Android unable read window content on few devices using accessibility service

Question

My requirement: Reading the text from pop up, dialog etc for particular app.

I have implemented an accessibility service and I am receiving proper events and data as

Answer 1

This is the code I use and it works for me:

public class USSDService extends AccessibilityService {

public static String TAG = USSDService.class.getSimpleName();

@Override
public void onAccessibilityEvent(AccessibilityEvent event) {
    Log.d(TAG, "onAccessibilityEvent");

    AccessibilityNodeInfo source = event.getSource();
    if(event.getEventType() == AccessibilityEvent.TYPE_WINDOW_STATE_CHANGED && !String.valueOf(event.getClassName()).contains("AlertDialog")) {
        return;
    }
    if(event.getEventType() == AccessibilityEvent.TYPE_WINDOW_CONTENT_CHANGED && (source == null || !source.getClassName().equals("android.widget.TextView"))) {
        return;
    }
    if(event.getEventType() == AccessibilityEvent.TYPE_WINDOW_CONTENT_CHANGED && TextUtils.isEmpty(source.getText())) {
        return;
    }

    List eventText;

    if(event.getEventType() == AccessibilityEvent.TYPE_WINDOW_STATE_CHANGED) {
        eventText = event.getText();
    } else {
        eventText = Collections.singletonList(source.getText());
    }

    String text = processUSSDText(eventText);

    if( TextUtils.isEmpty(text) ) return;

    // Close dialog
    performGlobalAction(GLOBAL_ACTION_BACK); // This works on 4.1+ only

    Log.d(TAG, text);
    // Handle USSD response here

}

private String processUSSDText(List eventText) {
    for (CharSequence s : eventText) {
        String text = String.valueOf(s);
        // Return text if text is the expected ussd response
        if( true ) {
            return text;
        }
    }
    return null;
}

@Override
public void onInterrupt() {
}

@Override
protected void onServiceConnected() {
    super.onServiceConnected();
    Log.d(TAG, "onServiceConnected");
    AccessibilityServiceInfo info = new AccessibilityServiceInfo();
    info.flags = AccessibilityServiceInfo.DEFAULT;
    info.packageNames = new String[]{"com.android.phone"};
    info.eventTypes = AccessibilityEvent.TYPE_WINDOW_STATE_CHANGED | AccessibilityEvent.TYPE_WINDOW_CONTENT_CHANGED;
    info.feedbackType = AccessibilityServiceInfo.FEEDBACK_GENERIC;
    setServiceInfo(info);
}
}

Declare it in Android manifest

Create a xml file that describes the accessibility service called ussd_service