Building a Desktop Qt Application with Rust and QML

Choosing Rust Qt Bindings

Rust has several Qt bindings to choose from, including Ritual, CXX-Qt, and qmetaobject. However, CXX-Qt is the most popular and widely used binding due to its reliability, performance, and versatility.

Getting Started with Rust and Qt

To get started with Rust and Qt, you’ll need to install Rust using the following command:

curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

Next, install Qt using the following command:

sudo apt-get install qt5-default

Application Components

Our application will consist of a QML file for the user interface and a Rust file for the business logic. We’ll use CXX-Qt to bridge the two languages.

Building the Application

To build the application, we’ll create a build.rs file that defines the build process. We’ll then use Cargo to build and run the application.

// build.rs
fn main() {
    // Define the build process
}

Using QML for the User Interface

QML is a declarative language that allows us to define the user interface of our application. We’ll create a main.qml file that defines the UI components and their properties.

// main.qml
import QtQuick 2.12
import QtQuick.Controls 2.12

ApplicationWindow {
    title: "My Application"
    width: 800
    height: 600
}

Adding Encryption

To add encryption to our application, we’ll use the Caesar Cipher algorithm. We’ll create a Rot struct that takes a string as input and returns the encrypted string.

// rot.rs
struct Rot {
    shift: u8,
}

impl Rot {
    fn new(shift: u8) -> Self {
        Rot { shift }
    }

    fn encrypt(&self, input: &str) -> String {
        // Implement the Caesar Cipher algorithm
    }
}

Encrypting with nrot

We can also use the nrot library to encrypt our string. We’ll add the nrot dependency to our Cargo.toml file and import it in our Rust file.

// Cargo.toml
[dependencies]
nrot = "0.1.0"

// main.rs
use nrot::Rot;

fn main() {
    let rot = Rot::new(3);
    let encrypted = rot.encrypt("Hello, World!");
    println!("{}", encrypted);
}

Using On-the-Fly Encryption

To encrypt the string as the user types, we can use on-the-fly encryption. We’ll remove the button component and update the encrypted string every time the user makes a change to the input field.

// main.qml
import QtQuick 2.12
import QtQuick.Controls 2.12

ApplicationWindow {
    title: "My Application"
    width: 800
    height: 600

    TextField {
        id: inputField
        anchors.centerIn: parent
        placeholderText: "Enter text to encrypt"

        onTextChanged: {
            // Update the encrypted string
        }
    }
}

Adding Decryption

To add decryption to our application, we’ll create a decrypt function that takes the encrypted string as input and returns the decrypted string.

// rot.rs
impl Rot {
    fn decrypt(&self, input: &str) -> String {
        // Implement the decryption algorithm
    }
}

Using a Custom Component to Avoid Duplication

To avoid duplicating code, we can create a custom component that encapsulates the input field and the encryption logic.

// EncryptInput.qml
import QtQuick 2.12
import QtQuick.Controls 2.12

Item {
    property alias text: inputField.text

    TextField {
        id: inputField
        anchors.centerIn: parent
        placeholderText: "Enter text to encrypt"

        onTextChanged: {
            // Update the encrypted string
        }
    }
}

Creating a GitHub CI Workflow

To ensure that our code is correct and functional, we can create a GitHub CI workflow that runs our tests and builds our application.

// .github/workflows/ci.yml
name: CI

on:
  push:
    branches:
      - main

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - name