Implement explicit text caching in the widget state tree

1 files changed, 113 insertions, 0 deletions

diff --git a/graphics/src/text.rs b/graphics/src/text.rs
new file mode 100644
index 00000000..bbe9d7cb
--- /dev/null
+++ b/graphics/src/text.rs
@@ -0,0 +1,113 @@
+pub mod cache;
+pub mod paragraph;
+
+pub use cache::Cache;
+pub use paragraph::Paragraph;
+
+pub use cosmic_text;
+
+use crate::core::font::{self, Font};
+use crate::core::text::Shaping;
+use crate::core::Size;
+
+use std::sync::{self, Arc, RwLock};
+
+#[allow(missing_debug_implementations)]
+pub struct FontSystem(RwLock<cosmic_text::FontSystem>);
+
+impl FontSystem {
+    pub fn new() -> Self {
+        FontSystem(RwLock::new(cosmic_text::FontSystem::new_with_fonts(
+            [cosmic_text::fontdb::Source::Binary(Arc::new(
+                include_bytes!("../fonts/Iced-Icons.ttf").as_slice(),
+            ))]
+            .into_iter(),
+        )))
+    }
+
+    pub fn get_mut(&mut self) -> &mut cosmic_text::FontSystem {
+        self.0.get_mut().expect("Lock font system")
+    }
+
+    pub fn write(&self) -> sync::RwLockWriteGuard<'_, cosmic_text::FontSystem> {
+        self.0.write().expect("Write font system")
+    }
+}
+
+impl Default for FontSystem {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+pub fn measure(buffer: &cosmic_text::Buffer) -> Size {
+    let (width, total_lines) = buffer
+        .layout_runs()
+        .fold((0.0, 0usize), |(width, total_lines), run| {
+            (run.line_w.max(width), total_lines + 1)
+        });
+
+    Size::new(width, total_lines as f32 * buffer.metrics().line_height)
+}
+
+pub fn to_attributes(font: Font) -> cosmic_text::Attrs<'static> {
+    cosmic_text::Attrs::new()
+        .family(to_family(font.family))
+        .weight(to_weight(font.weight))
+        .stretch(to_stretch(font.stretch))
+        .style(to_style(font.style))
+}
+
+fn to_family(family: font::Family) -> cosmic_text::Family<'static> {
+    match family {
+        font::Family::Name(name) => cosmic_text::Family::Name(name),
+        font::Family::SansSerif => cosmic_text::Family::SansSerif,
+        font::Family::Serif => cosmic_text::Family::Serif,
+        font::Family::Cursive => cosmic_text::Family::Cursive,
+        font::Family::Fantasy => cosmic_text::Family::Fantasy,
+        font::Family::Monospace => cosmic_text::Family::Monospace,
+    }
+}
+
+fn to_weight(weight: font::Weight) -> cosmic_text::Weight {
+    match weight {
+        font::Weight::Thin => cosmic_text::Weight::THIN,
+        font::Weight::ExtraLight => cosmic_text::Weight::EXTRA_LIGHT,
+        font::Weight::Light => cosmic_text::Weight::LIGHT,
+        font::Weight::Normal => cosmic_text::Weight::NORMAL,
+        font::Weight::Medium => cosmic_text::Weight::MEDIUM,
+        font::Weight::Semibold => cosmic_text::Weight::SEMIBOLD,
+        font::Weight::Bold => cosmic_text::Weight::BOLD,
+        font::Weight::ExtraBold => cosmic_text::Weight::EXTRA_BOLD,
+        font::Weight::Black => cosmic_text::Weight::BLACK,
+    }
+}
+
+fn to_stretch(stretch: font::Stretch) -> cosmic_text::Stretch {
+    match stretch {
+        font::Stretch::UltraCondensed => cosmic_text::Stretch::UltraCondensed,
+        font::Stretch::ExtraCondensed => cosmic_text::Stretch::ExtraCondensed,
+        font::Stretch::Condensed => cosmic_text::Stretch::Condensed,
+        font::Stretch::SemiCondensed => cosmic_text::Stretch::SemiCondensed,
+        font::Stretch::Normal => cosmic_text::Stretch::Normal,
+        font::Stretch::SemiExpanded => cosmic_text::Stretch::SemiExpanded,
+        font::Stretch::Expanded => cosmic_text::Stretch::Expanded,
+        font::Stretch::ExtraExpanded => cosmic_text::Stretch::ExtraExpanded,
+        font::Stretch::UltraExpanded => cosmic_text::Stretch::UltraExpanded,
+    }
+}
+
+fn to_style(style: font::Style) -> cosmic_text::Style {
+    match style {
+        font::Style::Normal => cosmic_text::Style::Normal,
+        font::Style::Italic => cosmic_text::Style::Italic,
+        font::Style::Oblique => cosmic_text::Style::Oblique,
+    }
+}
+
+pub fn to_shaping(shaping: Shaping) -> cosmic_text::Shaping {
+    match shaping {
+        Shaping::Basic => cosmic_text::Shaping::Basic,
+        Shaping::Advanced => cosmic_text::Shaping::Advanced,
+    }
+}