qtrs — Rust-style Qt6 bindings

A type-safe, builder-pattern-driven Qt6 GUI library for Rust. Built on cxx for zero-cost C++ interop, with RAII memory management and signal/callback bridging.

Features

Builder pattern — chain .title("X").size(800, 600).show()
RAII cleanup — automatic C++ deletion, parent-child aware (no double-free)
Signal bridging — Qt signals invoke Rust closures via a global trampoline
Layout ownership — adding a widget to a layout transfers ownership
.ui file loading — load Qt Designer .ui files at runtime (feature = "ui")
Zero unsafe in public API — all FFI is encapsulated

Quick Start

use qtrs::prelude::*;

fn main() {
    let app = Application::new();

    let mut window = Widget::new()
        .title("Hello, qtrs!")
        .size(400, 300)
        .build();

    let mut layout = VBoxLayout::with_parent(&window);

    let btn = PushButton::new("Click me")
        .on_clicked(|| println!("clicked!"))
        .build();
    let label = Label::new("Welcome!").build();

    layout.add_widget(Box::new(btn));
    layout.add_widget(Box::new(label));

    window.set_vlayout(layout.layout_ptr());
    window.show();

    app.exec();
}

Widgets

Type	Qt class	Signals
`Application`	`QApplication`	—
`Widget`	`QWidget`	—
`PushButton`	`QPushButton`	`on_clicked`
`Label`	`QLabel`	—
`LineEdit`	`QLineEdit`	`on_return_pressed`
`CheckBox`	`QCheckBox`	`on_toggled(bool)`
`ComboBox`	`QComboBox`	`on_current_text_changed`
`TextEdit`	`QTextEdit`	`on_text_changed`
`Slider`	`QSlider`	`on_value_changed(i32)`
`Timer`	`QTimer`	`on_timeout`
`VBoxLayout`	`QVBoxLayout`	—
`HBoxLayout`	`QHBoxLayout`	—
`GridLayout`	`QGridLayout`	—

Prerequisites

Qt6 with development headers:

Platform	Instructions
Debian / Ubuntu	`sudo apt install qt6-base-dev qt6-declarative-dev`
Fedora	`sudo dnf install qt6-qtbase-devel qt6-qtdeclarative-devel`
Arch	`sudo pacman -S qt6-base qt6-declarative`
macOS (Homebrew)	`brew install qt@6`
Windows	Install from qt.io or via vcpkg

macOS notes

After installing via Homebrew, tell pkg-config where to find Qt:

export PKG_CONFIG_PATH="$(brew --prefix qt@6)/lib/pkgconfig:$PKG_CONFIG_PATH"

Add this to your ~/.zshrc or ~/.bashrc for persistence.

Windows notes

The build script uses pkg-config to locate Qt. When using vcpkg, set the environment variable:

$env:PKG_CONFIG_PATH = "$env:VCPKG_ROOT\installed\x64-windows\lib\pkgconfig"

When using the official Qt installer, set CMAKE_PREFIX_PATH and ensure qmake6 is on your PATH.

$env:CMAKE_PREFIX_PATH = "C:\Qt\6.8.2\msvc2022_64"
$env:PATH += ";C:\Qt\6.8.2\msvc2022_64\bin"

A Microsoft Visual Studio build toolchain (MSVC) is required on Windows.

Installation

Add to your Cargo.toml:

[dependencies]
qtrs = "0.1.0"

Enable .ui file loading:

[dependencies]
qtrs = { version = "0.1.0", features = ["ui"] }

Memory management

Widgets are deleted automatically on Drop — unless they have a Qt parent (set explicitly or via layout). In that case Qt's parent-child tree handles deletion, preventing double-free.

Widget created without parent  ->  Drop deletes C++ object
Widget created with parent     ->  Drop skips deletion (Qt handles it)
Widget added to layout         ->  Layout takes ownership, Drop skips deletion

Thread safety

Qt GUI classes are not thread-safe. All widget creation, mutation, and the event loop must happen on the main thread.

License

MIT OR Apache-2.0 — see LICENSE-MIT and LICENSE-APACHE.

qtrs 0.2.1