| use super::{FontData, FontFamily, FontStyle, LayoutBox}; |
| |
| #[derive(Debug, Clone)] |
| pub struct FontError; |
| |
| impl std::fmt::Display for FontError { |
| fn fmt(&self, fmt: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> { |
| write!(fmt, "General Error")?; |
| Ok(()) |
| } |
| } |
| |
| impl std::error::Error for FontError {} |
| |
| #[derive(Clone)] |
| pub struct FontDataInternal(String, String); |
| |
| impl FontData for FontDataInternal { |
| type ErrorType = FontError; |
| fn new(family: FontFamily, style: FontStyle) -> Result<Self, FontError> { |
| Ok(FontDataInternal( |
| family.as_str().into(), |
| style.as_str().into(), |
| )) |
| } |
| |
| /// Note: This is only a crude estimatation, since for some backend such as SVG, we have no way to |
| /// know the real size of the text anyway. Thus using font-kit is an overkill and doesn't helps |
| /// the layout. |
| fn estimate_layout(&self, size: f64, text: &str) -> Result<LayoutBox, Self::ErrorType> { |
| let em = size / 1.24 / 1.24; |
| Ok(( |
| (0, -em.round() as i32), |
| ( |
| (em * 0.7 * text.len() as f64).round() as i32, |
| (em * 0.24).round() as i32, |
| ), |
| )) |
| } |
| } |