Architecture

Architecture

ToneForge uses a modular architecture with native C++ audio processing and Java UI components.

Main Components

┌─────────────────┐    ┌─────────────────┐    ┌─────────────────┐
│   AudioRecord   │───▶│  Audio Engine   │───▶│   AudioTrack    │
│   (Input)       │    │   (C++/JNI)     │    │   (Output)      │
└─────────────────┘    └─────────────────┘    └─────────────────┘

Audio Processing Pipeline

1. Capture: AudioRecord captures audio from microphone
2. Processing: Buffer sent to audio_engine.cpp via JNI
3. Effects: Sequential application according to configured order
4. Playback: AudioTrack plays processed audio

File Structure

app/src/main/
├── cpp/
│   ├── audio_engine.h      # Audio engine header
│   ├── audio_engine.cpp    # Effect implementations
│   ├── native-lib.cpp      # JNI methods
│   └── CMakeLists.txt      # Build configuration
├── java/
│   └── com/thiagofernendorech/toneforge/
│       ├── MainActivity.java              # Main interface and navigation
│       ├── AudioEngine.java               # Real-time audio pipeline
│       ├── EffectsFragment.java           # Effects interface and presets
│       ├── EffectOrderAdapter.java        # Effect order adapter
│       ├── HomeFragment.java              # Home screen
│       ├── TunerFragment.java             # Real-time tuner
│       ├── MetronomeFragment.java         # Metronome
│       ├── LooperFragment.java            # Loop recorder
│       ├── RecorderFragment.java          # Audio recorder
│       ├── LearningFragment.java          # Learning screen
│       ├── SettingsFragment.java          # Settings
│       ├── AudioBackgroundService.java    # Background audio service
│       ├── AudioStateManager.java         # Effect state management
│       ├── PipelineManager.java           # Audio pipeline management
│       ├── PermissionManager.java         # Permission management
│       ├── StateRecoveryManager.java      # State recovery
│       ├── PresetManager.java             # Preset management
│       ├── FavoritesManager.java          # Favorites management
│       ├── TooltipManager.java            # Tooltip management
│       └── FavoritePresetAdapter.java     # Favorite presets adapter
├── res/
│   ├── layout/
│   │   ├── activity_main.xml      # Main layout
│   │   ├── fragment_effects.xml   # Effects interface
│   │   ├── fragment_home.xml      # Home screen
│   │   ├── fragment_tuner.xml     # Tuner
│   │   ├── fragment_metronome.xml # Metronome
│   │   ├── fragment_looper.xml    # Looper
│   │   ├── fragment_recorder.xml  # Recorder
│   │   ├── fragment_learning.xml  # Learning
│   │   └── fragment_settings.xml  # Settings
│   ├── drawable/
│   │   ├── ic_*.xml               # Interface icons
│   │   ├── bg_gradient.xml        # Background gradient
│   │   ├── button_background.xml  # Button styles
│   │   └── round_button.xml       # Rounded buttons
│   ├── navigation/
│   │   └── nav_graph.xml          # Screen navigation
│   ├── anim/
│   │   ├── slide_in_*.xml         # Entry animations
│   │   └── slide_out_*.xml        # Exit animations
│   ├── values/
│   │   ├── colors.xml             # Theme colors
│   │   ├── strings.xml            # Localized strings
│   │   ├── arrays.xml             # Arrays (distortion types)
│   │   └── themes.xml             # App themes
│   ├── values-night/
│   │   └── themes.xml             # Dark theme
│   ├── mipmap-*/                  # App icons (different densities)
│   └── xml/
│       ├── backup_rules.xml       # Backup rules
│       └── data_extraction_rules.xml # Data extraction rules
└── AndroidManifest.xml            # App configuration

Technologies Used

• Gradle: Build system
• CMake: Native code build
• JNI: Java-C++ interface
• AudioRecord/AudioTrack: Android audio API
• Fragments: Multi-screen navigation
• RecyclerView: Drag-and-drop interface
• SharedPreferences: Data persistence

Background Processing

Continuous Audio

• ForegroundService: Keeps audio processing active with screen off
• Persistent notification: Shows audio status and quick controls
• Activation control: Switch in settings to enable/disable
• Pipeline management: Automatic recovery from errors

State Recovery

• Automatic saving: State saved when app goes to background
• Smart restoration: Settings restored when returning
• Recovery of: Pipeline, presets, oversampling, active effects
• Synchronization: Interface updated with real state

Permission System

• Required permissions: Microphone, notifications, storage
• Optional permissions: Overlay, battery optimization
• Automatic verification: Permission requests on startup
• Compatibility: Support for different Android versions

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See Development for setup and build instructions.