lemna 0.4.0

A Reactive UI framework for Rust
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use std::collections::HashMap;

use glyph_brush_layout::{ab_glyph::*, GlyphPositioner, SectionGeometry};
pub use glyph_brush_layout::{FontId, SectionGlyph, SectionText};
pub type Fonts = Vec<FontRef<'static>>;
pub type HorizontalAlign = glyph_brush_layout::HorizontalAlign;

#[derive(Default)]
pub struct FontCache {
    pub(crate) fonts: Fonts,
    pub(crate) font_names: HashMap<String, usize>,
}

impl FontCache {
    pub fn font(&self, name: &str) -> Option<FontId> {
        self.font_names.get(name).map(|i| FontId(*i))
    }

    pub fn font_or_default(&self, name: Option<&str>) -> FontId {
        if let Some(name) = name {
            if let Some(i) = self.font_names.get(name) {
                return FontId(*i);
            }
        }

        self.default_font()
    }

    pub fn default_font(&self) -> FontId {
        if self.fonts.first().is_some() {
            FontId(0)
        } else {
            panic!("Expected at least one default font to be present")
        }
    }

    /// bytes is an OpenType font
    pub fn add_font(&mut self, name: String, bytes: &'static [u8]) {
        let i = self.fonts.len();
        self.fonts.push(FontRef::try_from_slice(bytes).unwrap());
        self.font_names.insert(name, i);
    }

    pub fn layout_text(
        &self,
        text: &[SectionText],
        alignment: HorizontalAlign,
        pos: (f32, f32),
        bounds: (f32, f32),
    ) -> Vec<SectionGlyph> {
        // TODO: Should accept an AABB and a start pos within it.
        glyph_brush_layout::Layout::default()
            .h_align(alignment)
            .calculate_glyphs(
                &self.fonts,
                &SectionGeometry {
                    screen_position: pos,
                    bounds,
                },
                text,
            )
    }
}