APE-4296 | Android webview test app

[embashgit]

Token.io Android WebView SDK Demo Application

📋 Overview

This PR introduces a comprehensive Android demo application showcasing the Token.io WebView SDK
integration for secure payment processing. The application demonstrates best practices for payment
flow handling with robust WebView implementation and multi-regional support.

✨ Key Features

🌐 WebView Payment Integration

• Secure WebView Implementation: Custom UnifiedWebViewClient for handling payment redirects
• Dual Callback Support: Handles payment callbacks from both in-app WebView and external
  browsers
• Payment Flow Activities:
  • PaymentWebViewActivity - Main payment interface
  • PaymentResultActivity - Payment outcome display
  • WebViewActivity - General web content handling

🇫🇷 France Market Support

• Locale-aware Amount Formatting: Prevents locale-specific decimal separator issues (e.g.,
  French comma vs English decimal point)
• Multi-currency Support: EUR and GBP payment processing
• Localized Payment Experience: Proper handling of French banking redirects and callbacks

🛡️ Security & Configuration

• API Key Management: Secure BuildConfig integration with placeholder system
• Environment Configuration: Beta environment setup with configurable endpoints
• Deep Link Security: Proper intent filter configuration for payment callbacks

🏗️ Technical Implementation

Core Components

• PaymentSdk: Main SDK interface with simplified integration API
• PaymentRepository: Network layer for payment operations using Retrofit + Moshi
• Constants: Environment and configuration management
• Data Models: Type-safe payment request/response handling

WebView Architecture

Unified callback handling for all payment scenarios:
UnifiedWebViewClient -> PaymentWebViewActivity -> PaymentResultActivity
↓
External Browser Redirect -> MainActivity (Deep Link) -> PaymentResultActivity

Payment Flow

1. Initiation: Create PaymentRequest with creditor details and amount
2. WebView Launch: Secure payment interface with bank redirect handling
3. Callback Processing: Unified handling regardless of redirect method
4. Result Display: Clear payment outcome with appropriate messaging

🔧 Configuration

Manifest Setup

• Deep link configuration for paymentdemoapp://payment-complete
• Activity declarations with proper launch modes
• Intent filter on MainActivity for external callback handling

Build Configuration

• KSP for Moshi code generation
• Firebase integration for analytics and user onboarding
• Comprehensive dependency management

📱 User Experience

• Intuitive Interface: Clean material design with form validation
• Error Handling: Comprehensive error states and user feedback
• Loading States: Progress indicators during payment processing
• Accessibility: Proper content descriptions and navigation

🔄 Git Repository Cleanup

• Comprehensive .gitignore: Excludes build artifacts, IDE files, and APK outputs
• Security: API keys replaced with placeholders for safe version control
• Clean History: Removed accidentally committed build files and IDE configurations

🌍 Market Readiness

This implementation is production-ready for:

• UK Market: Faster Payments integration
• French Market: SEPA payment support with proper locale handling
• Multi-currency: GBP and EUR support with accurate formatting

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🔗 Related Issues: APE-4296
📊 Testing: Manual testing completed for both WebView and browser redirect scenarios
🎯 Target: UK and EU including France market deployment with WebView payment integration