Hot to get Android USB device permisson with QAndroidJniObject?

[dream_captain]

Hot to get Android USB device permisson with QAndroidJniObject.

Hello.I have an android device which should work as a usb host. At first i tried to use an intent approach as described here, and although i got a permission request dialog, the permission didn't apply. So i decided to get permissions from user directly.

Here's the java code i found that is used to request permissions.

public class MyUsbDevice extends Activity {

    private static MyUsbDevice m_instance;
    private static UsbManager m_usbManager;
    private static PendingIntent mPermissionIntent;
    private static HashMap<String, Integer> deviceCache = new HashMap<String, Integer>();
    private static final String ACTION_USB_PERMISSION = "com.android.example.USB_PERMISSION";


    public MyUsbDevice()
    {
        m_instance = this;
    }


    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        if (m_usbManager==null) {
            m_usbManager = (UsbManager) m_instance.getSystemService(USB_SERVICE);
        }

        mPermissionIntent = PendingIntent.getBroadcast(this, 0, new Intent(ACTION_USB_PERMISSION), 0);
        IntentFilter filter = new IntentFilter(ACTION_USB_PERMISSION);
        registerReceiver(mUsbReceiver, filter);
    }

    @Override
    public void onDestroy()
    {
        super.onDestroy();
    }


    private final BroadcastReceiver mUsbReceiver = new BroadcastReceiver() {
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            if (ACTION_USB_PERMISSION.equals(action)) {
                synchronized (this) {
                    UsbDevice device = (UsbDevice)intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
                    if (intent.getBooleanExtra(UsbManager.EXTRA_PERMISSION_GRANTED, false)) {
                        if(device != null){
                            m_instance.openDevice(device);
                        }
                    }
                }
            }
        }
    };


    public void openDevice(UsbDevice device)
    {
            UsbDeviceConnection devConn = m_usbManager.openDevice(device);
            Integer fd = devConn.getFileDescriptor();
            deviceCache.put(device.getDeviceName(), fd);
    }


    public static int tryOpenDevice()
    {
        HashMap<String, UsbDevice> deviceList = m_usbManager.getDeviceList();
        Iterator<UsbDevice> deviceIterator = deviceList.values().iterator();
        while(deviceIterator.hasNext()) {
            UsbDevice device = deviceIterator.next();
                m_usbManager.requestPermission(device, mPermissionIntent);
                break;
        }
        return 1;
    }


//  this call works
    public static int tes()
    {
        return 1;
    }

}

And JNI call from C++:

// this call works
int res1 = QAndroidJniObject::callStaticMethod<jint>("com/example/myusbdevice/MyUsbDevice", "test", "()I");

// this doesn't work
int res2 = QAndroidJniObject::callStaticMethod<jint>("com/example/myusbdevice/MyUsbDevice", "tryOpenDevice", "()I");

Nothing happens, i don't get any popup dialog. I think is't because i must somehow "create" an activity first, but how?

I'm very new to android, so any help will be appreciated.