Square and similar big payment processors having physical devices already using such techniques for years. These guys found something existing and try to patent it.
See: https://squareup.com/help/us/en/article/5069-accept-tips-with-the-square-app
In reference to the patent: WO2017144926A1
The document you cited is only a patent application. It may or may not ever become a patent. Even if it does get granted, it is very likely the claims will become narrowed. That said, the first claim (and only independent claim) is quite lengthy.
- Device for the implementation of cash-free payment, with the possibility of interactive tip input, which contains a server unit (3) that may be connected to a financial service provider's (1) accounting unit (la) via an information transmission channel (2), where the server unit (3) has a data traffic gate (3a) connected to the information transmission channel (2), a signal receipt input (3b) and display output (3c), a payment card reader part-unit (3d), data input part-unit (3e) and display (3f), the display output (3c) of the server unit (3) is connected to the display (3f), and the signal receipt input (3b) of the server unit (3) is connected to the payment card reader part-unit (3d) and the data input part-unit (3e), characterised by that the server unit (3) is coupled with a free data input unit (10), the free data input unit (10) having at least two selecting part-units (11) separated by a gap (T) and suitable for displaying different signals (1 la, 1 lb), a selection-sensing member (13) associated with the selecting part-unit (11) and a data transmission part unit (14) connected to the selection-sensing member (13), and the data transmission part unit (14) is connected to the signal receipt input (3b) of the server unit (3), where the selecting part-unit (11) has a screen (12), serving to display the given signals (11a, l ib), with display zones (12a, 12b) separated by a gap (T) from each other that are clearly associated with each of the given signals (11a, l ib), where the screen (12) with the display zones (12a, 12b) has an interactive data input touch screen at least in the vicinity of the display zones (12a, 12b) with a sensing surface (12c) suitable for changing at least one physical attribute of the display zones (12a, 12b), and the selection-sensing member (13) has selection transmission lines (13a, 13b) in signal- transmission connection with the sensing surface (12c) of the individual display zones (12a, 12b).
In order to infringe on this claim you would have to implement each and every step listed within it. As claims go this one is very complex and thus amenable to being circumvented. There are specific references to hardware so I don't see where your concern it that is it is patenting a "common software slider".
