Knowing is half the battle

As a developer, I often wonder which Android platforms my applications should support,especially as the number of Android-powered devices grows. Should my application only focus on the latest version of the platform or should it support older ones as well?

To help with this kind of decision, I am excited to announce the new
device dashboard. It provides information about deployed Android-powered devices that is helpful to developers as they build and update their apps. The dashboard provides the relative distribution of Android platform versions on devices running Android Market.

Android Platform Percentage of Devices 1.1 0.3% 1.5 27.7% 1.6 54.2% 2.0 2.9% 2.0.1 14.8%

The above graph shows the relative number of Android devices that have accessed Android Market during the first 14 days of December 2009.

From a developer's perspective, there are a number of interesting points on this graph:

• At this point, there's little incentive to make sure a new application is
  backward compatible with Android 1.0 and Android 1.1.
• Close to 30% of the devices are running Android 1.5. To take advantage of this significant install base, you may consider support for Android 1.5.
• Starting with Android 1.6, devices can have different screen densities & sizes. There are several devices out there that fall in this category, so make sure to adapt your application to support different screen sizes and take advantage of devices with small, low density (e.g QVGA) and normal, high density (e.g. WVGA) screens. Note that Android Market will not list your application on small screen devices unless its manifest explicitly indicates support for "small" screen sizes. Make sure you properly configure the emulator and test your application on different screen sizes before uploading to Market.
• A new SDK for Android 2.0.1 was released two weeks ago. All Android 2.0 devices will be updated to 2.0.1 before the end of the year, so if your application uses features specific to Android 2.0, you are encouraged to update it to take advantage of the latest Android 2.0.1 API instead.

In summary, Android 1.5, 1.6, and 2.0.1 are the 3 versions of the platform that are deployed in volume. Our goal is to provide you with the tools and information to make it easy for you to target specific versions of the platform or all the versions that are deployed in volume.

We plan to update the dashboard regularly to reflect deployment of new Android platforms. We also plan to expand the dashboard to include other information like devices per screen size and so on.

Come to Our Virtual Office Hours

Starting this week, we're going to be holding regular IRC office hours for Android app developers in the #android-dev channel on irc.freenode.net. Members of the Android team will be on hand to answer your technical questions. (Note that we will not be able to provide customer support for the phones themselves.)

We've arranged our office hours to accommodate as many different schedules as possible, for folks around the world. We will initially hold two sessions each week:

• 12/15/09 Tuesday, 9 a.m. to 10 a.m. PST
• 12/17/09, Thursday 5 p.m. to 6 p.m. PST
• 12/22/09, Tuesday 9 a.m. to 10 a.m. PST
• 01/06/10 Wednesday 9 a.m. to 10 a.m. PST
• 01/07/10 Thursday 5 p.m. to 6 p.m. PST

Check Wikipedia for a helpful list of IRC clients. Alternatively, you could use a web interface such as the one at freenode.net. We will try to answer as many as we can get through in the hour.

We hope to see you there!

Optimize your layouts

Writing user interface layouts for Android applications is easy, but it can sometimes be difficult to optimize them. Most often, heavy modifications made to existing XML layouts, like shuffling views around or changing the type of a container, lead to inefficiencies that go unnoticed.

Starting with the SDK Tools Revision 3 you can use a tool called layoutopt to automatically detect common problems. This tool is currently only available from the command line and its use is very simple - just open a terminal and launch the layoutopt command with a list of directories or XML files to analyze:

$ layoutopt samples/
samples/compound.xml
  7:23 The root-level <FrameLayout/> can be replaced with <merge/>
  11:21 This LinearLayout layout or its FrameLayout parent is useless samples/simple.xml
  7:7 The root-level <FrameLayout/> can be replaced with <merge/>
samples/too_deep.xml
  -1:-1 This layout has too many nested layouts: 13 levels, it should have <= 10!
  20:81 This LinearLayout layout or its LinearLayout parent is useless
  24:79 This LinearLayout layout or its LinearLayout parent is useless
  28:77 This LinearLayout layout or its LinearLayout parent is useless
  32:75 This LinearLayout layout or its LinearLayout parent is useless
  36:73 This LinearLayout layout or its LinearLayout parent is useless
  40:71 This LinearLayout layout or its LinearLayout parent is useless
  44:69 This LinearLayout layout or its LinearLayout parent is useless
  48:67 This LinearLayout layout or its LinearLayout parent is useless
  52:65 This LinearLayout layout or its LinearLayout parent is useless
  56:63 This LinearLayout layout or its LinearLayout parent is useless
samples/too_many.xml
  7:413 The root-level <FrameLayout/> can be replaced with <merge/>
  -1:-1 This layout has too many views: 81 views, it should have <= 80! samples/useless.xml
  7:19 The root-level <FrameLayout/> can be replaced with <merge/>
  11:17 This LinearLayout layout or its FrameLayout parent is useless

For each analyzed file, the tool will indicate the line numbers of each tag that could potentially be optimized. In some cases, layoutopt will also offer a possible solution.

The current version of layoutopt contains a dozen rules used to analyze your layout files and future versions will contain more. Future plans for this tool also include the ability to create and use your own analysis rules, to automatically modify the layouts with optimized XML, and to use it from within Eclipse and/or a standalone user interface.

Windows users: to start layoutopt, open the file called layoutopt.bat in the tools directory of the SDK and on the last line, replace %jarpath% with -jar %jarpath%.

Android SDK Updates

Today we are releasing updates to multiple components of the Android SDK:

• Android 2.0.1, revision 1
• Android 1.6, revision 2
• SDK Tools, revision 4

Android 2.0.1 is a minor update to Android 2.0. This update includes several bug fixes and behavior changes, such as application resource selection based on API level and changes to the value of some Bluetooth-related constants. For more detailed information, please see the Android 2.0.1 release notes.

To differentiate its behavior from Android 2.0, the API level of Android 2.0.1 is 6. All Android 2.0 devices will be updated to 2.0.1 before the end of the year, so developers will no longer need to support Android 2.0 at that time. Of course, developers of applications affected by the behavior changes should start compiling and testing their apps immediately.

We are also providing an update to the Android 1.6 SDK component. Revision 2 includes fixes to the compatibility mode for applications that don't support multiple screen sizes, as well as SDK fixes. Please see the Android 1.6, revision 2 release notes for the full list of changes.

Finally, we are also releasing an update to the SDK Tools, now in revision 4. This is a minor update with mostly bug fixes in the SDK Manager. A new version of the Eclipse plug-in that embeds those fixes is also available. For complete details, please see the SDK Tools, revision 4 and ADT 0.9.5 release notes.

One more thing: you can now follow us on twitter @AndroidDev.