The Android SDK ships with a number of powerful tools to help with common Android development tasks. The Android documentation is an essential reference for developers. The DDMS debugging tool, which is integrated into the Eclipse development environment as a perspective, is useful for monitoring emulators and devices. The Android emulator can be used for running and debugging Android applications virtually, without the need for an actual device. There are also a number of other tools for interacting with handsets and emulators in a variety of situations.
A. No. The documentation installed with the SDK was "frozen" at the time the SDK was released, which means it is specific to the version of the Android SDK you installed. The online documentation is always the latest version of the Android SDK. We recommend using the online documentation, unless you are working offline or have a slow Internet connection, in which case the local SDK documentation should suffice.
Q. Do you have to develop Android applications with Eclipse?
A. No. Eclipse is the preferred development environment for Android (and the IDE used by this book), but it is not required for Android development. The ADT plug-in for Eclipse provides a convenient entry point for many of the underlying development tools for creating, debugging, packaging, and signing Android applications. Developers who do not use Eclipse (or simply want access to these tools outside of the IDE) can run the underlying tools directly from the command line. For more information about developing using other IDEs, see the Android developer website at http://goo.gl/KXcZj.
Q. Is testing your application on the emulator alone sufficient?
A. No. The Android emulator simulates the functionality of a real device and can be a big time- and cost-saving tool for Android projects. It is a convenient tool for testing, but it can only pretend at real device behavior. The emulator cannot actually determine your real location or make a phone call. Also, the emulator is a generic device simulation and does not attempt to emulate any quirky details of a specific device or user experience. Just because your application runs fine on the emulator does not guarantee that it will work on the device.