Secure Gate

A simple package that helps you secure your app when it is hidden or inactive by covered with a blur screen and overlay Widget.

Setup

Wrap your page with SecureGate. All pages with the same controller will be shared the same behavior. It means that when one page is unlocked, all pages with the same controller will be unlocked:

class Page extends StatelessWidget {
  const Page({super.key});

  @override
  Widget build(BuildContext context) {
    return SecureGate(
        onFocus: (context, controller) async {
          if (await biometricAuthentication()) {
            controller.unlock();
          }
        }
        overlayBuilder: (context, controller) {
          return Center(
            child: ElevatedButton(
              onPressed: () {
                controller.unlock();
              },
              child: const Text('Main Secure Gate'),
            ),
          );
      },
      child: Scaffold(
        appBar: AppBar(
          title: const Text('Page'),
        ),
        body: const Center(
          child: Text('This is a secured page'),
        ),
      ),
    );
  }
}

Use with MaterialApp, this method will secure all pages:

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
      builder: (context, child) {
        return SecureGate(
          onFocus: (context, controller) async {
            if (await biometricAuthentication()) {
              controller.unlock();
            }
          }
          overlayBuilder: (context, controller) {
            return Center(
              child: ElevatedButton(
                onPressed: () {
                  controller.unlock();
                },
                child: const Text('Main Secure Gate'),
              ),
            );
          },
          child: child!,
        );
      },
    );
  }
}

Use with MaterialApp.router, this method will secure all pages:

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp.router(
        routerConfig: router,
        theme: pageColorsCtrler.themeData,
        darkTheme: ThemeData.dark(useMaterial3: false),
        themeMode: ThemeMode.light,
        builder: (BuildContext context, Widget? child) {
        return SecureGate(
            onFocus: (context, controller) async {
              if (await biometricAuthentication()) {
                controller.unlock();
              }
            }
            overlayBuilder: (context, controller) {
                return Center(
                    child: ElevatedButton(
                        onPressed: () {
                            controller.unlock();
                        },
                        child: const Text('Go'),
                    ),
                );
            },
            child: child!
          );
        },
    );
  }
}

The package uses a build-in singleton controller SecureGateController.instance, so if you want to separate the behavior into multiple places, you need to create a new controller by defining a new SecureGateController() and put it into the controller parameter.

Remember to dispose() the created controller when it's not in use. You can also dipose the build-in controller by calling SecureGateController.instance.close(), the package will automatically create a new one when it's needed to use.

You can also specify the color, blur and opacity value by modify its' parameters in the SecureGate.

Usage

• Call controller.lock() if you want to lock all pages that using the same controller by your self.

• Call controller.unlock() if you want to unlock any pages that using the same controller.

• Call controller.on() if you want to turn on the controller. This method will also lock() the screen by default, you can set the isLock to false to disable this behavior.

• Call controller.off() if you want to turn off the controller. You can not use lock() and unlock() when the controller is turned off, so remember to lock() or unlock() before using this method. This method will also unlock() the screen by default, you can set the isUnlock to false to disable this behavior.

Advanced

By default, the SecureGate uses a build-in controller named SecureGateController.instance. You can modify it to apply to all pages that wrapped with the SecureGate:

SecureGateController.instance.overlayBuilder = (context, controller) {
    return Center(
      child: ElevatedButton(
        onPressed: () {
          controller.unlock();
        },
        child: const Text('Go'),
      ),
    );
  };

SecureGateController.instance.onFocus = (controller) async {
      if (await biometricAuthentication()) {
        controller.unlock();
      }
    };

Or you can create a global overlayBuilder by setting the overlayBuilder parameter in the new controller and pass it into the SecureGate:

final secureGateController = SecureGateController(
  onFocus: (context, controller) async {
    if (await biometricAuthentication()) {
      controller.unlock();
    }
  }
  overlayBuilder: (context, controller) {
    return Center(
      child: ElevatedButton(
        onPressed: () {
          controller.unlock();
        },
        child: const Text('Go'),
      ),
    );
  },
);

class Page extends StatelessWidget {
  const Page({super.key});

  @override
  Widget build(BuildContext context) {
    return SecureGate(
      controller: secureGateController,
      child: Scaffold(
        appBar: AppBar(
          title: const Text('Page'),
        ),
        body: const Center(
          child: Text('This is a secured page'),
        ),
      ),
    );
  }
}

By default, the screen will be locked on start. If you want to change this behavior, you can set the lockOnStart in the controller to false, so the page will be unlocked on start.

The biometricAuthentication() is just an example that shows you how to implement it into your SecureGate. You can try it in the example.

Information

This package does not use any native way to secure the screen. So it may not works as expected in some cases. If you have any issue or suggestion, feel free to file an issue or a PR. Thank you.