Bug 1095098 - move do_QueryObject templates into their own header; r=froydnj

accessible/xpcom/xpcAccessibleTextRange.cpp

@@ -11,6 +11,7 @@
 
 #include "nsIMutableArray.h"
 #include "nsComponentManagerUtils.h"
+#include "nsQueryObject.h"
 
 using namespace mozilla;
 using namespace mozilla::a11y;

accessible/xul/XULTreeAccessible.cpp

@@ -17,6 +17,7 @@
 #include "Role.h"
 #include "States.h"
 #include "XULTreeGridAccessible.h"
+#include "nsQueryObject.h"
 
 #include "nsComponentManagerUtils.h"
 #include "nsIAccessibleRelation.h"

accessible/xul/XULTreeGridAccessible.cpp

@@ -13,6 +13,7 @@
 #include "Relation.h"
 #include "Role.h"
 #include "States.h"
+#include "nsQueryObject.h"
 
 #include "nsIBoxObject.h"
 #include "nsIMutableArray.h"

chrome/nsChromeRegistry.cpp

@@ -15,6 +15,7 @@
 #include "nsEscape.h"
 #include "nsNetUtil.h"
 #include "nsString.h"
+#include "nsQueryObject.h"
 
 #include "mozilla/CSSStyleSheet.h"
 #include "mozilla/dom/URL.h"

docshell/base/nsDSURIContentListener.cpp

@@ -14,6 +14,7 @@
 #include "nsIDOMWindow.h"
 #include "nsNetUtil.h"
 #include "nsAutoPtr.h"
+#include "nsQueryObject.h"
 #include "nsIHttpChannel.h"
 #include "nsIScriptSecurityManager.h"
 #include "nsError.h"

docshell/base/nsDocShell.cpp

@@ -59,6 +59,7 @@
 #include "nsContentPolicyUtils.h" // NS_CheckContentLoadPolicy(...)
 #include "nsISeekableStream.h"
 #include "nsAutoPtr.h"
+#include "nsQueryObject.h"
 #include "nsIWritablePropertyBag2.h"
 #include "nsIAppShell.h"
 #include "nsWidgetsCID.h"

dom/base/nsDOMWindowUtils.cpp

@@ -24,6 +24,7 @@
 #include "nsFrame.h"
 #include "mozilla/layers/ShadowLayers.h"
 #include "ClientLayerManager.h"
+#include "nsQueryObject.h"
 
 #include "nsIScrollableFrame.h"
 

dom/base/nsDocument.cpp

@@ -35,6 +35,7 @@
 #include "nsDocShell.h"
 #include "nsIDocShellTreeItem.h"
 #include "nsCOMArray.h"
+#include "nsQueryObject.h"
 #include "nsDOMClassInfo.h"
 #include "mozilla/Services.h"
 

dom/base/nsFrameMessageManager.cpp

@@ -44,6 +44,7 @@
 #include "mozilla/jsipc/CrossProcessObjectWrappers.h"
 #include "nsPrintfCString.h"
 #include "nsXULAppAPI.h"
+#include "nsQueryObject.h"
 #include <algorithm>
 
 #ifdef ANDROID

dom/base/nsGlobalWindow.cpp

@@ -120,6 +120,7 @@
 #include "nsIControllerContext.h"
 #include "nsGlobalWindowCommands.h"
 #include "nsAutoPtr.h"
+#include "nsQueryObject.h"
 #include "nsContentUtils.h"
 #include "nsCSSProps.h"
 #include "nsIDOMFileList.h"

dom/base/nsStyleLinkElement.cpp

@@ -30,6 +30,7 @@
 #include "nsUnicharInputStream.h"
 #include "nsContentUtils.h"
 #include "nsStyleUtil.h"
+#include "nsQueryObject.h"
 
 using namespace mozilla;
 using namespace mozilla::dom;

dom/base/nsTreeSanitizer.cpp

@@ -23,6 +23,7 @@
 #include "nsContentUtils.h"
 #include "nsIParserUtils.h"
 #include "nsIDocument.h"
+#include "nsQueryObject.h"
 
 using namespace mozilla;
 

dom/bluetooth/bluetooth1/BluetoothRilListener.cpp

@@ -14,6 +14,7 @@
 #include "nsITelephonyService.h"
 #include "nsServiceManagerUtils.h"
 #include "nsString.h"
+#include "nsQueryObject.h"
 
 USING_BLUETOOTH_NAMESPACE
 

dom/bluetooth/bluetooth2/BluetoothRilListener.cpp

@@ -13,6 +13,7 @@
 #include "nsITelephonyService.h"
 #include "nsServiceManagerUtils.h"
 #include "nsString.h"
+#include "nsQueryObject.h"
 
 USING_BLUETOOTH_NAMESPACE
 

dom/cache/TypeUtils.cpp

@@ -23,6 +23,7 @@
 #include "nsIAsyncInputStream.h"
 #include "nsIAsyncOutputStream.h"
 #include "nsIIPCSerializableInputStream.h"
+#include "nsQueryObject.h"
 #include "nsStreamUtils.h"
 #include "nsString.h"
 #include "nsURLParsers.h"

dom/camera/DOMCameraControlListener.cpp

@@ -9,6 +9,7 @@
 #include "CameraPreviewMediaStream.h"
 #include "mozilla/dom/CameraManagerBinding.h"
 #include "mozilla/dom/File.h"
+#include "nsQueryObject.h"
 
 using namespace mozilla;
 using namespace mozilla::dom;

dom/camera/DOMCameraManager.cpp

@@ -19,6 +19,7 @@
 #include "CameraPreferences.h"
 #include "mozilla/dom/BindingUtils.h"
 #include "mozilla/dom/PermissionMessageUtils.h"
+#include "nsQueryObject.h"
 
 using namespace mozilla;
 using namespace mozilla::dom;

dom/filehandle/FileStreamWrappers.cpp

@@ -17,6 +17,7 @@
 #include "nsIRunnable.h"
 #include "nsISeekableStream.h"
 #include "nsThreadUtils.h"
+#include "nsQueryObject.h"
 
 #ifdef DEBUG
 #include "nsXULAppAPI.h"

dom/html/HTMLFieldSetElement.cpp

@@ -9,6 +9,7 @@
 #include "mozilla/dom/HTMLFieldSetElement.h"
 #include "mozilla/dom/HTMLFieldSetElementBinding.h"
 #include "nsContentList.h"
+#include "nsQueryObject.h"
 
 NS_IMPL_NS_NEW_HTML_ELEMENT(FieldSet)
 

dom/html/HTMLFormElement.cpp

@@ -30,6 +30,7 @@
 #include "nsIMutableArray.h"
 #include "nsIFormAutofillContentService.h"
 #include "mozilla/BinarySearch.h"
+#include "nsQueryObject.h"
 
 // form submission
 #include "mozilla/Telemetry.h"

dom/html/HTMLLabelElement.cpp

@@ -12,6 +12,7 @@
 #include "mozilla/dom/HTMLLabelElementBinding.h"
 #include "nsFocusManager.h"
 #include "nsIDOMMouseEvent.h"
+#include "nsQueryObject.h"
 
 // construction, destruction
 

dom/html/HTMLMediaElement.cpp

@@ -38,6 +38,7 @@
 #include "nsIThreadInternal.h"
 #include "nsContentUtils.h"
 #include "nsIRequest.h"
+#include "nsQueryObject.h"
 
 #include "nsIScriptSecurityManager.h"
 #include "nsIXPConnect.h"

dom/html/nsGenericHTMLElement.cpp

@@ -17,6 +17,7 @@
 #include "nsAttrValueInlines.h"
 #include "nsCOMPtr.h"
 #include "nsIAtom.h"
+#include "nsQueryObject.h"
 #include "nsIContentInlines.h"
 #include "nsIContentViewer.h"
 #include "mozilla/css/StyleRule.h"

dom/indexedDB/IDBDatabase.cpp

@@ -50,6 +50,7 @@
 #include "nsThreadUtils.h"
 #include "ProfilerHelpers.h"
 #include "ReportInternalError.h"
+#include "nsQueryObject.h"
 
 // Include this last to avoid path problems on Windows.
 #include "ActorsChild.h"

dom/indexedDB/IDBObjectStore.cpp

@@ -41,6 +41,7 @@
 #include "mozilla/ipc/BackgroundChild.h"
 #include "mozilla/ipc/PBackgroundSharedTypes.h"
 #include "nsCOMPtr.h"
+#include "nsQueryObject.h"
 #include "ProfilerHelpers.h"
 #include "ReportInternalError.h"
 #include "WorkerPrivate.h"

dom/media/MediaDevices.cpp

@@ -11,6 +11,7 @@
 #include "nsIScriptGlobalObject.h"
 #include "nsIPermissionManager.h"
 #include "nsPIDOMWindow.h"
+#include "nsQueryObject.h"
 
 namespace mozilla {
 namespace dom {

dom/media/MediaPermissionGonk.cpp

@@ -12,6 +12,7 @@
 #include "nsIStringEnumerator.h"
 #include "nsISupportsArray.h"
 #include "nsJSUtils.h"
+#include "nsQueryObject.h"
 #include "nsPIDOMWindow.h"
 #include "nsTArray.h"
 #include "GetUserMediaRequest.h"

dom/media/systemservices/MediaChild.cpp

@@ -11,6 +11,7 @@
 #include "nsGlobalWindow.h"
 #include "mozilla/MediaManager.h"
 #include "prlog.h"
+#include "nsQueryObject.h"
 
 #undef LOG
 #if defined(PR_LOGGING)

dom/media/webspeech/recognition/SpeechRecognition.cpp

@@ -21,6 +21,7 @@
 #include "mozilla/dom/SpeechRecognitionEvent.h"
 #include "nsIObserverService.h"
 #include "nsServiceManagerUtils.h"
+#include "nsQueryObject.h"
 
 #include <algorithm>
 

dom/plugins/base/nsPluginHost.cpp

@@ -72,6 +72,7 @@
 #include "prprf.h"
 #include "nsThreadUtils.h"
 #include "nsIInputStreamTee.h"
+#include "nsQueryObject.h"
 
 #include "nsDirectoryServiceDefs.h"
 #include "nsAppDirectoryServiceDefs.h"

dom/svg/DOMSVGStringList.cpp

@@ -10,6 +10,7 @@
 #include "nsError.h"
 #include "nsCOMPtr.h"
 #include "nsSVGAttrTearoffTable.h"
+#include "nsQueryObject.h"
 #include <algorithm>
 
 // See the architecture comment in this file's header.

dom/svg/nsSVGElement.cpp

@@ -45,6 +45,7 @@
 #include "SVGAnimatedPathSegList.h"
 #include "SVGContentUtils.h"
 #include "nsIFrame.h"
+#include "nsQueryObject.h"
 #include <stdarg.h>
 #include "nsSMILMappedAttribute.h"
 #include "SVGMotionSMILAttr.h"

dom/workers/ServiceWorkerEvents.cpp

@@ -16,6 +16,7 @@
 #include "nsStreamUtils.h"
 #include "nsNetCID.h"
 #include "nsSerializationHelper.h"
+#include "nsQueryObject.h"
 
 #include "mozilla/dom/FetchEventBinding.h"
 #include "mozilla/dom/PromiseNativeHandler.h"

dom/workers/ServiceWorkerManager.cpp

@@ -40,6 +40,7 @@
 #include "nsGlobalWindow.h"
 #include "nsNetUtil.h"
 #include "nsProxyRelease.h"
+#include "nsQueryObject.h"
 #include "nsTArray.h"
 
 #include "RuntimeService.h"

dom/workers/WorkerPrivate.cpp

@@ -81,6 +81,7 @@
 #include "nsNetUtil.h"
 #include "nsPrintfCString.h"
 #include "nsProxyRelease.h"
+#include "nsQueryObject.h"
 #include "nsSandboxFlags.h"
 #include "prthread.h"
 #include "xpcpublic.h"

dom/xbl/nsXBLPrototypeHandler.cpp

@@ -6,6 +6,7 @@
 #include "mozilla/ArrayUtils.h"
 
 #include "nsCOMPtr.h"
+#include "nsQueryObject.h"
 #include "nsXBLPrototypeHandler.h"
 #include "nsXBLPrototypeBinding.h"
 #include "nsContentUtils.h"

dom/xul/nsXULElement.cpp

@@ -93,6 +93,7 @@
 #include "nsAttrValueInlines.h"
 #include "mozilla/Attributes.h"
 #include "nsIController.h"
+#include "nsQueryObject.h"
 #include <algorithm>
 
 // The XUL doc interface

editor/libeditor/IMETextTxn.cpp

@@ -13,6 +13,7 @@
 #include "nsError.h"                    // for NS_SUCCEEDED, NS_FAILED, etc
 #include "nsIPresShell.h"               // nsISelectionController constants
 #include "nsRange.h"                    // local var
+#include "nsQueryObject.h"              // for do_QueryObject
 
 using namespace mozilla;
 using namespace mozilla::dom;

editor/libeditor/InsertTextTxn.cpp

@@ -11,6 +11,7 @@
 #include "nsDebug.h"                    // for NS_ASSERTION, etc
 #include "nsEditor.h"                   // mEditor
 #include "nsError.h"                    // for NS_OK, etc
+#include "nsQueryObject.h"              // for do_QueryObject
 
 using namespace mozilla;
 using namespace mozilla::dom;

editor/libeditor/PlaceholderTxn.cpp

@@ -8,6 +8,7 @@
 #include "IMETextTxn.h"
 #include "nsGkAtoms.h"
 #include "mozilla/dom/Selection.h"
+#include "nsQueryObject.h"
 
 using namespace mozilla;
 using namespace mozilla::dom;

editor/libeditor/nsEditorEventListener.cpp

@@ -53,6 +53,7 @@
 #include "nsRange.h"
 #include "nsServiceManagerUtils.h"      // for do_GetService
 #include "nsString.h"                   // for nsAutoString
+#include "nsQueryObject.h"              // for do_QueryObject
 #ifdef HANDLE_NATIVE_TEXT_DIRECTION_SWITCH
 #include "nsContentUtils.h"             // for nsContentUtils, etc
 #include "nsIBidiKeyboard.h"            // for nsIBidiKeyboard

editor/libeditor/nsHTMLEditorEventListener.cpp

@@ -24,6 +24,7 @@
 #include "nsIHTMLObjectResizer.h"
 #include "nsISupportsImpl.h"
 #include "nsLiteralString.h"
+#include "nsQueryObject.h"
 #include "nsRange.h"
 
 using namespace mozilla;

layout/base/nsPresShell.cpp

@@ -176,6 +176,7 @@
 #include "nsIFrameInlines.h"
 #include "mozilla/gfx/2D.h"
 #include "nsSubDocumentFrame.h"
+#include "nsQueryObject.h"
 
 #ifdef ANDROID
 #include "nsIDocShellTreeOwner.h"

layout/inspector/inDOMUtils.cpp

@@ -45,6 +45,7 @@
 #include "nsColor.h"
 #include "nsStyleSet.h"
 #include "nsStyleUtil.h"
+#include "nsQueryObject.h"
 
 using namespace mozilla;
 using namespace mozilla::css;

layout/style/CSSStyleSheet.cpp

@@ -21,6 +21,7 @@
 #include "nsIDocument.h"
 #include "nsPresContext.h"
 #include "nsGkAtoms.h"
+#include "nsQueryObject.h"
 #include "nsString.h"
 #include "nsTArray.h"
 #include "nsIDOMCSSStyleSheet.h"

layout/style/nsDOMCSSDeclaration.cpp

@@ -18,6 +18,7 @@
 #include "nsIURI.h"
 #include "mozilla/dom/BindingUtils.h"
 #include "nsContentUtils.h"
+#include "nsQueryObject.h"
 
 using namespace mozilla;
 

layout/style/nsRuleWalker.h

@@ -14,6 +14,7 @@
 #include "nsRuleNode.h"
 #include "nsIStyleRule.h"
 #include "StyleRule.h"
+#include "nsQueryObject.h"
 
 class nsRuleWalker {
 public:

layout/style/nsStyleSet.cpp

@@ -38,6 +38,7 @@
 #include "nsPrintfCString.h"
 #include "nsIFrame.h"
 #include "RestyleManager.h"
+#include "nsQueryObject.h"
 
 #include <inttypes.h>
 

media/webrtc/signaling/src/peerconnection/PeerConnectionImpl.cpp

@@ -30,6 +30,7 @@
 #include "nsIPrefService.h"
 #include "nsIPrefBranch.h"
 #include "nsProxyRelease.h"
+#include "nsQueryObject.h"
 #include "prtime.h"
 
 #include "AudioConduit.h"

media/webrtc/signaling/test/signaling_unittests.cpp

@@ -32,6 +32,7 @@
 #include "nsIPrefService.h"
 #include "nsIPrefBranch.h"
 #include "nsIDNSService.h"
+#include "nsQueryObject.h"
 #include "nsWeakReference.h"
 #include "nricectx.h"
 #include "rlogringbuffer.h"

netwerk/protocol/http/HttpChannelParent.cpp

@@ -33,6 +33,7 @@
 #include "nsICachingChannel.h"
 #include "mozilla/LoadInfo.h"
 #include "nsIHttpHeaderVisitor.h"
+#include "nsQueryObject.h"
 
 using namespace mozilla::dom;
 using namespace mozilla::ipc;

netwerk/protocol/http/NullHttpTransaction.cpp

@@ -13,6 +13,7 @@
 #include "nsHttpRequestHead.h"
 #include "nsIHttpActivityObserver.h"
 #include "NullHttpChannel.h"
+#include "nsQueryObject.h"
 
 namespace mozilla {
 namespace net {

netwerk/protocol/http/nsHttpChannel.cpp

@@ -37,6 +37,7 @@
 #include "nsError.h"
 #include "nsPrintfCString.h"
 #include "nsAlgorithm.h"
+#include "nsQueryObject.h"
 #include "GeckoProfiler.h"
 #include "nsIConsoleService.h"
 #include "mozilla/Attributes.h"

profile/dirserviceprovider/nsProfileLock.cpp

@@ -6,6 +6,7 @@
 #include "nsProfileStringTypes.h"
 #include "nsProfileLock.h"
 #include "nsCOMPtr.h"
+#include "nsQueryObject.h"
 
 #if defined(XP_WIN)
 #include "mozilla/ProfileUnlockerWin.h"

storage/src/mozStoragePrivateHelpers.cpp

@@ -13,6 +13,7 @@
 #include "nsError.h"
 #include "mozilla/Mutex.h"
 #include "mozilla/CondVar.h"
+#include "nsQueryObject.h"
 #include "nsThreadUtils.h"
 #include "nsJSUtils.h"
 

toolkit/components/places/nsNavHistoryResult.cpp

@@ -18,6 +18,7 @@
 #include "nsUnicharUtils.h"
 #include "prtime.h"
 #include "prprf.h"
+#include "nsQueryObject.h"
 
 #include "nsCycleCollectionParticipant.h"
 

uriloader/base/nsDocLoader.cpp

@@ -20,6 +20,7 @@
 #include "nscore.h"
 #include "nsWeakPtr.h"
 #include "nsAutoPtr.h"
+#include "nsQueryObject.h"
 
 #include "nsIDOMWindow.h"
 

widget/cocoa/nsDeviceContextSpecX.mm

@@ -9,6 +9,7 @@
 #include <unistd.h>
 
 #include "nsAutoPtr.h"
+#include "nsQueryObject.h"
 #include "nsIServiceManager.h"
 #include "nsIPrintOptions.h"
 #include "nsPrintSettingsX.h"

widget/cocoa/nsMenuUtilsX.mm

@@ -17,6 +17,7 @@
 #include "nsIDOMDocument.h"
 #include "nsIDOMXULCommandEvent.h"
 #include "nsPIDOMWindow.h"
+#include "nsQueryObject.h"
 
 using namespace mozilla;
 

widget/cocoa/nsPrintDialogX.mm

@@ -9,6 +9,7 @@
 #include "nsIPrintSettings.h"
 #include "nsPrintSettingsX.h"
 #include "nsCOMPtr.h"
+#include "nsQueryObject.h"
 #include "nsServiceManagerUtils.h"
 #include "nsIWebProgressListener.h"
 #include "nsIStringBundle.h"

widget/cocoa/nsPrintOptionsX.mm

@@ -4,6 +4,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include "nsCOMPtr.h"
+#include "nsQueryObject.h"
 #include "nsIServiceManager.h"
 #include "nsPrintOptionsX.h"
 #include "nsPrintSettingsX.h"

widget/windows/LSPAnnotator.cpp

@@ -15,6 +15,7 @@
 #include "nsISupportsImpl.h"
 #include "nsServiceManagerUtils.h"
 #include "nsThreadUtils.h"
+#include "nsQueryObject.h"
 #include <windows.h>
 #include <ws2spi.h>
 

xpcom/base/moz.build

@@ -56,6 +56,7 @@ EXPORTS += [
     'nsISizeOf.h',
     'nsISupportsBase.h',
     'nsObjCExceptions.h',
+    'nsQueryObject.h',
     'nsRefPtr.h',
     'nsStackWalk.h',
     'nsTraceRefcnt.h',

xpcom/base/nsAutoPtr.h

@@ -759,94 +759,6 @@ operator!=(NSCAP_Zero* aLhs, const nsAutoArrayPtr<T>& aRhs)
 }
 
 
-/*****************************************************************************/
-
-template<class T>
-class MOZ_STACK_CLASS nsQueryObject : public nsCOMPtr_helper
-{
-public:
-  explicit nsQueryObject(T* aRawPtr)
-    : mRawPtr(aRawPtr)
-  {
-  }
-
-  virtual nsresult NS_FASTCALL operator()(const nsIID& aIID,
-                                          void** aResult) const override
-  {
-    nsresult status = mRawPtr ? mRawPtr->QueryInterface(aIID, aResult)
-                              : NS_ERROR_NULL_POINTER;
-    return status;
-  }
-private:
-  T* MOZ_NON_OWNING_REF mRawPtr;
-};
-
-template<class T>
-class MOZ_STACK_CLASS nsQueryObjectWithError : public nsCOMPtr_helper
-{
-public:
-  nsQueryObjectWithError(T* aRawPtr, nsresult* aErrorPtr)
-    : mRawPtr(aRawPtr), mErrorPtr(aErrorPtr)
-  {
-  }
-
-  virtual nsresult NS_FASTCALL operator()(const nsIID& aIID,
-                                          void** aResult) const
-  {
-    nsresult status = mRawPtr ? mRawPtr->QueryInterface(aIID, aResult)
-                              : NS_ERROR_NULL_POINTER;
-    if (mErrorPtr) {
-      *mErrorPtr = status;
-    }
-    return status;
-  }
-private:
-  T* MOZ_NON_OWNING_REF mRawPtr;
-  nsresult* mErrorPtr;
-};
-
-template<class T>
-inline nsQueryObject<T>
-do_QueryObject(T* aRawPtr)
-{
-  return nsQueryObject<T>(aRawPtr);
-}
-
-template<class T>
-inline nsQueryObject<T>
-do_QueryObject(nsCOMPtr<T>& aRawPtr)
-{
-  return nsQueryObject<T>(aRawPtr);
-}
-
-template<class T>
-inline nsQueryObject<T>
-do_QueryObject(nsRefPtr<T>& aRawPtr)
-{
-  return nsQueryObject<T>(aRawPtr);
-}
-
-template<class T>
-inline nsQueryObjectWithError<T>
-do_QueryObject(T* aRawPtr, nsresult* aErrorPtr)
-{
-  return nsQueryObjectWithError<T>(aRawPtr, aErrorPtr);
-}
-
-template<class T>
-inline nsQueryObjectWithError<T>
-do_QueryObject(nsCOMPtr<T>& aRawPtr, nsresult* aErrorPtr)
-{
-  return nsQueryObjectWithError<T>(aRawPtr, aErrorPtr);
-}
-
-template<class T>
-inline nsQueryObjectWithError<T>
-do_QueryObject(nsRefPtr<T>& aRawPtr, nsresult* aErrorPtr)
-{
-  return nsQueryObjectWithError<T>(aRawPtr, aErrorPtr);
-}
-
 /*****************************************************************************/
 
 #endif // !defined(nsAutoPtr_h)

xpcom/base/nsQueryObject.h

@@ -0,0 +1,107 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsQueryObject_h
+#define nsQueryObject_h
+
+#include "nsCOMPtr.h"
+#include "nsRefPtr.h"
+
+/*****************************************************************************/
+
+template<class T>
+class nsQueryObject : public nsCOMPtr_helper
+{
+public:
+  explicit nsQueryObject(T* aRawPtr)
+    : mRawPtr(aRawPtr)
+  {
+  }
+
+  virtual nsresult NS_FASTCALL operator()(const nsIID& aIID,
+                                          void** aResult) const
+  {
+    nsresult status = mRawPtr ? mRawPtr->QueryInterface(aIID, aResult)
+                              : NS_ERROR_NULL_POINTER;
+    return status;
+  }
+private:
+  T* mRawPtr;
+};
+
+template<class T>
+class nsQueryObjectWithError : public nsCOMPtr_helper
+{
+public:
+  nsQueryObjectWithError(T* aRawPtr, nsresult* aErrorPtr)
+    : mRawPtr(aRawPtr), mErrorPtr(aErrorPtr)
+  {
+  }
+
+  virtual nsresult NS_FASTCALL operator()(const nsIID& aIID,
+                                          void** aResult) const
+  {
+    nsresult status = mRawPtr ? mRawPtr->QueryInterface(aIID, aResult)
+                              : NS_ERROR_NULL_POINTER;
+    if (mErrorPtr) {
+      *mErrorPtr = status;
+    }
+    return status;
+  }
+private:
+  T* mRawPtr;
+  nsresult* mErrorPtr;
+};
+
+/*****************************************************************************/
+
+/*****************************************************************************/
+
+template<class T>
+inline nsQueryObject<T>
+do_QueryObject(T* aRawPtr)
+{
+  return nsQueryObject<T>(aRawPtr);
+}
+
+template<class T>
+inline nsQueryObject<T>
+do_QueryObject(nsCOMPtr<T>& aRawPtr)
+{
+  return nsQueryObject<T>(aRawPtr);
+}
+
+template<class T>
+inline nsQueryObject<T>
+do_QueryObject(nsRefPtr<T>& aRawPtr)
+{
+  return nsQueryObject<T>(aRawPtr);
+}
+
+template<class T>
+inline nsQueryObjectWithError<T>
+do_QueryObject(T* aRawPtr, nsresult* aErrorPtr)
+{
+  return nsQueryObjectWithError<T>(aRawPtr, aErrorPtr);
+}
+
+template<class T>
+inline nsQueryObjectWithError<T>
+do_QueryObject(nsCOMPtr<T>& aRawPtr, nsresult* aErrorPtr)
+{
+  return nsQueryObjectWithError<T>(aRawPtr, aErrorPtr);
+}
+
+template<class T>
+inline nsQueryObjectWithError<T>
+do_QueryObject(nsRefPtr<T>& aRawPtr, nsresult* aErrorPtr)
+{
+  return nsQueryObjectWithError<T>(aRawPtr, aErrorPtr);
+}
+
+/*****************************************************************************/
+
+#endif // !defined(nsQueryObject_h)

xpcom/tests/TestNsRefPtr.cpp

@@ -8,6 +8,7 @@
 #include "nsCOMPtr.h"
 #include "nsAutoPtr.h"
 #include "nsISupports.h"
+#include "nsQueryObject.h"
 
 #define NS_FOO_IID \
 { 0x6f7652e0,  0xee43, 0x11d1, \

xpfe/appshell/nsXULWindow.cpp

@@ -17,6 +17,7 @@
 #include "prprf.h"
 #include "nsThreadUtils.h"
 #include "nsNetCID.h"
+#include "nsQueryObject.h"
 
 //Interfaces needed to be included
 #include "nsIAppShell.h"