1 files changed, 13 insertions, 1 deletions
diff --git a/printing/printing_context_mac.mm b/printing/printing_context_mac.mm
index 25f0ef6..063197e 100644
--- a/printing/printing_context_mac.mm
+++ b/printing/printing_context_mac.mm
@@ -93,10 +93,12 @@ PrintingContext::Result PrintingContextMac::UpdatePrintSettings(
   std::string printer_name;
   int copies;
   bool collate;
+  bool two_sided;
   if (!job_settings.GetBoolean(kSettingLandscape, &landscape) ||
       !job_settings.GetString(kSettingPrinterName, &printer_name) ||
       !job_settings.GetInteger(kSettingCopies, &copies) ||
-      !job_settings.GetBoolean(kSettingCollate, &collate)) {
+      !job_settings.GetBoolean(kSettingCollate, &collate) ||
+      !job_settings.GetBoolean(kSettingTwoSided, &two_sided)) {
     return OnError();
   }
 
@@ -112,6 +114,9 @@ PrintingContext::Result PrintingContextMac::UpdatePrintSettings(
   if (!SetOrientationIsLandscape(landscape))
     return OnError();
 
+  if (!SetDuplexModeIsTwoSided(two_sided))
+    return OnError();
+
   [print_info_.get() updateFromPMPrintSettings];
 
   InitPrintSettingsFromPrintInfo(ranges);
@@ -173,6 +178,13 @@ bool PrintingContextMac::SetOrientationIsLandscape(bool landscape) {
   return true;
 }
 
+bool PrintingContextMac::SetDuplexModeIsTwoSided(bool two_sided) {
+  PMDuplexMode duplexSetting = two_sided ? kPMDuplexNoTumble : kPMDuplexNone;
+  PMPrintSettings pmPrintSettings =
+      static_cast<PMPrintSettings>([print_info_.get() PMPrintSettings]);
+  return PMSetDuplex(pmPrintSettings, duplexSetting) == noErr;
+}
+
 void PrintingContextMac::ParsePrintInfo(NSPrintInfo* print_info) {
   ResetSettings();
   print_info_.reset([print_info retain]);