How to conditionally use vendor-specific APIs for Android apps?

Question

With Android app stores offering marketplace-specific APIs, how do I build an Android app that conditionally uses vendor-specific libraries? For example, Amazon offers their own In-App Purchase and "GameCircle" APIs. Google has their own Licensing APIs, and now Ouya will have their own APIs for IAP and hardware controllers.

With the proliferation of these vendor-specific SDKs it's becoming difficult to maintain several separate builds of my Android games. I would like to know how to build my projects so that my code can just check at runtime for various APIs and use them if avaialble. Something like

if (amazon api is available)
  // Do some amazon-specific stuff

At build-time I would link with ALL the libraries then upload the same universal app to each store.

Answer 1

I'm using this currently.

private boolean isAmazonInstall()
{
    PackageManager pm = getPackageManager();
    String installationSource = pm.getInstallerPackageName(getPackageName());
    if (installationSource != null && installationSource.startsWith("com.amazon"))
    {
                    return true;
    }
            return false;
}

Allegedly, for an Amazon install, the return value of getInstallerPackageName is "com.amazon.venezia". For applications installed from Google Play, the result is "com.android.vending" (although it used to be "com.google.android.feedback". Manual APK installs return null.

I haven't been able to find official confirmation that this approach is valid. But I haven't been able to find any better approach.