Android sync adapter with appengine Google user accounts
android, android-syncadapter, google-app-engine
Solution
Perhaps you have misunderstood the Android account system. When you go to Settings -> Accounts & Sync and add a new account what you see then is a list of account types. Often there is a relationship between account types and apps, for example Facebook accounts are used together with Facebook. Normally you would add a new account type if you have a different backend system for handling authentication etc.
If I understand you correctly, you use Google accounts but want it to appear as your own account type. That sounds wrong to me. You'll end up reimplementing the Google account handling, with little value. I believe it is simpler for users if you simply piggyback on what Google provides you with. Your app / service / content provider can be seen when clicking on the account. For example, after installing "Tasks" by "Team Task" (disclaimer: I'm not affiliated with that company) they add "Sync Tasks" to the list of data & sync options.
But if you really want to create your own account type, follow the sample Sample Sync Adapter. Look for the Authenticator code and related resources (e.g., manifest, activity layout, etc.).
Problem
I am implementing a sync adapter for my app to sync with an appengine backend. On appengine I am using the built in User api for authentication. There is a post HERE that tells how to do it, however the app is listed under the gmail account. Ideally my app would be listed in the accounts. I don't want to ask the user for username and password, just use the existing google account for authentication. Has anyone done this before?? Update: I've been working on this and it looks like I could implement the AuthenticationService and store the users account name and leave the password as an empty string. In the getAuthToken() methods I should be able to simple return the google auth token. Will post once I get further along...