[GSoC 2025 Antonio Giordano] Single + Multi-track Genre Editing & Autocompletion (Test)

[sdv0001]

Implement Multi-track Genre Editing and Autocompletion in Track Info Dialog (Test)

📋 Process Documentation: For detailed development process, discussion, and implementation decisions, see the complete development tracking in GSoC 2025 Antonio Giordano.

Overview

This PR Test introduces comprehensive multi-track genre editing functionality to Mixxx's Track Info dialog, enabling users to efficiently manage genres across multiple selected tracks simultaneously. The implementation extends the existing single-track infrastructure while maintaining full backward compatibility and follows established UI patterns.

This represents the complete, production-ready implementation consolidating all development iterations, fixes, and optimizations into a single cohesive feature set.

✨ Features

Core Multi-track Functionality

• Common Genre Display: Shows only genres present in ALL selected tracks (intersection strategy)
• Bulk Genre Operations: Add or remove genres across all selected tracks simultaneously
• Smart Genre Preservation: Maintains track-specific genres while only modifying common ones
• Real-time UI Updates: Immediate visual feedback during genre editing operations

Enhanced User Experience

• Intuitive Interface: Familiar single-track UI seamlessly extended to multi-track scenarios
• Tag-based Genre Management: Visual genre tags with individual remove buttons
• Genre Autocompletion: Smart suggestions from existing genre database
• Drag & Drop Support: Reorder genres within the widget interface

🔧 Technical Implementation

Modified Components

WGenreTagInput Widget Enhancement

• Multi-track Mode: New operating mode specifically designed for bulk operations
• Configurable Auto-save: Selective automatic saving behavior for different contexts
• Manual Completer Setup: Genre autocompletion without requiring TrackCollection binding
• Enhanced State Management: Proper handling of single vs. multi-track scenarios

Dialog Integration

• DlgTrackInfoMulti: Complete integration of genre widget into multi-track workflow
• Intersection-based Loading: Displays only genres common to all selected tracks
• Smart Saving Strategy: Preserves track-specific genres while applying common changes
• Database Synchronization: Ensures consistency between DAO and track record data

Menu Integration

• WTrackMenu: Proper TrackCollection initialization for multi-track dialogs

Key Technical Decisions

Genre Loading Strategy (Intersection)

Track 1: [Dance;Pop, Jazz]
Track 2: [Pop, Jazz]
→ Widget displays: [Pop] (common genres only)

Genre Saving Strategy (Smart Preservation)

User adds "Electronic" to widget:
Track 1: [Dance, Rock, Pop, Electronic] (preserves Dance, Rock)
Track 2: [Jazz, Pop, Electronic] (preserves Jazz)
User removes "Pop" from widget:
Track 1: [Dance, Rock, Electronic]
Track 2: [Jazz, Electronic]

🏗️ Architecture

Database Layer

• Full integration with existing GenreDao for persistent storage
• Batch operations for improved performance with multiple tracks
• Automatic synchronization between database and UI state
• Fallback mechanisms for tracks with missing DAO entries

UI Layer

• Seamless integration with existing track selection workflow
• Consistent styling and behavior patterns across single/multi-track modes
• Proper Qt signal/slot connectivity for real-time updates
• Event filtering and focus management for optimal user experience

Data Integrity

• Comprehensive synchronization between GenreDao and TrackRecord systems
• Safe handling of concurrent track modifications
• Proper transaction handling for bulk database operations

🧪 Validation

Functionality Testing

• ✅ Single track editing remains unchanged
• ✅ Multi-track common genre detection works correctly
• ✅ Genre addition/removal operates on correct tracks
• ✅ Database consistency maintained across operations
• ✅ UI state properly synchronized with data changes

Edge Case Handling

• ✅ Empty genre lists handled gracefully
• ✅ Tracks with no common genres display correctly
• ✅ Database synchronization failures handled safely
• ✅ Concurrent track modifications managed properly

📋 Usage

1. Select Multiple Tracks: Choose 2+ tracks in the library view
2. Open Properties: Right-click → "Properties" or press Enter
3. Edit Common Genres: View/modify genres present in all selected tracks
4. Apply Changes: Click "Apply" or "OK" to save changes to all tracks
5. Preserve Individual Genres: Track-specific genres remain untouched