The Android SDK supplies developers with a number of powerful and useful tools. Throughout this book, you will use only a handful of them directly. This section takes a quick look at just a few of these tools, which will be covered in much more depth in the following chapters, as you dive into command-line development.
NOTE
For more detailed information about the other tools included in the Android SDK, consult the Android doc files.
Emulator.exe
Arguably one of the most important tools included in the Android SDK is emulator.exe. emulator.exe launches the Android Emulator. The Android Emulator is used to run your applications in a pseudo-Android environment. Given that, as of the writing of this book, there were no hardware devices yet released for the Android platform, emulator.exe is going to be your only means to test applications on a “native” platform.
You can run emulator.exe from the command line or execute it from within Eclipse. However, in the interest of giving you all the information you need to program with the Android SDK outside of Eclipse, Chapter 6 covers command-line usage of emulator.exe when you create your Hello World! applications.
When using the Android Emulator to test your applications, you have two choices for navigating the user interface. First, the emulator comes with usable buttons, as shown in Figure 4-1. You can use these buttons to navigate Android and any applications that you develop for the platform.
TIP
The Power On/Off, Volume Up, and Volume Down buttons are slightly hidden to the sides of the virtual device. They identify themselves when you hover the mouse pointer over them.Given that many higher-end phones now include a touch screen, the second input choice you have when using the emulator is a simulated touch screen. You use your mouse as a stylus. The objects on the emulator’s screen can be interacted with using the mouse.
adb.exe
Another tool that will become very useful to you when you are using command-line programming is Android Debug Bridge or adb (adb.exe). This tool allows you to issue commands to the Emulator.exe tool.
When you are working in a command-line environment, the adb tool allows you to do the following:
● Start and stop the server
● Install and uninstall applications
● Move files to and from the emulator
MKSDCARD.exe
MKSDCARD.exe is a very useful tool if you are testing an application that will need to read or write files to or from an SD Memory Card inserted into the mobile device. MKSDCARD.exe creates a small partition drive on your drive that will hold and retain the test files. The emulator will treat this partition like an SD Memory Card.
DX.exe
DX.exe is the compiler of the Android SDK. When run against your Java files, DX.exe will create files with .dex extensions—Dalvik executable format. These files are in the correct format to be understood by, and run on, an Android device.
NOTE
Android executable files are called Dalvik executable files as a reference to the Dalvik virtual machine that Android used to run all applications. The Dalvik virtual machine runs each application in its own thread with the same priority as core Android applications.
