3

I am developing a game (sort of) which uses OpenGL and has background music. Application runs only in landscape mode.

Problem I have, happens when user locks screen. At that point onStop() is called, screen orientation is changed and soon after my Activity is restarted as a result of orientation change. This means OpenGL surface is recreated, music starts playing again and all sorts of other things. This is counter-intuitive as locking screen should suspend CPU intensive operations, not start them.

Adding android:configChanges="orientation" to manifest did nothing. I do realize that I am probably missing screenSize in android:configChanges but I can not add it since I am targeting earlier API versions which do not have this option available.

So, question is: What's the proper way to handle this? On which event should I initialize my application so that everything works as expected?

MeanEYE
  • 967
  • 8
  • 24

6 Answers6

5

Adding screenSize to configChanges in manifest doesn't mean that your program won't run on older version. You just need to set targetSdkVersion to higher version and minSdkVersion to whatever you like. In intelljIDEA I set ModuleSKD to 4 in Project Structure so it doesn't highlight screenSize as invalid. It must be similar in Eclipse.

<uses-sdk android:minSdkVersion="8" android:targetSdkVersion="15" />

<activity android:name=".MyActivity"
      android:label="@string/app_name"
      android:configChanges="orientation|screenSize|keyboard|keyboardHidden|navigation">

Also you can check the version in code like this:

if (Build.VERSION.SDK_INT >= 11)

This way your app work on 2.2 as well as higher versions.

I think you won't need onConfigurationChanged because your game probably run only in landscape mode but if your interested have a look at my question very similar to yours and my own answer.

replace layout on orientation change

Community
  • 1
  • 1
Ali
  • 21,572
  • 15
  • 83
  • 95
  • When I try to add this to my manifest file Eclipse gives me this error: "Error: String types not allowed (at 'configChanges' with value 'orientation|screenSize| keyboard|keyboardHidden|navigation')." – MeanEYE Dec 30 '12 at 16:33
  • screenSize was introduced in Android 3.0, so I can't add it for 2.2. Still even removing that didn't help. – MeanEYE Dec 30 '12 at 16:43
  • @MeanEYE Please try IntellijIDEA, it's community version is free, and faster and more feature rich than eclipse. I don't have eclipse so I can't tell you what is the problem with first comment. – Ali Dec 30 '12 at 21:10
  • @MeanEYE There is no problem with that, you can use new tags while it run on older device. Again I tell you how I configure it in Intellij, you go to file menu, project structure, modules, select your module, and in dependency tab, select android 3.0+ as module sdk, so it won't complain about unknown attribute. in manifest set minsdk to 8 (2.2) or whatever. now your code compile without any error and it still works on 8+ devices. You can even call higher version API in your code by checking the right version. – Ali Dec 30 '12 at 21:13
  • @MeanEYE If you got Intellj and couldn't do it, tell me I will create a working project with this requirements for you. – Ali Dec 30 '12 at 21:17
  • This should be the accepted answer as it is correct for the question's root cause on Android. – Cory Trese Apr 25 '14 at 18:59
2

Add the tag

"android:configChanges="keyboard|keyboardHidden|orientation|screenSize|screenLayout" for your activity in Manifest.xml,

And Override the method

public void onConfigurationChanged(Configuration newConfig) {}
Mohan Krishna
  • 352
  • 3
  • 15
1

If your game is only for landscape mode, try to set android:screenOrientation="landscape" property in activity tag.

zasadnyy
  • 2,107
  • 2
  • 19
  • 26
1
        @Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onRestoreInstanceState(savedInstanceState);
}
@Override
protected void onSaveInstanceState(Bundle outState) {
    // TODO Auto-generated method stub
    super.onSaveInstanceState(outState);
}

Above are two methods in activity to save the state when orientation of activity changes.It saves data in the bundle object in the form of key value pairs.

No need to add any tag in Androidmanifest.xml file. for the above piece of code.

android:screenOrientation="landscape" this tag can be used to make your activity to run only in Landscape mode.This tag should be added activity tag present in Androidmanifest.xml

Meher
  • 2,545
  • 3
  • 26
  • 53
1

In your precise case I prefere to use this:

@Override
protected void onCreate(final Bundle savedInstance) {
    super.onCreate(savedInstance);
    setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
}

Works in all cases and forces your activity to be ONLY landscape.

shkschneider
  • 17,833
  • 13
  • 59
  • 112
1

I think you will need to accept the fact that when the phone locks, your Activity is paused and/or stopped. This means that you will need to start some of those things again. That's also what I understand after reading an Android Game development book with OpenGL.

What you can do is a bit more than what @421 suggested. In those onSaveInstanceState and onRestoreInstanceState, you can store the part of the song you are on and any other data that will allow the game to start again "smoothly" even though it may have to reload some things.

If you haven't found any other answer by now, this may be why. I've experienced many annoyances with games doing weird things once the phone locks. You just need to manually handle it correctly and smoothly.

leenephi
  • 900
  • 5
  • 13