Detect whether Windows is printing?

[emendelson]

I'm working on a script in which I want to close a program (the open-source document viewer Evince) after it finishes printing. Is there any way to detect whether Windows is currently printing, so that I can wait to close the program until printing is complete? (If I close Evince too early, it seems to stop printing the current file.)

I won't know which printer is being used. I've been experimenting with the following code, but it never reports whether that printing is actually occurring, even during a very long print job:

$intPrinters = 1
$objWMIService = ObjGet("winmgmts:\\" & @ComputerName & "\root\CIMV2")
$colItems = $objWMIService.ExecQuery("SELECT * FROM Win32_Printer")

While 1
    For $objItem In $colItems
        If $objItem.PrinterStatus = 4 Then
            MsgBox(0, "", "Printing")
        EndIf
        $intPrinters = $intPrinters + 1
    Next
    Sleep(100)
WEnd

I adapted this from the posts in this thread:

But probably I've misunderstood the original code.

The purpose of this test is simply to make sure that printing is NOT occurring, so that I can close the document window safely. I don't need to know that printing DID occur - only that it is not occurring at the present moment.

Many thanks for any help.

Edited March 13, 2011 by Edward Mendelson

[emendelson]

I figured out what I was doing wrong, and this code seems to work as a function to detect whether Windows is printing. I hope someone else might also find it useful:

Func TestPrinting()
    Dim $intPrinters, $objWMIService, $objItem, $colItems, $printing
    While 1
        $printing = 0
        $intPrinters = 1
        $objWMIService = ObjGet("winmgmts:\\" & @ComputerName & "\root\CIMV2")
        $colItems = $objWMIService.ExecQuery("SELECT * FROM Win32_Printer")
        For $objItem In $colItems
            If $objItem.PrinterStatus = 4 Then
                $printing = 1
                ; MsgBox(0, "", $objItem.Name & " Printing")
            EndIf
            $intPrinters = $intPrinters + 1
        Next
        If $printing = 0 Then
            ExitLoop
        EndIf
        Sleep(500)
    WEnd
EndFunc   ;==>TestPrinting

I don't have any good reason to set the Sleep interval at 500; it's just a wild guess. If there's any reason to make it larger or smaller, I'd be grateful to know what it ought to be!