Precondition:
The user has opened the app and has selected the soil layer.
Main success scenario:
First the user globally tells a pH topsoil value, soil weight and yield grade.
Then the user successfully adds, moves, removes, deletes and edits:
pH value areas for topsoil
pH value areas for subsoil
soil weight class
yield grade
in their map using the soil layer, where it differs from the global value.
This includes positioning the pH value areas in the appropriate locations and adjusting their values as needed.
A big brush is used to draw on the soil layer.
The user can check the values at individual spots by clicking on it.
Alternative scenario:
The user accidentally edits, moves or removes an element and uses undo to correct the mistake.
The user accidentally adds an element and deletes it with the "delete" or "undo" functionality.
Error scenario:
The user attempts to edit a soil weight class or pH value in a area that is not within the acceptable range and the app displays an error message.
The previous values stay unmodified.
Postcondition:
The user's map includes the added, moved or edited pH value areas as desired.
Non-functional Constraints:
is a brushing layer
The app must clearly communicate to the user the constraints for editing pH values in the soil layer.
Performance: Map sizes with more than 1ha in 100 raster elements (in 1a=100m²) per year with 4 values per raster element should be usable without noticeable delays and acceptable memory overhead
Notes:
pH values have one significant digit, not more (e.g. 4.5, 6.7, 8.4)