[userbinator]

This sounds like it would have to be a separate mode, since otherwise it would be very easily confused with scrolling which the slide gesture is already used for - and this could make selections more difficult if they're not contiguous and located far apart; compare

1. Scroll to the first item; tap to select it; scroll to the second item; tap to select it; perform the desired action with the selection.

2. Scroll to the first item; enter selection mode; tap to select it; exit selection mode (and hopefully it still keeps the selection!); scroll to the second item; enter selection mode; tap to select it; perform the desired action with the selection.

[kampopat]

OP here. It's actually a single mode. Since the view doesn't have a horizontal scroll, the selection is activated as soon as you slide your finger horizontally and will continue (horizontal or vertical) until you lift your finger. Of course this means that only the visible cells on screen can be selected in one go before you'd have to release (it will keep the selection) and then scroll down before selecting another group. Hope that clears it up!

[aidos]

@paulmalenke pointed out (currently below) that scrolling still works because this only triggers if you start selecting in a horizontal direction.

Given that, I don't think it needs another mode at all. Alos, the tap to select behaviour should still work as it always has. You don't really lose anything.