iced_graphics/
text.rs

1//! Draw text.
2pub mod cache;
3pub mod editor;
4pub mod paragraph;
5
6pub use cache::Cache;
7pub use editor::Editor;
8pub use paragraph::Paragraph;
9
10pub use cosmic_text;
11
12use crate::core::alignment;
13use crate::core::font::{self, Font};
14use crate::core::text::{Alignment, Ellipsis, Shaping, Wrapping};
15use crate::core::{Color, Pixels, Point, Rectangle, Size, Transformation};
16
17use std::borrow::Cow;
18use std::collections::HashSet;
19use std::sync::{Arc, OnceLock, RwLock, Weak};
20
21/// A text primitive.
22#[derive(Debug, Clone, PartialEq)]
23pub enum Text {
24    /// A paragraph.
25    #[allow(missing_docs)]
26    Paragraph {
27        paragraph: paragraph::Weak,
28        position: Point,
29        color: Color,
30        clip_bounds: Rectangle,
31        transformation: Transformation,
32    },
33    /// An editor.
34    #[allow(missing_docs)]
35    Editor {
36        editor: editor::Weak,
37        position: Point,
38        color: Color,
39        clip_bounds: Rectangle,
40        transformation: Transformation,
41    },
42    /// Some cached text.
43    Cached {
44        /// The contents of the text.
45        content: String,
46        /// The bounds of the text.
47        bounds: Rectangle,
48        /// The color of the text.
49        color: Color,
50        /// The size of the text in logical pixels.
51        size: Pixels,
52        /// The line height of the text.
53        line_height: Pixels,
54        /// The font of the text.
55        font: Font,
56        /// The horizontal alignment of the text.
57        align_x: Alignment,
58        /// The vertical alignment of the text.
59        align_y: alignment::Vertical,
60        /// The shaping strategy of the text.
61        shaping: Shaping,
62        /// The wrapping strategy of the text.
63        wrapping: Wrapping,
64        /// The ellipsis strategy of the text.
65        ellipsis: Ellipsis,
66        /// The clip bounds of the text.
67        clip_bounds: Rectangle,
68    },
69    /// Some raw text.
70    #[allow(missing_docs)]
71    Raw {
72        raw: Raw,
73        transformation: Transformation,
74    },
75}
76
77impl Text {
78    /// Returns the visible bounds of the [`Text`].
79    pub fn visible_bounds(&self) -> Option<Rectangle> {
80        match self {
81            Text::Paragraph {
82                position,
83                paragraph,
84                clip_bounds,
85                transformation,
86                ..
87            } => Rectangle::new(*position, paragraph.min_bounds)
88                .intersection(clip_bounds)
89                .map(|bounds| bounds * *transformation),
90            Text::Editor {
91                editor,
92                position,
93                clip_bounds,
94                transformation,
95                ..
96            } => Rectangle::new(*position, editor.bounds)
97                .intersection(clip_bounds)
98                .map(|bounds| bounds * *transformation),
99            Text::Cached {
100                bounds,
101                clip_bounds,
102                ..
103            } => bounds.intersection(clip_bounds),
104            Text::Raw { raw, .. } => Some(raw.clip_bounds),
105        }
106    }
107}
108
109/// The regular variant of the [Fira Sans] font.
110///
111/// It is loaded as part of the default fonts when the `fira-sans`
112/// feature is enabled.
113///
114/// [Fira Sans]: https://mozilla.github.io/Fira/
115#[cfg(feature = "fira-sans")]
116pub const FIRA_SANS_REGULAR: &[u8] = include_bytes!("../fonts/FiraSans-Regular.ttf").as_slice();
117
118/// Returns the global [`FontSystem`].
119pub fn font_system() -> &'static RwLock<FontSystem> {
120    static FONT_SYSTEM: OnceLock<RwLock<FontSystem>> = OnceLock::new();
121
122    FONT_SYSTEM.get_or_init(|| {
123        RwLock::new(FontSystem {
124            raw: cosmic_text::FontSystem::new_with_fonts([
125                cosmic_text::fontdb::Source::Binary(Arc::new(
126                    include_bytes!("../fonts/Iced-Icons.ttf").as_slice(),
127                )),
128                #[cfg(feature = "fira-sans")]
129                cosmic_text::fontdb::Source::Binary(Arc::new(
130                    include_bytes!("../fonts/FiraSans-Regular.ttf").as_slice(),
131                )),
132            ]),
133            loaded_fonts: HashSet::new(),
134            version: Version::default(),
135        })
136    })
137}
138
139/// A set of system fonts.
140pub struct FontSystem {
141    raw: cosmic_text::FontSystem,
142    loaded_fonts: HashSet<usize>,
143    version: Version,
144}
145
146impl FontSystem {
147    /// Returns the raw [`cosmic_text::FontSystem`].
148    pub fn raw(&mut self) -> &mut cosmic_text::FontSystem {
149        &mut self.raw
150    }
151
152    /// Loads a font from its bytes.
153    pub fn load_font(&mut self, bytes: Cow<'static, [u8]>) {
154        if let Cow::Borrowed(bytes) = bytes {
155            let address = bytes.as_ptr() as usize;
156
157            if !self.loaded_fonts.insert(address) {
158                return;
159            }
160        }
161
162        let _ = self
163            .raw
164            .db_mut()
165            .load_font_source(cosmic_text::fontdb::Source::Binary(Arc::new(
166                bytes.into_owned(),
167            )));
168
169        self.version = Version(self.version.0 + 1);
170    }
171
172    /// Returns the current [`Version`] of the [`FontSystem`].
173    ///
174    /// Loading a font will increase the version of a [`FontSystem`].
175    pub fn version(&self) -> Version {
176        self.version
177    }
178}
179
180/// A version number.
181#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Default)]
182pub struct Version(u32);
183
184/// A weak reference to a [`cosmic_text::Buffer`] that can be drawn.
185#[derive(Debug, Clone)]
186pub struct Raw {
187    /// A weak reference to a [`cosmic_text::Buffer`].
188    pub buffer: Weak<cosmic_text::Buffer>,
189    /// The position of the text.
190    pub position: Point,
191    /// The color of the text.
192    pub color: Color,
193    /// The clip bounds of the text.
194    pub clip_bounds: Rectangle,
195}
196
197impl PartialEq for Raw {
198    fn eq(&self, _other: &Self) -> bool {
199        // TODO: There is no proper way to compare raw buffers
200        // For now, no two instances of `Raw` text will be equal.
201        // This should be fine, but could trigger unnecessary redraws
202        // in the future.
203        false
204    }
205}
206
207/// Measures the dimensions of the given [`cosmic_text::Buffer`].
208pub fn measure(buffer: &cosmic_text::Buffer) -> (Size, bool) {
209    let (width, height, has_rtl) =
210        buffer
211            .layout_runs()
212            .fold((0.0, 0.0, false), |(width, height, has_rtl), run| {
213                (
214                    run.line_w.max(width),
215                    height + run.line_height,
216                    has_rtl || run.rtl,
217                )
218            });
219
220    (Size::new(width, height), has_rtl)
221}
222
223/// Aligns the given [`cosmic_text::Buffer`] with the given [`Alignment`]
224/// and returns its minimum [`Size`].
225pub fn align(
226    buffer: &mut cosmic_text::Buffer,
227    font_system: &mut cosmic_text::FontSystem,
228    alignment: Alignment,
229) -> Size {
230    let (min_bounds, has_rtl) = measure(buffer);
231    let mut needs_relayout = has_rtl;
232
233    if let Some(align) = to_align(alignment) {
234        let has_multiple_lines = buffer.lines.len() > 1
235            || buffer
236                .lines
237                .first()
238                .is_some_and(|line| line.layout_opt().is_some_and(|layout| layout.len() > 1));
239
240        if has_multiple_lines {
241            for line in &mut buffer.lines {
242                let _ = line.set_align(Some(align));
243            }
244
245            needs_relayout = true;
246        } else if let Some(line) = buffer.lines.first_mut() {
247            needs_relayout = line.set_align(None);
248        }
249    }
250
251    // TODO: Avoid relayout with some changes to `cosmic-text` (?)
252    if needs_relayout {
253        log::trace!("Relayouting paragraph...");
254
255        buffer.set_size(font_system, Some(min_bounds.width), Some(min_bounds.height));
256    }
257
258    min_bounds
259}
260
261/// Returns the attributes of the given [`Font`].
262pub fn to_attributes(font: Font) -> cosmic_text::Attrs<'static> {
263    cosmic_text::Attrs::new()
264        .family(to_family(font.family))
265        .weight(to_weight(font.weight))
266        .stretch(to_stretch(font.stretch))
267        .style(to_style(font.style))
268}
269
270fn to_family(family: font::Family) -> cosmic_text::Family<'static> {
271    match family {
272        font::Family::Name(name) => cosmic_text::Family::Name(name),
273        font::Family::SansSerif => cosmic_text::Family::SansSerif,
274        font::Family::Serif => cosmic_text::Family::Serif,
275        font::Family::Cursive => cosmic_text::Family::Cursive,
276        font::Family::Fantasy => cosmic_text::Family::Fantasy,
277        font::Family::Monospace => cosmic_text::Family::Monospace,
278    }
279}
280
281fn to_weight(weight: font::Weight) -> cosmic_text::Weight {
282    match weight {
283        font::Weight::Thin => cosmic_text::Weight::THIN,
284        font::Weight::ExtraLight => cosmic_text::Weight::EXTRA_LIGHT,
285        font::Weight::Light => cosmic_text::Weight::LIGHT,
286        font::Weight::Normal => cosmic_text::Weight::NORMAL,
287        font::Weight::Medium => cosmic_text::Weight::MEDIUM,
288        font::Weight::Semibold => cosmic_text::Weight::SEMIBOLD,
289        font::Weight::Bold => cosmic_text::Weight::BOLD,
290        font::Weight::ExtraBold => cosmic_text::Weight::EXTRA_BOLD,
291        font::Weight::Black => cosmic_text::Weight::BLACK,
292    }
293}
294
295fn to_stretch(stretch: font::Stretch) -> cosmic_text::Stretch {
296    match stretch {
297        font::Stretch::UltraCondensed => cosmic_text::Stretch::UltraCondensed,
298        font::Stretch::ExtraCondensed => cosmic_text::Stretch::ExtraCondensed,
299        font::Stretch::Condensed => cosmic_text::Stretch::Condensed,
300        font::Stretch::SemiCondensed => cosmic_text::Stretch::SemiCondensed,
301        font::Stretch::Normal => cosmic_text::Stretch::Normal,
302        font::Stretch::SemiExpanded => cosmic_text::Stretch::SemiExpanded,
303        font::Stretch::Expanded => cosmic_text::Stretch::Expanded,
304        font::Stretch::ExtraExpanded => cosmic_text::Stretch::ExtraExpanded,
305        font::Stretch::UltraExpanded => cosmic_text::Stretch::UltraExpanded,
306    }
307}
308
309fn to_style(style: font::Style) -> cosmic_text::Style {
310    match style {
311        font::Style::Normal => cosmic_text::Style::Normal,
312        font::Style::Italic => cosmic_text::Style::Italic,
313        font::Style::Oblique => cosmic_text::Style::Oblique,
314    }
315}
316
317fn to_align(alignment: Alignment) -> Option<cosmic_text::Align> {
318    match alignment {
319        Alignment::Default => None,
320        Alignment::Left => Some(cosmic_text::Align::Left),
321        Alignment::Center => Some(cosmic_text::Align::Center),
322        Alignment::Right => Some(cosmic_text::Align::Right),
323        Alignment::Justified => Some(cosmic_text::Align::Justified),
324    }
325}
326
327/// Converts some [`Shaping`] strategy to a [`cosmic_text::Shaping`] strategy.
328pub fn to_shaping(shaping: Shaping, text: &str) -> cosmic_text::Shaping {
329    match shaping {
330        Shaping::Auto => {
331            if text.is_ascii() {
332                cosmic_text::Shaping::Basic
333            } else {
334                cosmic_text::Shaping::Advanced
335            }
336        }
337        Shaping::Basic => cosmic_text::Shaping::Basic,
338        Shaping::Advanced => cosmic_text::Shaping::Advanced,
339    }
340}
341
342/// Converts some [`Wrapping`] strategy to a [`cosmic_text::Wrap`] strategy.
343pub fn to_wrap(wrapping: Wrapping) -> cosmic_text::Wrap {
344    match wrapping {
345        Wrapping::None => cosmic_text::Wrap::None,
346        Wrapping::Word => cosmic_text::Wrap::Word,
347        Wrapping::Glyph => cosmic_text::Wrap::Glyph,
348        Wrapping::WordOrGlyph => cosmic_text::Wrap::WordOrGlyph,
349    }
350}
351
352/// Converts some [`Ellipsis`] strategy to a [`cosmic_text::Ellipsize`] strategy.
353pub fn to_ellipsize(ellipsis: Ellipsis, max_height: f32) -> cosmic_text::Ellipsize {
354    let limit = cosmic_text::EllipsizeHeightLimit::Height(max_height);
355
356    match ellipsis {
357        Ellipsis::None => cosmic_text::Ellipsize::None,
358        Ellipsis::Start => cosmic_text::Ellipsize::Start(limit),
359        Ellipsis::Middle => cosmic_text::Ellipsize::Middle(limit),
360        Ellipsis::End => cosmic_text::Ellipsize::End(limit),
361    }
362}
363
364/// Converts some [`Color`] to a [`cosmic_text::Color`].
365pub fn to_color(color: Color) -> cosmic_text::Color {
366    let [r, g, b, a] = color.into_rgba8();
367
368    cosmic_text::Color::rgba(r, g, b, a)
369}
370
371/// Returns the ideal hint factor given the size and scale factor of some text.
372pub fn hint_factor(_size: Pixels, _scale_factor: Option<f32>) -> Option<f32> {
373    // TODO: Fix hinting in `cosmic-text`
374    // const MAX_HINTING_SIZE: f32 = 18.0;
375
376    // let hint_factor = scale_factor?;
377
378    // if size.0 * hint_factor < MAX_HINTING_SIZE {
379    //     Some(hint_factor)
380    // } else {
381    //     None
382    // }
383
384    None // Disable all text hinting for now
385}
386
387/// A text renderer coupled to `iced_graphics`.
388pub trait Renderer {
389    /// Draws the given [`Raw`] text.
390    fn fill_raw(&mut self, raw: Raw);
391}
iced_graphics/text.rs

iced_graphics/
text.rs
