Tolerate tool name being None

[ColinKinloch]

Here's a relevant link: https://gitlab.freedesktop.org/wayland/wayland-protocols/-/merge_requests/286

[odysseywestra]

Would it be better to give it an "Unknown Device" kind of output instead of None? That way the user knows there's a device connected, just there not tool_name assigned to it? If that doesn't matter then I'm fine pulling it in as is. @AesaraB what are your thoughts?

[jtojnar]

Would it be better to give it an "Unknown Device" kind of output instead of None? That way the user knows there's a device connected, just there not tool_name assigned to it?

It does not look like the name is used for anything user facing here:

• _device_name_uuid is used in https://github.com/ColinKinloch/mypaint/blob/9518ffd59a09e3989b0dea9e418d0b2272b3855f/gui/brushmanager.py#L995 and https://github.com/ColinKinloch/mypaint/blob/9518ffd59a09e3989b0dea9e418d0b2272b3855f/gui/brushmanager.py#L1007 to associate brush with device. IMO we should not be using the name there since if multiple devices lack a name, they will be stepping on each other’s toes.
• The eraser hack comes from 314f7c6. Ignoring it when name is missing is probably fine. (Ideally, we would remove it, hoping it is no longer necessary, but that is unrelated to this PR.)

[jtojnar]

Would be nice to include the link to the wayland stuff in the commit message so that the reasoning is accessible in the future (e.g. with git blame).

[odysseywestra]

Then I'm guessing the right course of actions instead of none is to generate a consistent random device ID then?

[jtojnar]

Well, random id would not be able to match anything because it would change between storing the brush and matching it against device. Maybe we could use the device id but that would not work when there are multiple devices with same id – I assume pencil and eraser would have the same id. And it is optional too.

Edit: Actually, the linked part of the spec does not sound relevant to me, I would expect zwp_tablet_tool_v2 to be relevant instead of zwp_tablet_v2.

Edit 2: Right, looks like GTK 4 splits them correctly but GTK 3, preceding Wayland, mixes Devices and tools somewhat. But GdkDeviceTool did appear in GTK 3.22. Maybe we should port to it and use the serial id. This would also make porting to GTK 4 easier.

[odysseywestra]

Yeah that sounds like that should be a better way to go then just putting an exception for a empty device name.

So I guess in terms of this pull request we would need to close it, and then open up another issue regarding this for porting to gtk4.

Unless @ColinKinloch, are willing to put in the work to address it?