1use crate::{
  2    color::Color,
  3    font_cache::FamilyId,
  4    json::{json, ToJson},
  5    text_layout::RunStyle,
  6    FontCache,
  7};
  8use anyhow::{anyhow, Result};
  9pub use font_kit::{
 10    metrics::Metrics,
 11    properties::{Properties, Stretch, Style, Weight},
 12};
 13use ordered_float::OrderedFloat;
 14use schemars::JsonSchema;
 15use serde::{de, Deserialize, Serialize};
 16use serde_json::Value;
 17use std::{cell::RefCell, sync::Arc};
 18
 19#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash, JsonSchema)]
 20pub struct FontId(pub usize);
 21
 22pub type GlyphId = u32;
 23
 24#[derive(Clone, Debug, Default, Eq, PartialEq, Serialize, Deserialize, JsonSchema)]
 25pub struct Features {
 26    pub calt: Option<bool>,
 27    pub case: Option<bool>,
 28    pub cpsp: Option<bool>,
 29    pub frac: Option<bool>,
 30    pub liga: Option<bool>,
 31    pub onum: Option<bool>,
 32    pub ordn: Option<bool>,
 33    pub pnum: Option<bool>,
 34    pub ss01: Option<bool>,
 35    pub ss02: Option<bool>,
 36    pub ss03: Option<bool>,
 37    pub ss04: Option<bool>,
 38    pub ss05: Option<bool>,
 39    pub ss06: Option<bool>,
 40    pub ss07: Option<bool>,
 41    pub ss08: Option<bool>,
 42    pub ss09: Option<bool>,
 43    pub ss10: Option<bool>,
 44    pub ss11: Option<bool>,
 45    pub ss12: Option<bool>,
 46    pub ss13: Option<bool>,
 47    pub ss14: Option<bool>,
 48    pub ss15: Option<bool>,
 49    pub ss16: Option<bool>,
 50    pub ss17: Option<bool>,
 51    pub ss18: Option<bool>,
 52    pub ss19: Option<bool>,
 53    pub ss20: Option<bool>,
 54    pub subs: Option<bool>,
 55    pub sups: Option<bool>,
 56    pub swsh: Option<bool>,
 57    pub titl: Option<bool>,
 58    pub tnum: Option<bool>,
 59    pub zero: Option<bool>,
 60}
 61
 62#[derive(Clone, Debug, JsonSchema)]
 63pub struct TextStyle {
 64    pub color: Color,
 65    pub font_family_name: Arc<str>,
 66    pub font_family_id: FamilyId,
 67    pub font_id: FontId,
 68    pub font_size: f32,
 69    #[schemars(with = "PropertiesDef")]
 70    pub font_properties: Properties,
 71    pub underline: Underline,
 72}
 73
 74impl TextStyle {
 75    pub fn refine(self, refinement: TextStyleRefinement) -> TextStyle {
 76        TextStyle {
 77            color: refinement.color.unwrap_or(self.color),
 78            font_family_name: refinement
 79                .font_family_name
 80                .unwrap_or_else(|| self.font_family_name.clone()),
 81            font_family_id: refinement.font_family_id.unwrap_or(self.font_family_id),
 82            font_id: refinement.font_id.unwrap_or(self.font_id),
 83            font_size: refinement.font_size.unwrap_or(self.font_size),
 84            font_properties: refinement.font_properties.unwrap_or(self.font_properties),
 85            underline: refinement.underline.unwrap_or(self.underline),
 86        }
 87    }
 88}
 89
 90pub struct TextStyleRefinement {
 91    pub color: Option<Color>,
 92    pub font_family_name: Option<Arc<str>>,
 93    pub font_family_id: Option<FamilyId>,
 94    pub font_id: Option<FontId>,
 95    pub font_size: Option<f32>,
 96    pub font_properties: Option<Properties>,
 97    pub underline: Option<Underline>,
 98}
 99
100#[derive(JsonSchema)]
101#[serde(remote = "Properties")]
102pub struct PropertiesDef {
103    /// The font style, as defined in CSS.
104    pub style: StyleDef,
105    /// The font weight, as defined in CSS.
106    pub weight: f32,
107    /// The font stretchiness, as defined in CSS.
108    pub stretch: f32,
109}
110
111#[derive(JsonSchema)]
112#[schemars(remote = "Style")]
113pub enum StyleDef {
114    /// A face that is neither italic not obliqued.
115    Normal,
116    /// A form that is generally cursive in nature.
117    Italic,
118    /// A typically-sloped version of the regular face.
119    Oblique,
120}
121
122#[derive(Copy, Clone, Debug, Default, PartialEq, JsonSchema)]
123pub struct HighlightStyle {
124    pub color: Option<Color>,
125    #[schemars(with = "Option::<f32>")]
126    pub weight: Option<Weight>,
127    pub italic: Option<bool>,
128    pub underline: Option<Underline>,
129    pub fade_out: Option<f32>,
130}
131
132impl Eq for HighlightStyle {}
133
134#[derive(Copy, Clone, Debug, Default, PartialEq, Eq, JsonSchema)]
135pub struct Underline {
136    pub color: Option<Color>,
137    #[schemars(with = "f32")]
138    pub thickness: OrderedFloat<f32>,
139    pub squiggly: bool,
140}
141
142#[allow(non_camel_case_types)]
143#[derive(Deserialize)]
144enum WeightJson {
145    thin,
146    extra_light,
147    light,
148    normal,
149    medium,
150    semibold,
151    bold,
152    extra_bold,
153    black,
154}
155
156thread_local! {
157    static FONT_CACHE: RefCell<Option<Arc<FontCache>>> = Default::default();
158}
159
160#[derive(Deserialize)]
161struct TextStyleJson {
162    color: Color,
163    family: String,
164    #[serde(default)]
165    features: Features,
166    weight: Option<WeightJson>,
167    size: f32,
168    #[serde(default)]
169    italic: bool,
170    #[serde(default)]
171    underline: UnderlineStyleJson,
172}
173
174#[derive(Deserialize)]
175struct HighlightStyleJson {
176    color: Option<Color>,
177    weight: Option<WeightJson>,
178    italic: Option<bool>,
179    underline: Option<UnderlineStyleJson>,
180    fade_out: Option<f32>,
181}
182
183#[derive(Deserialize)]
184#[serde(untagged)]
185enum UnderlineStyleJson {
186    Underlined(bool),
187    UnderlinedWithProperties {
188        #[serde(default)]
189        color: Option<Color>,
190        #[serde(default)]
191        thickness: Option<f32>,
192        #[serde(default)]
193        squiggly: bool,
194    },
195}
196
197impl TextStyle {
198    pub fn new(
199        font_family_name: impl Into<Arc<str>>,
200        font_size: f32,
201        font_properties: Properties,
202        font_features: Features,
203        underline: Underline,
204        color: Color,
205        font_cache: &FontCache,
206    ) -> Result<Self> {
207        let font_family_name = font_family_name.into();
208        let font_family_id = font_cache.load_family(&[&font_family_name], &font_features)?;
209        let font_id = font_cache.select_font(font_family_id, &font_properties)?;
210        Ok(Self {
211            color,
212            font_family_name,
213            font_family_id,
214            font_id,
215            font_size,
216            font_properties,
217            underline,
218        })
219    }
220
221    pub fn with_font_size(mut self, font_size: f32) -> Self {
222        self.font_size = font_size;
223        self
224    }
225
226    pub fn highlight(mut self, style: HighlightStyle, font_cache: &FontCache) -> Result<Self> {
227        let mut font_properties = self.font_properties;
228        if let Some(weight) = style.weight {
229            font_properties.weight(weight);
230        }
231        if let Some(italic) = style.italic {
232            if italic {
233                font_properties.style(Style::Italic);
234            } else {
235                font_properties.style(Style::Normal);
236            }
237        }
238
239        if self.font_properties != font_properties {
240            self.font_id = font_cache.select_font(self.font_family_id, &font_properties)?;
241        }
242        if let Some(color) = style.color {
243            self.color = Color::blend(color, self.color);
244        }
245        if let Some(factor) = style.fade_out {
246            self.color.fade_out(factor);
247        }
248        if let Some(underline) = style.underline {
249            self.underline = underline;
250        }
251
252        Ok(self)
253    }
254
255    pub fn to_run(&self) -> RunStyle {
256        RunStyle {
257            font_id: self.font_id,
258            color: self.color,
259            underline: self.underline,
260        }
261    }
262
263    fn from_json(json: TextStyleJson) -> Result<Self> {
264        FONT_CACHE.with(|font_cache| {
265            if let Some(font_cache) = font_cache.borrow().as_ref() {
266                let font_properties = properties_from_json(json.weight, json.italic);
267                Self::new(
268                    json.family,
269                    json.size,
270                    font_properties,
271                    json.features,
272                    underline_from_json(json.underline),
273                    json.color,
274                    font_cache,
275                )
276            } else {
277                Err(anyhow!(
278                    "TextStyle can only be deserialized within a call to with_font_cache"
279                ))
280            }
281        })
282    }
283
284    pub fn line_height(&self, font_cache: &FontCache) -> f32 {
285        font_cache.line_height(self.font_size)
286    }
287
288    pub fn cap_height(&self, font_cache: &FontCache) -> f32 {
289        font_cache.cap_height(self.font_id, self.font_size)
290    }
291
292    pub fn x_height(&self, font_cache: &FontCache) -> f32 {
293        font_cache.x_height(self.font_id, self.font_size)
294    }
295
296    pub fn em_width(&self, font_cache: &FontCache) -> f32 {
297        font_cache.em_width(self.font_id, self.font_size)
298    }
299
300    pub fn em_advance(&self, font_cache: &FontCache) -> f32 {
301        font_cache.em_advance(self.font_id, self.font_size)
302    }
303
304    pub fn descent(&self, font_cache: &FontCache) -> f32 {
305        font_cache.metric(self.font_id, |m| m.descent) * self.em_scale(font_cache)
306    }
307
308    pub fn baseline_offset(&self, font_cache: &FontCache) -> f32 {
309        font_cache.baseline_offset(self.font_id, self.font_size)
310    }
311
312    fn em_scale(&self, font_cache: &FontCache) -> f32 {
313        font_cache.em_scale(self.font_id, self.font_size)
314    }
315}
316
317impl From<TextStyle> for HighlightStyle {
318    fn from(other: TextStyle) -> Self {
319        Self::from(&other)
320    }
321}
322
323impl From<&TextStyle> for HighlightStyle {
324    fn from(other: &TextStyle) -> Self {
325        Self {
326            color: Some(other.color),
327            weight: Some(other.font_properties.weight),
328            italic: Some(other.font_properties.style == Style::Italic),
329            underline: Some(other.underline),
330            fade_out: None,
331        }
332    }
333}
334
335impl Default for UnderlineStyleJson {
336    fn default() -> Self {
337        Self::Underlined(false)
338    }
339}
340
341impl Default for TextStyle {
342    fn default() -> Self {
343        FONT_CACHE.with(|font_cache| {
344            let font_cache = font_cache.borrow();
345            let font_cache = font_cache
346                .as_ref()
347                .expect("TextStyle::default can only be called within a call to with_font_cache");
348
349            let font_family_id = font_cache.known_existing_family();
350            let font_id = font_cache
351                .select_font(font_family_id, &Default::default())
352                .expect("did not have any font in system-provided family");
353            let font_family_name = font_cache
354                .family_name(font_family_id)
355                .expect("we loaded this family from the font cache, so this should work");
356
357            Self {
358                color: Default::default(),
359                font_family_name,
360                font_family_id,
361                font_id,
362                font_size: 14.,
363                font_properties: Default::default(),
364                underline: Default::default(),
365            }
366        })
367    }
368}
369
370impl HighlightStyle {
371    fn from_json(json: HighlightStyleJson) -> Self {
372        Self {
373            color: json.color,
374            weight: json.weight.map(weight_from_json),
375            italic: json.italic,
376            underline: json.underline.map(underline_from_json),
377            fade_out: json.fade_out,
378        }
379    }
380
381    pub fn highlight(&mut self, other: HighlightStyle) {
382        match (self.color, other.color) {
383            (Some(self_color), Some(other_color)) => {
384                self.color = Some(Color::blend(other_color, self_color));
385            }
386            (None, Some(other_color)) => {
387                self.color = Some(other_color);
388            }
389            _ => {}
390        }
391
392        if other.weight.is_some() {
393            self.weight = other.weight;
394        }
395
396        if other.italic.is_some() {
397            self.italic = other.italic;
398        }
399
400        if other.underline.is_some() {
401            self.underline = other.underline;
402        }
403
404        match (other.fade_out, self.fade_out) {
405            (Some(source_fade), None) => self.fade_out = Some(source_fade),
406            (Some(source_fade), Some(dest_fade)) => {
407                let source_alpha = 1. - source_fade;
408                let dest_alpha = 1. - dest_fade;
409                let blended_alpha = source_alpha + (dest_alpha * source_fade);
410                let blended_fade = 1. - blended_alpha;
411                self.fade_out = Some(blended_fade);
412            }
413            _ => {}
414        }
415    }
416}
417
418impl From<Color> for HighlightStyle {
419    fn from(color: Color) -> Self {
420        Self {
421            color: Some(color),
422            ..Default::default()
423        }
424    }
425}
426
427impl<'de> Deserialize<'de> for TextStyle {
428    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
429    where
430        D: serde::Deserializer<'de>,
431    {
432        Self::from_json(TextStyleJson::deserialize(deserializer)?).map_err(de::Error::custom)
433    }
434}
435
436impl ToJson for TextStyle {
437    fn to_json(&self) -> Value {
438        json!({
439            "color": self.color.to_json(),
440            "font_family": self.font_family_name.as_ref(),
441            "font_properties": self.font_properties.to_json(),
442        })
443    }
444}
445
446impl<'de> Deserialize<'de> for HighlightStyle {
447    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
448    where
449        D: serde::Deserializer<'de>,
450    {
451        let json = serde_json::Value::deserialize(deserializer)?;
452        if json.is_object() {
453            Ok(Self::from_json(
454                serde_json::from_value(json).map_err(de::Error::custom)?,
455            ))
456        } else {
457            Ok(Self {
458                color: serde_json::from_value(json).map_err(de::Error::custom)?,
459                ..Default::default()
460            })
461        }
462    }
463}
464
465fn underline_from_json(json: UnderlineStyleJson) -> Underline {
466    match json {
467        UnderlineStyleJson::Underlined(false) => Underline::default(),
468        UnderlineStyleJson::Underlined(true) => Underline {
469            color: None,
470            thickness: 1.0.into(),
471            squiggly: false,
472        },
473        UnderlineStyleJson::UnderlinedWithProperties {
474            color,
475            thickness,
476            squiggly,
477        } => Underline {
478            color,
479            thickness: thickness.unwrap_or(1.).into(),
480            squiggly,
481        },
482    }
483}
484
485fn properties_from_json(weight: Option<WeightJson>, italic: bool) -> Properties {
486    let weight = weight.map(weight_from_json).unwrap_or_default();
487    let style = if italic { Style::Italic } else { Style::Normal };
488    *Properties::new().weight(weight).style(style)
489}
490
491fn weight_from_json(weight: WeightJson) -> Weight {
492    match weight {
493        WeightJson::thin => Weight::THIN,
494        WeightJson::extra_light => Weight::EXTRA_LIGHT,
495        WeightJson::light => Weight::LIGHT,
496        WeightJson::normal => Weight::NORMAL,
497        WeightJson::medium => Weight::MEDIUM,
498        WeightJson::semibold => Weight::SEMIBOLD,
499        WeightJson::bold => Weight::BOLD,
500        WeightJson::extra_bold => Weight::EXTRA_BOLD,
501        WeightJson::black => Weight::BLACK,
502    }
503}
504
505impl ToJson for Properties {
506    fn to_json(&self) -> crate::json::Value {
507        json!({
508            "style": self.style.to_json(),
509            "weight": self.weight.to_json(),
510            "stretch": self.stretch.to_json(),
511        })
512    }
513}
514
515impl ToJson for Style {
516    fn to_json(&self) -> crate::json::Value {
517        match self {
518            Style::Normal => json!("normal"),
519            Style::Italic => json!("italic"),
520            Style::Oblique => json!("oblique"),
521        }
522    }
523}
524
525impl ToJson for Weight {
526    fn to_json(&self) -> crate::json::Value {
527        if self.0 == Weight::THIN.0 {
528            json!("thin")
529        } else if self.0 == Weight::EXTRA_LIGHT.0 {
530            json!("extra light")
531        } else if self.0 == Weight::LIGHT.0 {
532            json!("light")
533        } else if self.0 == Weight::NORMAL.0 {
534            json!("normal")
535        } else if self.0 == Weight::MEDIUM.0 {
536            json!("medium")
537        } else if self.0 == Weight::SEMIBOLD.0 {
538            json!("semibold")
539        } else if self.0 == Weight::BOLD.0 {
540            json!("bold")
541        } else if self.0 == Weight::EXTRA_BOLD.0 {
542            json!("extra bold")
543        } else if self.0 == Weight::BLACK.0 {
544            json!("black")
545        } else {
546            json!(self.0)
547        }
548    }
549}
550
551impl ToJson for Stretch {
552    fn to_json(&self) -> serde_json::Value {
553        json!(self.0)
554    }
555}
556
557pub fn with_font_cache<F, T>(font_cache: Arc<FontCache>, callback: F) -> T
558where
559    F: FnOnce() -> T,
560{
561    FONT_CACHE.with(|cache| {
562        *cache.borrow_mut() = Some(font_cache);
563        let result = callback();
564        cache.borrow_mut().take();
565        result
566    })
567}