UPDATE: Google has just released an update to Android 4.0—the Ice Cream Sandwich release—before most devices ever received their first build. Google bumped the API Level up to 15 and called it 4.0.3.
This minor release has a short list of hidden gems inside it for developers in addition to what is found in the initial ICS release. At the top of that list are Intent selectors, which are designed to modify the types of applications an Intent will match without modifying the Intent contents themselves. Selectors are used to tell an Intent to match a specific system application, such as the Gallery, Browser, Calendar, Music, or Maps applications, regardless of what data contents the Intent includes. This allows developers to create direct requests to launch system applications without needing to rely on the implicit filtering behavior of Intent resolution.
For developers connecting their apps to other devices using Bluetooth, the long-awaited UUID discovery methods have been made public in API 15. Developers no longer need to use reflection or other crafty means to obtain the UUID of the service they want to connect with on a remote device in order to open the RFCOMM socket. Two new methods, fetchUuidsWithSdp() and getUuids(), are now available to start the discovery process and to monitor the results via Broadcast, or return the cached data from the last run discovery operation. This change goes a long way to making Android easier to use in working with a broad range of embedded Bluetooth devices.
Finally, the AOSP now includes a full complement of built-in device targets, including the Galaxy Nexus, Nexus S and Xoom tablet. Developers with one of these devices can build and run UserDebug versions of Android 4.0.3 on their development devices.
Android 4.0, codenamed Ice Cream Sandwich (ICS), brings to handsets all of the advances and enhancements introduced for tablets in the 3.x/Honeycomb releases, unifying all Android devices under a single set of developer APIs.
Since Honeycomb was only available on tablet devices, many developers may not even be aware of the features introduced to the platform at that time, and 4.0 may be your first introduction to many of these features. For this reason, we will point out several of the key Honeycomb features that you can now use on all Android devices.
ICS also brings with it a set of new features that developers will be interested in. This article will look at some of the most important changes you should have your eye on.
With Ice Cream Sandwich, the latest Android source will once again be visible to the public, and the shepherds of the Android open-source project (AOSP) have promised that the GitWeb interface will return soon. This is fantastic news as we developers can finally get a glimpse at much of the Honeycomb additions (like Fragments) that were previously hidden, as well as all the new APIs that ICS has to offer. (ICS is available now to developers in the SDK and will soon be available on devices.)