More helpful message if scanner is not detected

[Michael Nagel]

When Simple Scan does not detect any supported scanner it shows the following message:

No scanners detected
Please check your scanner is connected and powered on

It should acknowledge that there is a very realistic chance that the scanner is connected and powered on. It should include a link to these (or similar) wiki pages:

[2] https://help.ubuntu.com/community/ScanningHowTo
[3] https://wiki.ubuntu.com/HardwareSupportComponentsScanners

[Michael Nagel (nailor)]

From duplicate/related issue:

When SimpleScan fails to find a scanner it should provide instructions on how you can submit your device information to improve your experience.
The number of people who could easily provide information about there usb devices and get them supported in ubuntu but don't know how or where to do it will be very high, it's silly to not have a way for ubuntu to crowd source that information from users who when using a piece of software and are seemingly expecting there hardware to be recognised and finding it isn't. (e.g opening simplescan with no recognised scanner).

[Michael Nagel (nailor)]

(09:47:33) robert_ancell: nailora, not opposed to improving this message. It would be nice to get some data on if people have trouble with the messaging. As usual, designs and patches welcome

[Bryce Nesbitt (bryce2)]

It would also be helpful to have a button to "REFRESH" or "RETRY".
Currently I must quit Simple Scan, plug my scanner in, wait about 3 seconds, then start Simple Scan.
That's not very simple.

[Lalo Martins (lalo.martins)]

@bryce2, separate issue, but actually what I came here to report ;-) I found an existing bug: #499416

[Robert Ancell (robert-ancell)]

@bryce2, @lalo.martins - Simple Scan rescans for scanners each time any USB device is connected - is this not working for you guys? If so, can you file new bugs with ~/.cache/simple-scan/simple-scan.log and we can have a look why this is not working for you.

[Robert Ancell (robert-ancell)]

I've merged the support for Brother, Epson and Samsung scanner detection from lp:~robert-ancell/simple-scan/driver-link. I've opened bug 1482766 for the further changes in that branch to support HP scanners (needs working PackageKit support to install the libsane-hpaio package from the archive instead of linking to the website).