How to make Android Studio download dependencies sources and javadoc?

For Maven sources and docs the only thing I have found is to change the default settings.

File -> Other Settings -> Default Settings... -> Maven -> Importing

Checking the boxes to download Sources and Documentation

As we can see the answer from Xavier Ducrohet (Android SDK Tech LeadGoogle Inc.), as of July 26, 2013:

I don't think Gradle handles this at this point. I've talked to the devs and they are aware of it. We're looking at adding a hook in Gradle so that we can do it when the tooling API queries the model.

Currently Android Studio imports libraries with sources. As for java docs press F1.

Old answer:

As we are talking about early preview, simplest fix wins.

For now is just manually add them to the project in Project Structure dialog. Things are even worse as now Android Studio will strip module files (iml) from all dependencies which are not related to native Android Gradle configurations and tasks e.g. module has robolectric dependency and extra task and config localTest is added in build.gradle. After you open Android Studio it will remove dependency, you need to add it again.

For time being I am keeping iml files and .idea folder in my git. After launch

git checkout myproject/myproject.iml