The Lines screen (shown above) is used to add products to an order. Tapping the plus buttons increment the quantity ordered. Tapping anywhere else displays the details for an item, which allows the user to edit the quantity.
But the buttons are difficult to tap, and the details screen can be a distraction. The target area extends either side of the buttons, but they are too close to the scrollbar for that to help.
The proposed solution is to use a long press or ‘touch & hold’ gesture, to access the details screen. This is in line with Android design principles, and it frees up the tap gesture as a way to increment the quantity.
Minus buttons could be added to decrement the quantity. These would be in a different colour to the existing ones, and moved slightly to the left.
I will be conducting a survey of user preferences, and any solution will be pushed out to the beta channel, in the first instance.