                            Motion::Previous,
1065                        )?;
1066                    }
1067                }
1068            }
1069            Motion::Right => {
1070                let rtl_opt = self
1071                    .line_shape(font_system, cursor.line)
1072                    .map(|shape| shape.rtl);
1073                if let Some(rtl) = rtl_opt {
1074                    if rtl {
1075                        (cursor, cursor_x_opt) = self.cursor_motion(
1076                            font_system,
1077                            cursor,
1078                            cursor_x_opt,
1079                            Motion::Previous,
1080                        )?;
1081                    } else {
1082                        (cursor, cursor_x_opt) =
1083                            self.cursor_motion(font_system, cursor, cursor_x_opt, Motion::Next)?;
1084                    }
1085                }
1086            }
1087            Motion::Up => {
1088                let mut layout_cursor = self.layout_cursor(font_system, cursor)?;
1089
1090                if cursor_x_opt.is_none() {
1091                    cursor_x_opt = Some(
1092                        layout_cursor.glyph as i32, //TODO: glyph x position
1093                    );
1094                }
1095
1096                if layout_cursor.layout > 0 {
1097                    layout_cursor.layout -= 1;
1098                } else if layout_cursor.line > 0 {
1099                    layout_cursor.line -= 1;
1100                    layout_cursor.layout = usize::MAX;
1101                }
1102
1103                if let Some(cursor_x) = cursor_x_opt {
1104                    layout_cursor.glyph = cursor_x as usize; //TODO: glyph x position
1105                }
1106
1107                (cursor, cursor_x_opt) = self.cursor_motion(
1108                    font_system,
1109                    cursor,
1110                    cursor_x_opt,
1111                    Motion::LayoutCursor(layout_cursor),
1112                )?;
1113            }
1114            Motion::Down => {
1115                let mut layout_cursor = self.layout_cursor(font_system, cursor)?;
1116
1117                let layout_len = self.line_layout(font_system, layout_cursor.line)?.len();
1118
1119                if cursor_x_opt.is_none() {
1120                    cursor_x_opt = Some(
1121                        layout_cursor.glyph as i32, //TODO: glyph x position
1122                    );
1123                }
1124
1125                if layout_cursor.layout + 1 < layout_len {
1126                    layout_cursor.layout += 1;
1127                } else if layout_cursor.line + 1 < self.lines.len() {
1128                    layout_cursor.line += 1;
1129                    layout_cursor.layout = 0;
1130                }
1131
1132                if let Some(cursor_x) = cursor_x_opt {
1133                    layout_cursor.glyph = cursor_x as usize; //TODO: glyph x position
1134                }
1135
1136                (cursor, cursor_x_opt) = self.cursor_motion(
1137                    font_system,
1138                    cursor,
1139                    cursor_x_opt,
1140                    Motion::LayoutCursor(layout_cursor),
1141                )?;
1142            }
1143            Motion::Home => {
1144                let mut layout_cursor = self.layout_cursor(font_system, cursor)?;
1145                layout_cursor.glyph = 0;
1146                #[allow(unused_assignments)]
1147                {
1148                    (cursor, cursor_x_opt) = self.cursor_motion(
1149                        font_system,
1150                        cursor,
1151                        cursor_x_opt,
1152                        Motion::LayoutCursor(layout_cursor),
1153                    )?;
1154                }
1155                cursor_x_opt = None;
1156            }
1157            Motion::SoftHome => {
1158                let line = self.lines.get(cursor.line)?;
1159                cursor.index = line
1160                    .text()
1161                    .char_indices()
1162                    .find_map(|(i, c)| if c.is_whitespace() { None } else { Some(i) })
1163                    .unwrap_or(0);
1164                cursor_x_opt = None;
1165            }
1166            Motion::End => {
1167                let mut layout_cursor = self.layout_cursor(font_system, cursor)?;
1168                layout_cursor.glyph = usize::MAX;
1169                #[allow(unused_assignments)]
1170                {
1171                    (cursor, cursor_x_opt) = self.cursor_motion(
1172                        font_system,
1173                        cursor,
1174                        cursor_x_opt,
1175                        Motion::LayoutCursor(layout_cursor),
1176                    )?;
1177                }
1178                cursor_x_opt = None;
1179            }
1180            Motion::ParagraphStart => {
1181                cursor.index = 0;
1182                cursor_x_opt = None;
1183            }
1184            Motion::ParagraphEnd => {
1185                cursor.index = self.lines.get(cursor.line)?.text().len();
1186                cursor_x_opt = None;
1187            }
1188            Motion::PageUp => {
1189                if let Some(height) = self.height_opt {
1190                    (cursor, cursor_x_opt) = self.cursor_motion(
1191                        font_system,
1192                        cursor,
1193                        cursor_x_opt,
1194                        Motion::Vertical(-height as i32),
1195                    )?;
1196                }
1197            }
1198            Motion::PageDown => {
1199                if let Some(height) = self.height_opt {
1200                    (cursor, cursor_x_opt) = self.cursor_motion(
1201                        font_system,
1202                        cursor,
1203                        cursor_x_opt,
1204                        Motion::Vertical(height as i32),
1205                    )?;
1206                }
1207            }
1208            Motion::Vertical(px) => {
1209                // TODO more efficient, use layout run line height
1210                let lines = px / self.metrics().line_height as i32;
1211                match lines.cmp(&0) {
1212                    cmp::Ordering::Less => {
1213                        for _ in 0..-lines {
1214                            (cursor, cursor_x_opt) =
1215                                self.cursor_motion(font_system, cursor, cursor_x_opt, Motion::Up)?;
1216                        }
1217                    }
1218                    cmp::Ordering::Greater => {
1219                        for _ in 0..lines {
1220                            (cursor, cursor_x_opt) = self.cursor_motion(
1221                                font_system,
1222                                cursor,
1223                                cursor_x_opt,
1224                                Motion::Down,
1225                            )?;
1226                        }
1227                    }
1228                    cmp::Ordering::Equal => {}
1229                }
1230            }
1231            Motion::PreviousWord => {
1232                let line = self.lines.get(cursor.line)?;
1233                if cursor.index > 0 {
1234                    cursor.index = line
1235                        .text()
1236                        .unicode_word_indices()
1237                        .rev()
1238                        .map(|(i, _)| i)
1239                        .find(|&i| i < cursor.index)
1240                        .unwrap_or(0);
1241                } else if cursor.line > 0 {
1242                    cursor.line -= 1;
1243                    cursor.index = self.lines.get(cursor.line)?.text().len();
1244                }
1245                cursor_x_opt = None;
1246            }
1247            Motion::NextWord => {
1248                let line = self.lines.get(cursor.line)?;
1249                if cursor.index < line.text().len() {
1250                    cursor.index = line
1251                        .text()
1252                        .unicode_word_indices()
1253                        .map(|(i, word)| i + word.len())
1254                        .find(|&i| i > cursor.index)
1255                        .unwrap_or_else(|| line.text().len());
1256                } else if cursor.line + 1 < self.lines.len() {
1257                    cursor.line += 1;
1258                    cursor.index = 0;
1259                }
1260                cursor_x_opt = None;
1261            }
1262            Motion::LeftWord => {
1263                let rtl_opt = self
1264                    .line_shape(font_system, cursor.line)
1265                    .map(|shape| shape.rtl);
1266                if let Some(rtl) = rtl_opt {
1267                    if rtl {
1268                        (cursor, cursor_x_opt) = self.cursor_motion(
1269                            font_system,
1270                            cursor,
1271                            cursor_x_opt,
1272                            Motion::NextWord,
1273                        )?;
1274                    } else {
1275                        (cursor, cursor_x_opt) = self.cursor_motion(
1276                            font_system,
1277                            cursor,
1278                            cursor_x_opt,
1279                            Motion::PreviousWord,
1280                        )?;
1281                    }
1282                }
1283            }
1284            Motion::RightWord => {
1285                let rtl_opt = self
1286                    .line_shape(font_system, cursor.line)
1287                    .map(|shape| shape.rtl);
1288                if let Some(rtl) = rtl_opt {
1289                    if rtl {
1290                        (cursor, cursor_x_opt) = self.cursor_motion(
1291                            font_system,
1292                            cursor,
1293                            cursor_x_opt,
1294                            Motion::PreviousWord,
1295                        )?;
1296                    } else {
1297                        (cursor, cursor_x_opt) = self.cursor_motion(
1298                            font_system,
1299                            cursor,
1300                            cursor_x_opt,
1301                            Motion::NextWord,
1302                        )?;
1303                    }
1304                }
1305            }
1306            Motion::BufferStart => {
1307                cursor.line = 0;
1308                cursor.index = 0;
1309                cursor_x_opt = None;
1310            }
1311            Motion::BufferEnd => {
1312                cursor.line = self.lines.len().saturating_sub(1);
1313                cursor.index = self.lines.get(cursor.line)?.text().len();
1314                cursor_x_opt = None;
1315            }
1316            Motion::GotoLine(line) => {
1317                let mut layout_cursor = self.layout_cursor(font_system, cursor)?;
1318                layout_cursor.line = line;
1319                (cursor, cursor_x_opt) = self.cursor_motion(
1320                    font_system,
1321                    cursor,
1322                    cursor_x_opt,
1323                    Motion::LayoutCursor(layout_cursor),
1324                )?;
1325            }
1326        }
1327        Some((cursor, cursor_x_opt))
1328    }
1329
1330    /// Draw the buffer
1331    #[cfg(feature = "swash")]
1332    pub fn draw<F>(
1333        &self,
1334        font_system: &mut FontSystem,
1335        cache: &mut crate::SwashCache,
1336        color: Color,
1337        mut f: F,
1338    ) where
1339        F: FnMut(i32, i32, u32, u32, Color),
1340    {
1341        for run in self.layout_runs() {
1342            for glyph in run.glyphs {
1343                let physical_glyph = glyph.physical((0., 0.), 1.0);
1344                let glyph_color = glyph.color_opt.map_or(color, |some| some);
1345
1346                cache.with_pixels(
1347                    font_system,
1348                    physical_glyph.cache_key,
1349                    glyph_color,
1350                    |x, y, color| {
1351                        f(
1352                            physical_glyph.x + x,
1353                            run.line_y as i32 + physical_glyph.y + y,
1354                            1,
1355                            1,
1356                            color,
1357                        );
1358                    },
1359                );
1360            }
1361        }
1362    }
1363}
1364
1365impl BorrowedWithFontSystem<'_, Buffer> {
1366    /// Shape lines until cursor, also scrolling to include cursor in view
1367    pub fn shape_until_cursor(&mut self, cursor: Cursor, prune: bool) {
1368        self.inner
1369            .shape_until_cursor(self.font_system, cursor, prune);
1370    }
1371
1372    /// Shape lines until scroll
1373    pub fn shape_until_scroll(&mut self, prune: bool) {
1374        self.inner.shape_until_scroll(self.font_system, prune);
1375    }
1376
1377    /// Shape the provided line index and return the result
1378    pub fn line_shape(&mut self, line_i: usize) -> Option<&ShapeLine> {
1379        self.inner.line_shape(self.font_system, line_i)
1380    }
1381
1382    /// Lay out the provided line index and return the result
1383    pub fn line_layout(&mut self, line_i: usize) -> Option<&[LayoutLine]> {
1384        self.inner.line_layout(self.font_system, line_i)
1385    }
1386
1387    /// Set the current [`Metrics`]
1388    ///
1389    /// # Panics
1390    ///
1391    /// Will panic if `metrics.font_size` is zero.
1392    pub fn set_metrics(&mut self, metrics: Metrics) {
1393        self.inner.set_metrics(self.font_system, metrics);
1394    }
1395
1396    /// Set the current [`Wrap`]
1397    pub fn set_wrap(&mut self, wrap: Wrap) {
1398        self.inner.set_wrap(self.font_system, wrap);
1399    }
1400
1401    /// Set the current buffer dimensions
1402    pub fn set_size(&mut self, width_opt: Option<f32>, height_opt: Option<f32>) {
1403        self.inner.set_size(self.font_system, width_opt, height_opt);
1404    }
1405
1406    /// Set the current [`Metrics`] and buffer dimensions at the same time
1407    ///
1408    /// # Panics
1409    ///
1410    /// Will panic if `metrics.font_size` is zero.
1411    pub fn set_metrics_and_size(
1412        &mut self,
1413        metrics: Metrics,
1414        width_opt: Option<f32>,
1415        height_opt: Option<f32>,
1416    ) {
1417        self.inner
1418            .set_metrics_and_size(self.font_system, metrics, width_opt, height_opt);
1419    }
1420
1421    /// Set tab width (number of spaces between tab stops)
1422    pub fn set_tab_width(&mut self, tab_width: u16) {
1423        self.inner.set_tab_width(self.font_system, tab_width);
1424    }
1425
1426    /// Set text of buffer, using provided attributes for each line by default
1427    pub fn set_text(&mut self, text: &str, attrs: &Attrs, shaping: Shaping) {
1428        self.inner.set_text(self.font_system, text, attrs, shaping);
1429    }
1430
1431    /// Set text of buffer, using an iterator of styled spans (pairs of text and attributes)
1432    ///
1433    /// ```
1434    /// # use cosmic_text::{Attrs, Buffer, Family, FontSystem, Metrics, Shaping};
1435    /// # let mut font_system = FontSystem::new();
1436    /// let mut buffer = Buffer::new_empty(Metrics::new(32.0, 44.0));
1437    /// let attrs = Attrs::new().family(Family::Serif);
1438    /// buffer.set_rich_text(
1439    ///     &mut font_system,
1440    ///     [
1441    ///         ("hello, ", attrs.clone()),
1442    ///         ("cosmic\ntext", attrs.clone().family(Family::Monospace)),
1443    ///     ],
1444    ///     &attrs,
1445    ///     Shaping::Advanced,
1446    ///     None,
1447    /// );
1448    /// ```
1449    pub fn set_rich_text<'r, 's, I>(
1450        &mut self,
1451        spans: I,
1452        default_attrs: &Attrs,
1453        shaping: Shaping,
1454        alignment: Option<Align>,
1455    ) where
1456        I: IntoIterator<Item = (&'s str, Attrs<'r>)>,
1457    {
1458        self.inner
1459            .set_rich_text(self.font_system, spans, default_attrs, shaping, alignment);
1460    }
1461
1462    /// Apply a [`Motion`] to a [`Cursor`]
1463    pub fn cursor_motion(
1464        &mut self,
1465        cursor: Cursor,
1466        cursor_x_opt: Option<i32>,
1467        motion: Motion,
1468    ) -> Option<(Cursor, Option<i32>)> {
1469        self.inner
1470            .cursor_motion(self.font_system, cursor, cursor_x_opt, motion)
1471    }
1472
1473    /// Draw the buffer
1474    #[cfg(feature = "swash")]
1475    pub fn draw<F>(&mut self, cache: &mut crate::SwashCache, color: Color, f: F)
1476    where
1477        F: FnMut(i32, i32, u32, u32, Color),
1478    {
1479        self.inner.draw(self.font_system, cache, color, f);
1480    }
1481}