ColorDict (open-source clone)

A free, open-source, offline multi-dictionary viewer for Android, inspired by the classic ColorDict app: type a word once and see color-coded results from every enabled dictionary at the same time.

This is an independent re-implementation written from scratch. It is not affiliated with or endorsed by the authors of the original ColorDict application.

Features

• StarDict dictionary support — the de-facto standard free dictionary format:
  • .ifo / .idx / .dict (and gzip-compressed .idx.gz)
  • dictzip .dict.dz files with true random access (no full decompression)
  • .syn synonym files, 32-bit and 64-bit index offsets
  • all common article types: plain text, HTML, XDXF, Pango markup, phonetics, MediaWiki text, WordNet, and typed multi-block articles
• Aggregated, color-coded results — every enabled dictionary answers at once; each result card carries its dictionary's color, and suggestions show a colored dot per dictionary that knows the word
• Fast incremental search with case-insensitive prefix matching, synonym matching, and "similar words" when nothing matches exactly
• Dictionary manager — import via the system file picker (single files or whole folders), enable/disable, reorder priority, recolor, inspect, delete
• History & bookmarks, with configurable history size
• Cross-reference links (bword://) inside articles jump to the linked word
• Text-to-speech pronunciation, clipboard, share, and Wikipedia/Wiktionary/ web search shortcuts
• Third-party lookup API compatible with the well-known ColorDict intent (see below) — e-book readers that support ColorDict popups work out of the box
• Light/dark theme, adjustable definition text size
• Zero dependencies, no ads, no network permission — the app never touches the internet except when you tap a web link
• Ships with a tiny built-in sample glossary so the UI works on first launch

Getting dictionaries

The app reads dictionaries in StarDict format. Many free dictionaries are available on the web (e.g. conversions of FreeDict, Wiktionary, GCIDE, and WordNet). A dictionary is a set of files sharing one base name:

mydict.ifo        metadata (required)
mydict.idx        word index (or mydict.idx.gz)
mydict.dict       articles  (or mydict.dict.dz)
mydict.syn        synonyms  (optional)

Add them in ⋮ → Dictionaries → Import dictionary files… (or Import folder…), or copy the files with adb push to the app's dictionary folder (shown under How to add dictionaries in the app) and tap Rescan storage.

Lookup API for other apps

Any app can request a floating definition popup:

Intent intent = new Intent("colordict.intent.action.SEARCH");
intent.putExtra("EXTRA_QUERY", "hello");
// optional:
intent.putExtra("EXTRA_FULLSCREEN", false);   // true opens the full app
intent.putExtra("EXTRA_WIDTH", widthPx);      // popup geometry
intent.putExtra("EXTRA_HEIGHT", heightPx);
intent.putExtra("EXTRA_GRAVITY", Gravity.BOTTOM);
intent.putExtra("EXTRA_MARGIN_BOTTOM", marginPx);
startActivity(intent);

Selected text in any app also gets a Define entry (Android's process-text menu), and plain text can be shared to the app.

Installing on a phone

Grab the ready-to-install debug APK from the Releases page (or from any CI run's artifacts), allow installing from unknown sources, and open it. Pushing a v* tag builds and publishes a new release automatically.

Trying it on a computer

With Android Studio (the full app)

1. File → Open and select this folder, then let Gradle sync (it downloads the Android Gradle Plugin and SDK pieces on first run).

2. If it asks for an SDK, install Android SDK Platform 35 via Tools → SDK Manager.

3. Create an emulator in Tools → Device Manager (any device image, API 24+), then press Run ▶.

4. To test the popup API that other apps use, run this against the emulator:

   adb shell am start -a colordict.intent.action.SEARCH -e EXTRA_QUERY serene

Hardware acceleration matters: on Linux the emulator needs KVM (ls /dev/kvm), and on Windows/macOS it uses the platform hypervisor. If the emulator will not start, plug in a real phone with USB debugging instead — ./gradlew installDebug puts the app on it.

Without the Android SDK (desktop harness)

run-desktop.sh runs the same StarDict engine and color-coded renderer the app uses, in a small Swing window. It needs nothing but a JDK 17+ — no Android SDK, no Gradle, no emulator — so it is the quickest way to check dictionary parsing and lookups, or to try a dictionary file before copying it to your phone.

./run-desktop.sh                        # window, with the bundled sample glossary
./run-desktop.sh --dict ~/my-dicts      # also load your own dictionaries
./run-desktop.sh --lookup serene        # print one definition in the terminal
./run-desktop.sh --list                 # list the dictionaries that loaded

Windows: use run-desktop.bat with the same options.

Building from the command line

./gradlew assembleDebug     # installable APK at app/build/outputs/apk/debug/
./gradlew test              # StarDict engine unit tests (pure JVM)

Requirements: JDK 17+ and the Android SDK (compileSdk 35). CI builds a ready-to-install debug APK on every push — grab it from the workflow run's artifacts. Release builds are unsigned; sign with your own key to distribute.

Project layout

app/src/main/java/io/github/roviicc/colordict/
  engine/   Pure-Java StarDict engine (no Android imports, unit-tested):
            .ifo/.idx/.syn parsing, StarDict collation + binary search,
            dictzip random access, article parsing, and the color-coded
            definition renderer shared with the desktop harness
  data/     Repository, registry (order/color/enabled), history store, prefs
  ui/       Activities and views (Android framework only, no libraries)
desktop/    Swing harness that runs the engine on a PC with only a JDK
tools/      Python utilities: build/verify StarDict files, generate the
            bundled sample glossary, test fixtures, and launcher icons

Development conveniences:

python3 tools/stardict_make.py words.tsv out/ mydict --bookname "My Dict"
python3 tools/verify_stardict.py out/mydict.ifo --dump 10
python3 tools/gen_fixtures.py     # regenerate test fixtures + sample glossary

License

MIT. The bundled sample glossary was written for this project. "StarDict" refers to the open dictionary file format; all trademarks belong to their respective owners.