OpenSwift

A modern, lightweight Android keyboard inspired by SwiftKey. Features glide typing, intelligent word prediction, theme customization, and clipboard management.

Features

• Glide Typing — Swipe continuously across keys for fast text entry; path-aware word decoding using Damerau-Levenshtein distance
• Animated Feedback — Ripple effect on key tap, gradient fade on glide trail (v0.2+)
• Suggestion Pills — Rounded pill-shaped suggestions with preview text (v0.2+)
• Word Prediction — Context-aware next-word suggestions with bigram learning; fuzzy matching + frequency weighting
• Auto-Correct — Edit-distance-based error recovery with adaptive edit budget (handles transpositions like "teh" → "the")
• Multi-Layout — QWERTY, QWERTZ, AZERTY with long-press accent popups (á, à, â, ä, etc.)
• 10 Themes — AMOLED Black, Catppuccin Mocha, GitHub Dark, Swift Dark, Material Light, Pixel, Nord, Dracula, Tokyo Night, High Contrast WCAG AAA (dark-first default)
• Custom Themes — Create and edit themes with full color customization
• Emoji Grid — 60 tappable emoji (expandable in v0.4+)
• Clipboard Manager — Swipeable history of 25 recent items with delete-on-swipe
• Snippets/Text Expansion — Create custom trigger→expansion pairs for instant text insertion
• Learning Dictionary — Persistent per-word frequency tracking and bigram learning (local-only)
• Voice Input — Speech recognition with partial result streaming (v0.2+)
• Number Row — Dedicated digit row for quick number entry (v0.2+)
• Usage Analytics — Local-only keystroke, word, and correction tracking (no data leaves device)
• Accessibility — Full TalkBack support, key announcements, navigation support, reduced motion mode (v0.3+)
• Privacy Dashboard — View clipboard history, dictionary stats, and delete all data (v0.3+)
• Per-App Settings — Customize behavior per application (disable glide in games, adjust key height for email, etc.)
• Haptic & Sound Feedback — Customizable vibration (20ms default) and optional audio cues

Architecture

• OpenSwiftIME — Main InputMethodService; coordinates layout, prediction, and input flow
• KeyboardView — Custom View rendering keys, suggestions, and glide trail detection
• Predictor — Scoring engine for next-word and auto-correct suggestions
• GlideDecoder — Polyline-to-word decoding using anchored key subsequence matching
• WordList + UserDictionary — Frequency-based word store + per-user bigram learning
• Settings + ClipboardHistory — Persistent user preferences and clipboard state
• Themes + Layouts — 6 built-in themes and 3 keyboard layouts

Building

./gradlew assembleRelease

Output: app/build/outputs/apk/release/app-release.apk

Installation

1. Download the APK from Releases
2. Enable installation from unknown sources (Settings > Security)
3. Install the APK
4. Go to Settings > Languages & input > On-screen keyboard > Manage on-screen keyboards
5. Enable OpenSwift
6. Set OpenSwift as default input method
7. Open any text field and start typing!

See SETUP.md for detailed setup, first-use tips, and troubleshooting.

Documentation

• SETUP.md — Installation, first use, common tasks, troubleshooting
• GUIDE.md — Power-user reference (glide tips, snippets, custom themes, accents)
• CONTRIBUTING.md — For developers (dev setup, architecture, contributing features)
• ROADMAP.md — Planned features (v0.2–v1.0) and future ideas
• EXAMPLES.md — Snippet packs, theme palettes, per-app configs, accessibility setup

Settings

• Theme — 6 built-in themes + custom theme editor
• Keyboard Layout — QWERTY, QWERTZ, AZERTY
• Glide Typing — Enable/disable swipe-to-type
• Auto-Correct — Toggle fuzzy correction
• Auto-Capitalize — Auto-capitalize after punctuation
• Haptic Feedback — Vibration on keypress (20ms default)
• Sound Feedback — Optional audio cues
• Key Height — Adjust keyboard size (48–72 dp)

How It Works

Glide Typing

1. User swipes across keys; samples collected at each keypress
2. Anchor keys identified at gesture turning points
3. Dictionary words scored by:
   • Starting key match (required)
   • Ending key match (required)
   • Subsequence coverage (all anchors present in order)
   • Word frequency + user history bonus
4. Top result committed

Word Prediction

For the current incomplete word:

• Prefix match wins (if word starts with typed prefix)
• Fuzzy match (Damerau-Levenshtein ≤ edit budget)
• Frequency weighting: log10(frequency + user-count + 1)
• Bigram boost: +1.5× if word likely follows previous word (user learns)

Auto-Correct

Applied on space/enter:

• If word length ≥ 3 and not in dictionary, find closest match
• Bounded edit distance; frequency-weighted
• Learns user's correction pattern

Performance

• Dictionary: 3500+ common English words in raw resource
• Prediction: O(n) scan with early exit (edit distance budget)
• Glide decoding: O(m·n) (m anchors, n dictionary words)
• Memory: ~8 MB (word list + user dictionary)

Tech Stack

• Language: Kotlin
• UI: Custom View (KeyboardView) + Jetpack Compose (Settings)
• Persistence: SharedPreferences (settings, clipboard, user dictionary)
• Dictionary: 3500-word frequency-weighted English word list
• Targeting: minSdk 26 (Android 8), targetSdk 35
• Build System: Gradle 8+, ProGuard minification (R8)

Privacy & Security

• Zero cloud dependency — No network requests, no account required
• Local-only — All data stored in app's private SharedPreferences
• Open source — MIT licensed; code is auditable
• No telemetry — No analytics, no crash reporting, no ads
• Device learns — User bigrams and word frequencies stay on-device
• Clipboard history — Cleared on uninstall

Roadmap

See ROADMAP.md for detailed v0.2, v0.3, v0.4, v1.0 milestones.

v0.2 (Next): UI polish (ripple effects, animated suggestions), clipboard panel, number row toggle, onboarding wizard

v0.3: Multilingual support (German, French, Spanish), advanced input methods, language detection

v0.4: Cloud sync (optional), plugin system, custom input engines

v1.0: Stable release, performance optimization, expanded emoji pack

Contributing

OpenSwift is open to community contributions. See CONTRIBUTING.md for:

• Development setup
• Code style guidelines
• How to add new features (example: adding a Dvorak layout)
• Pull request workflow

Ideas for contributions:

• New keyboard layouts (Dvorak, Colemak, Bépo, etc.)
• Language packs (German, French, Spanish word lists)
• Additional themes
• Accessibility improvements
• Performance optimizations

License

MIT — see LICENSE