Configuring an AVD

You can test programs directly on an Android device through a USB connection between your development computer and the device. Later we will see how to do that, but for rapid development it is very useful to configure emulators that simulate various actual Android devices on your development computer.

Advantages of a Virtual Device

Testing with Android Virtual Devices (AVD) has several advantages:

• You don't have to have actual hardware running Android to begin developing programs.


• You can configure many different virtual devices having different characteristics (for example, running different versions of Android with various asumptions about SD card size, size of the screen, available input devices, network connectivity, and so on). This is extremely useful in being certain that your program performs robustly across the variety of platforms on which it may be deployed.

Of course the proof of the pudding is that it should run on actual devices, and emulators do a fairly good job but not a perfect one of simulating actual devices, so ultimately you want to test on real devices. However, using emulators for initial testing and development can greatly speed up the development cycle because they can simulate a variety of conditions that no single device would exhibit.

Configuring a Basic AVD

To configure a basic Android Virtual Device (AVD)

1. Open Eclipse and select Window > Android SDK and AVD Manager.

2. In the resulting window,

   
   

   

   
   

   select Virtual Devices in the left panel and click the New button on the right. This launches a new window to configure an AVD, as illustrated in the following figure.

   
   

   

   
   


3. In the first blank of this new window, give the device a name of your choice. Let's choose Simple2.2, indicating that this will be a relatively minimal device running Android 2.2.


4. Under the Target dropdown, select Android 2.2 - API Level 8.


5. Under SD Card enter 1024 for Size and be sure that the MiB dropdown is selected.


6. For Skin select Built-In and Default (HGVA).


7. Leave everything else as is and click Create AVD.

After a while (be patient, it may take a minute or so) this should create a new AVD with the characteristics specified that will appear in the list if Virtual Devices is selected in the left panel, as illustrated in the following figure.

Close the Android SDK and AVD Manager window. You now have a basic AVD to test programs running Android 2.2 or earlier. Later we will configure devices with other characteristics in a similar manner.

Configuring an AVD with Google Maps API Capability

Since the Google maps API is compatible with but separate from the basic Android API, an emulator that will display mapping information must be configured using both the Android and Google Maps API. An attempt to launch an app including Google Mapping using the Simple2.2 emulator configured earlier without mapping capability will give an error message:

[2010-06-08 11:20:26 - MapTutorial] Uploading MapTutorial.apk onto device 'emulator-5554'
[2010-06-08 11:20:26 - MapTutorial] Installing MapTutorial.apk...
[2010-06-08 11:20:27 - MapTutorial] Installation error: INSTALL_FAILED_MISSING_SHARED_LIBRARY
[2010-06-08 11:20:27 - MapTutorial] Please check logcat output for more details.
[2010-06-08 11:20:28 - MapTutorial] Launch canceled!

The missing shared library in this case corresponds to the Google maps API that the Simple2.2 emulator (emulator-5554 in the logged output) does not know anything about. We can remedy this by configuring a new emulator for Android 2.2 that has access to the mapping API.

1. Open Eclipse and select Window > Android SDK and AVD Manager.


2. In the resulting window, select Virtual Devices in the left panel and click the New button on the right. This launches a new window to configure an AVD.


3. In the first blank of this new window, give the device the name Maps2.2 (or a descriptive name of your choice).


4. Under the Target dropdown, select Google APIs (Google Inc) - API Level 8. (Note: we want both Android 2.2 and the corresponding Google API, but the Eclipse plugin knows to automatically pair Android 2.2 with Google API Level 8 if we choose the latter, though it will not say so explicitly at this point.)


5. Under SD Card enter 1024 for Size and be sure that the MiB dropdown is selected.


6. For Skin select Built-In and Default (HGVA).


7. Leave everything else as is and click Create AVD.

After a while (it can take a minute or so), this should create a new AVD with the characteristics specified that will appear in the list of Virtual Devices is selected in the left panel. Close the Android SDK and AVD Manager window. You now have a basic AVD to test programs running Android 2.2 with Google mapping capability.

Controlling the AVD with Keyboard Keys

Once you have an AVD (emulator) running you can use the following keyboard mappings to control it.

*Note:to use keypad keys, you must first disable NumLock on your development computer.

For example, if you disable NumLock on the keypad on your keyboard you can use 7 on the keypad to toggle between portrait and landscape orientation for the emulator.