金刚经 · Diamond Sutra (Android)

A native Android reader for the 《金刚般若波罗蜜经》 (Diamond Sutra, Kumārajīva translation), built with Jetpack Compose and Material 3. It presents the complete scripture across all 32 chapters (分) with chapter-by-chapter and full-text reading, Mandarin text-to-speech with live highlighting, and an adjustable, comfortable reading experience — fully offline.

This is the Android twin of the iOS 金刚经 app (App Store), mirroring the same feature set in the Tertiary Infotech house style.

Features

• 📖 Complete scripture — all 32 分, from「法会因由分第一」to「应化非真分第三十二」.
• 📜 Two reading modes — per-chapter reader, or a continuous full-text scroll of the whole sutra.
• 🔍 Full-text search — search across all 32 分, with matches highlighted and tap-to-jump to the chapter.
• 🔊 Read-aloud (TTS) — Mandarin recitation via Android's on-device TextToSpeech, with the currently-spoken passage highlighted live, play/pause/stop, and adjustable speed (慢 / 正常 / 快).
• 📿 Recitation counter (持诵) — an interactive tap counter with haptics, daily + lifetime totals, and a configurable daily target (21 / 49 / 108 / 1080).
• 🔖 Bookmarks (收藏) — save chapters for quick return; swipe to remove.
• 📊 Reading progress — per-chapter read tracking with a progress ring and "continue reading".
• ☀️ Verse of the day (每日一偈) — a daily famous line, with an optional daily local-notification reminder.
• 📤 Share — share any chapter's text via the system share sheet.
• 🔠 Adjustable text size — scale the body type up or down; the preference persists.
• 🌙 Light & dark mode — a warm "sutra paper" Material 3 theme (same tokens as the iOS app).
• 📡 Fully offline — all text is bundled in the app; no network, no account, no data collected.
• 💬 Feedback via WhatsApp and an About page (Tertiary Infotech house style).

Screens

The app uses the house-style five-tab bottom navigation:

经文 (Read)	持诵 (Recite)	收藏 (Bookmarks)	反馈 (Feedback)	关于 (About)
Daily verse, progress ring, search, 32-chapter list, 全文 + 设置 in the top bar	Tap counter with daily / lifetime totals + target	Saved chapters, swipe to remove	Title + message → WhatsApp	App info, developer, content source, version

设置 (Settings — font size, speech speed, daily reminder, progress reset) opens from the gear icon on the Read tab.

Tech stack

• Kotlin · Jetpack Compose (Material 3, NavigationBar, Scaffold, edge-to-edge)
• android.speech.tts.TextToSpeech — Mandarin read-aloud with onRangeStart live highlighting
• AlarmManager + BroadcastReceiver — daily 每日一偈 local notification (reboot-safe)
• SharedPreferences — persists bookmarks, progress, recitation counts and preferences
• minSdk 26 (Android 8.0), target/compile SDK 36

Project structure

app/src/main/java/com/tertiaryinfotech/jingangjing/
  MainActivity.kt            # entry point: theme + speech + reminder re-arm
  AppStore.kt                # persisted state: bookmarks, progress, counter, prefs
  model/Models.kt            # SutraChapter / SearchHit / Verse
  data/SutraData.kt          # full text of all 32 分 + search + verse-of-the-day
  speech/SpeechManager.kt    # TextToSpeech wrapper (play/pause/stop + highlight range)
  notify/Reminders.kt        # AlarmManager scheduler + notification + boot receiver
  ui/Theme.kt                # Material 3 theme (iOS color tokens ported)
  ui/RootScreen.kt           # bottom tabs: 经文 / 持诵 / 收藏 / 反馈 / 关于
  ui/HomeScreen.kt           # daily verse, progress ring, search, chapter list
  ui/ChapterDetailScreen.kt  # per-chapter reader (TTS + highlight + font + bookmark + share)
  ui/FullTextScreen.kt       # continuous full-sutra reading
  ui/ReciteScreen.kt         # 持诵 recitation counter
  ui/BookmarksScreen.kt      # 收藏 saved chapters
  ui/SettingsScreen.kt       # 设置 font / speed / daily reminder / progress reset
  ui/FeedbackScreen.kt       # WhatsApp feedback form
  ui/AboutScreen.kt          # app / developer / source / version
screenshots/                 # emulator screenshots
play-assets/                 # Play Store listing assets (icon, feature graphic, screenshots)
CHANGELOG.md                 # release notes (source of Play "What's new")

Building

Requires JDK 17+ (Android Studio's bundled JBR works) and the Android SDK.

./gradlew assembleDebug          # debug APK
./gradlew bundleRelease          # signed AAB (needs keystore.properties, not checked in)

Release signing reads keystore.properties at the repo root:

RELEASE_STORE_FILE=jingangjing-upload-keystore.jks
RELEASE_STORE_PASSWORD=...
RELEASE_KEY_ALIAS=jingangjing
RELEASE_KEY_PASSWORD=...

The keystore and keystore.properties are git-ignored — keep them backed up privately.

Acknowledgements

• Scripture: 《金刚般若波罗蜜经》, 姚秦三藏法师 鸠摩罗什 译 (public domain).
• Developed by Tertiary Infotech Academy Pte Ltd — tertiaryinfotech.com

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一切有为法，如梦幻泡影，如露亦如电，应作如是观。