Scrolling gesture is generated when you try to tap the touch screen. It's because when you tap it your finger flattens changing the touch shape, so its center moves quite a lot in a normal tap. We need to start the scrolling gesture after some distance, when it's clear the finger moves. The former prototypes used 15 pixels, but it would be better to use some DPI-based value.

Glass recognizes the gesture, so I'm filing the issue there. I think I could implement the logic on Scenegraph side, but I'm afraid that some platforms are already doing that, so in this case I would at least need some flag that tells me whether or not such a smudge factor is applied somewhere in the native.