Android

When generating an Android project, Briefcase produces a Gradle project.

Icon format

Android projects use .png format icons, in round and square variants. An application must provide the icons in the following sizes, for 2 variants:

  • round:

    • 48px

    • 72px

    • 96px

    • 144px

    • 192px

  • square:

    • 48px

    • 72px

    • 96px

    • 144px

    • 192px

Splash Image format

Android projects use .png format splash screen images. A splash screen should be a square image with a transparent background. It must be specified in a range of sizes and variants, to suit different possible device sizes and device display densities:

  • normal (typical phones; up to 480 density-independent pixels):

    • 320px

    • 480px (hdpi)

    • 640px (xhdpi)

    • 1280px (xxxhdpi)

  • large (large format phones, or phone-tablet “phablet” hybrids; up to 720 density-indpendent pixels):

    • 480px

    • 720px (hdpi)

    • 960px (xhdpi)

    • 1920px (xxxhdpi)

  • xlarge (tablets; larger than 720 density-independent pixels)

    • 720px

    • 1080px (hdpi)

    • 1440px (xhdpi)

    • 2880px (xxxhdpi)

Consult the Android documentation for more details on devices, sizes, and display densities. This list of common devices with their sizes and DPI may also be helpful.

You can specify a background color for the splash screen using the splash_background_color configuration setting.

Android projects do not support installer images.

Application configuration

The following options can be added to the tool.briefcase.app.<appname>.android section of your pyproject.toml file.

version_code

In addition to a version number, Android projects require a version “code”. This code is an integer version of your version number that must increase with every new release pushed to the Play Store.

Briefcase will attempt to generate a version code by combining the version number with the build number. It does this by using each part of the main version number (padded to 3 digits if necessary) and the build number as 2 significant digits of the final version code:

  • Version 1.0, build 1 becomes 1000001 (i.e, 1, 00, 00, 01)

  • Version 1.2, build 37 becomes 1020037 (i.e., 1, 02, 00, 37)

  • Version 1.2.37, build 42 becomes 1023742 (i.e, 1, 02, 37, 42)

  • Version 2020.6, build 4 becomes 2020060004 (i.e., 2020, 06, 00, 04)

If you want to manually specify a version code by defining version_code in your application configuration. If provided, this value will override any auto-generated value.

Additional options

The following options can be provided at the command line when producing Android projects:

run

-d <device> / --device <device>

The device or emulator to target. Can be specified as:

  • @ followed by an AVD name (e.g., @beePhone); or

  • a device ID (a hexadecimal identifier associated with a specific hardware device); or

  • a JSON dictionary specifying the properties of a device that will be created. This dictionary must have, at a minimum, an AVD name:

    $ briefcase run -d '{"avd":"new-device"}'
    

    You may also specify:

    • device_type (e.g., pixel) - the type of device to emulate

    • skin (e.g., pixel_3a) - the skin to apply to the emulator

    • system_image (e.g., system-images;android-31;default;arm64-v8a) - the Android system image to use in the emulator.

    If any of these attributes are not specified, they will fall back to reasonable defaults.

--Xemulator=<value>

A configuration argument to be passed to the emulator on startup. For example, to start the emulator in “headless” mode (i.e., without a display window), specify --Xemulator=-no-window. See the Android documentation for details on the full list of options that can be provided.

You may specify multiple --Xemulator arguments; each one specifies a single argument to pass to the emulator, in the order they are specified.

--shutdown-on-exit

Instruct Briefcase to shut down the emulator when the run finishes. This is especially useful if you are running in headless mode, as the emulator will continue to run in the background, but there will be no visual manifestation that it is running. It may also be useful as a cleanup mechanism when running in a CI configuration.

Application configuration

The following options can be added to the tool.briefcase.app.<appname>.android section of your pyproject.toml file:

build_gradle_extra_content

A string providing additional Gradle settings to use when building your app. This will be added verbatim to the end of your app/build.gradle file.