Viet+

Vietnamese Input Method for Linux
_{Zero underline • No pre-edit buffer • Backspace-Replay sync • Built in Rust}

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What is Viet+?

Viet+ is a Vietnamese input method for Linux that takes a fundamentally different approach from every other IME: Direct Input.

Most Vietnamese IMEs use a pre-edit buffer — you type into a temporary buffer with an ugly underline, and the text only becomes real Vietnamese when you commit it. This causes duplicate text, underline distraction, broken copy/paste, and desync between the engine state and what's on screen.

Viet+ eliminates all of this. Keystrokes are instantly converted to Unicode — what you type is what you see. No buffer. No underline. No duplication.

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Features

Feature	How It Works
Direct Input	No pre-edit buffer. Keystrokes instantly become text via uinput injection
VNI & Telex	Both input methods fully supported, switchable at runtime via Ctrl+Shift
Bamboo Engine	Transformation model — composition, marks, tones, flexible backtracking
Smart Clusters	uo→ươ with backtrack, ua→ưa horn placement
Macro Expansion	ko → không, dc → được, add your own
Casing Preservation	Tieengs → Tiếng, TIEENGS → TIẾNG
App Memory	Per-app Vietnamese/English state, saved to overrides.toml
Hot Reload	Config changes apply without restart
Window-Switch Reset	Engine clears automatically on Alt+Tab
CPU Priority	Pinned to P-cores (0-3) + nice(-10) for low-latency input
Uinput Injection	/dev/uinput for reliable injection on X11 and Wayland
Terminal Support	✅ Works in all major terminals: kitty, alacritty, gnome-terminal, konsole, foot, wezterm, st, urxvt, xterm
Password Auto-Detection	4 layers: AT-SPI2 → sudo process → window-title → window-class
Tray Icon	Shows current mode: Red VN / Blue TLX / Gray EN
GNOME/Wayland	Native GNOME Shell D-Bus integration

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Input Methods

Both VNI and Telex are fully supported. Switch via Ctrl+LeftShift or the tray menu.

VNI

Key	Result	Example
1	á (sắc)	a1 → á
2	à (huyền)	a2 → à
3	ả (hỏi)	a3 → ả
4	ã (ngã)	a4 → ã
5	ạ (nặng)	a5 → ạ
6	â/ê/ô	a6→â, e6→ê, o6→ô
7	ơ/ư	o7→ơ, u7→ư
8	ă	a8→ă
9	đ	d9→đ

Telex

Key	Result	Example
s	á (sắc)	as→á
f	à (huyền)	af→à
r	ả (hỏi)	ar→ả
x	ã (ngã)	ax→ã
j	ạ (nặng)	aj→ạ
aa	â	aa→â
ee	ê	ee→ê
oo	ô	oo→ô
ow	ơ	ow→ơ
aw	ă	aw→ă
uw	ư	uw→ư
dd	đ	dd→đ
w	ươ	chuongw→chương

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Key Bindings

Combo	Action
Ctrl+Space	Toggle Vietnamese ON/OFF
Ctrl+LeftShift	Toggle VNI ↔ Telex

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Password Detection

4-layer automatic detection. When a password field is detected, Vietnamese is automatically disabled:

Layer	Method	Detects
1	AT-SPI2 D-Bus (a11y role check)	Password fields in accessible apps
2	Process tree (pstree)	sudo / passwd in terminal
3	Window title keywords	password, sudo in title
4	Window class matching	pinentry, polkit, kwallet dialogs

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Distro Support

Tier	Distro	Install Method	Status
✅ Supported	Ubuntu, Debian, Linux Mint, Pop!_OS, elementary OS, Zorin, Neon	apt (auto-detected)	Tested, one-command install
✅ Supported	Fedora, RHEL, CentOS	dnf (auto-detected)	Tested, one-command install
✅ Supported	Arch, Manjaro	pacman (auto-detected)	Tested, one-command install
⚠️ Might support	openSUSE, Solus, Void	zypper/eopkg/xbps (manual)	Package names may differ; run install.sh and install missing deps manually if it fails
❌ Not supported	NixOS, Alpine, Gentoo, others	N/A	No package manager entry — install deps manually, then cargo build --release

⚠️ Tray icon note: GNOME (Ubuntu) and Cinnamon (Mint) need a StatusNotifier watcher for the tray to appear:

• Ubuntu: sudo apt install gnome-shell-extension-appindicator
• Mint: pre-installed; works out of the box

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Installation

One-Command Install

Works on all ✅ Supported distros above. The script auto-detects your package manager:

From GitHub (recommended):

git clone https://github.com/vndangkhoa/vietc.git /tmp/vietc \
  && cd /tmp/vietc && sudo ./install.sh

From Forgejo (self-hosted):

git clone https://git.khoavo.myds.me/vndangkhoa/vietc.git /tmp/vietc \
  && cd /tmp/vietc && sudo ./install.sh

The script installs dependencies, compiles, installs to /usr/bin/, sets up uinput udev rules, and adds your user to the input group.

After install: Log out and log back in, then launch vietc-tray from your application menu.

One-Command Uninstall

From GitHub:

curl -sSL https://raw.githubusercontent.com/vndangkhoa/vietc/main/uninstall.sh | sudo bash

From Forgejo:

curl -sSL https://git.khoavo.myds.me/vndangkhoa/vietc/raw/branch/main/uninstall.sh | sudo bash

Manual Build & Run

# Install dependencies
sudo apt install git curl build-essential pkg-config \
  libx11-dev libxtst-dev libevdev-dev libdbus-1-dev libwayland-dev wl-clipboard

# Enable accessibility (Ubuntu Wayland — for password detection)
gsettings set org.gnome.desktop.a11y.applications screen-reader-enabled true

# Build
git clone https://github.com/vndangkhoa/vietc.git
cd vietc
cargo build --release

# Run (Mint — no sudo needed for uinput)
./target/release/vietc

# Run (Ubuntu — needs sudo for keyboard grab)
sudo ./target/release/vietc

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Configuration

Config file: ~/.config/vietc/config.toml or ./vietc.toml

input_method = "vni"            # "vni" or "telex"
toggle_key = "space"            # Ctrl+Space to toggle VN/EN
toggle_method_key = "shift"     # Ctrl+Shift to toggle VNI/Telex
start_enabled = true            # Vietnamese by default
grab = true                     # grab keyboard (evdev)

[password_detection]
enabled = true
check_atspi2 = true
check_window_title = true
title_keywords = ["password", "passphrase", "secret", "mật khẩu", "sudo"]
password_apps = ["pinentry", "pinentry-gtk-2", "pinentry-qt",
  "lxqt-sudo", "kdesudo", "gksudo",
  "polkit-gnome-authentication-agent-1",
  "kwallet", "gnome-keyring", "ssh-askpass"]

[app_state]
enabled = true
english_apps = ["code", "vim"]
vietnamese_apps = ["telegram", "discord", "firefox"]
bypass_apps = ["steam"]

### Terminal Usage

Viet+ works perfectly in terminals. When running inside a terminal (e.g., gnome-terminal, kitty), Vietnamese input is automatically enabled:

```toml
terminal_input_method = "vni"    # Automatically switch to VNI when running in a terminal app

Supported terminals: kitty, alacritty, gnome-terminal, konsole, foot, wezterm, st, urxvt, xterm

Type Vietnamese directly — no pre-edit buffer, no underline, no duplication. Just type VNI or Telex digits and see Unicode characters instantly! terminal_apps = ["kitty", "alacritty", "gnome-terminal", "konsole", "foot", "wezterm", "st", "urxvt", "xterm"] terminal_input_method = "vni"

[macros] ko = "không" dc = "được" vs = "với"

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## Architecture

vietc/ ├── engine/ # Vietnamese composition engine (bamboo-core port) ├── protocol/ # Keyboard capture & injection │ ├── uinput_monitor.rs # /dev/uinput injection (primary) │ ├── x11_inject.rs # XTest injection (fallback) │ ├── x11_capture.rs # XRecord key capture │ └── wayland_im.rs # Wayland IM protocol (stub) ├── daemon/ # Main daemon process │ ├── main.rs # Event loops, grab, signal handling │ ├── config.rs # TOML config loader + hot reload │ ├── app_state.rs # Per-app VN/EN memory + password detection │ ├── password_detector.rs # AT-SPI2 D-Bus password field detection │ └── display.rs # X11/Wayland/compositor detection ├── ui/ # System tray icon (ksni) │ └── tray.rs # Tray with VN/TLX/EN mode display ├── cli/ # Interactive test harness └── uinputd/ # Privileged uinput socket daemon

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## Roadmap

### v0.1.8
- Wayland input method protocol (`zwp_input_method_v2`) — eliminates clipboard + backspace race, fixes missing spaces permanently
- Event-based AT-SPI2 focus monitoring (subscribe to a11y focus events, no polling)

### v0.1.9
- GitHub Actions CI for automated .deb builds
- Flatpak re-add for immutable distros

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## License

MIT License — see [LICENSE](LICENSE) for details.

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<p align="center">
  <sub>Made with love for the Vietnamese Linux community</sub>
</p>