text_system.rs

  1use crate::{
  2    point, px, size, Bounds, DevicePixels, Font, FontFeatures, FontId, FontMetrics, FontRun,
  3    FontStyle, FontWeight, GlyphId, LineLayout, Pixels, PlatformTextSystem, Point,
  4    RenderGlyphParams, Result, ShapedGlyph, ShapedRun, SharedString, Size, SUBPIXEL_VARIANTS,
  5};
  6use anyhow::anyhow;
  7use cocoa::appkit::{CGFloat, CGPoint};
  8use collections::{BTreeSet, HashMap};
  9use core_foundation::{
 10    array::CFIndex,
 11    attributed_string::{CFAttributedStringRef, CFMutableAttributedString},
 12    base::{CFRange, TCFType},
 13    number::CFNumber,
 14    string::CFString,
 15};
 16use core_graphics::{
 17    base::{kCGImageAlphaPremultipliedLast, CGGlyph},
 18    color_space::CGColorSpace,
 19    context::CGContext,
 20};
 21use core_text::{
 22    font::CTFont,
 23    font_descriptor::{
 24        kCTFontSlantTrait, kCTFontSymbolicTrait, kCTFontWeightTrait, kCTFontWidthTrait,
 25    },
 26    line::CTLine,
 27    string_attributes::kCTFontAttributeName,
 28};
 29use font_kit::{
 30    font::Font as FontKitFont,
 31    handle::Handle,
 32    hinting::HintingOptions,
 33    metrics::Metrics,
 34    properties::{Style as FontkitStyle, Weight as FontkitWeight},
 35    source::SystemSource,
 36    sources::mem::MemSource,
 37};
 38use parking_lot::{RwLock, RwLockUpgradableReadGuard};
 39use pathfinder_geometry::{
 40    rect::{RectF, RectI},
 41    transform2d::Transform2F,
 42    vector::{Vector2F, Vector2I},
 43};
 44use smallvec::SmallVec;
 45use std::{borrow::Cow, char, cmp, convert::TryFrom, ffi::c_void, sync::Arc};
 46
 47use super::open_type;
 48
 49#[allow(non_upper_case_globals)]
 50const kCGImageAlphaOnly: u32 = 7;
 51
 52pub(crate) struct MacTextSystem(RwLock<MacTextSystemState>);
 53
 54#[derive(Clone, PartialEq, Eq, Hash)]
 55struct FontKey {
 56    font_family: SharedString,
 57    font_features: FontFeatures,
 58}
 59
 60struct MacTextSystemState {
 61    memory_source: MemSource,
 62    system_source: SystemSource,
 63    fonts: Vec<FontKitFont>,
 64    font_selections: HashMap<Font, FontId>,
 65    font_ids_by_postscript_name: HashMap<String, FontId>,
 66    font_ids_by_font_key: HashMap<FontKey, SmallVec<[FontId; 4]>>,
 67    postscript_names_by_font_id: HashMap<FontId, String>,
 68}
 69
 70impl MacTextSystem {
 71    pub(crate) fn new() -> Self {
 72        Self(RwLock::new(MacTextSystemState {
 73            memory_source: MemSource::empty(),
 74            system_source: SystemSource::new(),
 75            fonts: Vec::new(),
 76            font_selections: HashMap::default(),
 77            font_ids_by_postscript_name: HashMap::default(),
 78            font_ids_by_font_key: HashMap::default(),
 79            postscript_names_by_font_id: HashMap::default(),
 80        }))
 81    }
 82}
 83
 84impl Default for MacTextSystem {
 85    fn default() -> Self {
 86        Self::new()
 87    }
 88}
 89
 90impl PlatformTextSystem for MacTextSystem {
 91    fn add_fonts(&self, fonts: Vec<Cow<'static, [u8]>>) -> Result<()> {
 92        self.0.write().add_fonts(fonts)
 93    }
 94
 95    fn all_font_names(&self) -> Vec<String> {
 96        let collection = core_text::font_collection::create_for_all_families();
 97        let Some(descriptors) = collection.get_descriptors() else {
 98            return Vec::new();
 99        };
100        let mut names = BTreeSet::new();
101        for descriptor in descriptors.into_iter() {
102            names.extend(lenient_font_attributes::family_name(&descriptor));
103        }
104        if let Ok(fonts_in_memory) = self.0.read().memory_source.all_families() {
105            names.extend(fonts_in_memory);
106        }
107        names.into_iter().collect()
108    }
109
110    fn all_font_families(&self) -> Vec<String> {
111        self.0
112            .read()
113            .system_source
114            .all_families()
115            .expect("core text should never return an error")
116    }
117
118    fn font_id(&self, font: &Font) -> Result<FontId> {
119        let lock = self.0.upgradable_read();
120        if let Some(font_id) = lock.font_selections.get(font) {
121            Ok(*font_id)
122        } else {
123            let mut lock = RwLockUpgradableReadGuard::upgrade(lock);
124            let font_key = FontKey {
125                font_family: font.family.clone(),
126                font_features: font.features,
127            };
128            let candidates = if let Some(font_ids) = lock.font_ids_by_font_key.get(&font_key) {
129                font_ids.as_slice()
130            } else {
131                let font_ids = lock.load_family(&font.family, font.features)?;
132                lock.font_ids_by_font_key.insert(font_key.clone(), font_ids);
133                lock.font_ids_by_font_key[&font_key].as_ref()
134            };
135
136            let candidate_properties = candidates
137                .iter()
138                .map(|font_id| lock.fonts[font_id.0].properties())
139                .collect::<SmallVec<[_; 4]>>();
140
141            let ix = font_kit::matching::find_best_match(
142                &candidate_properties,
143                &font_kit::properties::Properties {
144                    style: font.style.into(),
145                    weight: font.weight.into(),
146                    stretch: Default::default(),
147                },
148            )?;
149
150            let font_id = candidates[ix];
151            lock.font_selections.insert(font.clone(), font_id);
152            Ok(font_id)
153        }
154    }
155
156    fn font_metrics(&self, font_id: FontId) -> FontMetrics {
157        self.0.read().fonts[font_id.0].metrics().into()
158    }
159
160    fn typographic_bounds(&self, font_id: FontId, glyph_id: GlyphId) -> Result<Bounds<f32>> {
161        Ok(self.0.read().fonts[font_id.0]
162            .typographic_bounds(glyph_id.0)?
163            .into())
164    }
165
166    fn advance(&self, font_id: FontId, glyph_id: GlyphId) -> Result<Size<f32>> {
167        self.0.read().advance(font_id, glyph_id)
168    }
169
170    fn glyph_for_char(&self, font_id: FontId, ch: char) -> Option<GlyphId> {
171        self.0.read().glyph_for_char(font_id, ch)
172    }
173
174    fn glyph_raster_bounds(&self, params: &RenderGlyphParams) -> Result<Bounds<DevicePixels>> {
175        self.0.read().raster_bounds(params)
176    }
177
178    fn rasterize_glyph(
179        &self,
180        glyph_id: &RenderGlyphParams,
181        raster_bounds: Bounds<DevicePixels>,
182    ) -> Result<(Size<DevicePixels>, Vec<u8>)> {
183        self.0.read().rasterize_glyph(glyph_id, raster_bounds)
184    }
185
186    fn layout_line(&self, text: &str, font_size: Pixels, font_runs: &[FontRun]) -> LineLayout {
187        self.0.write().layout_line(text, font_size, font_runs)
188    }
189
190    fn wrap_line(
191        &self,
192        text: &str,
193        font_id: FontId,
194        font_size: Pixels,
195        width: Pixels,
196    ) -> Vec<usize> {
197        self.0.read().wrap_line(text, font_id, font_size, width)
198    }
199}
200
201impl MacTextSystemState {
202    fn add_fonts(&mut self, fonts: Vec<Cow<'static, [u8]>>) -> Result<()> {
203        let fonts = fonts
204            .into_iter()
205            .map(|bytes| match bytes {
206                Cow::Borrowed(embedded_font) => {
207                    let data_provider = unsafe {
208                        core_graphics::data_provider::CGDataProvider::from_slice(embedded_font)
209                    };
210                    let font = core_graphics::font::CGFont::from_data_provider(data_provider)
211                        .map_err(|_| anyhow!("Could not load an embedded font."))?;
212                    let font = font_kit::loaders::core_text::Font::from_core_graphics_font(font);
213                    Ok(Handle::from_native(&font))
214                }
215                Cow::Owned(bytes) => Ok(Handle::from_memory(Arc::new(bytes), 0)),
216            })
217            .collect::<Result<Vec<_>>>()?;
218        self.memory_source.add_fonts(fonts.into_iter())?;
219        Ok(())
220    }
221
222    fn load_family(&mut self, name: &str, features: FontFeatures) -> Result<SmallVec<[FontId; 4]>> {
223        let name = if name == ".SystemUIFont" {
224            ".AppleSystemUIFont"
225        } else {
226            name
227        };
228
229        let mut font_ids = SmallVec::new();
230        let family = self
231            .memory_source
232            .select_family_by_name(name)
233            .or_else(|_| self.system_source.select_family_by_name(name))?;
234        for font in family.fonts() {
235            let mut font = font.load()?;
236
237            open_type::apply_features(&mut font, features);
238
239            // This block contains a precautionary fix to guard against loading fonts
240            // that might cause panics due to `.unwrap()`s up the chain.
241            {
242                // We use the 'm' character for text measurements in various spots
243                // (e.g., the editor). However, at time of writing some of those usages
244                // will panic if the font has no 'm' glyph.
245                //
246                // Therefore, we check up front that the font has the necessary glyph.
247                let has_m_glyph = font.glyph_for_char('m').is_some();
248
249                // HACK: The 'Segoe Fluent Icons' font does not have an 'm' glyph,
250                // but we need to be able to load it for rendering Windows icons in
251                // the Storybook (on macOS).
252                let is_segoe_fluent_icons = font.full_name() == "Segoe Fluent Icons";
253
254                if !has_m_glyph && !is_segoe_fluent_icons {
255                    // I spent far too long trying to track down why a font missing the 'm'
256                    // character wasn't loading. This log statement will hopefully save
257                    // someone else from suffering the same fate.
258                    log::warn!(
259                        "font '{}' has no 'm' character and was not loaded",
260                        font.full_name()
261                    );
262                    continue;
263                }
264            }
265
266            // We've seen a number of panics in production caused by calling font.properties()
267            // which unwraps a downcast to CFNumber. This is an attempt to avoid the panic,
268            // and to try and identify the incalcitrant font.
269            let traits = font.native_font().all_traits();
270            if unsafe {
271                !(traits
272                    .get(kCTFontSymbolicTrait)
273                    .downcast::<CFNumber>()
274                    .is_some()
275                    && traits
276                        .get(kCTFontWidthTrait)
277                        .downcast::<CFNumber>()
278                        .is_some()
279                    && traits
280                        .get(kCTFontWeightTrait)
281                        .downcast::<CFNumber>()
282                        .is_some()
283                    && traits
284                        .get(kCTFontSlantTrait)
285                        .downcast::<CFNumber>()
286                        .is_some())
287            } {
288                log::error!(
289                    "Failed to read traits for font {:?}",
290                    font.postscript_name().unwrap()
291                );
292                continue;
293            }
294
295            let font_id = FontId(self.fonts.len());
296            font_ids.push(font_id);
297            let postscript_name = font.postscript_name().unwrap();
298            self.font_ids_by_postscript_name
299                .insert(postscript_name.clone(), font_id);
300            self.postscript_names_by_font_id
301                .insert(font_id, postscript_name);
302            self.fonts.push(font);
303        }
304        Ok(font_ids)
305    }
306
307    fn advance(&self, font_id: FontId, glyph_id: GlyphId) -> Result<Size<f32>> {
308        Ok(self.fonts[font_id.0].advance(glyph_id.0)?.into())
309    }
310
311    fn glyph_for_char(&self, font_id: FontId, ch: char) -> Option<GlyphId> {
312        self.fonts[font_id.0].glyph_for_char(ch).map(GlyphId)
313    }
314
315    fn id_for_native_font(&mut self, requested_font: CTFont) -> FontId {
316        let postscript_name = requested_font.postscript_name();
317        if let Some(font_id) = self.font_ids_by_postscript_name.get(&postscript_name) {
318            *font_id
319        } else {
320            let font_id = FontId(self.fonts.len());
321            self.font_ids_by_postscript_name
322                .insert(postscript_name.clone(), font_id);
323            self.postscript_names_by_font_id
324                .insert(font_id, postscript_name);
325            self.fonts
326                .push(font_kit::font::Font::from_core_graphics_font(
327                    requested_font.copy_to_CGFont(),
328                ));
329            font_id
330        }
331    }
332
333    fn is_emoji(&self, font_id: FontId) -> bool {
334        self.postscript_names_by_font_id
335            .get(&font_id)
336            .map_or(false, |postscript_name| {
337                postscript_name == "AppleColorEmoji" || postscript_name == ".AppleColorEmojiUI"
338            })
339    }
340
341    fn raster_bounds(&self, params: &RenderGlyphParams) -> Result<Bounds<DevicePixels>> {
342        let font = &self.fonts[params.font_id.0];
343        let scale = Transform2F::from_scale(params.scale_factor);
344        Ok(font
345            .raster_bounds(
346                params.glyph_id.0,
347                params.font_size.into(),
348                scale,
349                HintingOptions::None,
350                font_kit::canvas::RasterizationOptions::GrayscaleAa,
351            )?
352            .into())
353    }
354
355    fn rasterize_glyph(
356        &self,
357        params: &RenderGlyphParams,
358        glyph_bounds: Bounds<DevicePixels>,
359    ) -> Result<(Size<DevicePixels>, Vec<u8>)> {
360        if glyph_bounds.size.width.0 == 0 || glyph_bounds.size.height.0 == 0 {
361            Err(anyhow!("glyph bounds are empty"))
362        } else {
363            // Add an extra pixel when the subpixel variant isn't zero to make room for anti-aliasing.
364            let mut bitmap_size = glyph_bounds.size;
365            if params.subpixel_variant.x > 0 {
366                bitmap_size.width += DevicePixels(1);
367            }
368            if params.subpixel_variant.y > 0 {
369                bitmap_size.height += DevicePixels(1);
370            }
371            let bitmap_size = bitmap_size;
372
373            let mut bytes;
374            let cx;
375            if params.is_emoji {
376                bytes = vec![0; bitmap_size.width.0 as usize * 4 * bitmap_size.height.0 as usize];
377                cx = CGContext::create_bitmap_context(
378                    Some(bytes.as_mut_ptr() as *mut _),
379                    bitmap_size.width.0 as usize,
380                    bitmap_size.height.0 as usize,
381                    8,
382                    bitmap_size.width.0 as usize * 4,
383                    &CGColorSpace::create_device_rgb(),
384                    kCGImageAlphaPremultipliedLast,
385                );
386            } else {
387                bytes = vec![0; bitmap_size.width.0 as usize * bitmap_size.height.0 as usize];
388                cx = CGContext::create_bitmap_context(
389                    Some(bytes.as_mut_ptr() as *mut _),
390                    bitmap_size.width.0 as usize,
391                    bitmap_size.height.0 as usize,
392                    8,
393                    bitmap_size.width.0 as usize,
394                    &CGColorSpace::create_device_gray(),
395                    kCGImageAlphaOnly,
396                );
397            }
398
399            // Move the origin to bottom left and account for scaling, this
400            // makes drawing text consistent with the font-kit's raster_bounds.
401            cx.translate(
402                -glyph_bounds.origin.x.0 as CGFloat,
403                (glyph_bounds.origin.y.0 + glyph_bounds.size.height.0) as CGFloat,
404            );
405            cx.scale(
406                params.scale_factor as CGFloat,
407                params.scale_factor as CGFloat,
408            );
409
410            let subpixel_shift = params
411                .subpixel_variant
412                .map(|v| v as f32 / SUBPIXEL_VARIANTS as f32);
413            cx.set_allows_font_subpixel_positioning(true);
414            cx.set_should_subpixel_position_fonts(true);
415            cx.set_allows_font_subpixel_quantization(false);
416            cx.set_should_subpixel_quantize_fonts(false);
417            self.fonts[params.font_id.0]
418                .native_font()
419                .clone_with_font_size(f32::from(params.font_size) as CGFloat)
420                .draw_glyphs(
421                    &[params.glyph_id.0 as CGGlyph],
422                    &[CGPoint::new(
423                        (subpixel_shift.x / params.scale_factor) as CGFloat,
424                        (subpixel_shift.y / params.scale_factor) as CGFloat,
425                    )],
426                    cx,
427                );
428
429            if params.is_emoji {
430                // Convert from RGBA with premultiplied alpha to BGRA with straight alpha.
431                for pixel in bytes.chunks_exact_mut(4) {
432                    pixel.swap(0, 2);
433                    let a = pixel[3] as f32 / 255.;
434                    pixel[0] = (pixel[0] as f32 / a) as u8;
435                    pixel[1] = (pixel[1] as f32 / a) as u8;
436                    pixel[2] = (pixel[2] as f32 / a) as u8;
437                }
438            }
439
440            Ok((bitmap_size, bytes))
441        }
442    }
443
444    fn layout_line(&mut self, text: &str, font_size: Pixels, font_runs: &[FontRun]) -> LineLayout {
445        // Construct the attributed string, converting UTF8 ranges to UTF16 ranges.
446        let mut string = CFMutableAttributedString::new();
447        {
448            string.replace_str(&CFString::new(text), CFRange::init(0, 0));
449            let utf16_line_len = string.char_len() as usize;
450
451            let mut ix_converter = StringIndexConverter::new(text);
452            for run in font_runs {
453                let utf8_end = ix_converter.utf8_ix + run.len;
454                let utf16_start = ix_converter.utf16_ix;
455
456                if utf16_start >= utf16_line_len {
457                    break;
458                }
459
460                ix_converter.advance_to_utf8_ix(utf8_end);
461                let utf16_end = cmp::min(ix_converter.utf16_ix, utf16_line_len);
462
463                let cf_range =
464                    CFRange::init(utf16_start as isize, (utf16_end - utf16_start) as isize);
465
466                let font: &FontKitFont = &self.fonts[run.font_id.0];
467                unsafe {
468                    string.set_attribute(
469                        cf_range,
470                        kCTFontAttributeName,
471                        &font.native_font().clone_with_font_size(font_size.into()),
472                    );
473                }
474
475                if utf16_end == utf16_line_len {
476                    break;
477                }
478            }
479        }
480
481        // Retrieve the glyphs from the shaped line, converting UTF16 offsets to UTF8 offsets.
482        let line = CTLine::new_with_attributed_string(string.as_concrete_TypeRef());
483
484        let mut runs = Vec::new();
485        for run in line.glyph_runs().into_iter() {
486            let attributes = run.attributes().unwrap();
487            let font = unsafe {
488                attributes
489                    .get(kCTFontAttributeName)
490                    .downcast::<CTFont>()
491                    .unwrap()
492            };
493            let font_id = self.id_for_native_font(font);
494
495            let mut ix_converter = StringIndexConverter::new(text);
496            let mut glyphs = SmallVec::new();
497            for ((glyph_id, position), glyph_utf16_ix) in run
498                .glyphs()
499                .iter()
500                .zip(run.positions().iter())
501                .zip(run.string_indices().iter())
502            {
503                let glyph_utf16_ix = usize::try_from(*glyph_utf16_ix).unwrap();
504                ix_converter.advance_to_utf16_ix(glyph_utf16_ix);
505                glyphs.push(ShapedGlyph {
506                    id: GlyphId(*glyph_id as u32),
507                    position: point(position.x as f32, position.y as f32).map(px),
508                    index: ix_converter.utf8_ix,
509                    is_emoji: self.is_emoji(font_id),
510                });
511            }
512
513            runs.push(ShapedRun { font_id, glyphs })
514        }
515
516        let typographic_bounds = line.get_typographic_bounds();
517        LineLayout {
518            runs,
519            font_size,
520            width: typographic_bounds.width.into(),
521            ascent: typographic_bounds.ascent.into(),
522            descent: typographic_bounds.descent.into(),
523            len: text.len(),
524        }
525    }
526
527    fn wrap_line(
528        &self,
529        text: &str,
530        font_id: FontId,
531        font_size: Pixels,
532        width: Pixels,
533    ) -> Vec<usize> {
534        let mut string = CFMutableAttributedString::new();
535        string.replace_str(&CFString::new(text), CFRange::init(0, 0));
536        let cf_range = CFRange::init(0, text.encode_utf16().count() as isize);
537        let font = &self.fonts[font_id.0];
538        unsafe {
539            string.set_attribute(
540                cf_range,
541                kCTFontAttributeName,
542                &font.native_font().clone_with_font_size(font_size.into()),
543            );
544
545            let typesetter = CTTypesetterCreateWithAttributedString(string.as_concrete_TypeRef());
546            let mut ix_converter = StringIndexConverter::new(text);
547            let mut break_indices = Vec::new();
548            while ix_converter.utf8_ix < text.len() {
549                let utf16_len = CTTypesetterSuggestLineBreak(
550                    typesetter,
551                    ix_converter.utf16_ix as isize,
552                    width.into(),
553                ) as usize;
554                ix_converter.advance_to_utf16_ix(ix_converter.utf16_ix + utf16_len);
555                if ix_converter.utf8_ix >= text.len() {
556                    break;
557                }
558                break_indices.push(ix_converter.utf8_ix);
559            }
560            break_indices
561        }
562    }
563}
564
565#[derive(Clone)]
566struct StringIndexConverter<'a> {
567    text: &'a str,
568    utf8_ix: usize,
569    utf16_ix: usize,
570}
571
572impl<'a> StringIndexConverter<'a> {
573    fn new(text: &'a str) -> Self {
574        Self {
575            text,
576            utf8_ix: 0,
577            utf16_ix: 0,
578        }
579    }
580
581    fn advance_to_utf8_ix(&mut self, utf8_target: usize) {
582        for (ix, c) in self.text[self.utf8_ix..].char_indices() {
583            if self.utf8_ix + ix >= utf8_target {
584                self.utf8_ix += ix;
585                return;
586            }
587            self.utf16_ix += c.len_utf16();
588        }
589        self.utf8_ix = self.text.len();
590    }
591
592    fn advance_to_utf16_ix(&mut self, utf16_target: usize) {
593        for (ix, c) in self.text[self.utf8_ix..].char_indices() {
594            if self.utf16_ix >= utf16_target {
595                self.utf8_ix += ix;
596                return;
597            }
598            self.utf16_ix += c.len_utf16();
599        }
600        self.utf8_ix = self.text.len();
601    }
602}
603
604#[repr(C)]
605pub(crate) struct __CFTypesetter(c_void);
606
607type CTTypesetterRef = *const __CFTypesetter;
608
609#[link(name = "CoreText", kind = "framework")]
610extern "C" {
611    fn CTTypesetterCreateWithAttributedString(string: CFAttributedStringRef) -> CTTypesetterRef;
612
613    fn CTTypesetterSuggestLineBreak(
614        typesetter: CTTypesetterRef,
615        start_index: CFIndex,
616        width: f64,
617    ) -> CFIndex;
618}
619
620impl From<Metrics> for FontMetrics {
621    fn from(metrics: Metrics) -> Self {
622        FontMetrics {
623            units_per_em: metrics.units_per_em,
624            ascent: metrics.ascent,
625            descent: metrics.descent,
626            line_gap: metrics.line_gap,
627            underline_position: metrics.underline_position,
628            underline_thickness: metrics.underline_thickness,
629            cap_height: metrics.cap_height,
630            x_height: metrics.x_height,
631            bounding_box: metrics.bounding_box.into(),
632        }
633    }
634}
635
636impl From<RectF> for Bounds<f32> {
637    fn from(rect: RectF) -> Self {
638        Bounds {
639            origin: point(rect.origin_x(), rect.origin_y()),
640            size: size(rect.width(), rect.height()),
641        }
642    }
643}
644
645impl From<RectI> for Bounds<DevicePixels> {
646    fn from(rect: RectI) -> Self {
647        Bounds {
648            origin: point(DevicePixels(rect.origin_x()), DevicePixels(rect.origin_y())),
649            size: size(DevicePixels(rect.width()), DevicePixels(rect.height())),
650        }
651    }
652}
653
654impl From<Vector2I> for Size<DevicePixels> {
655    fn from(value: Vector2I) -> Self {
656        size(value.x().into(), value.y().into())
657    }
658}
659
660impl From<RectI> for Bounds<i32> {
661    fn from(rect: RectI) -> Self {
662        Bounds {
663            origin: point(rect.origin_x(), rect.origin_y()),
664            size: size(rect.width(), rect.height()),
665        }
666    }
667}
668
669impl From<Point<u32>> for Vector2I {
670    fn from(size: Point<u32>) -> Self {
671        Vector2I::new(size.x as i32, size.y as i32)
672    }
673}
674
675impl From<Vector2F> for Size<f32> {
676    fn from(vec: Vector2F) -> Self {
677        size(vec.x(), vec.y())
678    }
679}
680
681impl From<FontWeight> for FontkitWeight {
682    fn from(value: FontWeight) -> Self {
683        FontkitWeight(value.0)
684    }
685}
686
687impl From<FontStyle> for FontkitStyle {
688    fn from(style: FontStyle) -> Self {
689        match style {
690            FontStyle::Normal => FontkitStyle::Normal,
691            FontStyle::Italic => FontkitStyle::Italic,
692            FontStyle::Oblique => FontkitStyle::Oblique,
693        }
694    }
695}
696
697// Some fonts may have no attributest despite `core_text` requiring them (and panicking).
698// This is the same version as `core_text` has without `expect` calls.
699mod lenient_font_attributes {
700    use core_foundation::{
701        base::{CFRetain, CFType, TCFType},
702        string::{CFString, CFStringRef},
703    };
704    use core_text::font_descriptor::{
705        kCTFontFamilyNameAttribute, CTFontDescriptor, CTFontDescriptorCopyAttribute,
706    };
707
708    pub fn family_name(descriptor: &CTFontDescriptor) -> Option<String> {
709        unsafe { get_string_attribute(descriptor, kCTFontFamilyNameAttribute) }
710    }
711
712    fn get_string_attribute(
713        descriptor: &CTFontDescriptor,
714        attribute: CFStringRef,
715    ) -> Option<String> {
716        unsafe {
717            let value = CTFontDescriptorCopyAttribute(descriptor.as_concrete_TypeRef(), attribute);
718            if value.is_null() {
719                return None;
720            }
721
722            let value = CFType::wrap_under_create_rule(value);
723            assert!(value.instance_of::<CFString>());
724            let s = wrap_under_get_rule(value.as_CFTypeRef() as CFStringRef);
725            Some(s.to_string())
726        }
727    }
728
729    unsafe fn wrap_under_get_rule(reference: CFStringRef) -> CFString {
730        assert!(!reference.is_null(), "Attempted to create a NULL object.");
731        let reference = CFRetain(reference as *const ::std::os::raw::c_void) as CFStringRef;
732        TCFType::wrap_under_create_rule(reference)
733    }
734}
735
736#[cfg(test)]
737mod tests {
738    use crate::{font, px, FontRun, GlyphId, MacTextSystem, PlatformTextSystem};
739
740    #[test]
741    fn test_wrap_line() {
742        let fonts = MacTextSystem::new();
743        let font_id = fonts.font_id(&font("Helvetica")).unwrap();
744
745        let line = "one two three four five\n";
746        let wrap_boundaries = fonts.wrap_line(line, font_id, px(16.), px(64.0));
747        assert_eq!(wrap_boundaries, &["one two ".len(), "one two three ".len()]);
748
749        let line = "aaa ααα ✋✋✋ 🎉🎉🎉\n";
750        let wrap_boundaries = fonts.wrap_line(line, font_id, px(16.), px(64.0));
751        assert_eq!(
752            wrap_boundaries,
753            &["aaa ααα ".len(), "aaa ααα ✋✋✋ ".len(),]
754        );
755    }
756
757    #[test]
758    fn test_layout_line_bom_char() {
759        let fonts = MacTextSystem::new();
760        let font_id = fonts.font_id(&font("Helvetica")).unwrap();
761        let line = "\u{feff}";
762        let mut style = FontRun {
763            font_id,
764            len: line.len(),
765        };
766
767        let layout = fonts.layout_line(line, px(16.), &[style]);
768        assert_eq!(layout.len, line.len());
769        assert!(layout.runs.is_empty());
770
771        let line = "a\u{feff}b";
772        style.len = line.len();
773        let layout = fonts.layout_line(line, px(16.), &[style]);
774        assert_eq!(layout.len, line.len());
775        assert_eq!(layout.runs.len(), 1);
776        assert_eq!(layout.runs[0].glyphs.len(), 2);
777        assert_eq!(layout.runs[0].glyphs[0].id, GlyphId(68u32)); // a
778                                                                 // There's no glyph for \u{feff}
779        assert_eq!(layout.runs[0].glyphs[1].id, GlyphId(69u32)); // b
780    }
781}