The switch case statement allows the compiler to optimize code. More
specifically, if the values are densely packed, then the compiler may
generate a jump table. The switch statement also looks cleaner.
As for the if statements in adjustWorkArea(), they were overlooked by
me after LayerSurfaceV1Interface::exclusiveEdge() had been introduced.
The layer-shell protocol allows wayland clients to create surfaces that
can be used for building desktop environment components such as panels,
notifications, etc.
The support for the plasma-shell protocol will be dropped once plasma in
all its entirety is ported to the layer-shell protocol.
