java.lang.IllegalStateException: Cannot perform this action on a not sealed instance

Question

I am using accessibility service to find a button on screen and click it, but for some reason I am getting the follow error:

java.lang.IllegalStateException: Cannot perform this action on a not sealed instance.
    at android.view.accessibility.AccessibilityNodeInfo.enforceSealed(AccessibilityNodeInfo.java:3046)
    at android.view.accessibility.AccessibilityNodeInfo.findAccessibilityNodeInfosByText(AccessibilityNodeInfo.java:1529)
    at com.myapp.adapters.Adapter_Click$11.run(Adapter_Click.java:1874)
    at android.os.Handler.handleCallback(Handler.java:873)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loop(Looper.java:193)
    at android.app.ActivityThread.main(ActivityThread.java:6718)
    at java.lang.reflect.Method.invoke(Method.java:-2)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)

And the line that it refers to is:

List<AccessibilityNodeInfo> list = source.findAccessibilityNodeInfosByText("Accept".toLowerCase());

And then I use this to click the button:

if (view.performAction(AccessibilityNodeInfo.ACTION_CLICK)) 
{
  Log.e(TAG, "Button clicked");
}

I didn't see any issues with this for the last year until I just recently updated to AndroidX. Is there a way to check if it is a sealed instance before trying to click it? I even tried to wrap it in a try/catch and it still crashes my app.

Debonair

Can you share your .xml file which you have created to use Accessibility Service? – Arjan

Answer 1

(It's kind of a pain, but if a node gets ditched most functionality on it breaks horribly -- even refresh(). It's strange, since as far as I know you're allowed to retain instances as long as you need them.)

You can easily check if one is still valid by checking if getClassName() returns null -- if it does, drop it like a hot potato! You can't do anything with it anymore -- don't even recycle() it because something already did that underneath your feet.

Dolhenty

Can you please add to your answer, what might cause that object to be "ditched" right before the use of it? – Hephaestus

The OS' accessibility service likes to recycle nodes on a regular basis. I had done a bunch of research on it before but I don't remember the specifics offhand. Btw, by ditch I meant recycle. – Dolhenty

Hey where did you come up with the getClassName check? That's brilliant if it works... I'm just a bit hesitant to rely on it. – Kraska

I think it was trial and error initially, then I checked the Android source code to check how it handles the recycling because it felt so obtuse. So, it should be reliable; I had no trouble with it, though that project was put aside after a few months so I can't claim we tested a lot of devices. – Dolhenty

Answer 2

Sealing is done to make nodes immutable. These kind of exceptions often come when a service uses a node after it's been recycled.

Bucephalus