[bluetooth] Computer pairing is unimplemented but the UI still lets you try it

[Sebastien Bacher]

Using rtm 228 on krillin, the settings code let you try to pair any device but doesn't have code to deal with all types. If you try to pair i.e a laptop to your phone, the UI shows the pairing button, but clicking on it just brings you back to the devices list without doing anything.

<https://wiki.ubuntu.com/Bluetooth#Listing_devices>: "If a device is of a type that Ubuntu Touch does not currently work with, it should be present (so that you don’t think there’s a problem with the hardware) but greyed out and with a ⛔ no entry icon."

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Matthew Paul Thomas (mpt)]

The spec says: "If a device is of a type that Ubuntu Touch does not currently work with, it should be present (so that you don’t think there’s a problem with the hardware) but greyed out." <https://wiki.ubuntu.com/Bluetooth#Listing_devices>

Given that, I don't understand what you mean by "disable the pairing button". Since the item is greyed out, you'd never get to the dialog with the "Pair" button in the first place.

[Sebastien Bacher (seb128)]

Thanks mpt, in fact I overlooked that part of the specification but changed the code to disable the connect button [1]. Some extra questions for you then...

- do you consider it better to disable the device line rather than the connect button (disabling the button means you can look at the device details, not sure if that's useful if you cannot connect though)

- having the item simply disabled doesn't convey well the reason why it is disabled (I first though it was a bug), is that worth opening a new bug about?

[1] http://bazaar.launchpad.net/~system-settings-touch/ubuntu-system-settings/trunk/revision/1328

[Matthew Paul Thomas (mpt)]

I guess the choices are:
(A) not show the device at all -- people would double-check that the device is turned on, try to get closer, etc
(B) show it insensitive -- people wonder why it's insensitive
(C) show it as normal (crowding out devices you can actually use), but with some kind of "You can't pair with this" message in place of the "Pair" button (well, why didn't you tell me that before I came here?)
(D) show it as normal (again crowding out devices you can actually use), displaying an explanatory error when you tap "Pair" (again, why didn't you tell me that before?)

I think B is the least bad, avoiding both the problems where you think something is wrong with the hardware and where you're annoyed by being led down a garden path. I'd be interested in ideas for better communicating that unimplemented device types are unusable, without involving a separate screen for them. Maybe using a 🚫 no-entry symbol for their icon?

[Sebastien Bacher (seb128)]

@mpt, what about having a caption at the bottom of the list stating "non supported device types are listed can't be selected" or similar?

[Matthew Paul Thomas (mpt)]

I think if we're having to explain what we're doing, we're doing the wrong thing.

This is a bit more important now that the pocket PC will let you connect more than just audio devices. I've updated the spec with the no-entry icon. <https://wiki.ubuntu.com/Bluetooth?action=diff&rev2=64&rev1=63>