Sleep O'Clock is a minimalist bedside mobile application built in Flutter, engineered to simultaneously solve two key nocturnal challenges: adult sleep hygiene (minimizing blue light disruption to the circadian rhythm) and toddler sleep training (a zero-text visual trainer for preschoolers), featuring advanced hardware-aware protections for modern displays.

Software Architecture & Engineering

• Clean Architecture + DDD: Layered architecture strictly decoupling domain entities, use cases (CheckWakeUpConditionUseCase), data sources, and presentation. The clock core feature manages its own isolated dependency injection container (clock_injection_container.dart via get_it), ensuring low coupling and high testability.
• Reactive State Management (BLoC): Powered by flutter_bloc with immutable events for atomic mode switching (Adult/Child, Day/Night, Red Mode), brightness levels, and precision timer triggers.
• Functional Error Handling: Rigorous functional approach with dartz (Either<Failure, T>), ensuring uninterrupted stability throughout the night with zero silent crashes.
• Declarative Routing: Configured with go_router for clean transitions and deep-linking readiness.

Hardware-Aware UX Challenges & Innovation

Unlike generic clock apps, Sleep O'Clock was architected around the physical constraints of smartphone displays and human circadian biology:

• Intelligent Anti Burn-in Protection (OLED/AMOLED): Keeping displays illuminated overnight with static elements causes irreversible pixel degradation (burn-in). I engineered an imperceptible pixel-shift mechanism via AnimatedAlign that smoothly shifts display coordinates every minute, evenly distributing diode wear without distracting the sleeping user.
• Red Mode (Melatonin Preservation): Instantly toggled via a double-tap gesture, the app suppresses blue and green wavelengths, switching to a soothing deep red spectrum that avoids suppressing melatonin secretion.
• Toddler Sleep Trainer (Zero-Text UX): For children aged 2 to 5 who cannot yet read digital clocks, the app functions as a visual circadian guide. It presents a gentle nocturnal theme (dark sky, pulsing moon and stars) and transitions smoothly at the scheduled hour into a daytime state (radiant sun and clouds), instinctively informing the child when it is time to wake up.
• Intuitive Gestures & Active Wakelock: Drag-to-dim brightness control (5% to 100%), full immersion hiding OS status/navigation bars, and continuous display stability using wakelock_plus.
• Product Telemetry: Anonymous Firebase Analytics integration (com.jhh.solutions.sleep_oclock) monitoring feature adoption and session health.

Status: Continuously evolving product — Epic 1 (Toddler Sleep Routine & Anti Burn-in) delivered and validated by JHH Solutions.