[sane-devel] SANE_Device issue

[Ralph Little]

Hi,

On Wed, May 28, 2025 at 9:32 PM Ben Olden-Cooligan <ben.cyanfish at gmail.com>
wrote:

> It's very hacky but I get around this in NAPS2 by creating a temporary
> config dir with only the one backend for the specified device.
>

It certainly sounds a bit janky, but I didn't think of this. It might be
the only option to get the information without an API change.

The other option actually is just to replace that descriptive information
with something nondescript like "None" or "Unknown".
Doesn't look all that great but it would avoid the delay on startup.

Cheers,
Ralph


>
> https://github.com/cyanfish/naps2/blob/master/NAPS2.Sdk/Scan/Internal/Sane/SaneScanDriver.cs#L324
>
> Certainly it would be nice if there was an API for this but there doesn't
> seem to be.
>
>
> On Wed, May 28, 2025, 21:24 Ralph Little <skelband at gmail.com> wrote:
>
>> Hi Devs,
>> I'm looking at an issue that affects xsane that I have had a number of
>> complaints about.
>>
>> When xsane starts, it calls sane_get_devices() regardless of whether or
>> not a specific device was specified by the user. The main issue is the long
>> delay before xsane starts up while device polling is happening, which *can*
>> be annoying long.
>>
>> On the face of it, this seems pointless if we already know which device
>> the user wants to use. However, in various places, xsane uses the
>> descriptive information for that device that we get in the SANE_Device
>> structure which can only be got from sane_get_devices() This seems like a
>> gaping hole in the protocol that the information about a specific device
>> cannot be determined without searching for all devices.
>>
>> Does anyone have any ideas how we might get around this without breaking
>> backwards compatibility in the SANE API and have I missed some official
>> method whereby this information might be obtained?
>>
>> Cheers,
>> Ralph
>>
>>
>>
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