## Code Quality Improvements
### Global State Removal
- Eliminated global drag_info dictionary
- Moved drag_state management into TimeTracker class
- Removed all global drag_info dependencies
### Updated Components
- **ClickableCell constructor**: Added time_tracker parameter for proper reference
- **ClickableCell methods**: Updated to use self.time_tracker.drag_info
- **TimeTracker methods**: Updated on_global_drag() and on_global_up()
- **Instance creation**: Updated ClickableCell instantiation calls
### Benefits Achieved
- **Better Encapsulation**: State properly contained within class boundaries
- **Thread Safety**: Reduced race conditions from shared global state
- **Testability**: Individual instance testing now possible
- **Instance Isolation**: Multiple TimeTracker instances work independently
- **Maintainability**: Clearer code structure with explicit dependencies
### Verification
- ✅ All drag functionality preserved (paint/erase operations)
- ✅ Drag state management works correctly
- ✅ Multiple instances properly isolated
- ✅ All 6 existing test suites pass (no regressions)
- ✅ New comprehensive test suite created and passing
- ✅ Application starts and runs correctly
## Files Modified
- **time_tracker.py**: Global state removal and class attribute implementation
- **AGENTS.md**: Updated coding guidelines for class preferences
- **TODO.md**: Marked drag_info task as completed, updated progress
- **tests/test_drag_info_class_attribute.py**: New comprehensive test suite
## Testing
- Added complete test suite for drag_info functionality
- Tests verify global state removal and class attribute access
- Confirms multiple instance isolation
- Validates drag state management
Code quality significantly improved with zero functional regressions.
