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use std::collections::HashSet; use pango; use pango::prelude::*; use crate::sys::pango as sys_pango; use super::itemize::ItemizeIterator; use crate::ui_model::StyledLine; pub struct Context { font_metrics: FontMetrix, font_features: FontFeatures, line_space: i32, } impl Context { pub fn new(pango_context: pango::Context) -> Self { Context { line_space: 0, font_metrics: FontMetrix::new(pango_context, 0), font_features: FontFeatures::new(), } } pub fn update(&mut self, pango_context: pango::Context) { self.font_metrics = FontMetrix::new(pango_context, self.line_space); } pub fn update_font_features(&mut self, font_features: FontFeatures) { self.font_features = font_features; } pub fn update_line_space(&mut self, line_space: i32) { self.line_space = line_space; let pango_context = self.font_metrics.pango_context.clone(); self.font_metrics = FontMetrix::new(pango_context, self.line_space); } pub fn itemize(&self, line: &StyledLine) -> Vec<pango::Item> { let attr_iter = line.attr_list.get_iterator(); ItemizeIterator::new(&line.line_str) .flat_map(|(offset, len)| { pango::itemize( &self.font_metrics.pango_context, &line.line_str, offset as i32, len as i32, &line.attr_list, attr_iter.as_ref(), ) }).collect() } pub fn create_layout(&self) -> pango::Layout { pango::Layout::new(&self.font_metrics.pango_context) } pub fn font_description(&self) -> &pango::FontDescription { &self.font_metrics.font_desc } pub fn cell_metrics(&self) -> &CellMetrics { &self.font_metrics.cell_metrics } pub fn font_features(&self) -> &FontFeatures { &self.font_features } pub fn font_families(&self) -> HashSet<glib::GString> { self.font_metrics .pango_context .list_families() .iter() .filter_map(pango::FontFamilyExt::get_name) .collect() } } struct FontMetrix { pango_context: pango::Context, cell_metrics: CellMetrics, font_desc: pango::FontDescription, } impl FontMetrix { pub fn new(pango_context: pango::Context, line_space: i32) -> Self { let font_metrics = pango_context.get_metrics(None, None).unwrap(); let font_desc = pango_context.get_font_description().unwrap(); FontMetrix { pango_context, cell_metrics: CellMetrics::new(&font_metrics, line_space), font_desc, } } } pub struct CellMetrics { pub line_height: f64, pub char_width: f64, pub ascent: f64, pub underline_position: f64, pub underline_thickness: f64, pub pango_ascent: i32, pub pango_descent: i32, pub pango_char_width: i32, } impl CellMetrics { fn new(font_metrics: &pango::FontMetrics, line_space: i32) -> Self { CellMetrics { pango_ascent: font_metrics.get_ascent(), pango_descent: font_metrics.get_descent(), pango_char_width: font_metrics.get_approximate_digit_width(), ascent: f64::from(font_metrics.get_ascent()) / f64::from(pango::SCALE), line_height: f64::from(font_metrics.get_ascent() + font_metrics.get_descent()) / f64::from(pango::SCALE) + f64::from(line_space), char_width: f64::from(font_metrics.get_approximate_digit_width()) / f64::from(pango::SCALE), underline_position: f64::from( font_metrics.get_ascent() - font_metrics.get_underline_position(), ) / f64::from(pango::SCALE), underline_thickness: f64::from(font_metrics.get_underline_thickness()) / f64::from(pango::SCALE), } } #[cfg(test)] pub fn new_hw(line_height: f64, char_width: f64) -> Self { CellMetrics { pango_ascent: 0, pango_descent: 0, pango_char_width: 0, ascent: 0.0, line_height, char_width, underline_position: 0.0, underline_thickness: 0.0, } } } pub struct FontFeatures { attr: Option<pango::Attribute>, } impl FontFeatures { pub fn new() -> Self { FontFeatures { attr: None } } pub fn from(font_features: String) -> Self { if font_features.trim().is_empty() { return Self::new(); } FontFeatures { attr: sys_pango::attribute::new_features(&font_features), } } pub fn insert_into(&self, attr_list: &pango::AttrList) { if let Some(ref attr) = self.attr { attr_list.insert(attr.clone()); } } }