Auto-Disconnect feature / QNAP qpkg not up-to-date

That was a fast response! :)

I see your point about the "keep-alive" packets and I'd love to verify this. Is there a "communication dump" that can be triggered (something like vhui64.exe --verbose --really-verbose --debug-all ;))?

While looking through the other forum posts, I saw that other users were also "complaining" about the "auto-use" feature. Personally speaking, having a generic "auto-unuse" feature would make VirtualHere an really, really perfect product, although I have to admit, that I wouldn't know what the trigger(s) would be for the auto-disconnect (reg-ex of binary data, throughput/sec below threshold, ...). For the printer case, I could see that the window app could have an additional feature that would itself check the printer spooler (e.g. in config.ini having an List e.g. AutoConnectPrinter=LexmarkXYZ/USBIDToConnect,CannonABC/USBIDToConnect,...).

Just out of curiosity, the windows client in written in which language? My current guess in plain C. If I can provide you code that would do the spooler check, would you think of adding it to the windows client? :)

Thanks for the reference to usblyzer; didn't know that existed :).

I wouldn't go that far as to automatically map the USB port to the printer; I'd rather see it like this:
* User connects the USB printer (drivers get installed, etc...)
* User opens up the VirtualHere UI and right-clicks on the USB port and would select "Auto connect to Printer..." (instead of auto-use)
* A simple dialog with the printer enum would show the printers. User selects the printer he/she thinks it the right one

A background thread would get the printer handler [OpenPrinter("MyPrinterString", &hPrinter, NULL)] and fires up a FindFirstPrinterChangeNotification(hPrinter, PRINTER_CHANGE_JOB, PRINTER_NOTIFY_CATEGORY_ALL). Waiting for return value to be signaled with the WaitForSingleObject(...). As soon as a print job is added, set, deleted or written to then the connected to.

Would you consider adding this to VirtualHere if I wrote a simple C application that would do the print spooler checking (and call VirtualHere's API)?

Cool :). I'll try to get it done this or next week. You can then use the code as you wish (you'll get the sources, naturally). And just for the books: I don't want anything in return. It's your product and you decide what you want to put in it ;). But I would be happy if it was in ;)

Ok.... here it is.... it's a rather small C example that will call the VirtualHere UI whenever a print job event was received. The printer name and USB address are hard-coded - was a bit lazy ;)

--------------------
#include
#include
#include "windows.h"

#define PRINTER_NAME "Samsung CLX-216x Series"
#define USB_PRINTER_ADDRESS "268435467"

int main(int argc, char* argv[]) {
HANDLE hPrinter = INVALID_HANDLE_VALUE;
HANDLE hChangeNotificationObject = INVALID_HANDLE_VALUE;

printf("INFO: Starting...\n");

// initialize

if (OpenPrinter(PRINTER_NAME, &hPrinter, NULL) == 0) {
printf("ERR: Could not open printer\n");
exit(1);
} else {
printf("INFO: Printer handle is 0x%08X\n", hPrinter);
}

hChangeNotificationObject = FindFirstPrinterChangeNotification(hPrinter, PRINTER_CHANGE_JOB, 0, NULL);
if (hChangeNotificationObject == INVALID_HANDLE_VALUE) {
printf("ERR: Could not get a notification object\n");
} else {
printf("INFO: notification object handle is 0x%08X\n", hChangeNotificationObject);
}

printf("Waiting for change notification... Try to print something like the test page...\n");
WaitForSingleObject(hChangeNotificationObject, INFINITE);

// we've got an event... connect the USB port via API
system("vhui64.exe -t \"USE," USB_PRINTER_ADDRESS "\"");

// cleanup

if (hChangeNotificationObject != INVALID_HANDLE_VALUE) {
if (FindClosePrinterChangeNotification(hChangeNotificationObject) == 0) {
printf("ERR: Could not close notification object\n");
} else {
printf("INFO: Notification object closed\n");
}
}

if (hPrinter != INVALID_HANDLE_VALUE) {
if (ClosePrinter(hPrinter) == 0) {
printf("ERR: Could not close printer\n");
} else {
printf("INFO: Printer handle closed\n");
}
}

printf("INFO: done.\n");
}

http://pastebin.com/GL0VSzuW

I'm actually intested in both connecting and disconnecting... I just thought I could start with the auto-connect ;). I'll try to expand the code to do both of them.