Hi, [CC to the list, I guess that was intended :-)]
On Thu, Feb 13, 2003 at 11:18:46AM -0800, Derry Bryson wrote: [I wrote:] > > No, sorry. That's not how it works. It only works for TWAIN because > > the user is forced to manually install a driver for every single > > scanner and Windows users usally have only one scanner at a single > > computer. Think about what would happen if all the scanner drivers had > > been provided by Microsoft together with the operating system and > > installed by default. If the drivers didn't check for the existance of > > the devices, the TWAIN list would be endless. > > > > I see your point. I was only looking at the number of backends and not > really considering how many scanners really are supported. > > I will have to give this more thought. It doesn't seem like a good idea > to go through the detection process every time an app requests the device > list. Usually it happens only once during the runtime of the application even if the standard allows that the list changes during runtime. But keeping a fixed list doesn't work, as devices (especially USB) can be plugged in and out everytime. In an ideal world, you would plug-in any (supported) scanner and run the scan application without any other setup action. That works for most USB scanners nowerdays. And keep in mind that the device file/address of the device may change after replugging, so even if you have a list of device files, the scanner may have changed meanwhile. Bye, Henning
