Starting point on fix of grapheme rendering

src/cmd_line.rs

@@ -28,7 +28,7 @@ pub struct Level {
 }
 
 impl Level {
-    pub fn insert(&mut self, c: &str, shift: bool, render_state: &shell::RenderState) {
+    pub fn insert(&mut self, c: String, shift: bool, render_state: &shell::RenderState) {
         self.model_layout.insert_char(c, shift);
         self.update_preferred_size(render_state);
     }
@@ -405,7 +405,7 @@ impl CmdLine {
         let mut state = self.state.borrow_mut();
 
         if let Some(level) = state.levels.get_mut((level - 1) as usize) {
-            level.insert(&c, shift, render_state);
+            level.insert(c, shift, render_state);
             level.update_cache(&*render_state);
         } else {
             error!("Level {} does not exists", level);

src/shell.rs

@@ -1156,9 +1156,8 @@ impl State {
     }
 
     pub fn on_put(&mut self, text: String) -> RepaintMode {
-        let ch = text.chars().last().unwrap_or(' ');
         let double_width = text.is_empty();
-        RepaintMode::Area(self.model.put(ch, double_width, self.cur_attrs.as_ref()))
+        RepaintMode::Area(self.model.put(text, double_width, self.cur_attrs.as_ref()))
     }
 
     pub fn on_clear(&mut self) -> RepaintMode {

src/ui_model/cell.rs

@@ -76,24 +76,30 @@ impl Attrs {
     }
 }
 
+const EMPTY_STRING: String = String::new();
+
 #[derive(Clone)]
 pub struct Cell {
     pub attrs: Attrs,
-    pub ch: char,
+    pub ch: String,
     pub dirty: bool,
 }
 
 impl Cell {
-    pub fn new(ch: char) -> Cell {
+    pub fn new_empty() -> Cell {
+        Cell::new(EMPTY_STRING)
+    }
+
+    pub fn new(ch: String) -> Cell {
         Cell {
             attrs: Attrs::new(),
-            ch: ch,
+            ch,
             dirty: true,
         }
     }
 
     pub fn clear(&mut self) {
-        self.ch = ' ';
+        self.ch = EMPTY_STRING;
         self.attrs.clear();
         self.dirty = true;
     }

src/ui_model/line.rs

@@ -21,7 +21,7 @@ pub struct Line {
 impl Line {
     pub fn new(columns: usize) -> Self {
         Line {
-            line: vec![Cell::new(' '); columns].into_boxed_slice(),
+            line: vec![Cell::new_empty(); columns].into_boxed_slice(),
             item_line: vec![None; columns].into_boxed_slice(),
             cell_to_item: vec![-1; columns].into_boxed_slice(),
             dirty_line: true,
@@ -257,7 +257,7 @@ impl StyledLine {
                 continue;
             }
 
-            line_str.push(cell.ch);
+            line_str.push_str(&cell.ch);
             let len = line_str.len() - byte_offset;
 
             for _ in 0..len {

src/ui_model/mod.rs

@@ -93,7 +93,7 @@ impl UiModel {
         (self.cur_row, self.cur_col)
     }
 
-    pub fn put(&mut self, ch: char, double_width: bool, attrs: Option<&Attrs>) -> ModelRect {
+    pub fn put(&mut self, ch: String, double_width: bool, attrs: Option<&Attrs>) -> ModelRect {
         let mut changed_region = self.cur_point();
         let line = &mut self.model[self.cur_row];
         line.dirty_line = true;

src/ui_model/model_layout.rs

@@ -8,7 +8,7 @@ pub struct ModelLayout {
     pub model: UiModel,
     rows_filled: usize,
     cols_filled: usize,
-    lines: Vec<Vec<(Option<Attrs>, Vec<char>)>>,
+    lines: Vec<Vec<(Option<Attrs>, Vec<String>)>>,
 }
 
 impl ModelLayout {
@@ -23,7 +23,7 @@ impl ModelLayout {
         }
     }
 
-    pub fn layout_append(&mut self, mut lines: Vec<Vec<(Option<Attrs>, Vec<char>)>>) {
+    pub fn layout_append(&mut self, mut lines: Vec<Vec<(Option<Attrs>, Vec<String>)>>) {
         let rows_filled = self.rows_filled;
         let take_from = self.lines.len();
 
@@ -32,7 +32,7 @@ impl ModelLayout {
         self.layout_replace(rows_filled, take_from);
     }
 
-    pub fn layout(&mut self, lines: Vec<Vec<(Option<Attrs>, Vec<char>)>>) {
+    pub fn layout(&mut self, lines: Vec<Vec<(Option<Attrs>, Vec<String>)>>) {
         self.lines = lines;
         self.layout_replace(0, 0);
     }
@@ -67,12 +67,11 @@ impl ModelLayout {
         }
     }
 
-    pub fn insert_char(&mut self, c: &str, shift: bool) {
-        if c.is_empty() {
+    pub fn insert_char(&mut self, ch: String, shift: bool) {
+        if ch.is_empty() {
             return;
         }
 
-        let ch = c.chars().next().unwrap();
         let (row, col) = self.model.get_cursor();
 
         if shift {
@@ -85,7 +84,7 @@ impl ModelLayout {
         self.model.set_cursor(row, col);
     }
 
-    fn insert_into_lines(&mut self, ch: char) {
+    fn insert_into_lines(&mut self, ch: String) {
         let line = &mut self.lines[0];
 
         let cur_col = self.model.cur_col;
@@ -152,7 +151,7 @@ impl ModelLayout {
         }
     }
 
-    fn count_lines(lines: &[Vec<(Option<Attrs>, Vec<char>)>], max_columns: usize) -> usize {
+    fn count_lines(lines: &[Vec<(Option<Attrs>, Vec<String>)>], max_columns: usize) -> usize {
         let mut row_count = 0;
 
         for line in lines {