Losing All Touch Input: When Switching from Unity to Android Activity Back

Unity Engine
,
1

I’m hitting a maddening bug:

When launching an Android activity from Unity, then **finish()**ing back to Unity – if you do this too many times, touch events are no longer recognized (e.g. Input.GetTouch shows no touches, even when there are some). This behavior persists until you kill the app.

Going between Android and Unity (often) is absolutely crucial to our app; there’s no possible way around that.

I can reproduce it consistently with a simple project:

APK: http://x.dzog.us/private/unitytouchfail/androidtouchtest.apk
Unity Project: http://x.dzog.us/private/unitytouchfail/AndroidTouchFail-unityproject.zip
Android Project: http://x.dzog.us/private/unitytouchfail/UnityTouchFail-androideclipse.zip

containing a button that launches an Android activity, which itself has a button to finish().

After 32 times I lose all touch ability in Unity – but everything else works.

This happens on every device I’ve tested: Nexus 4, Galaxy Nexus, LG Optimus, and various others. In Unity 3.5 and 4.

Has anyone seen this? Any clue as to what’s going on, or possible workarounds?

2

If anyone has any clues or leads or even random thoughts, it’s all appreciated. I’m working nonstop on this against the clock.

The Android activity can just be:

public class MainActivity extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        finish();
    }
}

to replicate this.

Returning to Unity 32 times: no touch input!

3

Tested your app ,and yes, the touch input just breaks after enough switchings.
Also tested some of my apps, apps with plugins (Unity activity extended) happened this same: touch Input breaks.
But on app that was just Unity with no plugins, it crashes after 32 switches O_o (with this error: http://forum.unity3d.com/threads/132492-java-lang-IllegalStateException-stop()-called-on-uninitialized-AudioTrack)

Edit: crash seems to happen only on Unity 3.x apps

(Tested on Galaxy Tab Plus, with 4.2.2)