PyQt5 vs Flutter

PyQt5 vs Flutter for Desktop APPs: Does a Python APP as shown on https://github.com/mrmoein/GUI-DNS-changer-for-linux/ also work across platforms on laptops and smartphones?

Key Points

• Research suggests that PyQt5 is generally better suited for laptops due to its maturity, extensive desktop feature set, and seamless integration with desktop operating systems like Windows, macOS, and Linux.
• It seems likely that Flutter excels on smartphones with its mobile-first design, but it can work on laptops, though it’s less optimized for desktop use cases compared to PyQt5.
• The evidence leans toward PyQt5 offering a more robust and native-feeling experience for laptops, while Flutter’s desktop support is still maturing and better suited for cross-platform consistency with mobile.

Answer

For laptops (Windows, macOS, Linux), PyQt5 is typically the better choice over Flutter, though both can work. Here’s a detailed comparison to help you decide:

PyQt5 for Laptops

Advantages:

1. Maturity for Desktop: PyQt5, built on Qt, is a well-established framework designed for desktop applications, offering a rich set of widgets, native look-and-feel, and deep integration with desktop OS features (e.g., file dialogs, system trays).
2. Cross-Platform: It runs smoothly on Windows, macOS, and Linux with minimal adjustments, making it ideal for laptop environments.
3. System Interaction: Python with PyQt5 can easily interface with system-level operations (e.g., changing DNS settings via subprocess for nmcli, netsh, or networksetup), leveraging Python’s extensive libraries.
4. Community and Resources: PyQt5 has a long history, extensive documentation, and a large community, which is beneficial for troubleshooting and finding desktop-specific examples.
5. Performance: While Python isn’t compiled to native code, PyQt5’s underlying Qt is highly optimized, providing a responsive experience on laptops.

Disadvantages:

1. Mobile Limitations: PyQt5 can be adapted for smartphones (via Qt for mobile), but it’s not optimized for touch interfaces or mobile deployment, requiring significant rework compared to Flutter.
2. Learning Curve: While Python is beginner-friendly, mastering PyQt5’s API and Qt’s concepts (e.g., signals and slots) can be more complex than Flutter’s declarative UI approach.

Flutter for Laptops

Advantages:

1. Single Codebase: Flutter allows you to use the same Dart codebase for laptops (Windows, macOS, Linux) and smartphones (Android, iOS), ensuring consistency if you’re targeting both platforms.
2. Modern UI: Flutter’s widget system offers a sleek, customizable UI that can mimic modern app designs (e.g., Material Design), which might appeal to users across devices.
3. Rapid Development: Flutter’s hot reload and declarative UI make prototyping and iteration faster, which could streamline development for both laptops and smartphones.
4. Growing Desktop Support: Flutter’s desktop support has improved significantly (e.g., stable for Windows, macOS, Linux as of 2023), with features like window management and native menu bars.

Disadvantages:

1. Desktop Maturity: Flutter’s desktop support is newer and less mature than PyQt5’s, with fewer desktop-specific features (e.g., limited native integration for system trays or advanced window management compared to Qt).
2. System Interaction: Dart lacks Python’s direct system-level access, requiring platform channels to native code (e.g., C++/Rust for laptops), adding complexity for DNS changes compared to PyQt5’s straightforward subprocess approach.
3. Performance Overhead: Flutter renders its UI via Skia, which can introduce slight overhead compared to PyQt5’s native Qt widgets, though this is rarely noticeable on modern laptops.
4. Community Focus: Flutter’s community and resources are heavily mobile-focused, with less emphasis on desktop-specific use cases.

DNS-Changer Context

For a DNS-Changer app specifically:

• PyQt5:
  • UI: PyQt5 provides a native desktop experience with minimal effort.
  • Smartphones: Less practical due to deployment challenges and lack of touch optimization.
• Flutter:
  • UI: Consistent across laptops and smartphones, but less native-feeling on desktops.
  • Smartphones: Excels here, as discussed previously.

Laptops: Requires platform channels for DNS changes, adding complexity:

import 'package:flutter/services.dart';

const platform = MethodChannel('dns_changer');
Future<void> changeDNS(String dns) async {
  try {
    await platform.invokeMethod('setDNS', {"dns": dns});
  } on PlatformException catch (e) {
    print("Failed: ${e.message}");
  }
}

Native code (e.g., C++ for Windows/Linux, Objective-C for macOS) must be written separately.

Laptops: Easily integrates with OS-specific DNS commands (e.g., nmcli on Linux, netsh on Windows, networksetup on macOS) using Python’s subprocess. Example:

import subprocess
import platform

def change_dns(dns_servers):
    system = platform.system()
    dns_string = " ".join(dns_servers)
    if system == "Linux":
        subprocess.run(["sudo", "nmcli", "con", "mod", "active_connection", "ipv4.dns", dns_string])
    elif system == "Windows":
        subprocess.run(["netsh", "interface", "ip", "set", "dns", "Ethernet", "static", dns_servers[0]])
    elif system == "Darwin":
        subprocess.run(["sudo", "networksetup", "-setdnsservers", "Wi-Fi", dns_string])

Recommendation

• For Laptops Only: Use PyQt5. It’s better tailored for desktop environments, offering a native experience, simpler system integration, and a mature ecosystem. It’s the practical choice if your focus is laptops (Windows, macOS, Linux).
• For Laptops + Smartphones: Use Flutter. If you want a single codebase for both laptops and smartphones, Flutter is the better option despite its desktop immaturity. It ensures consistency and leverages your mobile development efforts, though you’ll need to handle platform-specific DNS logic via channels.

Practical Considerations

• Development Effort: PyQt5 is quicker for laptops alone; Flutter requires more setup (e.g., native code) but pays off for multi-platform apps.
• User Experience: PyQt5 feels more “at home” on laptops; Flutter might feel slightly foreign but offers a modern, unified look.
• Future-Proofing: Flutter’s desktop support is improving rapidly, making it a forward-looking choice if you anticipate broader platform needs.

Conclusion

For a DNS-Changer app targeting laptops, PyQt5 is the superior choice due to its desktop optimization, ease of system interaction, and native integration. Use Flutter if you also need smartphone support from the same codebase, accepting the trade-off of added complexity for desktop DNS functionality. If your priority is laptops now with potential mobile expansion later, start with PyQt5 and consider porting to Flutter as needed.

Wir erstellen jetzt die DNS-Changer App für den Laptops in PyQt5 und für Smartphones in Flutter.

Below is a step-by-step guide to creating a DNS-Changer app for laptops using PyQt5 and for smartphones using Flutter. Each section includes setup, code, and explanations tailored to the respective platforms.

DNS-Changer App for Laptops with PyQt5

Step 1: Set Up Your Environment

• Development Tools: Use a text editor like Visual Studio Code or PyCharm.

Install PyQt5: Use pip to install PyQt5:

pip3 install PyQt5

Install Python: Ensure Python 3.x is installed (python3 --version). Install if needed:

sudo apt update && sudo apt install python3 python3-pip

Step 2: Create the Project Structure

• Create a file dns_changer.py.

Create a directory:

mkdir dns_changer_pyqt5
cd dns_changer_pyqt5

Step 3: Write the PyQt5 Code

Here’s a complete DNS-Changer app with a GUI for laptops:

import sys
import subprocess
import platform
from PyQt5.QtWidgets import QApplication, QWidget, QVBoxLayout, QPushButton, QLabel, QLineEdit, QMessageBox

class DNSChangerApp(QWidget):
    def __init__(self):
        super().__init__()
        self.initUI()

    def initUI(self):
        self.setWindowTitle('DNS Changer - Laptops')
        self.setGeometry(100, 100, 400, 300)

        # Layout
        layout = QVBoxLayout()

        # Current DNS Label
        self.current_dns_label = QLabel('Current DNS: Not checked yet', self)
        layout.addWidget(self.current_dns_label)
        self.update_current_dns()

        # Predefined DNS Buttons
        cloudflare_btn = QPushButton('Set Cloudflare DNS (1.1.1.1, 1.0.0.1)', self)
        cloudflare_btn.clicked.connect(lambda: self.change_dns(['1.1.1.1', '1.0.0.1']))
        layout.addWidget(cloudflare_btn)

        google_btn = QPushButton('Set Google DNS (8.8.8.8, 8.8.4.4)', self)
        google_btn.clicked.connect(lambda: self.change_dns(['8.8.8.8', '8.8.4.4']))
        layout.addWidget(google_btn)

        # Custom DNS Input
        self.custom_dns_input = QLineEdit(self)
        self.custom_dns_input.setPlaceholderText('Enter custom DNS (comma-separated, e.g., 1.1.1.1,1.0.0.1)')
        layout.addWidget(self.custom_dns_input)

        custom_btn = QPushButton('Set Custom DNS', self)
        custom_btn.clicked.connect(self.set_custom_dns)
        layout.addWidget(custom_btn)

        # Reset Button
        reset_btn = QPushButton('Reset to Automatic', self)
        reset_btn.clicked.connect(self.reset_dns)
        layout.addWidget(reset_btn)

        self.setLayout(layout)

    def change_dns(self, dns_servers):
        system = platform.system()
        dns_string = " ".join(dns_servers)
        try:
            if system == "Linux":
                active_conn = self.get_active_connection_linux()
                if active_conn:
                    subprocess.run(["sudo", "nmcli", "con", "mod", active_conn, "ipv4.dns", dns_string], check=True)
                    subprocess.run(["sudo", "nmcli", "con", "up", active_conn], check=True)
            elif system == "Windows":
                subprocess.run(["netsh", "interface", "ip", "set", "dns", "Ethernet", "static", dns_servers[0]], check=True)
                if len(dns_servers) > 1:
                    subprocess.run(["netsh", "interface", "ip", "add", "dns", "Ethernet", dns_servers[1], "index=2"], check=True)
            elif system == "Darwin":  # macOS
                subprocess.run(["sudo", "networksetup", "-setdnsservers", "Wi-Fi", dns_string], check=True)
            else:
                raise NotImplementedError("Platform not supported")
            QMessageBox.information(self, "Success", f"DNS set to {dns_string}")
            self.update_current_dns()
        except subprocess.CalledProcessError as e:
            QMessageBox.critical(self, "Error", f"Failed to set DNS: {str(e)}")

    def reset_dns(self):
        system = platform.system()
        try:
            if system == "Linux":
                active_conn = self.get_active_connection_linux()
                if active_conn:
                    subprocess.run(["sudo", "nmcli", "con", "mod", active_conn, "ipv4.dns", ""], check=True)
                    subprocess.run(["sudo", "nmcli", "con", "up", active_conn], check=True)
            elif system == "Windows":
                subprocess.run(["netsh", "interface", "ip", "set", "dns", "Ethernet", "dhcp"], check=True)
            elif system == "Darwin":
                subprocess.run(["sudo", "networksetup", "-setdnsservers", "Wi-Fi", "Empty"], check=True)
            else:
                raise NotImplementedError("Platform not supported")
            QMessageBox.information(self, "Success", "DNS reset to automatic")
            self.update_current_dns()
        except subprocess.CalledProcessError as e:
            QMessageBox.critical(self, "Error", f"Failed to reset DNS: {str(e)}")

    def set_custom_dns(self):
        dns_input = self.custom_dns_input.text().strip()
        if dns_input:
            dns_servers = [x.strip() for x in dns_input.split(",")]
            self.change_dns(dns_servers)
        else:
            QMessageBox.warning(self, "Warning", "Please enter at least one DNS server")

    def get_active_connection_linux(self):
        try:
            result = subprocess.run(["nmcli", "-t", "-f", "NAME,STATE", "con", "show"], 
                                    capture_output=True, text=True, check=True)
            for line in result.stdout.splitlines():
                name, state = line.split(":")
                if state == "activated":
                    return name
            return None
        except subprocess.CalledProcessError:
            return None

    def update_current_dns(self):
        system = platform.system()
        try:
            if system == "Linux":
                active_conn = self.get_active_connection_linux()
                if active_conn:
                    result = subprocess.run(["nmcli", "con", "show", active_conn], 
                                            capture_output=True, text=True, check=True)
                    for line in result.stdout.splitlines():
                        if "ipv4.dns" in line:
                            dns = line.split()[-1]
                            self.current_dns_label.setText(f"Current DNS: {dns}")
                            return
            elif system == "Windows":
                result = subprocess.run(["netsh", "interface", "ip", "show", "dns", "Ethernet"], 
                                        capture_output=True, text=True, check=True)
                for line in result.stdout.splitlines():
                    if "DNS" in line and "configured" in line:
                        dns = line.split(":")[-1].strip()
                        self.current_dns_label.setText(f"Current DNS: {dns}")
                        return
            elif system == "Darwin":
                result = subprocess.run(["networksetup", "-getdnsservers", "Wi-Fi"], 
                                        capture_output=True, text=True, check=True)
                dns = result.stdout.strip()
                self.current_dns_label.setText(f"Current DNS: {dns if dns else 'Automatic'}")
                return
            self.current_dns_label.setText("Current DNS: Unknown")
        except subprocess.CalledProcessError:
            self.current_dns_label.setText("Current DNS: Error retrieving")

if __name__ == '__main__':
    app = QApplication(sys.argv)
    ex = DNSChangerApp()
    ex.show()
    sys.exit(app.exec_())

Step 4: Explanation of the Code

• Imports: PyQt5 for GUI, subprocess for system commands, platform for OS detection.
• UI: A window with buttons for Cloudflare and Google DNS, a text field for custom DNS, and a reset button.
• DNS Logic: Platform-specific commands (nmcli for Linux, netsh for Windows, networksetup for macOS).
• Feedback: Uses QMessageBox for success/error messages and updates the current DNS label.

Step 5: Run the App

On Windows/macOS, run without sudo if admin privileges are available:

python3 dns_changer.py

Execute with sudo on Linux due to root requirements:

sudo python3 dns_changer.py

Step 6: Test and Deploy

• Test each button and custom input on your target OS.
• Find the executable in dist/ folder.

Package with PyInstaller for distribution:

pip3 install pyinstaller
pyinstaller --onefile dns_changer.py

DNS-Changer App for Smartphones with Flutter

Step 1: Set Up Your Environment

• Install Flutter: Follow Flutter Install.
• IDE: Use Visual Studio Code or Android Studio with Flutter/Dart plugins.

Verify Setup:

flutter doctor

Step 2: Create the Project Structure

Start a new Flutter project:

flutter create dns_changer_flutter
cd dns_changer_flutter

Step 3: Write the Flutter Code

Here’s a basic Flutter app with platform channels for DNS changes:

lib/main.dart

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';

void main() {
  runApp(DNSChangerApp());
}

class DNSChangerApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'DNS Changer - Smartphones',
      theme: ThemeData(primarySwatch: Colors.blue),
      home: DNSChangerHomePage(),
    );
  }
}

class DNSChangerHomePage extends StatefulWidget {
  @override
  _DNSChangerHomePageState createState() => _DNSChangerHomePageState();
}

class _DNSChangerHomePageState extends State<DNSChangerHomePage> {
  static const platform = MethodChannel('dns_changer');
  String selectedDNS = "None";

  Future<void> changeDNS(String dns) async {
    try {
      final String result = await platform.invokeMethod('setDNS', {"dns": dns});
      setState(() {
        selectedDNS = dns;
      });
      ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text(result)));
    } on PlatformException catch (e) {
      ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text("Failed: ${e.message}")));
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('DNS Changer')),
      body: Padding(
        padding: EdgeInsets.all(16.0),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            Text('Current DNS: $selectedDNS', style: TextStyle(fontSize: 18)),
            SizedBox(height: 20),
            ElevatedButton(
              onPressed: () => changeDNS('1.1.1.1'),
              child: Text('Set Cloudflare DNS (1.1.1.1)'),
            ),
            ElevatedButton(
              onPressed: () => changeDNS('8.8.8.8'),
              child: Text('Set Google DNS (8.8.8.8)'),
            ),
            TextField(
              decoration: InputDecoration(labelText: 'Custom DNS'),
              onSubmitted: (value) => changeDNS(value),
            ),
          ],
        ),
      ),
    );
  }
}

Android Native Code (android/app/src/main/kotlin/com/example/dns_changer_flutter/MainActivity.kt)

package com.example.dns_changer_flutter

import io.flutter.embedding.android.FlutterActivity
import io.flutter.embedding.engine.plugins.FlutterPlugin
import io.flutter.plugin.common.MethodCall
import io.flutter.plugin.common.MethodChannel
import android.net.ConnectivityManager
import android.content.Context
import android.os.Build

class MainActivity: FlutterActivity() {
    private val CHANNEL = "dns_changer"

    override fun configureFlutterEngine(flutterEngine: FlutterEngine) {
        super.configureFlutterEngine(flutterEngine)
        MethodChannel(flutterEngine.dartExecutor.binaryMessenger, CHANNEL).setMethodCallHandler { call, result ->
            if (call.method == "setDNS") {
                val dns = call.argument<String>("dns")
                if (dns != null && setDNS(dns)) {
                    result.success("DNS set successfully")
                } else {
                    result.error("UNAVAILABLE", "DNS setting failed or not supported", null)
                }
            } else {
                result.notImplemented()
            }
        }
    }

    private fun setDNS(dns: String): Boolean {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
            val cm = getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager
            val linkProperties = cm.getLinkProperties(cm.activeNetwork)
            linkProperties?.privateDnsServerName = dns
            return true
        }
        return false // Simplified; requires root or older API for non-private DNS
    }
}

Add Android Permissions (android/app/src/main/AndroidManifest.xml)

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.CHANGE_NETWORK_STATE" />

iOS Native Code (ios/Runner/AppDelegate.swift)

import UIKit
import Flutter
import NetworkExtension

@UIApplicationMain
@objc class AppDelegate: FlutterAppDelegate {
  override func application(
    _ application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
  ) -> Bool {
    let controller = window?.rootViewController as! FlutterViewController
    let dnsChannel = FlutterMethodChannel(name: "dns_changer", binaryMessenger: controller.binaryMessenger)

    dnsChannel.setMethodCallHandler { (call: FlutterMethodCall, result: @escaping FlutterResult) in
      if call.method == "setDNS" {
        guard let dns = call.arguments as? String else {
          result(FlutterError(code: "INVALID_ARG", message: "DNS argument missing", details: nil))
          return
        }
        self.setDNS(dns: dns, result: result)
      } else {
        result(FlutterMethodNotImplemented)
      }
    }

    return super.application(application, didFinishLaunchingWithOptions: launchOptions)
  }

  private func setDNS(dns: String, result: @escaping FlutterResult) {
    let manager = NEVPNManager.shared()
    manager.loadFromPreferences { error in
      if let error = error {
        result(FlutterError(code: "LOAD_ERROR", message: error.localizedDescription, details: nil))
        return
      }
      let protocolConfig = NEVPNProtocolIKEv2()
      protocolConfig.serverAddress = dns
      protocolConfig.remoteIdentifier = dns
      protocolConfig.useExtendedAuthentication = true
      manager.protocolConfiguration = protocolConfig
      manager.isEnabled = true
      manager.saveToPreferences { error in
        if let error = error {
          result(FlutterError(code: "SAVE_ERROR", message: error.localizedDescription, details: nil))
        } else {
          result("DNS set successfully")
        }
      }
    }
  }
}

Add iOS Permissions (ios/Runner/Info.plist)

<key>UIBackgroundModes</key>
<array>
  <string>fetch</string>
  <string>remote-notification</string>
</array>

Step 4: Explanation of the Code

• Flutter/Dart: Creates a simple UI with buttons and a text field, using a MethodChannel to call native DNS-changing functions.
• Android: Implements a basic private DNS setting (Android 9+), though full functionality may require root for older versions.
• iOS: Sets up a minimal VPN profile to change DNS, requiring user approval via system prompts.

Step 5: Run the App

Test on iOS (requires macOS and Xcode):

flutter run

Test on Android:

flutter run

Step 6: Test and Deploy

• Test each DNS option on both platforms.

Build for release:

flutter build apk  # Android
flutter build ios  # iOS (on macOS)

Comparison and Notes

• PyQt5 (Laptops):
  • Pros: Native desktop experience, straightforward DNS changes, mature ecosystem.
  • Cons: Not optimized for smartphones.
• Flutter (Smartphones):
  • Pros: Single codebase for Android/iOS, modern UI, mobile-first design.
  • Cons: Requires native code for DNS changes, less seamless on desktops.

Practical Tips

• Laptops: PyQt5 assumes “Ethernet” (Windows) or “Wi-Fi” (macOS) as the interface; adjust for your network setup.
• Smartphones: The iOS implementation is basic; enhance with a full VPN profile for production use. Android’s private DNS is limited to newer versions.

This dual approach gives you a robust solution for both platforms tailored to their strengths! Let me know if you need further refinements.

Let's now add the function of a Wireguard VPN client for both the laptop and smartphones.

• As soon as the VPN client has connected to the server, all network traffic including DNS resolution should run via the VPN server.
• The APP user can either host his Wireguard VPN server himself or use our SaaS (Software-as-a-Service) Wireguard VPN server.

Below are step-by-step guides for implementing a WireGuard VPN client for both laptops (using PyQt5) and smartphones (using Flutter). The goal is to ensure that once the VPN client connects to the server, all network traffic, including DNS resolution, is routed through the VPN server. The app user can either self-host their WireGuard VPN server or use a provided SaaS WireGuard VPN server. I'll include instructions for both scenarios.

WireGuard VPN Client for Laptops with PyQt5

Step 1: Set Up Your Environment

• Development Tools: Use Visual Studio Code or PyCharm.

Install WireGuard Tools: For managing the VPN connection on Linux (Windows/macOS users install the official WireGuard client separately).

sudo apt install wireguard

Install PyQt5: For the GUI.

pip3 install PyQt5

Install Python: Ensure Python 3.x is installed (python3 --version).

sudo apt update && sudo apt install python3 python3-pip

Step 2: Create the Project Structure

• Create a file dns_changer_wireguard.py.

Create a directory:

mkdir dns_changer_wireguard_pyqt5
cd dns_changer_wireguard_pyqt5

Step 3: Write the PyQt5 Code with WireGuard Integration

This code provides a GUI to connect to a WireGuard VPN server and ensures all traffic, including DNS, routes through the VPN.

import sys
import subprocess
import platform
from PyQt5.QtWidgets import QApplication, QWidget, QVBoxLayout, QPushButton, QLabel, QLineEdit, QMessageBox, QComboBox

class WireGuardDNSChangerApp(QWidget):
    def __init__(self):
        super().__init__()
        self.initUI()

    def initUI(self):
        self.setWindowTitle('WireGuard DNS Changer - Laptops')
        self.setGeometry(100, 100, 400, 350)

        # Layout
        layout = QVBoxLayout()

        # Status Label
        self.status_label = QLabel('VPN Status: Disconnected', self)
        layout.addWidget(self.status_label)

        # Server Selection
        self.server_combo = QComboBox(self)
        self.server_combo.addItems(["Self-Hosted Server", "SaaS WireGuard Server"])
        layout.addWidget(QLabel("Select VPN Server:"))
        layout.addWidget(self.server_combo)

        # Config Input
        self.config_input = QLineEdit(self)
        self.config_input.setPlaceholderText('Enter WireGuard config file path or SaaS config')
        layout.addWidget(self.config_input)

        # Connect Button
        connect_btn = QPushButton('Connect to VPN', self)
        connect_btn.clicked.connect(self.connect_vpn)
        layout.addWidget(connect_btn)

        # Disconnect Button
        disconnect_btn = QPushButton('Disconnect VPN', self)
        disconnect_btn.clicked.connect(self.disconnect_vpn)
        layout.addWidget(disconnect_btn)

        self.setLayout(layout)

    def connect_vpn(self):
        config_path = self.config_input.text().strip()
        if not config_path:
            QMessageBox.warning(self, "Warning", "Please enter a config file path")
            return

        system = platform.system()
        try:
            if system == "Linux":
                # Copy config to /etc/wireguard/wg0.conf and start
                subprocess.run(["sudo", "cp", config_path, "/etc/wireguard/wg0.conf"], check=True)
                subprocess.run(["sudo", "wg-quick", "up", "wg0"], check=True)
            elif system == "Windows":
                # Assumes WireGuard client installed; import and activate
                subprocess.run(["wireguard", "/installtunnel", config_path], check=True)
                subprocess.run(["wireguard", "/activatetunnel", "wg0"], check=True)
            elif system == "Darwin":  # macOS
                subprocess.run(["sudo", "wireguard-go", "wg0"], check=True)
                subprocess.run(["sudo", "wg", "setconf", "wg0", config_path], check=True)
                subprocess.run(["sudo", "ifconfig", "wg0", "up"], check=True)
            else:
                raise NotImplementedError("Platform not supported")

            self.status_label.setText("VPN Status: Connected")
            QMessageBox.information(self, "Success", "Connected to VPN. All traffic routed through server.")
        except subprocess.CalledProcessError as e:
            QMessageBox.critical(self, "Error", f"Failed to connect: {str(e)}")

    def disconnect_vpn(self):
        system = platform.system()
        try:
            if system == "Linux":
                subprocess.run(["sudo", "wg-quick", "down", "wg0"], check=True)
            elif system == "Windows":
                subprocess.run(["wireguard", "/deactivatetunnel", "wg0"], check=True)
            elif system == "Darwin":
                subprocess.run(["sudo", "ifconfig", "wg0", "down"], check=True)
            else:
                raise NotImplementedError("Platform not supported")

            self.status_label.setText("VPN Status: Disconnected")
            QMessageBox.information(self, "Success", "Disconnected from VPN")
        except subprocess.CalledProcessError as e:
            QMessageBox.critical(self, "Error", f"Failed to disconnect: {str(e)}")

if __name__ == '__main__':
    app = QApplication(sys.argv)
    ex = WireGuardDNSChangerApp()
    ex.show()
    sys.exit(app.exec_())

Step 4: Configure WireGuard for Full Traffic Routing

• SaaS Server: Obtain the .conf file from your SaaS provider, ensuring AllowedIPs = 0.0.0.0/0, ::/0 and a DNS setting are included.

Self-Hosted Server Config Example (wg0.conf):

[Interface]
PrivateKey = <client_private_key>
Address = 10.0.0.2/24
DNS = 1.1.1.1  # Use server's DNS or a public one like Cloudflare

[Peer]
PublicKey = <server_public_key>
Endpoint = <server_ip>:51820
AllowedIPs = 0.0.0.0/0, ::/0  # Route all IPv4 and IPv6 traffic
PersistentKeepalive = 25

Step 5: Run the App

• Enter the path to your .conf file and click "Connect to VPN".

On Windows/macOS (after installing WireGuard client):

python3 dns_changer_wireguard.py

On Linux (requires sudo):

sudo python3 dns_changer_wireguard.py

Step 6: Test and Verify

• Check IP: Visit whatismyipaddress.com to confirm the server’s IP.
• DNS Leak Test: Use dnsleaktest.com to ensure DNS queries route through the VPN.

WireGuard VPN Client for Smartphones with Flutter

Step 1: Set Up Your Environment

• Install Flutter: Follow Flutter Install.
• IDE: Use Visual Studio Code or Android Studio.

Verify Setup:

flutter doctor

Step 2: Create the Project Structure

Start a new Flutter project:

flutter create dns_changer_wireguard_flutter
cd dns_changer_wireguard_flutter

Step 3: Write the Flutter Code with WireGuard Integration

This app integrates with the official WireGuard app via intents (Android) and native code (iOS).

lib/main.dart

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:open_file/open_file.dart'; // Add to pubspec.yaml: open_file: ^3.3.2

void main() {
  runApp(DNSChangerWireGuardApp());
}

class DNSChangerWireGuardApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'WireGuard DNS Changer - Smartphones',
      theme: ThemeData(primarySwatch: Colors.blue),
      home: DNSChangerHomePage(),
    );
  }
}

class DNSChangerHomePage extends StatefulWidget {
  @override
  _DNSChangerHomePageState createState() => _DNSChangerHomePageState();
}

class _DNSChangerHomePageState extends State<DNSChangerHomePage> {
  static const platform = MethodChannel('dns_changer');
  String status = "Disconnected";

  Future<void> connectVPN(String configPath) async {
    try {
      // For Android, use intent to open WireGuard app with config
      // For iOS, use native code to manage tunnel
      final String result = await platform.invokeMethod('connectVPN', {"configPath": configPath});
      setState(() {
        status = "Connected";
      });
      ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text(result)));
    } on PlatformException catch (e) {
      ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text("Failed: ${e.message}")));
    }
  }

  Future<void> disconnectVPN() async {
    try {
      final String result = await platform.invokeMethod('disconnectVPN');
      setState(() {
        status = "Disconnected";
      });
      ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text(result)));
    } on PlatformException catch (e) {
      ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text("Failed: ${e.message}")));
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('WireGuard DNS Changer')),
      body: Padding(
        padding: EdgeInsets.all(16.0),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            Text('VPN Status: $status', style: TextStyle(fontSize: 18)),
            SizedBox(height: 20),
            DropdownButton<String>(
              value: "Self-Hosted Server",
              items: ["Self-Hosted Server", "SaaS WireGuard Server"]
                  .map((String value) => DropdownMenuItem<String>(
                        value: value,
                        child: Text(value),
                      ))
                  .toList(),
              onChanged: (_) {},
            ),
            TextField(
              decoration: InputDecoration(labelText: 'Config File Path'),
              onSubmitted: (value) => connectVPN(value),
            ),
            ElevatedButton(
              onPressed: () => connectVPN("path_to_config.conf"), // Replace with actual path
              child: Text('Connect to VPN'),
            ),
            ElevatedButton(
              onPressed: disconnectVPN,
              child: Text('Disconnect VPN'),
            ),
          ],
        ),
      ),
    );
  }
}

Android Native Code (android/app/src/main/kotlin/com/example/dns_changer_wireguard_flutter/MainActivity.kt)

package com.example.dns_changer_wireguard_flutter

import io.flutter.embedding.android.FlutterActivity
import io.flutter.embedding.engine.plugins.FlutterPlugin
import io.flutter.plugin.common.MethodCall
import io.flutter.plugin.common.MethodChannel
import android.content.Intent
import android.net.Uri

class MainActivity: FlutterActivity() {
    private val CHANNEL = "dns_changer"

    override fun configureFlutterEngine(flutterEngine: FlutterEngine) {
        super.configureFlutterEngine(flutterEngine)
        MethodChannel(flutterEngine.dartExecutor.binaryMessenger, CHANNEL).setMethodCallHandler { call, result ->
            when (call.method) {
                "connectVPN" -> {
                    val configPath = call.argument<String>("configPath")
                    if (configPath != null) {
                        val intent = Intent(Intent.ACTION_VIEW)
                        intent.setDataAndType(Uri.parse("file://$configPath"), "application/x-wireguard-config")
                        intent.setPackage("com.wireguard.android")
                        startActivity(intent)
                        result.success("VPN connection initiated")
                    } else {
                        result.error("INVALID_PATH", "Config path missing", null)
                    }
                }
                "disconnectVPN" -> {
                    // Simplified; requires WireGuard app to handle disconnect
                    result.success("Disconnect requested (manual action needed in WireGuard app)")
                }
                else -> result.notImplemented()
            }
        }
    }
}

iOS Native Code (ios/Runner/AppDelegate.swift)

import UIKit
import Flutter
import NetworkExtension

@UIApplicationMain
@objc class AppDelegate: FlutterAppDelegate {
  override func application(
    _ application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
  ) -> Bool {
    let controller = window?.rootViewController as! FlutterViewController
    let channel = FlutterMethodChannel(name: "dns_changer", binaryMessenger: controller.binaryMessenger)

    channel.setMethodCallHandler { (call: FlutterMethodCall, result: @escaping FlutterResult) in
      switch call.method {
      case "connectVPN":
        guard let args = call.arguments as? [String: String],
              let configPath = args["configPath"] else {
          result(FlutterError(code: "INVALID_ARG", message: "Config path missing", details: nil))
          return
        }
        self.connectVPN(configPath: configPath, result: result)
      case "disconnectVPN":
        self.disconnectVPN(result: result)
      default:
        result(FlutterMethodNotImplemented)
      }
    }

    return super.application(application, didFinishLaunchingWithOptions: launchOptions)
  }

  private func connectVPN(configPath: String, result: @escaping FlutterResult) {
    let manager = NEVPNManager.shared()
    manager.loadFromPreferences { error in
      if let error = error {
        result(FlutterError(code: "LOAD_ERROR", message: error.localizedDescription, details: nil))
        return
      }
      let configURL = URL(fileURLWithPath: configPath)
      do {
        let configData = try String(contentsOf: configURL)
        let tunnel = NETunnelProviderProtocol()
        tunnel.providerBundleIdentifier = "com.wireguard.ios" // Requires WireGuard app
        tunnel.providerConfiguration = ["config": configData]
        manager.protocolConfiguration = tunnel
        manager.isEnabled = true
        manager.saveToPreferences { error in
          if let error = error {
            result(FlutterError(code: "SAVE_ERROR", message: error.localizedDescription, details: nil))
          } else {
            manager.connection.startVPNTunnel()
            result("VPN connected")
          }
        }
      } catch {
        result(FlutterError(code: "CONFIG_ERROR", message: error.localizedDescription, details: nil))
      }
    }
  }

  private func disconnectVPN(result: @escaping FlutterResult) {
    let manager = NEVPNManager.shared()
    manager.loadFromPreferences { error in
      if let error = error {
        result(FlutterError(code: "LOAD_ERROR", message: error.localizedDescription, details: nil))
        return
      }
      manager.connection.stopVPNTunnel()
      result("VPN disconnected")
    }
  }
}

Step 4: Configure WireGuard for Full Traffic Routing

• SaaS Server: Use the provided .conf file, ensuring AllowedIPs = 0.0.0.0/0, ::/0 and DNS are set.

Self-Hosted Server Config Example (wg0.conf):

[Interface]
PrivateKey = <client_private_key>
Address = 10.0.0.2/24
DNS = 1.1.1.1  # Server DNS or public DNS

[Peer]
PublicKey = <server_public_key>
Endpoint = <server_ip>:51820
AllowedIPs = 0.0.0.0/0, ::/0  # Route all traffic
PersistentKeepalive = 25

Step 5: Run the App

• Install the WireGuard app on your device (Google Play/App Store).
• Enter the config file path (e.g., downloaded to device storage) and tap "Connect to VPN".

Test on Android/iOS:

flutter run

Step 6: Test and Verify

• Check IP: Use a browser to visit whatismyipaddress.com.
• DNS Leak Test: Visit dnsleaktest.com to confirm DNS routing.

Additional Notes

• Self-Hosted Setup: Users must generate keys (wg genkey | tee privatekey | wg pubkey > publickey), configure the server (e.g., on Ubuntu with wg-quick), and share the client config.
• SaaS Option: Provide a download link or QR code for the SaaS config file in your app documentation.
• Security: Ensure the server enforces DNS routing (e.g., via iptables on Linux) to prevent leaks.
• Deployment: Package the PyQt5 app with PyInstaller for laptops and Flutter app with flutter build apk/flutter build ios for smartphones.

These guides ensure all traffic, including DNS, routes through the VPN, offering flexibility for self-hosted or SaaS servers. Let me know if you need further details!