Print Preview: Remembering last used printer.

printing/backend/print_backend_cups.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "printing/backend/print_backend.h"
 
 #include <dlfcn.h>
 #include <errno.h>
 #if !defined(OS_MACOSX)
 #include <gcrypt.h>
@@ skipping 138 matching lines @@
     printer_list->push_back(printer_info);
   }
 
   cupsFreeDests(num_dests, destinations);
 
   VLOG(1) << "CUPS: Enumerated " << printer_list->size() << " printers.";
   return true;
 }
 
 std::string PrintBackendCUPS::GetDefaultPrinterName() {
-  // TODO(thestig) Figure out why cupsGetDefault() lies about the default
-  // printer. :-(
-  // Return an empty string for now.
-  return std::string();
+  cups_dest_t *dests;
+  int num_dests = cupsGetDests(&dests);
+  cups_dest_t* dest = cupsGetDest(NULL, NULL, num_dests, dests);
+  return dest ? std::string(dest->name) : std::string();

[Lei Zhang, 2011/06/08 00:41:59]

I'm glad you found a reliable way to get the default printer! However, let's
write it to handle the "2" version of the CUPS function as well:

  cups_dest_t *dests;
  int num_dests = GetDests(&dests);
  cups_dest_t* dest = cupsGetDest(NULL, NULL, num_dests, dests);
  return dest ? std::string(dest->name) : std::string();

Also, please retain a comment to indicate cupsGetDefault() returns the wrong
result.

[dpapad, 2011/06/08 16:33:56]

Done.

 }
 
 bool PrintBackendCUPS::GetPrinterCapsAndDefaults(
     const std::string& printer_name,
     PrinterCapsAndDefaults* printer_info) {
   DCHECK(printer_info);
 
   VLOG(1) << "CUPS: Getting Caps and Defaults for: " << printer_name;
 
   FilePath ppd_path(GetPPD(printer_name.c_str()));
@@ skipping 104 matching lines @@
                    << ", HTTP error: " << http_error;
         file_util::Delete(ppd_path, false);
         ppd_path.clear();
       }
     }
   }
   return ppd_path;
 }
 
 }  // namespace printing