I personally use the i3 window manager, but i guess these simple examples can be added in one way or another for other WM/DE solutions.

bindsym Mod4+Shift+w   exec --no-startup-id bwp --next
bindsym Mod4+Control+w exec --no-startup-id bwp --prev
bindsym Mod4+x         exec --no-startup-id bwp --lock --wallpaper

When bwp is executed without any arguments it will reset the wallpaper to the last known one (or a random one if none is found). So add this to your startup script, for example ~/.config/i3/config:

exec --no-startup-id bwp