Sunday, March 11, 2012

Lights-out mode in Android

As I noted in the last post, Google and players like it when you use the "lights out" option to hide the status bar during games. I spent a couple hours today figuring out how to do that.

1) Wrap all of this code in a check to see if we are on Android 3 or higher so we can still run on 2.3.

if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.HONEYCOMB) {

2) Find the right view. We create a GLView in our startup code, so this part is easy for us. Otherwise you'd want to add an android id to the top view in the layout file, and then use findViewById to find it.

(in layout definition) android:id="@+id/RootView"
(in startup code) View root=findViewById(;

3) Toggle the visibility flag to SYSTEM_UI_FLAG_LOW_PROFILE


4) Set up a visibility listener to re-hide the menu bar after a delay when it becomes visible again. Otherwise when you touch the bar it will stay visible forever. We add the delay in because things go wonky if you rehide in the unhide notification.


new View.OnSystemUiVisibilityChangeListener()


public void onSystemUiVisibilityChange(int visibility)


if (visibility == 0)


Runnable rehideRunnable = new Runnable()


public void run() {





Handler rehideHandler = new Handler();

rehideHandler.postDelayed(rehideRunnable, 2000);




Wednesday, March 7, 2012

Tips every Android developer should know, or things we're doing wrong and need to fix in our Android builds.

A couple Google engineers, Dan Galpin and Ian Lewis, gave a talk at GDC this morning on things people do that prevent their apps from getting featured. Here are my notes on what they said.

1) Don't run in compatibility mode. Google hates the menu button on newer Android devices, so set the target SDK version to the newest (15).

2) Games that use the lights out menu option are cool. This is View.Status_Bar_Hidden.

3) Don't override the basic button behavior like volume or home or power. The back button is fair game though. Back should be treated as the escape key and not a quick exit button because it is easy to accidentally press it on honeycomb and ice cream sandwich.

4) Don't use a "do you want to quit" button when hitting back from the main menu. Just exit.

5) Don't play music on the lock screen when coming back from sleep. This one has driven us nuts trying to figure out. You have to overload onWindowFocusChanged as well as the sleep functions, and they can be called in any order.

6) Gracefully cleanup your OGL contexts.

7) For in-app purchases, don't assume your app will be open when the confirmation comes through.

8) Always have a tablet promo graphic. They scale this down to use it for feature spots on phones. This is the big banner that shows up when viewing the game on the web or on a tablet.

9) Localizing the market text is recommended, with the languages EFIGS-CJK.