[Mono-bugs] [Bug 80519][Nor] New - System.Drawing.Printing doesn't find the default printer.

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Changed by vlad.dimitrov at gmail.com.

http://bugzilla.ximian.com/show_bug.cgi?id=80519

--- shadow/80519	2007-01-14 12:15:12.000000000 -0500
+++ shadow/80519.tmp.21067	2007-01-14 12:15:12.000000000 -0500
@@ -0,0 +1,88 @@
+Bug#: 80519
+Product: Mono: Class Libraries
+Version: 1.2
+OS: GNU/Linux [Other]
+OS Details: 
+Status: NEW   
+Resolution: 
+Severity: 
+Priority: Normal
+Component: Sys.Drawing.
+AssignedTo: mono-bugs at ximian.com                            
+ReportedBy: vlad.dimitrov at gmail.com               
+QAContact: mono-bugs at ximian.com
+TargetMilestone: ---
+URL: 
+Cc: 
+Summary: System.Drawing.Printing doesn't find the default printer.
+
+1) PreviewPrintController throws exception because it doesn't have valid 
+PrinterSettings associated with the PrintDocument 
+2) PrintDocument has some PrinterSetttings but they are not valid because 
+the PrinterName is empty
+3) PrinterName is empty because SysPrn.Service.DefaultPrinter is empty.
+4) Since System.Drawing.Printing.PrinterSettings.InstalledPrinters (witch 
+gets it from SysPrn.Service.InstalledPrinters) returns my printer name 
+this means that SysPrn.Service has "cups_installed" set to true
+5) This leads me to the conclusion that "IntPtr cupsGetDefault ();" from 
+"libcups" returns empty string 
+
+Based on the information here:
+
+http://www.cups.org/documentation.php/api-cups.html#cupsGetDefault2
+
+It says "Applications should use the cupsGetDests() and cupsGetDest() 
+functions to get the user-defined default printer, as this function does 
+not support the lpoptions-defined default printer."
+
+I made a test on my machine (Ubuntu 6.06) and found a solution that works 
+on my machine. I used some code from mono as a code base and this piece of 
+code finds my default printer. 
+
+        private void button2_Click (object sender, EventArgs e)
+        {
+            int printerCount;
+            IntPtr savedDests = IntPtr.Zero;
+            IntPtr dests;
+            CUPS_DESTS dest = new CUPS_DESTS (); 
+            int destStructSize = Marshal.SizeOf (typeof (CUPS_DESTS));
+            string defPrinter = string.Empty;
+
+            //if (cups_installed == false)
+            //    return col;
+
+            printerCount = cupsGetDests (ref savedDests); 
+
+            dests = savedDests;
+            for (int i = 0; i < printerCount; i++) {
+                dest = (CUPS_DESTS) Marshal.PtrToStructure (dests, typeof 
+(CUPS_DESTS));
+
+                if (dest.is_default != 0) {
+                    defPrinter = Marshal.PtrToStringAnsi (dest.name);
+                }
+                // Free allocated unmanaged memory
+                Marshal.FreeHGlobal (dest.name);
+                Marshal.FreeHGlobal (dest.instance);
+                Marshal.FreeHGlobal (dest.options);
+                dests = new IntPtr (dests.ToInt64 () + destStructSize); 
+            }
+            // Free allocated unmanaged memory
+            Marshal.FreeHGlobal (savedDests);
+
+            textBox1.Text = defPrinter;
+        }
+
+        [DllImport ("libcups", CharSet = CharSet.Ansi)]
+        static extern int cupsGetDests (ref IntPtr dests);
+        
+        public struct CUPS_DESTS
+        {
+            public IntPtr name;
+            public IntPtr instance;
+            public int is_default; 
+            public int num_options;
+            public IntPtr options;
+        }
+
+I hope this should be enough to fix the problem.