SimpleNote - Android Note-Taking App

A modern, user-friendly note-taking application for Android with secure user authentication and intuitive design. This android application was created for Mobile Development course in Sharif University of Technology. Figma design: https://www.figma.com/design/qTmbl7cAJiUBxypcbrI4ON/Note-Taking-App-UI---Design-System?node-id=1945-2807&p=f&t=rPBSHCpb6D8MuNYz-0

📱 Features

🔐 User Authentication

• User Registration: Create new accounts with email and password
• Secure Login: Authentication with encrypted password storage
• Password Management: Change password functionality with validation
• User Isolation: Each user can only access their own notes

📝 Note Management

• Create Notes: Add new notes with title and content
• Edit Notes: Modify existing notes with real-time saving
• Delete Notes: Remove notes with confirmation dialog
• Search Notes: Real-time search through note titles and content
• Grid Layout: Beautiful 2-column card-based note display

🎨 User Interface

• Modern Design: Clean, intuitive interface with card-based layout
• Search Functionality: Instant search with 300ms debounce
• Empty State: Helpful illustrations when no notes exist
• Responsive Layout: Optimized for different screen sizes
• Bottom Navigation: Easy access to home and settings

🔒 Security Features

• Encrypted Storage: User credentials stored securely
• User-Specific Data: Complete data isolation between users
• Secure Database: All operations filtered by authenticated user

🛠️ Technical Stack

Architecture

• Language: Kotlin
• Architecture Pattern: MVVM with Repository Pattern
• Database: Room (SQLite)
• UI: Android View System with Data Binding
• Navigation: Android Navigation Component

Dependencies

• Room Database: Local data persistence
• Coroutines: Asynchronous programming
• Navigation Component: Fragment navigation
• Material Design: Modern UI components
• Encrypted SharedPreferences: Secure credential storage

📦 Project Structure

app/src/main/
├── java/com/example/simplenote/
│   ├── activities/
│   │   ├── LoginActivity.kt
│   │   ├── RegisterActivity.kt
│   │   ├── MainActivity.kt
│   │   └── OnboardingActivity.kt
│   ├── fragments/
│   │   ├── FirstFragment.kt (Main Notes List)
│   │   ├── NoteEditorFragment.kt
│   │   ├── SettingsFragment.kt
│   │   └── ChangePasswordFragment.kt
│   ├── database/
│   │   ├── AppDatabase.kt
│   │   ├── Note.kt (Entity)
│   │   ├── NoteDao.kt
│   │   └── NoteRepository.kt
│   ├── adapters/
│   │   └── NoteAdapter.kt
│   └── utils/
│       ├── UserManager.kt
│       └── UiUtils.kt
└── res/
    ├── layout/ (All UI layouts)
    ├── drawable/ (Icons and graphics)
    ├── values/ (Colors, strings, themes)
    └── navigation/ (Navigation graph)

🚀 Getting Started

Prerequisites

• Android Studio Arctic Fox or later
• Android SDK 21 or higher
• Kotlin 1.5.0 or later

Installation

1. Clone the repository

git clone https://github.com/yourusername/SimpleNote.git

2. Open the project in Android Studio

3. Sync the project with Gradle files

4. Run the app on an emulator or physical device

Building the Project

./gradlew assembleDebug

Running Tests

./gradlew test

🗄️ Database Schema

Notes Table

CREATE TABLE notes (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    title TEXT NOT NULL,
    content TEXT NOT NULL,
    lastEdited INTEGER NOT NULL,
    username TEXT NOT NULL
);

Database Migrations

• Version 1 → 2: Added user authentication
• Version 2 → 3: Added username column to notes for user isolation

🎯 Key Features Implementation

User Authentication Flow

1. Onboarding: Welcome screen with app introduction
2. Registration: Create account with email/password validation
3. Login: Secure authentication with encrypted storage
4. Session Management: Persistent login state

Note Management Flow

1. List View: Grid display of user's notes with search
2. Create/Edit: Rich text editor with auto-save
3. Delete: Confirmation dialog before deletion
4. Search: Real-time filtering of notes

Security Implementation

• Password Encryption: Secure hashing for user passwords
• Data Isolation: Database queries filtered by username
• Secure Storage: EncryptedSharedPreferences for sensitive data

🎨 UI/UX Features

Design Elements

• Color Scheme: Purple primary (#5B45FE) with clean backgrounds
• Typography: Modern, readable fonts with proper hierarchy
• Icons: Consistent iconography throughout the app
• Animations: Smooth transitions and interactions

User Experience

• Intuitive Navigation: Bottom navigation with clear labels
• Search Experience: Instant results with debounced input
• Empty States: Helpful guidance when no content exists
• Confirmation Dialogs: Prevent accidental data loss

📱 Screenshots

Main Features

• Note List: Grid view with search functionality
• Note Editor: Clean editing interface with auto-save
• Settings: User preferences and account management
• Authentication: Login and registration screens

🔧 Configuration

Database Configuration

• Database Name: note_database
• Version: 3
• Migration Strategy: Automatic with fallback

Security Configuration

• Encryption: AES-256 for SharedPreferences
• Key Management: Android Keystore integration
• Session Timeout: Configurable in UserManager