Secure TextField

A Flutter package that provides a secure text field widget which blocks copy, paste, cut, and select all operations across iOS, Android, and web platforms.

Features

✅ Cross-platform support: Works on iOS, Android, and web browsers
✅ Comprehensive blocking: Prevents copy, paste, cut, and select all operations
✅ Keyboard shortcuts prevention: Blocks Ctrl+C/V/X/A and Cmd+C/V/X/A
✅ Context menu blocking: Disables right-click and long-press context menus
✅ All TextField features: Supports all standard TextField properties and callbacks
✅ Platform-specific handling: Optimized behavior for each platform
✅ Comprehensive testing: High test coverage with unit and widget tests

Getting started

Add the package to your pubspec.yaml:

dependencies:
  secure_textfield: ^0.1.0

Then run:

flutter pub get

Usage

Import the package and use SecureTextField instead of the standard TextField:

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

class MyWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return SecureTextField(
      decoration: InputDecoration(
        labelText: 'Secure Input',
        hintText: 'Copy/paste is blocked here',
        border: OutlineInputBorder(),
      ),
      onChanged: (value) {
        print('Text changed: $value');
      },
    );
  }
}

Password Field Example

SecureTextField(
  obscureText: true,
  decoration: InputDecoration(
    labelText: 'Password',
    prefixIcon: Icon(Icons.lock),
    border: OutlineInputBorder(),
  ),
)

Multiline Example

SecureTextField(
  maxLines: 4,
  decoration: InputDecoration(
    labelText: 'Comments',
    hintText: 'Enter your comments here...',
    border: OutlineInputBorder(),
    alignLabelWithHint: true,
  ),
)

With Controller

final TextEditingController controller = TextEditingController();

SecureTextField(
  controller: controller,
  decoration: InputDecoration(
    labelText: 'Controlled Input',
    border: OutlineInputBorder(),
  ),
  onSubmitted: (value) {
    print('Submitted: $value');
  },
)

Supported Properties

SecureTextField supports all the same properties as Flutter's standard TextField:

• controller: TextEditingController for managing text
• decoration: InputDecoration for styling
• obscureText: Hide text input (for passwords)
• maxLines: Number of lines (1 for single line, null for unlimited)
• maxLength: Maximum character count
• onChanged: Callback when text changes
• onSubmitted: Callback when user submits
• keyboardType: Type of keyboard to show
• textInputAction: Action button on keyboard
• style: Text styling
• textAlign: Text alignment
• enabled: Enable/disable the field
• autofocus: Auto-focus on widget creation
• readOnly: Make field read-only
• focusNode: Custom focus management
• And many more...

Platform-Specific Behavior

iOS

• Blocks Cmd+C, Cmd+V, Cmd+X, Cmd+A keyboard shortcuts
• Disables long-press context menu
• Prevents text selection gestures

Android

• Blocks Ctrl+C, Ctrl+V, Ctrl+X, Ctrl+A keyboard shortcuts
• Disables long-press context menu
• Prevents text selection handles

Web

• Blocks both Ctrl and Cmd keyboard shortcuts
• Disables right-click context menu
• Prevents browser's built-in copy/paste functionality

Example App

Check out the example app for a comprehensive demonstration of all features:

cd example
flutter run

Testing

The package includes comprehensive tests covering:

• Widget behavior and rendering
• Platform-specific functionality
• Keyboard shortcut blocking
• All TextField property support
• Edge cases and error scenarios

Run tests with:

flutter test

Test Coverage

Generate and view test coverage:

# Generate coverage report
flutter test --coverage

# View coverage in browser (requires lcov)
genhtml coverage/lcov.info -o coverage/html
open coverage/html/index.html

Coverage reports are automatically generated and uploaded to Codecov on every PR and push to main.

Contributing

Contributions are welcome! Please feel free to submit a Pull Request. For major changes, please open an issue first to discuss what you would like to change.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Additional Information

• Issue Tracker: GitHub Issues
• Documentation: Check the API documentation for detailed information about all available properties and methods
• Changelog: See CHANGELOG.md for version history

Security Considerations

This package provides UI-level protection against copy/paste operations. For sensitive data:

1. Use additional server-side validation
2. Implement proper data encryption
3. Consider using secure storage solutions
4. Be aware that determined users may still find ways to extract data

The package is designed to prevent casual copy/paste operations and improve user experience, but should not be relied upon as the sole security measure for highly sensitive data.