SupernoteReader

A minimal, open-source ebook reader built specifically for the Supernote A6X2 Nomad (and compatible Supernote devices). Designed from the ground up for e-ink — no animations, no cloud, no accounts.

Supports EPUB and PDF. Everything is local.

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Features

Library

• Scans /Document/Books/ automatically on launch
• Cover art extracted from EPUB metadata and PDF first page
• Author name displayed on each card
• Reading progress bar per book
• Sort by title (A–Z), author, or recently read

Reader

• EPUB: full text reflow with 5 font families and adjustable size (14–28 sp)
• EPUB: table of contents navigation — tap ☰ in the bottom bar to jump to any chapter
• PDF: full-page rendering at native resolution
• Per-book dark mode (inverts all colours — text, cover, PDF pages)
• Font and theme changes are live — see the effect behind the settings modal before confirming
• Sidebar buttons (the physical strips on the Nomad) turn pages
• Full-screen e-ink refresh every 8 page turns to clear ghosting

E-ink first

• Zero animations anywhere in the app
• Hard shadows only (no blur)
• Stylus resting on screen does not trigger navigation
• Static loading states — no spinners

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Building

Requirements

• macOS or Linux
• Android Studio installed (provides the JDK and Android SDK)
• A USB-C cable and a Supernote Nomad with sideloading enabled

First-time setup

git clone https://github.com/your-username/SupernoteReader.git
cd SupernoteReader
bash setup.sh

setup.sh downloads two things that are not committed to the repo:

• gradle/wrapper/gradle-wrapper.jar
• Font files into app/src/main/res/font/ (Literata, Merriweather, Lora, Source Serif 4, Atkinson Hyperlegible)

Build

./gradlew assembleDebug
# Output: app/build/outputs/apk/debug/app-debug.apk

If Gradle can't find Java, prefix with the Android Studio JDK path:

JAVA_HOME="/Applications/Android Studio.app/Contents/jbr/Contents/Home" ./gradlew assembleDebug

For a release build:

./gradlew assembleRelease

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Installing on the Nomad

The Nomad runs Chauvet OS (Android 11) with no Google Play Store. Installation is via ADB.

1. Enable sideloading on the Nomad

Settings → Security & Privacy → Sideloading → ON

2. Connect via USB-C

Plug the Nomad into your computer. It will not mount as a storage volume on Mac — that's expected. ADB works regardless.

On first connection, the Nomad may show an "Allow USB debugging?" prompt. Accept it.

3. Verify the connection

adb devices
# Should show something like: 192.168.x.x:5555   device

4. Install

Download SupernoteReader.apk from the latest release, then:

adb install -r SupernoteReader.apk

The -r flag reinstalls over an existing version without losing data.

The Nomad's built-in file manager cannot install APKs directly — ADB is required.

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Adding books

The app creates /Document/Books/ on first launch. This folder is visible in the Supernote file manager under Document → Books.

Via ADB:

adb push book.epub /storage/emulated/0/Document/Books/book.epub
adb push book.pdf  /storage/emulated/0/Document/Books/book.pdf

Via the Supernote web interface or USB transfer: Copy .epub or .pdf files into Document/Books/ using whatever transfer method you use for your Nomad.

Reading progress is keyed by absolute file path. Renaming or moving a file resets its progress.

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Usage

Navigation

• Sidebar buttons — the physical strips on the right edge of the Nomad turn pages (forward / back)
• ← Back in the toolbar returns to the library

Font & theme settings

Tap Font in the top-right of the toolbar. Changes apply live — the book updates behind the modal so you can judge the effect before confirming. Cancel reverts everything. Theme (light/dark) is per-book.

Table of contents (EPUB only)

Tap ☰ on the left side of the bottom bar. The chapter list opens, scrolled to the current chapter. Tap any entry to jump there instantly.

Sort order (library)

Tap the sort label in the top-right of the library header to cycle through:

• A–Z — alphabetical by title
• Author — alphabetical by author, then title
• Recent — books you've read most recently first

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Architecture

Single-activity app. Jetpack Compose + Navigation. Two screens: Gallery → Reader.

com.supernote.reader
├── MainActivity          Entry point; hides system bars; routes sidebar key events
├── AppNavigation         NavHost (gallery ↔ reader/{bookPath})
├── PageTurnRelay         Singleton SharedFlow bridging Activity key events to the reader
├── data/
│   ├── BookItem          Domain model (title, author, cover, progress, lastRead)
│   ├── BookFormat        EPUB | PDF
│   ├── BookRepository    Scans Books/ folder; parallel cover extraction; in-memory cache
│   └── ProgressStore     DataStore: page, total, font, font size, theme, lastRead per book
├── util/
│   ├── EpubParser        ZipFile + Jsoup: single-pass extraction of meta + spine + TOC
│   ├── EpubPaginator     Character-count pagination; font-size aware; per-spine-item tracking
│   └── PdfPaginator      PdfRenderer wrapper
└── ui/
    ├── gallery/
    │   ├── BookGalleryScreen    4-column grid; sort controls; lifecycle-aware refresh
    │   ├── BookGalleryViewModel Parallel scan; sort modes (Alpha, Author, Recent)
    │   └── BookCard             Cover + author + title + progress bar
    └── reader/
        ├── BookReaderScreen     Toolbar + content + TOC/font modals
        ├── BookReaderViewModel  EPUB repagination on font change; TOC resolution; page jumps
        ├── EpubReaderView       Renders text blocks; dark mode colour inversion
        ├── PdfReaderView        Renders PDF page bitmap via Coil; dark mode colour filter
        ├── TocSheet             Chapter list modal; scrolls to current chapter
        └── ReaderOptionsSheet   Font/size/theme picker; live preview; cancel reverts

Key constraints (e-ink device)

• No animations — all transitions are instant state swaps
• No ripple or touch feedback
• Stylus touch events ignored for navigation (pen resting on screen)
• Full-screen white flash every 8 page turns to clear e-ink ghosting
• Hard-offset shadows only (2×3 dp solid, no blur)

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Tech stack

Layer	Library
UI	Jetpack Compose + Material 3
Navigation	Compose Navigation
Persistence	DataStore Preferences
Image loading	Coil 2
EPUB parsing	Jsoup (custom ZIP + OPF/NCX/NAV parser)
PDF rendering	Android PdfRenderer
Fonts	Literata, Merriweather, Lora, Source Serif 4, Atkinson Hyperlegible

• Min SDK / Target SDK: 30 (Android 11)
• Compile SDK: 34
• Kotlin 2.0 / AGP 8.5

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Target device

Supernote A6X2 Nomad

• Chauvet OS (Android 11, no GMS)
• 7.8" E Ink, 1404 × 1872 px @ 300 PPI
• Wacom EMR stylus
• Physical sidebar buttons (ratta-slide input device, key codes 310 / 301)

The app should work on other Android 11+ devices but is not optimised for colour LCD displays.

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License

MIT