Switch Between Password and PIN, Depending on Location

[madra]

[I hope i've not messed this up, by editing some of the personal info before uploading!]

This is a simple flow [based on the usual example WiFi proximity ones] that will switch your phone screen lock to use a PIN no. at home and a password when away from home. Most of the examples of this kind of thing tend to just turn off your screen lock completely when you're at home. I prefer to still retain some privacy, so I use a simpler PIN at home and a longer password when outside.

NOTE: On my phone, when I wake the screen after my location has changed, the login screen is usually still showing the password entry method from the previous time I opened it [eg. I was at home last time I unlocked the phone. Now I'm away from home, so it's locked with a password, but the phone is still showing a numerical entry field, as if waiting for a PIN no.]. Don't panic if this happens [as I did the first time!]. Just click the power button twice, to turn the screen off and on again and the password entry dialogue will update to the appropriate one.