CHAPTER 15: Developing for Android Wearable Devices 553Optimization will be necessary to achieve the optimal performance and user experience, since the
application is operating back and forth over a Bluetooth “wireless expanse” between the Android
device running your application and the smartwatch peripheral that is displaying the application and
processing the touchscreen event handling for your user interface. This is obviously going to slow
down performance, due to the user experience (user interface event generation and event handling)
having to travel back and forth through the air via a Bluetooth wireless data connection.
This is also most likely the reason why Android OS upgraded its Bluetooth support from Bluetooth
3.0 to Bluetooth 4.0 in a recent version (4.4) of the Android OS. This faster Bluetooth 4.0 allows
the best performance possible between a peripheral and True Android device. I am covering this
distinction up front, because I want you to be aware that there are two completely different ways
that smartwatches can function (true or native, versus peripheral or remote). Android 5.0, which
I cover in Chapter 16, upgrades Bluetooth even further, to Bluetooth 4.1, which puts Bluetooth
devices in the cloud!
Now that the Android Wear SDK has been released with Android 5.0, there are actually three
application development approaches to Android wearable applications development. I will cover
them in the next section of this chapter.
Development Strategy: Android, Wear SDK, or Plug-In
There are three ways that Android wearable applications can be developed currently—by using the
full or True Android SDK (true or native smartwatch apps), by using the recent Android Wear SDK
(which was released in the Summer of 2014 along with the Android 5.0 API Level 20 OS, which is
covered in Chapter 16), and by adding SDK plug-ins, usually called “add-ons” using the Android
SDK Manager in Eclipse ADT (Android 4.4.4).
You learned about the Eclipse Android SDK Manager (from the Window menu) at the beginning of
this book, when you installed and set up your Android SDK development environment in Eclipse
ADT. A good example of a smartwatch that uses an SDK add-on approach is the Sony smartwatch.
The Sony Add-on SDK is currently at version 2.1. You can access it from the following URL (the
Sony smartwatch repository address). Enter it into the Android SDK Manager by using the
Tools ➤ Manage Add-On Sites menu sequence:
http://dl-developer.sonymobile.com/sdk-manager/Sony-Add-on-SDK.xml
Don’t do this, of course, unless you have a Sony smartwatch 2 or 3, and need to develop for it. I am
developing for the Sony smartwatch 2 and 3 for my upcoming Pro Android Wearables book title.
Figure 15-1 show the add-on once it is installed in the Eclipse ADT SDK Manager tool.