Bug 1432285 - Implement an nsPrintingPromptService::GetSingleton method and make XPCOM use that. r=bobowen

MozReview-Commit-ID: AsiAnJrxKlB

toolkit/components/printingui/nsPrintingPromptService.cpp

@@ -5,12 +5,16 @@
 
 #include "nsPrintingPromptService.h"
 
+#include "mozilla/ClearOnShutdown.h"
+#include "mozilla/RefPtr.h"
+#include "mozilla/StaticPtr.h"
 #include "nsIDOMWindow.h"
 #include "nsIServiceManager.h"
 #include "nsISupportsUtils.h"
 #include "nsString.h"
 #include "nsIPrintDialogService.h"
 #include "nsPIDOMWindow.h"
+#include "nsXULAppAPI.h"
 
 // Printing Progress Includes
 #if !defined(XP_MACOSX)
@@ -23,10 +27,31 @@ static const char* kPrtPrvProgressDialogURL =
   "chrome://global/content/printPreviewProgress.xul";
 #endif
 
+using namespace mozilla;
+
 NS_IMPL_ISUPPORTS(nsPrintingPromptService,
                   nsIPrintingPromptService,
                   nsIWebProgressListener)
 
+
+StaticRefPtr<nsPrintingPromptService> sSingleton;
+
+/* static */ already_AddRefed<nsPrintingPromptService>
+nsPrintingPromptService::GetSingleton()
+{
+  MOZ_ASSERT(XRE_IsParentProcess(),
+             "The content process must use nsPrintingProxy");
+
+  if (!sSingleton) {
+    sSingleton = new nsPrintingPromptService();
+    sSingleton->Init();
+    ClearOnShutdown(&sSingleton);
+  }
+
+  return do_AddRef(sSingleton);
+}
+
+
 nsPrintingPromptService::nsPrintingPromptService() = default;
 
 nsPrintingPromptService::~nsPrintingPromptService() = default;

toolkit/components/printingui/nsPrintingPromptService.h

@@ -31,22 +31,21 @@ class nsIDOMWindow;
 class nsIDialogParamBlock;
 #endif
 
-class nsPrintingPromptService
+class nsPrintingPromptService final
   : public nsIPrintingPromptService
   , public nsIWebProgressListener
 {
-
 public:
-  nsPrintingPromptService();
-
-  nsresult Init();
+  static already_AddRefed<nsPrintingPromptService> GetSingleton();
 
   NS_DECL_NSIPRINTINGPROMPTSERVICE
   NS_DECL_NSIWEBPROGRESSLISTENER
   NS_DECL_ISUPPORTS
 
 protected:
+  nsPrintingPromptService();
   virtual ~nsPrintingPromptService();
+  nsresult Init();
 
 private:
 #if !defined(XP_MACOSX)

toolkit/xre/nsEmbeddingModule.cpp

@@ -38,7 +38,8 @@ NS_GENERIC_FACTORY_CONSTRUCTOR(nsBaseCommandController)
 #ifdef MOZ_XUL
 NS_GENERIC_FACTORY_CONSTRUCTOR(nsDialogParamBlock)
 #ifdef NS_PRINTING
-NS_GENERIC_FACTORY_CONSTRUCTOR_INIT(nsPrintingPromptService, Init)
+NS_GENERIC_FACTORY_SINGLETON_CONSTRUCTOR(nsPrintingPromptService,
+                                         nsPrintingPromptService::GetSingleton)
 #ifdef PROXY_PRINTING
 NS_GENERIC_FACTORY_SINGLETON_CONSTRUCTOR(nsPrintingProxy,
                                          nsPrintingProxy::GetInstance)