Unofficial Onyx SDK Docs

GitHub: https://github.com/progressive-kiwi/onyx-inking-unofficial-docs

Warning

AI-Generated Documentation

This documentation was produced by an AI assistant (Claude). Knowledge was acquired from four sources: (1) decompiling the SDK AARs with javap to extract public method signatures; (2) five debug session logs recording every attempted fix for the blink/gesture-lock problem on a real Boox NoteMax; (3) the official OnyxAndroidDemo repository and its bundled Markdown docs; and (4) open-source apps that ship Onyx SDK integrations (notable, PngNote).

Method descriptions that could not be verified against source or Javadoc are individually marked [AI Generated]. Treat all unmarked content as best-effort reverse-engineering, not official Onyx documentation.

Unofficial Onyx SDK Docs

Low-latency stylus input for Onyx BOOX e-ink Android devices, using the onyxsdk-pen TouchHelper API to bypass the standard MotionEvent stack and draw directly through the device’s Wacom I2C digitizer at sub-20 ms latency.

Inking

• Getting Started
  • Prerequisites
  • Step 1 — Add the Boox Maven repository
  • Step 2 — Add SDK dependencies
  • Step 3 — Initialise the hidden-API bypass
  • Step 4 — Create an ink overlay view
  • Step 5 — Connect activity lifecycle
  • Step 6 — Verify with logcat
• Architecture
  • Overview
  • Key components
  • Coordinate system
  • Dual-rendering model
  • Gesture interaction
  • Module dependency graph
  • System app vs user app
• SDK Setup
  • Maven repositories
  • Dependencies
  • Available SDK versions
  • Hidden-API bypass
  • JNI libraries
  • Checking what is in the APK
• TouchHelper API
  • Lifecycle state machine
  • Creating the helper
  • Setting the active region
  • Opening and enabling
  • Handling view size changes
  • Activity lifecycle integration
  • Cleanup
  • Implementing RawInputCallback
  • TouchPointList
  • Handling the Any? type wrapper
  • Pen shape classes
  • MultiViewTouchHelper
• EPD Rendering
  • EPD waveform basics
  • How the SDK uses waveforms
  • EpdController API
  • Rendering strategy choices
  • Ghosting and the GC refresh
  • Syncthing / build cache interference
• Troubleshooting
  • MotionEvent fallback instead of TouchHelper
  • SDK classes not bundled (compileOnly mistake)
  • Transitive dependency resolution failure
  • DeviceFeatureUtil not found
  • Empty region / no pen events
  • EpdController class poisoning by diagnostic code
  • TouchHelper created before view is laid out
  • setLimitRect with view-local instead of screen-absolute coordinates
  • Pen events not firing after SDK init (missing enable call)
  • System gestures broken after inking
  • Pen panning the page instead of drawing
  • Application disabled by Boox power management
  • TouchPoint import changes across SDK versions
  • FreeReflection / hiddenapibypass bootstrap failure log
  • Duplicate class from Syncthing / file sync
  • Logcat diagnostic reference
• Sample Implementations
  • OnyxAndroidDemo
  • PngNote
  • notable

API Reference

• Overview
• onyxsdk-pen
• onyxsdk-base
• onyxsdk-device

At a glance

Target device	Onyx BOOX (NoteMax, Max 3, …)
Android API	33+ (Android 13)
SDK version (current)	onyxsdk-pen:1.4.12
Maven repository	https://repo.boox.com/repository/maven-public/
Digitizer	Wacom I2C (/dev/input/eventX)
Drawing waveform	A2 (fast, hardware-accelerated)

Note

The Onyx SDK classes are not provided by the OS classpath. They must be bundled inside your APK. See SDK Setup for the correct Gradle configuration.