https://github.com/timbortnik/widget
Open-source Android weather widget — home-screen meteogram with 48-hour and 7-day forecasts. No ads, no tracking, no account. Powered by Open-Meteo
https://github.com/timbortnik/widget
android android-widget flutter forecast home-widget kotlin material-you meteogram no-tracking open-meteo open-source privacy weather weather-app weather-widget
Last synced: 12 days ago
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Open-source Android weather widget — home-screen meteogram with 48-hour and 7-day forecasts. No ads, no tracking, no account. Powered by Open-Meteo
- Host: GitHub
- URL: https://github.com/timbortnik/widget
- Owner: timbortnik
- License: other
- Created: 2026-01-01T11:15:08.000Z (5 months ago)
- Default Branch: main
- Last Pushed: 2026-05-31T13:02:21.000Z (12 days ago)
- Last Synced: 2026-05-31T14:21:28.686Z (12 days ago)
- Topics: android, android-widget, flutter, forecast, home-widget, kotlin, material-you, meteogram, no-tracking, open-meteo, open-source, privacy, weather, weather-app, weather-widget
- Language: Dart
- Homepage: https://play.google.com/store/apps/details?id=org.bortnik.meteogram
- Size: 10.1 MB
- Stars: 1
- Watchers: 0
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
- Security: SECURITY.md
Awesome Lists containing this project
README
# Meteograph
Open-source Android weather widget that puts a detailed forecast directly on
your home screen — no ads, no tracking, no account. Choose a 48-hour or 7-day
meteogram with temperature, precipitation, and daylight on a single glanceable
chart. Powered by the free Open-Meteo API.
## Features
- **Two home-screen widgets**: 48-hour chart (46h forecast + 6h past) and
7-day chart, both rendered natively via AndroidSVG
- **Meteogram chart** with:
- Temperature line with gradient fill
- Precipitation bars
- Daylight intensity (computed from cloud cover and sun position)
- Current time marker
- Weekday labels (weekly) / hour labels (48h)
- **Smart refresh**:
- Foreground timer checks every minute for stale data (>15 min) and
redraws at half-hour boundaries
- AlarmManager (~15 min inexact) catches up on device wake
- WorkManager periodic task (~30 min) with network-connected constraint
- BOOT_COMPLETED refresh on device restart
- Event-driven updates (screen unlock, network change, locale/timezone change)
- **Flexible location**:
- GPS with reverse geocoding (native platform geocoder)
- City search via Open-Meteo geocoding API
- Recent cities remembered
- Berlin default when GPS unavailable
- **Material You** dynamic color support (Android 12+)
- **Light/dark theme** following system preference
- **36 languages** supported
- **Locale-aware units** (°F for US/Liberia/Myanmar, °C elsewhere; 12/24h time)
- **Offline support** with smart caching:
- Automatic cache fallback when offline
- Fibonacci retry backoff (1, 2, 3, 5, 8 min) for background refresh
- Visual "OFFLINE" watermark on stale data (>1 hour old)
- Cached location and city name preserved
- **No API key required** — uses free Open-Meteo API
- **No ads, no tracking, no account**
## Screenshots
## Installation
### Prerequisites
- Flutter 3.x
- Android SDK
- Android device or emulator
### Build & Run
```bash
# Get dependencies
flutter pub get
# Generate localizations
flutter gen-l10n
# Build options (via Makefile)
make debug # x86_64 only (68MB) - for emulator
make release # arm64 only (19MB) - for phones
make install # Build release + install on device
make install-debug # Build debug + install on emulator
```
### Install Widget
1. Install the app on your device
2. Open the app and let it load weather data
3. Long-press on home screen → Widgets
4. Find "Meteograph" and drag to home screen
5. Tap widget to refresh data
## Project Structure
```
lib/
├── main.dart # App entry point, edge-to-edge setup
├── generated/version.dart # Generated git version info (gitignored)
├── l10n/ # Localization files (36 languages)
│ ├── app_en.arb # English (template)
│ └── app_*.arb # ar, be, bg, bn, bs, cs, da, de, el, es,
│ # fi, fr, hi, hr, is, it, ja, jv, ka, ko,
│ # mk, nl, no, pa, pl, pt, ro, sk, sq, sv,
│ # ta, tr, uk, vi, zh
├── screens/
│ └── home_screen.dart # Main app screen (both chart panels)
├── services/
│ ├── location_service.dart # GPS + city search + reverse geocoding
│ ├── widget_service.dart # Home widget updates via home_widget
│ ├── native_svg_service.dart # Method channel to Kotlin (SVG / weather / cache)
│ ├── units_service.dart # Temperature unit and 12/24h logic
│ └── material_you_service.dart # Material You color pass-through
├── theme/
│ └── app_theme.dart # Colors, themes, Material You mapping
└── widgets/
└── native_svg_chart_view.dart # PlatformView wrapper for native SVG
android/app/src/main/kotlin/.../
├── MainActivity.kt # Flutter activity + method channel
├── MeteogramApplication.kt # Receiver registration, alarm schedule
├── MeteogramWidgetProvider.kt # Base widget (48h) — shared logic
├── MeteogramWeeklyWidgetProvider.kt # 7-day variant (extends base)
├── WidgetEventReceiver.kt # Locale / timezone / network receiver
├── WidgetAlarmScheduler.kt # 15-min inexact AlarmManager
├── WidgetAlarmReceiver.kt # Alarm broadcast handler
├── BootCompletedReceiver.kt # Refresh on device boot
├── WidgetUtils.kt # Shared widget helpers
├── WidgetChartColors.kt # Material You color resolver
├── WeatherUpdateWorker.kt # WorkManager periodic refresh (~30 min)
├── WeatherFetcher.kt # Native HTTP client for Open-Meteo
├── WeatherDataParser.kt # Cached-weather parser + chart views
├── SvgChartGenerator.kt # Native SVG generator (single source of truth)
├── MaterialYouColorExtractor.kt # Dynamic color extraction
├── MaterialYouColorWorker.kt # Background color updates
├── SvgChartPlatformView.kt # In-app native SVG rendering
└── SvgChartViewFactory.kt # PlatformView factory
android/app/src/main/res/
├── layout/meteogram_widget.xml # 48h widget layout
├── layout/meteogram_widget_weekly.xml # 7-day widget layout
├── xml/meteogram_widget_info.xml
├── xml/meteogram_widget_weekly_info.xml
└── drawable/widget_background.xml
```
## API
Uses [Open-Meteo](https://open-meteo.com/) free APIs (no API key required):
### Weather Forecast
```
GET https://api.open-meteo.com/v1/forecast
?latitude={lat}
&longitude={lon}
&hourly=temperature_2m,precipitation,cloud_cover
&timezone=UTC
&past_hours=32
&forecast_days=7
```
The 32-hour past window keeps the weekly chart's "now" line at the same
fraction of width as the 48-hour chart. The 48-hour chart slices a smaller
window (6h past + 46h future) from the same cache.
Returns hourly data for:
- `temperature_2m` — temperature in Celsius
- `precipitation` — rain/snow in mm
- `cloud_cover` — cloud coverage percentage (0-100)
Daylight intensity is computed locally from cloud cover and solar position.
### City Search (Geocoding)
```
GET https://geocoding-api.open-meteo.com/v1/search
?name={query}
&count=8
&language={locale}
```
The `language` parameter uses the user's current locale so results come
back in their preferred language.
## Widget Technical Details
### Android Widget
The home screen widgets use:
- `HomeWidgetProvider` from the home_widget package
- `RemoteViews` for native Android widget rendering
- SVG chart generated in Kotlin (`SvgChartGenerator.kt`) and rasterised via AndroidSVG
- AlarmManager (~15 min inexact), WorkManager (~30 min with network constraint),
and BOOT_COMPLETED for reliable background refresh
- Event receivers for unlock / network / locale / timezone changes
**RemoteViews Limitations:**
- Only supports: TextView, ImageView, LinearLayout, RelativeLayout, FrameLayout
- Does NOT support: View, Space, custom views
### Data Flow
1. **Foreground**: `home_screen.dart` → `NativeSvgService.fetchWeather()` →
Kotlin `WeatherFetcher` pulls from Open-Meteo → caches to SharedPreferences
2. **SVG generation**: `SvgChartGenerator.kt` reads the cache and produces an
SVG string — single source of truth used by both the in-app chart and both widgets
3. **In-app**: SVG rendered via native PlatformView (AndroidSVG)
4. **Widget**: SVG rasterised to a bitmap and shown in an ImageView
5. **Background**: AlarmManager / WorkManager / BOOT_COMPLETED / event receivers
trigger a native refresh + widget re-render, Flutter engine stays off
## Customization
### Colors
Edit `lib/theme/app_theme.dart` for the in-app UI and
`android/app/src/main/kotlin/.../SvgChartGenerator.kt` for the chart itself
(`SvgChartColors.light` / `SvgChartColors.dark`). Example from the Dart side:
```dart
static const light = MeteogramColors(
temperatureLine: Color(0xFFFF6B6B), // Coral red
precipitationBar: Color(0xFF1A9D92), // Deeper teal (legibility on white)
daylightBar: Color(0xFFFF8F00), // Dark amber
nowIndicator: Color(0xFFFFE66D), // Golden yellow
// ...
);
```
### Widget Background
Edit `android/app/src/main/res/drawable/widget_background.xml`:
```xml
```
## Adding Languages
1. Create `lib/l10n/app_XX.arb` (copy from app_en.arb)
2. Translate all strings
3. Run `flutter gen-l10n`
Supported locales are auto-detected from ARB files.
## Dependencies
| Package | Purpose |
|---------|---------|
| home_widget | Android/iOS widget support |
| geolocator | GPS location |
| geocoding | Reverse geocoding (city names) |
| http | API requests |
| path_provider | File storage |
| shared_preferences | Settings storage |
| intl | Locale-aware formatting |
Material You theming uses native Android color extraction (`MaterialYouColorExtractor.kt`).
## License
Business Source License 1.1 - see [LICENSE](LICENSE)
- Free for non-commercial and personal use
- Commercial use requires a license
- Converts to MIT on 2029-01-01
## Contributing
Contributions welcome! Please read the existing code style and test your changes.
## Acknowledgments
- Weather data: [Open-Meteo](https://open-meteo.com/)
- Widget support: [home_widget](https://pub.dev/packages/home_widget)
- SVG rendering: [AndroidSVG](https://bigbadaboom.github.io/androidsvg/)