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Access to Bukuloka digital library: textbooks, scientific references, and monographs
Flexible subscription system — per book, per day, or bundled packages
Advanced PDF annotation system with highlights, underlines, free-hand drawing, and sticky notes
Encrypted DRM protection with screenshot and screen recording prevention
Offline-first architecture with Room database and background download using WorkManager
Comprehensive reading experience with bookmarks, progress tracking, and chapter navigation
Subscription management with duration-based access control and bundle support
Students and lecturers in Indonesia face challenges accessing academic books: physical books are expensive, availability is limited in stores, and campus libraries often run out of stock for popular references.
Existing e-book platforms mostly focus on fiction/popular books, while the demand for textbooks, scientific references, and monographs continues to grow among academics.
Publishers also struggle with piracy concerns, while readers need professional annotation tools for academic study — highlights for key concepts, notes for citations, and offline access for studying anywhere.
Built Bukuloka Reader for Android as the flagship app for Indonesia's academic digital library platform. The app provides access to thousands of textbooks and references with flexible subscription pricing (per book, per day, or bundled packages) — far more affordable than physical books.
Implemented professional-grade reading features: complete annotation system (4 types with customizable colors), encrypted DRM protection for publisher security, offline-first architecture with Room database, and background downloads via WorkManager for seamless content access.
Technical obstacles encountered during development and the architectural decisions made to overcome them.
Real-time PDF annotation with gesture-based creation across different screen sizes
Implemented normalized coordinate system (0.0-1.0) for annotations, ensuring consistency across devices. Built draggable floating tool panel with 4 annotation types (highlight, underline, drawing, sticky notes), each supporting multiple colors and real-time preview during creation.
Secure PDF storage with content protection against piracy
Implemented encrypted DRM protection where e-books are secured immediately after download. Content is stored in protected internal storage and decrypted only in-memory during reading, ensuring files are never exposed in plaintext form.
Preventing screen capture and recording of protected content
Applied secure window flags to prevent screenshots and screen recording while reading e-books, similar to streaming apps like Netflix. This ensures content cannot be captured through screen recording apps or system screenshots.
Background download queue with progress tracking and retry mechanism
Built WorkManager-based download system with foreground service notifications showing real-time progress. Implemented automatic retry with exponential backoff (up to 3 attempts), queue management for concurrent downloads, and DRM protection applied before marking complete.
Offline-first architecture with cross-device sync for reading progress
Created dual-layer data persistence: Room database for local offline access, synced with remote server for reading history and annotations. Implemented conflict resolution for bookmarks/annotations when syncing across multiple devices.
Token management for long-lived sessions without security compromise
Built JWT-based authentication with refresh token mechanism stored in EncryptedSharedPreferences. Automatic token refresh occurs transparently before expiration, enabling 30-day sessions while maintaining security through short-lived access tokens.
Duration-based access control for time-limited subscriptions
Implemented access validation system that checks subscription status and expiration dates at book open. Built countdown UI for active subscriptions, automatic access revocation upon expiry, and renewal flow for expired bundles - all synchronized with backend.
The application follows clean architecture principles with clear separation between UI, domain logic, and data layers. Kotlin Coroutines handle asynchronous operations, while Room Database provides offline-first capability. PDF rendering uses Android native PDF renderer with custom annotation overlay system.
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