Filter real input devices

Question

I'm trying to get list of connected gamepads following way:

InputDevice.getDeviceIds()
        .map { InputDevice.getDevice(it) }
        .filter { it.sources and InputDeviceCompat.SOURCE_GAMEPAD == InputDeviceCompat.SOURCE_GAMEPAD }
        .forEach {
            Log.i("gamepads", "$it")
        }

In general, it should return only gamepads, but for my Nexus TV this block finds 2 more devices, both of the same kind:

Input Device 4: virtual-search
Descriptor: 38c59f5a8771de8bd485da05030eb001094d7936
Generation: 10
Location: built-in
Keyboard Type: non-alphabetic
Has Vibrator: false
Has mic: false
Sources: 0x701 ( keyboard dpad gamepad )

Fun fact: while these devices are obviously virtual, call InputDevice.isVirtual() returns false for both of it.

So, easiest solution will be to filter devices based on mLocation field of InputDevice. Fortunately, InputDevice have public method to check it. Unfortunately, this method InputDevice.isExternal() is marked as hidden, thus unavailable.

Is there any other way to filter out these virtual devices without accessing hidden methods/fields via reflection?

I checked it with all devices disconnected — i.e. no USB cable for ADB, no remote, no gamepads — these two inputs are still present. — OleGG, Jan 20 '18 at 06:57
I'm wondering if its the 'endpoint' for the 'Android TV Remote Control App' so when you are using it, the TV app doesn't know the difference. That does assume Google is doing something behind the scenes to make it available and I don't know why there would be two of them. Just a thought. — Morrison Chang, Jan 20 '18 at 07:09

score 1 · Accepted Answer · answered Jan 20 '18 at 07:09

It looks like possible solution is to filter devices based on vendorId. For these virtual-search ones InputDevice.getVendorId() returns 0, while it's non-zero for real external devices.

Of course, I'm barring myself from using some noname devices with empty vendor id, but it's still better than access hidden methods that are effectively not guaranteed to work.

Filter real input devices

1 Answers1