Fix rendering, draw curved underline

appveyor.yml

@@ -3,7 +3,7 @@ environment:
     PROJECT_NAME: rustfmt
   matrix:
     - TARGET: x86_64-pc-windows-gnu
-      RUST_VERSION: 1.18.0
+      RUST_VERSION: 1.20.0
 
 install:
 #  - ps: Start-FileDownload "https://static.rust-lang.org/dist/channel-rust-stable"

src/render/itemize.rs

@@ -1,11 +1,11 @@
 use std::str::CharIndices;
 
-pub struct ItemizeIterator <'a> {
+pub struct ItemizeIterator<'a> {
     char_iter: CharIndices<'a>,
     line: &'a str,
 }
 
-impl <'a> ItemizeIterator <'a> {
+impl<'a> ItemizeIterator<'a> {
     pub fn new(line: &'a str) -> Self {
         ItemizeIterator {
             char_iter: line.char_indices(),
@@ -14,7 +14,7 @@ impl <'a> ItemizeIterator <'a> {
     }
 }
 
-impl <'a> Iterator for ItemizeIterator<'a> {
+impl<'a> Iterator for ItemizeIterator<'a> {
     type Item = (usize, usize);
 
     fn next(&mut self) -> Option<Self::Item> {
@@ -26,7 +26,7 @@ impl <'a> Iterator for ItemizeIterator<'a> {
 
                 if start_index.is_none() && !is_whitespace {
                     start_index = Some(index);
-                } 
+                }
                 if start_index.is_some() && is_whitespace {
                     break index;
                 }

src/render/mod.rs

@@ -81,12 +81,18 @@ pub fn render(
                     // TODO: properly draw undercurl
                     let sp = color_model.actual_cell_sp(cell);
                     ctx.set_source_rgba(sp.0, sp.1, sp.2, 0.7);
-                    ctx.set_dash(&[4.0, 2.0], 0.0);
-                    ctx.set_line_width(underline_thickness);
-                    ctx.move_to(line_x, line_y + underline_position);
-                    ctx.line_to(line_x + char_width, line_y + underline_position);
-                    ctx.stroke();
-                    ctx.set_dash(&[], 0.0);
+                    ctx.show_error_underline(
+                        line_x,
+                        line_y + underline_position,
+                        char_width,
+                        underline_thickness * 5.0,
+                    );
+                //ctx.set_dash(&[4.0, 2.0], 0.0);
+                //ctx.set_line_width(underline_thickness);
+                //ctx.move_to(line_x, line_y + underline_position);
+                //ctx.line_to(line_x + char_width, line_y + underline_position);
+                //ctx.stroke();
+                //ctx.set_dash(&[], 0.0);
                 } else if cell.attrs.underline {
                     ctx.set_source_rgb(fg.0, fg.1, fg.2);
                     ctx.set_line_width(underline_thickness);

src/sys/pango/item.rs

@@ -41,8 +41,4 @@ impl Item {
     pub fn offset(&self) -> (usize, usize, usize) {
         (self.0.offset as usize, self.0.length as usize, self.0.num_chars as usize)
     }
-
-    pub fn length(&self) -> i32 {
-        self.0.length
-    }
 }

src/ui_model/line.rs

@@ -69,11 +69,10 @@ impl Line {
 
     fn set_cell_to_item(&mut self, new_item: &PangoItemPosition) -> bool {
         let start_item_idx = self.cell_to_item(new_item.start_cell);
-        let start_item_len = if start_item_idx >= 0 {
+        let start_item_cells_count = if start_item_idx >= 0 {
             self.item_line[start_item_idx as usize]
                 .as_ref()
-                .map(|item| item.item.length())
-                .unwrap_or(-1)
+                .map_or(-1, |item| item.cells_count as i32)
         } else {
             -1
         };
@@ -84,7 +83,7 @@ impl Line {
         // in case different item length was in previous iteration
         // mark all item as dirty
         if start_item_idx != new_item.start_cell as i32 ||
-            new_item.item.length() != start_item_len || start_item_idx == -1 ||
+            new_item.cells_count() != start_item_cells_count || start_item_idx == -1 ||
             end_item_idx == -1
         {
             self.initialize_cell_item(new_item.start_cell, new_item.end_cell, new_item.item);
@@ -237,6 +236,11 @@ impl<'a> PangoItemPosition<'a> {
             end_cell,
         }
     }
+
+    #[inline]
+    fn cells_count(&self) -> i32 {
+        (self.end_cell - self.start_cell) as i32 + 1
+    }
 }
 
 pub struct StyledLine {