ratatui · Wybxc · Aug 18, 2025 · junkdog · Sep 7, 2025 · junkdog
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/Cargo.toml b/Cargo.toml
@@ -43,3 +43,4 @@ console_error_panic_hook = "0.1.7"
 thiserror = "2.0.12"
 bitvec = { version = "1.0.1", default-features = false, features = ["alloc", "std"] }
 beamterm-renderer = "0.1.1"
+unicode-width = "0.2.0"
diff --git a/examples/unicode/Cargo.toml b/examples/unicode/Cargo.toml
@@ -0,0 +1,9 @@
+[package]
+name = "minimal"
+version = "0.1.0"
+edition = "2021"
+publish = false
+
+[dependencies]
+ratzilla = { path = "../../" }
+examples-shared = { path = "../shared" }
diff --git a/examples/unicode/index.html b/examples/unicode/index.html
@@ -0,0 +1,36 @@
+<!doctype html>
+<html lang="en">
+
+<head>
+  <meta charset="UTF-8" />
+  <meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=no" />
+  <link rel="preload" as="style" crossorigin href="https://fontsapi.zeoseven.com/442/main/result.css"
+    onload="this.rel='stylesheet'" onerror="this.href='https://fontsapi-storage.zeoseven.com/442/main/result.css'" />
+  <noscript>
+    <link rel="stylesheet" href="https://fontsapi.zeoseven.com/442/main/result.css" />
+  </noscript>
+  <title>Ratzilla</title>
+  <style>
+    body {
+      margin: 0;
+      width: 100%;
+      height: 100vh;
+      display: flex;
+      flex-direction: column;
+      justify-content: center;
+      align-items: center;
+      align-content: center;
+      background-color: #121212;
+    }
+
+    pre {
+      font-family: "Maple Mono NF CN", monospace;
+      font-size: 15px;
+      margin: 0px;
+    }
+  </style>
+</head>
+
+<body></body>
+
+</html>
diff --git a/examples/unicode/src/main.rs b/examples/unicode/src/main.rs
@@ -0,0 +1,40 @@
+use std::io;
+
+use ratzilla::ratatui::{
+    layout::Alignment,
+    style::Color,
+    widgets::{Block, Paragraph},
+};
+
+use ratzilla::WebRenderer;
+
+use examples_shared::backend::{BackendType, MultiBackendBuilder};
+
+fn main() -> io::Result<()> {
+    let terminal = MultiBackendBuilder::with_fallback(BackendType::Dom).build_terminal()?;
+
+    terminal.draw_web(move |f| {
+        f.render_widget(
+            Paragraph::new(
+                [
+                    "Hello, world!",
+                    "你好，世界！",
+                    "世界、こんにちは。",
+                    // "헬로우 월드！",
+                    // "👨💻👋🌐",
+                ]
+                .join("\n"),
+            )
+            .alignment(Alignment::Center)
+            .block(
+                Block::bordered()
+                    .title("Ratzilla")
+                    .title_alignment(Alignment::Center)
+                    .border_style(Color::Yellow),
+            ),
+            f.area(),
+        );
+    });
+
+    Ok(())
+}
diff --git a/src/backend/dom.rs b/src/backend/dom.rs
@@ -6,6 +6,7 @@ use ratatui::{
     layout::{Position, Size},
     prelude::Backend,
 };
+use unicode_width::UnicodeWidthStr;
 use web_sys::{
     wasm_bindgen::{prelude::Closure, JsCast},
     window, Document, Element, Window,
@@ -148,27 +149,30 @@ impl DomBackend {
     fn prerender(&mut self) -> Result<(), Error> {
         for line in self.buffer.iter() {
             let mut line_cells: Vec<Element> = Vec::new();
-            let mut hyperlink: Vec<Cell> = Vec::new();
+            let mut hyperlink: Vec<(Cell, bool)> = Vec::new();
+            let mut skip = 0;
             for (i, cell) in line.iter().enumerate() {
+                let overwritten = skip > 0;
+                skip = std::cmp::max(skip, cell.symbol().width()).saturating_sub(1);
                 if cell.modifier.contains(HYPERLINK_MODIFIER) {
-                    hyperlink.push(cell.clone());
+                    hyperlink.push((cell.clone(), overwritten));
                     // If the next cell is not part of the hyperlink, close it
                     if !line
                         .get(i + 1)
                         .map(|c| c.modifier.contains(HYPERLINK_MODIFIER))
                         .unwrap_or(false)
                     {
                         let anchor = create_anchor(&self.document, &hyperlink)?;
-                        for link_cell in &hyperlink {
-                            let span = create_span(&self.document, link_cell)?;
+                        for (link_cell, overwritten) in &hyperlink {
+                            let span = create_span(&self.document, link_cell, *overwritten)?;
                             self.cells.push(span.clone());
                             anchor.append_child(&span)?;
                         }
                         line_cells.push(anchor);
                         hyperlink.clear();
                     }
                 } else {
-                    let span = create_span(&self.document, cell)?;
+                    let span = create_span(&self.document, cell, overwritten)?;
                     self.cells.push(span.clone());
                     line_cells.push(span);
                 }
@@ -192,14 +196,22 @@ impl DomBackend {
     /// accordingly.
     fn update_grid(&mut self) -> Result<(), Error> {
         for (y, line) in self.buffer.iter().enumerate() {
+            let mut skip = 0;
             for (x, cell) in line.iter().enumerate() {
+                let overwritten = skip > 0;
+                skip = std::cmp::max(skip, cell.symbol().width()).saturating_sub(1);
                 if cell.modifier.contains(HYPERLINK_MODIFIER) {
                     continue;
                 }
                 if cell != &self.prev_buffer[y][x] {
                     let elem = self.cells[y * self.buffer[0].len() + x].clone();
                     elem.set_inner_html(cell.symbol());
-                    elem.set_attribute("style", &get_cell_style_as_css(cell))?;
+                    if overwritten {
+                        // If the cell is overwritten, hide it
+                        elem.set_attribute("style", "display: none;")?;
+                    } else {
+                        elem.set_attribute("style", &get_cell_style_as_css(cell))?;
+                    }
                 }
             }
         }

diff --git a/src/backend/utils.rs b/src/backend/utils.rs
@@ -14,23 +14,31 @@ use web_sys::{
 };
 
 /// Creates a new `<span>` element with the given cell.
-pub(crate) fn create_span(document: &Document, cell: &Cell) -> Result<Element, Error> {
+pub(crate) fn create_span(
+    document: &Document,
+    cell: &Cell,
+    overwritten: bool,
+) -> Result<Element, Error> {
     let span = document.create_element("span")?;
     span.set_inner_html(cell.symbol());
 
-    let style = get_cell_style_as_css(cell);
-    span.set_attribute("style", &style)?;
+    if overwritten {
+        span.set_attribute("style", "display: none;")?;
+    } else {
+        let style = get_cell_style_as_css(cell);
+        span.set_attribute("style", &style)?;
+    }
     Ok(span)
 }
 
 /// Creates a new `<a>` element with the given cells.
-pub(crate) fn create_anchor(document: &Document, cells: &[Cell]) -> Result<Element, Error> {
+pub(crate) fn create_anchor(document: &Document, cells: &[(Cell, bool)]) -> Result<Element, Error> {
     let anchor = document.create_element("a")?;
     anchor.set_attribute(
         "href",
-        &cells.iter().map(|c| c.symbol()).collect::<String>(),
+        &cells.iter().map(|c| c.0.symbol()).collect::<String>(),
     )?;
-    anchor.set_attribute("style", &get_cell_style_as_css(&cells[0]))?;
+    anchor.set_attribute("style", &get_cell_style_as_css(&cells[0].0))?;
     Ok(anchor)
 }