Implement font features (#94)

Cargo.toml

@@ -6,7 +6,6 @@ build = "build.rs"
 
 [dependencies]
 cairo-rs = "0.4"
-pango = "0.4"
 pango-sys = "0.6"
 pangocairo = "0.5"
 pangocairo-sys = "0.7"
@@ -51,6 +50,10 @@ atty = "0.2"
 [build-dependencies]
 phf_codegen = "0.7"
 
+[dependencies.pango]
+features = ["v1_38"]
+version = "0.4"
+
 [dependencies.gtk]
 version = "0.4"
 features = ["v3_22"]

runtime/plugin/nvim_gui_shim.vim

@@ -52,8 +52,10 @@ function s:GuiFontCommand(fname, bang) abort
 		call GuiFont(a:fname, a:bang ==# '!')
 	endif
 endfunction
-command! -nargs=? -bang Guifont call s:GuiFontCommand("<args>", "<bang>")
+command! -nargs=1 -bang Guifont call s:GuiFontCommand("<args>", "<bang>")
-command! -nargs=? -bang GuiFont call s:GuiFontCommand("<args>", "<bang>")
+command! -nargs=1 -bang GuiFont call s:GuiFontCommand("<args>", "<bang>")
+
+command! -nargs=? GuiFontFeatures call rpcnotify(1, 'Gui', 'FontFeatures', <q-args>)
 
 command! NGToggleSidebar call rpcnotify(1, 'Gui', 'Command', 'ToggleSidebar')
 

src/nvim/redraw_handler.rs

@@ -86,6 +86,7 @@ pub fn call_gui_event(
 ) -> result::Result<(), String> {
     match method {
         "Font" => call!(ui->set_font(args: str)),
+        "FontFeatures" => call!(ui->set_font_features(args: str)),
         "Clipboard" => match try_str!(args[0]) {
             "Set" => match try_str!(args[1]) {
                 "*" => ui.clipboard_primary_set(try_str!(args[2])),

src/render/context.rs

@@ -8,18 +8,24 @@ use ui_model::StyledLine;
 use super::itemize::ItemizeIterator;
 
 pub struct Context {
-    state: ContextState,
+    font_metrics: FontMetrix,
+    font_features: FontFeatures,
 }
 
 impl Context {
     pub fn new(pango_context: pango::Context) -> Self {
         Context {
-            state: ContextState::new(pango_context),
+            font_metrics: FontMetrix::new(pango_context),
+            font_features: FontFeatures::new(),
         }
     }
 
     pub fn update(&mut self, pango_context: pango::Context) {
-        self.state = ContextState::new(pango_context);
+        self.font_metrics = FontMetrix::new(pango_context);
+    }
+
+    pub fn update_font_features(&mut self, font_features: FontFeatures) {
+        self.font_features = font_features;
     }
 
     pub fn itemize(&self, line: &StyledLine) -> Vec<sys_pango::Item> {
@@ -28,7 +34,7 @@ impl Context {
         ItemizeIterator::new(&line.line_str)
             .flat_map(|(offset, len)| {
                 sys_pango::pango_itemize(
-                    &self.state.pango_context,
+                    &self.font_metrics.pango_context,
                     &line.line_str,
                     offset,
                     len,
@@ -40,32 +46,34 @@ impl Context {
     }
 
     pub fn create_layout(&self) -> pango::Layout {
-        pango::Layout::new(&self.state.pango_context)
+        pango::Layout::new(&self.font_metrics.pango_context)
     }
 
-    #[inline]
     pub fn font_description(&self) -> &pango::FontDescription {
-        &self.state.font_desc
+        &self.font_metrics.font_desc
     }
 
-    #[inline]
     pub fn cell_metrics(&self) -> &CellMetrics {
-        &self.state.cell_metrics
+        &self.font_metrics.cell_metrics
+    }
+
+    pub fn font_features(&self) -> &FontFeatures {
+        &self.font_features
     }
 }
 
-struct ContextState {
+struct FontMetrix {
     pango_context: pango::Context,
     cell_metrics: CellMetrics,
     font_desc: pango::FontDescription,
 }
 
-impl ContextState {
+impl FontMetrix {
     pub fn new(pango_context: pango::Context) -> Self {
         let font_metrics = pango_context.get_metrics(None, None).unwrap();
         let font_desc = pango_context.get_font_description().unwrap();
 
-        ContextState {
+        FontMetrix {
             pango_context,
             cell_metrics: CellMetrics::new(&font_metrics),
             font_desc,
@@ -115,3 +123,34 @@ impl CellMetrics {
         }
     }
 }
+
+pub struct FontFeatures {
+    features: Option<String>,
+}
+
+impl FontFeatures {
+    pub fn new() -> Self {
+        FontFeatures {  
+            features: None,
+        }
+    }
+
+    pub fn from(font_features: String) -> Self {
+        if font_features.trim().is_empty() {
+            return Self::new();
+        }
+
+        FontFeatures {
+            features: Some(font_features)
+        }
+    }
+
+    pub fn insert_attr(&self, attr_list: &pango::AttrList, end_idx: usize) {
+        if let Some(ref features) = self.features {
+            let mut attr = sys_pango::attribute::new_features(features).unwrap();
+            attr.set_start_index(0);
+            attr.set_end_index(end_idx as u32);
+            attr_list.insert(attr);
+        }
+    }
+}

src/render/mod.rs

@@ -2,7 +2,7 @@ mod context;
 mod itemize;
 mod model_clip_iterator;
 
-pub use self::context::Context;
+pub use self::context::{Context, FontFeatures};
 pub use self::context::CellMetrics;
 use self::model_clip_iterator::{ModelClipIteratorFactory, RowView};
 
@@ -210,7 +210,7 @@ pub fn shape_dirty(
 ) {
     for line in ui_model.model_mut() {
         if line.dirty_line {
-            let styled_line = ui_model::StyledLine::from(line, color_model);
+            let styled_line = ui_model::StyledLine::from(line, color_model, ctx.font_features());
             let items = ctx.itemize(&styled_line);
             line.merge(&styled_line, &items);
 

src/shell.rs

@@ -276,6 +276,17 @@ impl State {
         self.on_redraw(&RepaintMode::All);
     }
 
+    pub fn set_font_features(&mut self, font_features: String) {
+        let font_features = render::FontFeatures::from(font_features);
+
+        self.render_state
+            .borrow_mut()
+            .font_ctx
+            .update_font_features(font_features);
+        self.model.clear_glyphs();
+        self.on_redraw(&RepaintMode::All);
+    }
+
     pub fn open_file(&self, path: &str) {
         if let Some(mut nvim) = self.nvim() {
             nvim.command_async(&format!("e {}", path))

src/sys/pango/attribute.rs

@@ -0,0 +1,12 @@
+use pango_sys;
+use pango;
+
+use glib::translate::*;
+
+pub fn new_features(features: &str) -> Option<pango::Attribute> {
+    unsafe {
+        from_glib_full(pango_sys::pango_attr_font_features_new(
+                features.to_glib_none().0,
+                ))
+    }
+}

src/sys/pango/mod.rs

@@ -2,6 +2,8 @@ mod item;
 mod analysis;
 mod attr_iterator;
 
+pub mod attribute;
+
 pub use self::item::Item;
 pub use self::analysis::Analysis;
 pub use self::attr_iterator::{AttrIterator, AttrIteratorFactory};

src/ui_model/line.rs

@@ -1,10 +1,12 @@
 use std::ops::{Index, IndexMut};
 
+use sys::pango as sys_pango;
+use pango;
+
+use render;
 use color;
 use super::cell::Cell;
 use super::item::Item;
-use sys::pango as sys_pango;
-use pango;
 
 pub struct Line {
     pub line: Box<[Cell]>,
@@ -242,8 +244,7 @@ pub struct StyledLine {
 }
 
 impl StyledLine {
-    pub fn from(line: &Line, color_model: &color::ColorModel) -> Self {
+    pub fn from(line: &Line, color_model: &color::ColorModel, font_features: &render::FontFeatures) -> Self {
-
         let average_capacity = line.line.len() * 4 * 2; // code bytes * grapheme cluster
 
         let mut line_str = String::with_capacity(average_capacity);
@@ -278,6 +279,7 @@ impl StyledLine {
         }
 
         style_attr.insert(&attr_list);
+        font_features.insert_attr(&attr_list, line_str.len());
 
         StyledLine {
             line_str,
@@ -410,7 +412,7 @@ mod tests {
         line[1].ch = "b".to_owned();
         line[2].ch = "c".to_owned();
 
-        let styled_line = StyledLine::from(&line, &color::ColorModel::new());
+        let styled_line = StyledLine::from(&line, &color::ColorModel::new(), &render::FontFeatures::new());
         assert_eq!("abc", styled_line.line_str);
         assert_eq!(3, styled_line.cell_to_byte.len());
         assert_eq!(0, styled_line.cell_to_byte[0]);