Android application developed in Kotlin for the Mobile Application Development course – Faculty of Letters and Sciences, Informatics Specialization, UPG Ploiești.
This project implements a robust mobile solution featuring Fragments, SQLite persistence, HTTP communication, email integration, and a dedicated logging system.
- Decimal / Hexadecimal Calculator.
- Custom Virtual Keyboard with digits '0-F'.
- Mathematical Operations:
- ➕ Addition
- ➖ Subtraction
- ✖️ Multiplication
- Automatic Conversion between Base 10 and Base 16.
- Selectable Calculation History.
- Email Integration for exporting history.
- Remote Server Communication via HTTP/HTTPS.
- Internet Connection Logs.
- Local Data Persistence using SQLite.
The application is modularized using Fragments, providing a smooth user experience:
| Fragment | Description |
|---|---|
| Calcul | Keyboard interface, math operations, and base conversion logic |
| Istoric | Calculation history management (ListView + SQLite) |
| Feature for sending the calculation history via email | |
| Log | Displaying the internet connection logs |
Navigation between screens is handled via ViewPager2.
The application uses a local database to ensure data persistence across sessions.
calcul
operatie,operand1,operand2,bazanumeratie,rezultat,dataora
istoric
linie,culoare
emailuri
adresa_email
💡 Note: Upon startup, the history is automatically loaded from the database. To improve readability, entries are color-coded: Base 10 values are displayed in green, while Base 16 values appear in pink.
When the '=' button is pressed, the app sends an HTTPS request in the following format:
user_numberBase_operand1_operator_operand2
The result received from the server is displayed side-by-side with the locally calculated result for verification.
The application tracks significant events to facilitate debugging and monitoring:
- Server connection (Success/Error)
- Message sent
- Response received
- Network errors
- Disconnection
Log Specifications:
- Saved as a text file in Internal Storage.
- Read and parsed during application startup.
- Displayed within the Log fragment.
- The complete history can be shared via email.
- Implemented using Explicit Intents.
- Recipient email addresses are stored in the emailuri table.
- The email field provides Auto-suggestions based on previously used addresses.
- Contextual UI: Buttons 'A-F' are automatically disabled when in Base 10 mode.
- Real-time Conversion: Values convert automatically when switching between bases.
- Visual Distinction:
- Base 10 -> Green
- Base 16 -> Pink
- Smart Scrolling: The history automatically scrolls to the most recent values.
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Full technical documentation regarding the implementation details can be found in the docs folder.
- Language: Kotlin
- UI Components: Android Fragment, ViewPager2
- Database: SQLite
- Networking: HTTPS (Volley library)
- Inter-app Comm: Explicit Intent (Email)
- Storage: Internal Storage (File I/O)