Virtual Cloud Print Driver for Mac.

cloud_print/virtual_driver/posix/printer_driver_util_mac.mm

+// 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 "cloud_print/virtual_driver/posix/printer_driver_util_posix.h"
+
+#import <ApplicationServices/ApplicationServices.h>
+#import <Foundation/NSAutoreleasePool.h>
+#import <Foundation/NSAppleEventDescriptor.h>
+#import <CoreServices/CoreServices.h>
+
+#include "base/logging.h"
+#include "base/mac/foundation_util.h"
+
+#include <cups/backend.h>
+
+#include <stdlib.h>
+#include <string>
+
+// Duplicated is content/common/cloud_print_class_mac.h
+const AEEventClass cloudPrintClass = 'GCPp';
+
+void LaunchPrintDialog(std::string outputPath,
+                       std::string jobTitle,
+                       std::string user) {
+  NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
+  OSStatus status = noErr;
+  FSRef ref;
+  // Generate the bundle ID for the Service process.
+  std::string bundleID =  base::mac::BaseBundleID();
+  bundleID = bundleID + ".helper";
+  CFStringRef bundleIDCF = CFStringCreateWithCString(
+                               NULL,
+                               bundleID.c_str(),
+                               kCFStringEncodingUTF8);
+  CFURLRef* kDontWantURL = NULL;
+  // Locate the service process with the help of the bundle ID.
+  status = LSFindApplicationForInfo(kLSUnknownCreator, bundleIDCF,
+                                    NULL, &ref, kDontWantURL);
+
+  if (status != noErr) {
+    LOG(ERROR) <<"Couldn't find the service process";
+    exit(CUPS_BACKEND_CANCEL);
+  }
+  // Create the AppleEvent parameters.
+  NSAppleEventDescriptor* printPath = [NSAppleEventDescriptor
+      descriptorWithString:[NSString stringWithUTF8String:outputPath.c_str()]];
+  NSAppleEventDescriptor* title = [NSAppleEventDescriptor
+      descriptorWithString:[NSString stringWithUTF8String:jobTitle.c_str()]];
+  NSAppleEventDescriptor* mime = [NSAppleEventDescriptor
+      descriptorWithString:@"application/pdf"];
+
+  // Create and populate the list of parameters.
+  // Note that the array starts at index 1.
+  NSAppleEventDescriptor* parameters = [NSAppleEventDescriptor listDescriptor];

[Scott Byer, 2011/08/02 23:52:52]

The order of construction here is funny; I would not even start constructing
parameters until after the event was created.

Also, there's a nil check on event but not on parameters. Both affect whether
you send a valid message.

[abeera, 2011/08/03 20:34:47]

Done.

+  [parameters insertDescriptor:mime atIndex:1];
+  [parameters insertDescriptor:printPath atIndex:2];
+  [parameters insertDescriptor:title atIndex:3];
+  NSAppleEventDescriptor* event =
+      [NSAppleEventDescriptor appleEventWithEventClass:cloudPrintClass
+                                               eventID:cloudPrintClass
+                                      targetDescriptor:nil
+                                              returnID:kAutoGenerateReturnID
+                                         transactionID:kAnyTransactionID];
+
+  if(event == nil) {
+    LOG(ERROR) << "Unable to Create Event";
+    exit(CUPS_BACKEND_CANCEL);
+  }
+  // Set the application launch parameters.
+  // We are just using launch services to deliver our Apple Event.
+  LSApplicationParameters params = {0, kLSLaunchDefaults , &ref, NULL, NULL,

[Scott Byer, 2011/08/02 23:52:52]

...I would move this down to just above where the initial event is set

[abeera, 2011/08/03 20:34:47]

Done.

+                                    NULL, NULL};
+  // Create the actual Apple Event.
+  [event setParamDescriptor:parameters forKeyword:cloudPrintClass];

[Scott Byer, 2011/08/02 23:52:52]

...and I would move this up to as soon as parameters was constructed.

The idea is to increase the locality of what's being done. Avoid card shuffling
initialization sequences.

[abeera, 2011/08/03 20:34:47]

Done.

+  params.initialEvent =(AppleEvent*) [event aeDesc];

[Scott Byer, 2011/08/02 23:52:52]

nit: space after =, prefer static_cast<>()

[abeera, 2011/08/03 20:34:47]

Done.

+  // Deliver the Apple Event using launch services.
+  status = LSOpenApplication(&params, NULL);
+  if (status != noErr) {
+    LOG(ERROR) <<"Unable to launch";

[Scott Byer, 2011/08/02 23:52:52]

nit: space after operator

[abeera, 2011/08/03 20:34:47]

Done.

+    LOG(ERROR) << GetMacOSStatusErrorString(status);
+    LOG(ERROR) << GetMacOSStatusCommentString(status);
+    exit(CUPS_BACKEND_CANCEL);
+  }
+
+  [pool release];
+  return;
+}