Kivy Screenshot Generator

Generate screenshots for a Kivy application across different screens and languages.

A Python/Kivy port of flutter_screenshot_generator.

Installation

# requirements.txt
kivy-screenshot-generator @ git+https://github.com/lyskouski/kivy_screenshot_generator.git@v1.0.0

On Linux, install xvfb (sudo apt install xvfb): screenshots are rendered in a virtual display, so devices larger than your monitor keep their exact resolution and no windows pop up.

Implementation

# ./example/capture.py
from kivy_screenshot_generator import ScreenshotGenerator


def get_app():
    # Imported here: the Kivy window must be created after the device settings are applied
    from main import MyApp
    return MyApp(locale=gen.job.locale)


async def tap(tester):
    await tester.tap(tester.find_by_id('add'))
    await tester.pump()


gen = ScreenshotGenerator(locales=['en_US', 'de_DE'], fn_get_app=get_app)
gen.inject('1_home')
gen.inject('2_tap', before=tap)

if __name__ == '__main__':
    gen.run()

Each screenshot is taken by a fresh process running the same script with the device's window size (in physical pixels) and pixel density (dp/sp), so every step starts from a newly built app. Results are stored as screenshots/<locale>/<device>/<step>.png.

• fn_get_app() returns the App instance (not running yet). Import the app inside it: a window created on import would get the default size.
• fn_init(device, config, locale) (optional, sync or async) runs before fn_get_app, e.g. to prepare preferences or an isolated profile directory.
• gen.job holds the current step, device and locale inside the screenshot process. The app can also read SCREENSHOT_DEVICE, SCREENSHOT_PLATFORM, SCREENSHOT_LOCALE and SCREENSHOT_STEP.

Steps

before receives a ScreenshotTester (the counterpart of Flutter's WidgetTester):

Configuration

from kivy_screenshot_generator import ScreenshotConfig, ScreenshotPresets

# Presets: comprehensive() (default), mobile_only(), ios_only(), android_only(), desktop_only(), ci_optimized()
config = ScreenshotPresets.mobile_only()
config.output_directory = 'docs/screenshots'
config.workers = 4

ScreenshotGenerator(locales=['en_US'], fn_get_app=get_app, config=config)

Devices are listed in PlatformDevices (iPhones, iPads, Android phones and tablets, desktops) with the sizes required by Apple App Store and Google Play.

Usage

# Run all
python capture.py

# Limit by devices
SCREENSHOT_DEVICES="iPhone 15 Pro" python capture.py

# Limit by languages
SCREENSHOT_LOCALES=en_US python capture.py

# Limit by steps
SCREENSHOT_STEPS=2_tap python capture.py

# Skip devices for which a folder already exists
SKIP_EXISTANT=true python capture.py

# Parallel processes / force or disable the virtual display
SCREENSHOT_WORKERS=4 SCREENSHOT_HEADLESS=1 python capture.py

The exit code is non-zero when any screenshot fails; the output of the failed process is printed.

Results: iPhone 14

.

Production example

https://github.com/lyskouski/app-language/blob/main/tools/capture_screenshots.py

Development

pip install -e .[test]
pytest

Release

# Create and activate a virtual environment
python3 -m venv .venv
source .venv/bin/activate

# Install the packaging tools inside it
python -m pip install --upgrade pip build twine

# Build the package
python -m build

# Upload to TestPyPI
python -m twine upload --repository testpypi dist/*

# Upload to PyPI
python -m twine upload dist/*

Support (Sponsorship)

If you'd like to contribute financially towards the efforts, please consider these options:

• Github Sponsorship
• Paypal
• Patreon
• Donorbox

Or, buy a coffee.