diff --git a/accessible/src/base/nsCaretAccessible.cpp b/accessible/src/base/nsCaretAccessible.cpp
index 5f7b26f07c98..3aa147e4ddb0 100644
--- a/accessible/src/base/nsCaretAccessible.cpp
+++ b/accessible/src/base/nsCaretAccessible.cpp
@@ -51,7 +51,8 @@
 #include "nsISelection2.h"
 #include "nsServiceManagerUtils.h"
 #include "nsIViewManager.h"
-#include "nsIWidget.h"
+
+class nsIWidget;
 
 NS_IMPL_ISUPPORTS1(nsCaretAccessible, nsISelectionListener)
   
diff --git a/accessible/src/msaa/nsDocAccessibleWrap.cpp b/accessible/src/msaa/nsDocAccessibleWrap.cpp
index a1913263b013..9efd1e0128fa 100644
--- a/accessible/src/msaa/nsDocAccessibleWrap.cpp
+++ b/accessible/src/msaa/nsDocAccessibleWrap.cpp
@@ -49,7 +49,6 @@
 #include "nsIURI.h"
 #include "nsIViewManager.h"
 #include "nsIWebNavigation.h"
-#include "nsIWidget.h"
 
 /* For documentation of the accessibility architecture, 
  * see http://lxr.mozilla.org/seamonkey/source/accessible/accessible-docs.html
diff --git a/accessible/src/msaa/nsTextAccessibleWrap.cpp b/accessible/src/msaa/nsTextAccessibleWrap.cpp
index 2da66e36b262..e93004ef6446 100644
--- a/accessible/src/msaa/nsTextAccessibleWrap.cpp
+++ b/accessible/src/msaa/nsTextAccessibleWrap.cpp
@@ -45,7 +45,6 @@
 #include "nsPresContext.h"
 #include "nsIPresShell.h"
 #include "nsIRenderingContext.h"
-#include "nsIWidget.h"
 #include "nsIComponentManager.h"
 
 // --------------------------------------------------------
@@ -212,9 +211,6 @@ nsresult nsTextAccessibleWrap::GetCharacterExtents(PRInt32 aStartOffset, PRInt32
   nsIFrame *frame = GetFrame();
   NS_ENSURE_TRUE(frame, NS_ERROR_FAILURE);
 
-  nsIWidget *widget = frame->GetWindow();
-  NS_ENSURE_TRUE(widget, NS_ERROR_FAILURE);
-  
   nsPoint startPoint, endPoint;
   nsIFrame *startFrame = GetPointFromOffset(frame, aStartOffset, PR_TRUE, startPoint);
   nsIFrame *endFrame = GetPointFromOffset(frame, aEndOffset, PR_FALSE, endPoint);
diff --git a/content/base/src/nsContentSink.cpp b/content/base/src/nsContentSink.cpp
index bc4ebff77883..51cf63ef9273 100644
--- a/content/base/src/nsContentSink.cpp
+++ b/content/base/src/nsContentSink.cpp
@@ -89,6 +89,7 @@
 #include "nsNodeInfoManager.h"
 #include "nsTimer.h"
 #include "nsIAppShell.h"
+#include "nsIWidget.h"
 #include "nsWidgetsCID.h"
 #include "nsIDOMNSDocument.h"
 #include "nsIRequest.h"
diff --git a/content/events/public/nsEventDispatcher.h b/content/events/public/nsEventDispatcher.h
index 6647d1a3bc5f..6c5391faa0a5 100644
--- a/content/events/public/nsEventDispatcher.h
+++ b/content/events/public/nsEventDispatcher.h
@@ -39,11 +39,13 @@
 #ifndef nsEventDispatcher_h___
 #define nsEventDispatcher_h___
 
-#include "nsGUIEvent.h"
+#include "nsCOMPtr.h"
+#include "nsEvent.h"
 
 class nsIContent;
 class nsIDocument;
 class nsPresContext;
+class nsIDOMEvent;
 class nsPIDOMEventTarget;
 class nsIScriptGlobalObject;
 class nsEventTargetChainItem;
diff --git a/content/events/src/nsEventStateManager.h b/content/events/src/nsEventStateManager.h
index e4e3c2b1d727..35da3b069f8d 100644
--- a/content/events/src/nsEventStateManager.h
+++ b/content/events/src/nsEventStateManager.h
@@ -40,7 +40,7 @@
 #define nsEventStateManager_h__
 
 #include "nsIEventStateManager.h"
-#include "nsGUIEvent.h"
+#include "nsEvent.h"
 #include "nsIContent.h"
 #include "nsIObserver.h"
 #include "nsWeakReference.h"
diff --git a/content/events/src/nsIMEStateManager.h b/content/events/src/nsIMEStateManager.h
index 9fec1c2ff2a7..1c80693643fd 100644
--- a/content/events/src/nsIMEStateManager.h
+++ b/content/events/src/nsIMEStateManager.h
@@ -40,7 +40,6 @@
 #define nsIMEStateManager_h__
 
 #include "nscore.h"
-#include "nsGUIEvent.h"
 
 class nsIContent;
 class nsPIDOMWindow;
diff --git a/docshell/base/nsDocShell.h b/docshell/base/nsDocShell.h
index ed9130000927..8cbb7e7dadfb 100644
--- a/docshell/base/nsDocShell.h
+++ b/docshell/base/nsDocShell.h
@@ -108,6 +108,7 @@
 #include "nsIURIClassifier.h"
 #include "nsIChannelClassifier.h"
 #include "nsILoadContext.h"
+#include "nsIWidget.h"
 
 class nsIScrollableView;
 class nsDocShell;
diff --git a/dom/base/nsWindowRoot.cpp b/dom/base/nsWindowRoot.cpp
index 3ffdd6b59533..7ca6d5c3d6a2 100644
--- a/dom/base/nsWindowRoot.cpp
+++ b/dom/base/nsWindowRoot.cpp
@@ -54,6 +54,7 @@
 #include "nsString.h"
 #include "nsEventDispatcher.h"
 #include "nsIProgrammingLanguage.h"
+#include "nsGUIEvent.h"
 
 #include "nsCycleCollectionParticipant.h"
 
diff --git a/editor/libeditor/html/nsHTMLEditor.cpp b/editor/libeditor/html/nsHTMLEditor.cpp
index a16858c83308..5dede6c5a75c 100644
--- a/editor/libeditor/html/nsHTMLEditor.cpp
+++ b/editor/libeditor/html/nsHTMLEditor.cpp
@@ -128,7 +128,6 @@
 
 #include "nsIFrame.h"
 #include "nsIView.h"
-#include "nsIWidget.h"
 #include "nsIParserService.h"
 #include "nsIEventStateManager.h"
 
diff --git a/embedding/components/printingui/src/win/nsPrintDialogUtil.cpp b/embedding/components/printingui/src/win/nsPrintDialogUtil.cpp
index d744980e9157..e1b5e6f70b75 100644
--- a/embedding/components/printingui/src/win/nsPrintDialogUtil.cpp
+++ b/embedding/components/printingui/src/win/nsPrintDialogUtil.cpp
@@ -71,7 +71,6 @@ WIN_LIBS=                                       \
 #include "nsString.h"
 #include "nsIServiceManager.h"
 #include "nsReadableUtils.h"
-#include "nsIWidget.h"
 #include "nsIPrintSettings.h"
 #include "nsIPrintSettingsWin.h"
 #include "nsIPrintOptions.h"
diff --git a/embedding/components/windowwatcher/src/nsWindowWatcher.cpp b/embedding/components/windowwatcher/src/nsWindowWatcher.cpp
index f8eb9b6fd35c..4f2d6004a83f 100644
--- a/embedding/components/windowwatcher/src/nsWindowWatcher.cpp
+++ b/embedding/components/windowwatcher/src/nsWindowWatcher.cpp
@@ -87,6 +87,7 @@
 #include "nsIDeviceContext.h"
 #include "nsIDOMStorage.h"
 #include "nsPIDOMStorage.h"
+#include "nsIWidget.h"
 
 #include "nsIPrefBranch.h"
 #include "nsIPrefService.h"
diff --git a/embedding/qa/testembed/BrowserView.cpp b/embedding/qa/testembed/BrowserView.cpp
index d0cb82eff95b..efb3353374f1 100644
--- a/embedding/qa/testembed/BrowserView.cpp
+++ b/embedding/qa/testembed/BrowserView.cpp
@@ -77,9 +77,6 @@
 #include "PrintProgressDialog.h"
 //#include "PrintSetupDialog.h"
 
-// Mozilla Includes
-#include "nsIWidget.h"
-
 #ifdef _DEBUG
 #define new DEBUG_NEW
 #undef THIS_FILE
diff --git a/embedding/qa/testembed/BrowserView.h b/embedding/qa/testembed/BrowserView.h
index 9e8d9e6dbd16..76560b7bde06 100644
--- a/embedding/qa/testembed/BrowserView.h
+++ b/embedding/qa/testembed/BrowserView.h
@@ -105,8 +105,6 @@ public:
 	nsCOMPtr<nsIBaseWindow> mBaseWindow;
 	nsCOMPtr<nsIWebNavigation> mWebNav;	
 
-	typedef void* nsNativeWidget;
-
 	//nsCOMPtr<nsISHistory> mSessionHistory; // de: added in 5/11/01
 
 	void UpdateBusyState(PRBool aBusy);
diff --git a/gfx/public/nsIDeviceContext.h b/gfx/public/nsIDeviceContext.h
index 6ab0973a782d..9be3213a2953 100644
--- a/gfx/public/nsIDeviceContext.h
+++ b/gfx/public/nsIDeviceContext.h
@@ -42,10 +42,10 @@
 #include "nsISupports.h"
 #include "nsCoord.h"
 #include "nsRect.h"
-#include "nsIWidget.h"
 #include "nsIRenderingContext.h"
 // XXX we need only gfxTypes.h, but we cannot include it directly.
 #include "gfxPoint.h"
+#include "nsNativeWidget.h"
 
 class nsIView;
 class nsIFontMetrics;
diff --git a/gfx/src/thebes/nsThebesDeviceContext.cpp b/gfx/src/thebes/nsThebesDeviceContext.cpp
index 124c40bafb1e..f2b7eec31a37 100644
--- a/gfx/src/thebes/nsThebesDeviceContext.cpp
+++ b/gfx/src/thebes/nsThebesDeviceContext.cpp
@@ -44,6 +44,7 @@
 #include "nsThebesDeviceContext.h"
 #include "nsThebesRenderingContext.h"
 
+#include "nsIWidget.h"
 #include "nsIView.h"
 #include "nsILookAndFeel.h"
 
diff --git a/gfx/tests/coverage/main.cpp b/gfx/tests/coverage/main.cpp
index 3daa83821424..cd6f85bb68af 100644
--- a/gfx/tests/coverage/main.cpp
+++ b/gfx/tests/coverage/main.cpp
@@ -34,7 +34,6 @@
  * the terms of any one of the MPL, the GPL or the LGPL.
  *
  * ***** END LICENSE BLOCK ***** */
-#include "nsIWidget.h"
 
 extern nsresult CoverageTest(int * argc, char **argv);
 
diff --git a/layout/base/nsStyleConsts.h b/layout/base/nsStyleConsts.h
index c6e656277f1c..fa38abe8c3a7 100644
--- a/layout/base/nsStyleConsts.h
+++ b/layout/base/nsStyleConsts.h
@@ -42,7 +42,6 @@
 #define nsStyleConsts_h___
 
 #include "nsFont.h"
-#include "nsIWidget.h"
 
 // cairo doesn't support invert
 // #define GFX_HAS_INVERT
diff --git a/layout/forms/nsHTMLButtonControlFrame.cpp b/layout/forms/nsHTMLButtonControlFrame.cpp
index 1964b9c0bc18..2a22dc375c39 100644
--- a/layout/forms/nsHTMLButtonControlFrame.cpp
+++ b/layout/forms/nsHTMLButtonControlFrame.cpp
@@ -54,7 +54,6 @@
 #include "nsCSSAnonBoxes.h"
 #include "nsIImage.h"
 #include "nsStyleConsts.h"
-#include "nsIWidget.h"
 #include "nsIComponentManager.h"
 #include "nsIDocument.h"
 #include "nsButtonFrameRenderer.h"
diff --git a/layout/generic/nsFrameFrame.cpp b/layout/generic/nsFrameFrame.cpp
index 54f26aab7f1a..ad291a5a84dd 100644
--- a/layout/generic/nsFrameFrame.cpp
+++ b/layout/generic/nsFrameFrame.cpp
@@ -79,7 +79,6 @@
 #include "nsXPIDLString.h"
 #include "nsIScrollable.h"
 #include "nsINameSpaceManager.h"
-#include "nsIWidget.h"
 #include "nsWeakReference.h"
 #include "nsIDOMWindow.h"
 #include "nsIDOMDocument.h"
diff --git a/layout/generic/nsGfxScrollFrame.h b/layout/generic/nsGfxScrollFrame.h
index fed84dd7d9a3..3c2a45451158 100644
--- a/layout/generic/nsGfxScrollFrame.h
+++ b/layout/generic/nsGfxScrollFrame.h
@@ -46,7 +46,6 @@
 #include "nsIScrollableFrame.h"
 #include "nsIScrollPositionListener.h"
 #include "nsIStatefulFrame.h"
-#include "nsGUIEvent.h"
 #include "nsThreadUtils.h"
 #include "nsIScrollableView.h"
 #include "nsIView.h"
diff --git a/layout/generic/nsHTMLContainerFrame.cpp b/layout/generic/nsHTMLContainerFrame.cpp
index 0d5ccc862d34..17df23a7961b 100644
--- a/layout/generic/nsHTMLContainerFrame.cpp
+++ b/layout/generic/nsHTMLContainerFrame.cpp
@@ -49,7 +49,6 @@
 #include "nsGkAtoms.h"
 #include "nsLayoutUtils.h"
 #include "nsCSSAnonBoxes.h"
-#include "nsIWidget.h"
 #include "nsILinkHandler.h"
 #include "nsGUIEvent.h"
 #include "nsIDocument.h"
diff --git a/layout/generic/nsImageFrame.cpp b/layout/generic/nsImageFrame.cpp
index b066ec28c261..d7ebd44e1ff3 100644
--- a/layout/generic/nsImageFrame.cpp
+++ b/layout/generic/nsImageFrame.cpp
@@ -48,7 +48,6 @@
 #include "nsIRenderingContext.h"
 #include "nsIPresShell.h"
 #include "nsIImage.h"
-#include "nsIWidget.h"
 #include "nsGkAtoms.h"
 #include "nsIDocument.h"
 #include "nsINodeInfo.h"
diff --git a/layout/style/nsCSSProps.cpp b/layout/style/nsCSSProps.cpp
index baba0ebe527b..9c489ec36f5b 100644
--- a/layout/style/nsCSSProps.cpp
+++ b/layout/style/nsCSSProps.cpp
@@ -44,6 +44,7 @@
 #include "nsCSSProps.h"
 #include "nsCSSKeywords.h"
 #include "nsStyleConsts.h"
+#include "nsIWidget.h"
 #include "nsThemeConstants.h"  // For system widget appearance types
 
 #include "nsILookAndFeel.h" // for system colors
diff --git a/layout/style/nsRuleNode.cpp b/layout/style/nsRuleNode.cpp
index 01638b953a22..16c43b00a5dd 100644
--- a/layout/style/nsRuleNode.cpp
+++ b/layout/style/nsRuleNode.cpp
@@ -52,6 +52,7 @@
 #include "nscore.h"
 #include "nsIServiceManager.h"
 #include "nsIDeviceContext.h"
+#include "nsIWidget.h"
 #include "nsILookAndFeel.h"
 #include "nsIPresShell.h"
 #include "nsIThebesFontMetrics.h"
diff --git a/layout/style/nsStyleStruct.cpp b/layout/style/nsStyleStruct.cpp
index 918811abe64f..4e092dcc6570 100644
--- a/layout/style/nsStyleStruct.cpp
+++ b/layout/style/nsStyleStruct.cpp
@@ -50,6 +50,7 @@
 #include "nsString.h"
 #include "nsPresContext.h"
 #include "nsIDeviceContext.h"
+#include "nsIWidget.h"
 #include "nsIStyleRule.h"
 #include "nsCRT.h"
 
diff --git a/layout/xul/base/public/nsXULPopupManager.h b/layout/xul/base/public/nsXULPopupManager.h
index 30dca1ffa43f..cf39ccdc7c91 100644
--- a/layout/xul/base/public/nsXULPopupManager.h
+++ b/layout/xul/base/public/nsXULPopupManager.h
@@ -44,7 +44,6 @@
 #include "prlog.h"
 #include "nsGUIEvent.h"
 #include "nsIContent.h"
-#include "nsIWidget.h"
 #include "nsIRollupListener.h"
 #include "nsIMenuRollup.h"
 #include "nsIDOMKeyListener.h"
diff --git a/layout/xul/base/src/nsBox.cpp b/layout/xul/base/src/nsBox.cpp
index f23eab955473..c8a0bd545897 100644
--- a/layout/xul/base/src/nsBox.cpp
+++ b/layout/xul/base/src/nsBox.cpp
@@ -51,7 +51,6 @@
 #include "nsIDOMNode.h"
 #include "nsIDOMNamedNodeMap.h"
 #include "nsIDOMAttr.h"
-#include "nsIWidget.h"
 #include "nsIRenderingContext.h"
 #include "nsIDocument.h"
 #include "nsIDeviceContext.h"
diff --git a/layout/xul/base/src/nsBoxFrame.cpp b/layout/xul/base/src/nsBoxFrame.cpp
index 9808e412f082..6c8af8e2bec9 100644
--- a/layout/xul/base/src/nsBoxFrame.cpp
+++ b/layout/xul/base/src/nsBoxFrame.cpp
@@ -87,7 +87,6 @@
 #include "nsCSSAnonBoxes.h"
 #include "nsIScrollableView.h"
 #include "nsHTMLContainerFrame.h"
-#include "nsIWidget.h"
 #include "nsIEventStateManager.h"
 #include "nsIDOMDocument.h"
 #include "nsIDOMElement.h"
diff --git a/layout/xul/base/src/nsBoxObject.cpp b/layout/xul/base/src/nsBoxObject.cpp
index 8e4d7386d806..88dbce94f640 100644
--- a/layout/xul/base/src/nsBoxObject.cpp
+++ b/layout/xul/base/src/nsBoxObject.cpp
@@ -48,7 +48,6 @@
 #include "nsReadableUtils.h"
 #include "nsIDOMClassInfo.h"
 #include "nsIView.h"
-#include "nsIWidget.h"
 #ifdef MOZ_XUL
 #include "nsIDOMXULElement.h"
 #else
diff --git a/layout/xul/base/src/nsDocElementBoxFrame.cpp b/layout/xul/base/src/nsDocElementBoxFrame.cpp
index f2d80a89553a..03de7d6eaced 100644
--- a/layout/xul/base/src/nsDocElementBoxFrame.cpp
+++ b/layout/xul/base/src/nsDocElementBoxFrame.cpp
@@ -39,7 +39,6 @@
 #include "nsCSSRendering.h"
 #include "nsIDocument.h"
 #include "nsPresContext.h"
-#include "nsIWidget.h"
 #include "nsPageFrame.h"
 #include "nsIRenderingContext.h"
 #include "nsGUIEvent.h"
diff --git a/layout/xul/base/src/nsMenuBarFrame.h b/layout/xul/base/src/nsMenuBarFrame.h
index d766176914ad..4160e72b838e 100644
--- a/layout/xul/base/src/nsMenuBarFrame.h
+++ b/layout/xul/base/src/nsMenuBarFrame.h
@@ -52,7 +52,6 @@
 #include "nsMenuFrame.h"
 #include "nsMenuBarListener.h"
 #include "nsMenuParent.h"
-#include "nsIWidget.h"
 
 class nsIContent;
 
diff --git a/layout/xul/base/src/nsMenuFrame.cpp b/layout/xul/base/src/nsMenuFrame.cpp
index 2427c7c46752..60494f162e22 100644
--- a/layout/xul/base/src/nsMenuFrame.cpp
+++ b/layout/xul/base/src/nsMenuFrame.cpp
@@ -54,7 +54,6 @@
 #include "nsMenuPopupFrame.h"
 #include "nsMenuBarFrame.h"
 #include "nsIView.h"
-#include "nsIWidget.h"
 #include "nsIDocument.h"
 #include "nsIDOMNSDocument.h"
 #include "nsIDOMDocument.h"
diff --git a/layout/xul/base/src/nsMenuPopupFrame.h b/layout/xul/base/src/nsMenuPopupFrame.h
index 63f9248411a9..4a0025b3f5b6 100644
--- a/layout/xul/base/src/nsMenuPopupFrame.h
+++ b/layout/xul/base/src/nsMenuPopupFrame.h
@@ -54,10 +54,11 @@
 
 #include "nsBoxFrame.h"
 #include "nsMenuParent.h"
-#include "nsIWidget.h"
 
 #include "nsITimer.h"
 
+class nsIWidget;
+
 // XUL popups can be in several different states. When opening a popup, the
 // state changes as follows:
 //   ePopupClosed - initial state
diff --git a/layout/xul/base/src/nsResizerFrame.cpp b/layout/xul/base/src/nsResizerFrame.cpp
index 59aa35eb6aeb..6329b8f24786 100644
--- a/layout/xul/base/src/nsResizerFrame.cpp
+++ b/layout/xul/base/src/nsResizerFrame.cpp
@@ -45,7 +45,6 @@
 #include "nsGkAtoms.h"
 #include "nsINameSpaceManager.h"
 
-#include "nsIWidget.h"
 #include "nsPresContext.h"
 #include "nsIDocShell.h"
 #include "nsIDocShellTreeItem.h"
diff --git a/view/public/nsIView.h b/view/public/nsIView.h
index b0e7e5c1bcca..9b6117ca8cff 100644
--- a/view/public/nsIView.h
+++ b/view/public/nsIView.h
@@ -38,16 +38,19 @@
 #ifndef nsIView_h___
 #define nsIView_h___
 
+#include "nsISupports.h"
 #include "nsCoord.h"
 #include "nsRect.h"
 #include "nsPoint.h"
-#include "nsIWidget.h"
+#include "nsNativeWidget.h"
+#include "nsWidgetInitData.h"
 
 class nsIViewManager;
 class nsIScrollableView;
 class nsViewManager;
 class nsView;
 class nsWeakView;
+class nsIWidget;
 
 // Enumerated type to indicate the visibility of a layer.
 // hide - the layer is not shown.
diff --git a/view/src/nsView.h b/view/src/nsView.h
index 4e23dd89119e..8baf66500c5f 100644
--- a/view/src/nsView.h
+++ b/view/src/nsView.h
@@ -39,7 +39,6 @@
 #define nsView_h___
 
 #include "nsIView.h"
-#include "nsIWidget.h"
 #include "nsRegion.h"
 #include "nsRect.h"
 #include "nsCRT.h"
diff --git a/view/src/nsViewManager.h b/view/src/nsViewManager.h
index d252bd1ab045..c34ed20a93a2 100644
--- a/view/src/nsViewManager.h
+++ b/view/src/nsViewManager.h
@@ -40,7 +40,6 @@
 #include "nsCOMPtr.h"
 #include "nsIViewManager.h"
 #include "nsCRT.h"
-#include "nsIWidget.h"
 #include "nsITimer.h"
 #include "prtime.h"
 #include "prinrval.h"
diff --git a/widget/public/Makefile.in b/widget/public/Makefile.in
index 377a38daa885..3dfad713dfc8 100644
--- a/widget/public/Makefile.in
+++ b/widget/public/Makefile.in
@@ -50,6 +50,8 @@ EXPORTS		= \
 		nsIWidget.h \
 		nsGUIEvent.h \
 		nsEvent.h \
+		nsNativeWidget.h \
+		nsWidgetInitData.h \
 		nsIEventListener.h \
 		nsWidgetsCID.h \
 		nsILookAndFeel.h \
diff --git a/widget/public/nsEvent.h b/widget/public/nsEvent.h
index 96b19c732384..e960f92c42cd 100644
--- a/widget/public/nsEvent.h
+++ b/widget/public/nsEvent.h
@@ -57,6 +57,15 @@ enum nsEventStatus {
   nsEventStatus_eConsumeDoDefault  
 };
 
+/**
+ * sizemode is an adjunct to widget size
+ */
+enum nsSizeMode {
+  nsSizeMode_Normal = 0,
+  nsSizeMode_Minimized,
+  nsSizeMode_Maximized
+};
+
 class nsEvent;
 
 class nsGUIEvent;
@@ -68,6 +77,7 @@ class nsScrollbarEvent;
 class nsScrollPortEvent;
 class nsInputEvent;
 class nsMouseEvent;
+class nsDragEvent;
 class nsAccessibleEvent;
 class nsKeyEvent;
 class nsTextEvent;
diff --git a/widget/public/nsGUIEvent.h b/widget/public/nsGUIEvent.h
index 40c5e049e4b3..730417c27dd1 100644
--- a/widget/public/nsGUIEvent.h
+++ b/widget/public/nsGUIEvent.h
@@ -425,15 +425,6 @@ class nsHashKey;
  * nsEvent.h.
  */
 
-/**
- * sizemode is an adjunct to widget size
- */
-enum nsSizeMode {
-  nsSizeMode_Normal = 0,
-  nsSizeMode_Minimized,
-  nsSizeMode_Maximized
-};
-
 /**
  * different types of (top-level) window z-level positioning
  */
diff --git a/widget/public/nsIEventListener.h b/widget/public/nsIEventListener.h
index 059ccd3756db..6a35014ba6b3 100644
--- a/widget/public/nsIEventListener.h
+++ b/widget/public/nsIEventListener.h
@@ -39,8 +39,7 @@
 #define nsIEventListener_h__
 
 #include "nsISupports.h"
-
-class nsGUIEvent;
+#include "nsEvent.h"
 
 /**
  * Event listener interface.
diff --git a/widget/public/nsIMenuRollup.h b/widget/public/nsIMenuRollup.h
index b20e6a1691ac..b852149e4c31 100644
--- a/widget/public/nsIMenuRollup.h
+++ b/widget/public/nsIMenuRollup.h
@@ -40,9 +40,10 @@
 #define nsIMenuRollup_h___
 
 #include "nsISupports.h"
-#include "nsIWidget.h"
 #include "nsTArray.h"
 
+class nsIWidget;
+
 #define NS_IMENUROLLUP_IID \
   {0x2b65d177, 0xc3e4, 0x4564, \
     { 0x8d, 0xed, 0x86, 0xd2, 0xfa, 0x2f, 0x65, 0x9a }}
diff --git a/widget/public/nsIWidget.h b/widget/public/nsIWidget.h
index 503db2bb950d..fcc15c7f4610 100644
--- a/widget/public/nsIWidget.h
+++ b/widget/public/nsIWidget.h
@@ -47,6 +47,8 @@
 #include "nsEvent.h"
 #include "nsCOMPtr.h"
 #include "nsITheme.h"
+#include "nsNativeWidget.h"
+#include "nsWidgetInitData.h"
 
 // forward declarations
 class   nsIAppShell;
@@ -66,12 +68,14 @@ class   nsIContent;
 
 /**
  * Callback function that processes events.
+ *
  * The argument is actually a subtype (subclass) of nsEvent which carries
- * platform specific information about the event. Platform specific code knows
- * how to deal with it.
- * The return value determines whether or not the default action should take place.
+ * platform specific information about the event. Platform specific code
+ * knows how to deal with it.
+ *
+ * The return value determines whether or not the default action should take
+ * place.
  */
-
 typedef nsEventStatus (* EVENT_CALLBACK)(nsGUIEvent *event);
 
 /**
@@ -117,70 +121,6 @@ typedef void* nsNativeWidget;
 #define NS_STYLE_WINDOW_SHADOW_NONE             0
 #define NS_STYLE_WINDOW_SHADOW_DEFAULT          1
 
-/**
- * Border styles
- */
-
-enum nsWindowType {     // Don't alter previously encoded enum values - 3rd party apps may look at these
-  // default top level window
-  eWindowType_toplevel,
-  // top level window but usually handled differently by the OS
-  eWindowType_dialog,
-  // used for combo boxes, etc
-  eWindowType_popup,
-  // child windows (contained inside a window on the desktop (has no border))
-  eWindowType_child,
-  // windows that are invisible or offscreen
-  eWindowType_invisible,
-  // plugin window
-  eWindowType_plugin,
-  // java plugin window
-  eWindowType_java,
-  // MacOSX sheet (special dialog class)
-  eWindowType_sheet
-};
-
-enum nsPopupType {
-  ePopupTypePanel,
-  ePopupTypeMenu,
-  ePopupTypeTooltip,
-  ePopupTypeAny = 0xF000 // used only to pass to nsXULPopupManager::GetTopPopup
-};
-
-enum nsBorderStyle
-{
-  // no border, titlebar, etc.. opposite of all
-  eBorderStyle_none     = 0,
-
-  // all window decorations
-  eBorderStyle_all      = 1 << 0,
-
-  // enables the border on the window.  these are only for decoration and are not resize hadles
-  eBorderStyle_border   = 1 << 1,
-
-  // enables the resize handles for the window.  if this is set, border is implied to also be set
-  eBorderStyle_resizeh  = 1 << 2,
-
-  // enables the titlebar for the window
-  eBorderStyle_title    = 1 << 3,
-
-  // enables the window menu button on the title bar.  this being on should force the title bar to display
-  eBorderStyle_menu     = 1 << 4,
-
-  // enables the minimize button so the user can minimize the window.
-  //   turned off for tranient windows since they can not be minimized separate from their parent
-  eBorderStyle_minimize = 1 << 5,
-
-  // enables the maxmize button so the user can maximize the window
-  eBorderStyle_maximize = 1 << 6,
-
-  // show the close button
-  eBorderStyle_close    = 1 << 7,
-
-  // whatever the OS wants... i.e. don't do anything
-  eBorderStyle_default  = -1
-};
-
 /**
  * Cursor types.
  */
@@ -230,47 +170,12 @@ enum nsCursor {   ///(normal cursor,       usually rendered as an arrow)
                 eCursorCount
                 }; 
 
-enum nsContentType {
-  eContentTypeInherit = -1,
-  eContentTypeUI = 0,
-  eContentTypeContent = 1,
-  eContentTypeContentFrame = 2
-};
-
 enum nsTopLevelWidgetZPlacement { // for PlaceBehind()
   eZPlacementBottom = 0,  // bottom of the window stack
   eZPlacementBelow,       // just below another widget
   eZPlacementTop          // top of the window stack
 };
 
-/**
- * Basic struct for widget initialization data.
- * @see Create member function of nsIWidget
- */
-
-struct nsWidgetInitData {
-  nsWidgetInitData()
-    : clipChildren(PR_FALSE), 
-      clipSiblings(PR_FALSE), 
-      mDropShadow(PR_FALSE),
-      mListenForResizes(PR_FALSE),
-      mWindowType(eWindowType_child),
-      mBorderStyle(eBorderStyle_default),
-      mContentType(eContentTypeInherit),
-      mUnicode(PR_TRUE),
-      mPopupHint(ePopupTypePanel)
-  {
-  }
-
-  // when painting exclude area occupied by child windows and sibling windows
-  PRPackedBool  clipChildren, clipSiblings, mDropShadow;
-  PRPackedBool  mListenForResizes;
-  nsWindowType mWindowType;
-  nsBorderStyle mBorderStyle;
-  nsContentType mContentType;  // Exposed so screen readers know what's UI
-  PRPackedBool mUnicode;
-  nsPopupType mPopupHint;
-};
 
 /**
  * The base class for all the widgets. It provides the interface for
diff --git a/widget/public/nsNativeWidget.h b/widget/public/nsNativeWidget.h
new file mode 100644
index 000000000000..732f6754ca7c
--- /dev/null
+++ b/widget/public/nsNativeWidget.h
@@ -0,0 +1,46 @@
+/* -*- Mode: C++; tab-width: 40; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is mozilla.org code.
+ *
+ * The Initial Developer of the Original Code is
+ * Netscape Communications Corporation.
+ * Portions created by the Initial Developer are Copyright (C) 1998
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+#ifndef nsNativeWidget_h__
+#define nsNativeWidget_h__
+
+// Hide the native window systems real window type so as to avoid
+// including native window system types and APIs. This is necessary
+// to ensure cross-platform code.
+typedef void* nsNativeWidget;
+
+#endif // nsNativeWidget_h__
diff --git a/widget/public/nsWidgetInitData.h b/widget/public/nsWidgetInitData.h
new file mode 100644
index 000000000000..9fa686479e17
--- /dev/null
+++ b/widget/public/nsWidgetInitData.h
@@ -0,0 +1,144 @@
+/* -*- Mode: C++; tab-width: 40; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is mozilla.org code.
+ *
+ * The Initial Developer of the Original Code is
+ * Netscape Communications Corporation.
+ * Portions created by the Initial Developer are Copyright (C) 1998
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+#ifndef nsWidgetInitData_h__
+#define nsWidgetInitData_h__
+
+#include "prtypes.h"
+
+/**
+ * Window types
+ *
+ * Don't alter previously encoded enum values - 3rd party apps may look at
+ * these.
+ */
+enum nsWindowType {
+  eWindowType_toplevel,  // default top level window
+  eWindowType_dialog,    // top level window but usually handled differently
+                         // by the OS
+  eWindowType_popup,     // used for combo boxes, etc
+  eWindowType_child,     // child windows (contained inside a window on the
+                         // desktop (has no border))
+  eWindowType_invisible, // windows that are invisible or offscreen
+  eWindowType_plugin,    // plugin window
+  eWindowType_java,      // java plugin window
+  eWindowType_sheet      // MacOSX sheet (special dialog class)
+};
+
+/**
+ * Popup types
+ *
+ * For eWindowType_popup
+ */
+enum nsPopupType {
+  ePopupTypePanel,
+  ePopupTypeMenu,
+  ePopupTypeTooltip,
+  ePopupTypeAny      = 0xF000 // used only to pass to
+                              // nsXULPopupManager::GetTopPopup
+};
+
+/**
+ * Border styles
+ */
+enum nsBorderStyle {
+  eBorderStyle_none     = 0,      // no border, titlebar, etc.. opposite of
+                                  // all
+  eBorderStyle_all      = 1 << 0, // all window decorations
+  eBorderStyle_border   = 1 << 1, // enables the border on the window. these
+                                  // are only for decoration and are not
+                                  // resize handles
+  eBorderStyle_resizeh  = 1 << 2, // enables the resize handles for the
+                                  // window. if this is set, border is
+                                  // implied to also be set
+  eBorderStyle_title    = 1 << 3, // enables the titlebar for the window
+  eBorderStyle_menu     = 1 << 4, // enables the window menu button on the
+                                  // title bar. this being on should force
+                                  // the title bar to display
+  eBorderStyle_minimize = 1 << 5, // enables the minimize button so the user
+                                  // can minimize the window. turned off for
+                                  // tranient windows since they can not be
+                                  // minimized separate from their parent
+  eBorderStyle_maximize = 1 << 6, // enables the maxmize button so the user
+                                  // can maximize the window
+  eBorderStyle_close    = 1 << 7, // show the close button
+  eBorderStyle_default  = -1      // whatever the OS wants... i.e. don't do
+                                  // anything
+};
+
+/**
+ * Content types
+ *
+ * Exposed so screen readers know what's UI
+ */
+enum nsContentType {
+  eContentTypeInherit      = -1,
+  eContentTypeUI           = 0,
+  eContentTypeContent      = 1,
+  eContentTypeContentFrame = 2
+};
+
+/**
+ * Basic struct for widget initialization data.
+ * @see Create member function of nsIWidget
+ */
+
+struct nsWidgetInitData {
+  nsWidgetInitData() :
+      mWindowType(eWindowType_child),
+      mBorderStyle(eBorderStyle_default),
+      mContentType(eContentTypeInherit),
+      mPopupHint(ePopupTypePanel),
+      clipChildren(PR_FALSE), 
+      clipSiblings(PR_FALSE), 
+      mDropShadow(PR_FALSE),
+      mListenForResizes(PR_FALSE),
+      mUnicode(PR_TRUE)
+  {
+  }
+
+  nsWindowType  mWindowType;
+  nsBorderStyle mBorderStyle;
+  nsContentType mContentType;  // Exposed so screen readers know what's UI
+  nsPopupType   mPopupHint;
+  // when painting exclude area occupied by child windows and sibling windows
+  PRPackedBool  clipChildren, clipSiblings, mDropShadow;
+  PRPackedBool  mListenForResizes;
+  PRPackedBool  mUnicode;
+};
+
+#endif // nsWidgetInitData_h__
diff --git a/widget/src/cocoa/nsChildView.h b/widget/src/cocoa/nsChildView.h
index a30371640a0d..4516b654af32 100644
--- a/widget/src/cocoa/nsChildView.h
+++ b/widget/src/cocoa/nsChildView.h
@@ -54,7 +54,6 @@
 #include "nsIScrollableView.h"
 #include "nsWeakPtr.h"
 
-#include "nsIWidget.h"
 #include "nsIAppShell.h"
 
 #include "nsIEventListener.h"
diff --git a/widget/src/cocoa/nsCocoaUtils.h b/widget/src/cocoa/nsCocoaUtils.h
index 66c9b964e123..7b36cf8328b8 100644
--- a/widget/src/cocoa/nsCocoaUtils.h
+++ b/widget/src/cocoa/nsCocoaUtils.h
@@ -44,9 +44,10 @@
 #import <Cocoa/Cocoa.h>
 
 #include "nsRect.h"
-#include "nsIWidget.h"
 #include "nsObjCExceptions.h"
 
+class nsIWidget;
+
 // "Borrowed" in part from the QTKit framework's QTKitDefines.h.  This is
 // needed when building on OS X Tiger (10.4.X) or with a 10.4 SDK.  It won't
 // be used when building on Leopard (10.5.X) or higher (or with a 10.5 or
diff --git a/widget/src/cocoa/nsDragService.mm b/widget/src/cocoa/nsDragService.mm
index ab30466470c2..867002082d18 100644
--- a/widget/src/cocoa/nsDragService.mm
+++ b/widget/src/cocoa/nsDragService.mm
@@ -50,7 +50,6 @@
 #include "nsIDOMNode.h"
 #include "nsRect.h"
 #include "nsPoint.h"
-#include "nsIWidget.h"
 #include "nsIImage.h"
 #include "nsICharsetConverterManager.h"
 #include "nsIIOService.h"
diff --git a/widget/src/cocoa/nsMenuUtilsX.h b/widget/src/cocoa/nsMenuUtilsX.h
index 97646e7d57d4..00200820adc6 100644
--- a/widget/src/cocoa/nsMenuUtilsX.h
+++ b/widget/src/cocoa/nsMenuUtilsX.h
@@ -40,7 +40,7 @@
 #define nsMenuUtilsX_h_
 
 #include "nscore.h"
-#include "nsGUIEvent.h"
+#include "nsEvent.h"
 #include "nsMenuBaseX.h"
 
 #import <Cocoa/Cocoa.h>
diff --git a/widget/src/qt/nsFilePicker.cpp b/widget/src/qt/nsFilePicker.cpp
index 3b1e9d8d7f05..3f1529baddc5 100644
--- a/widget/src/qt/nsFilePicker.cpp
+++ b/widget/src/qt/nsFilePicker.cpp
@@ -46,6 +46,7 @@
 #include "nsEnumeratorUtils.h"
 #include "nsNetUtil.h"
 #include "nsReadableUtils.h"
+#include "nsIWidget.h"
 
 #include <qfile.h>
 #include <qstringlist.h>
diff --git a/widget/src/windows/nsDeviceContextSpecWin.h b/widget/src/windows/nsDeviceContextSpecWin.h
index f8ff426f2a2c..ff28210ef426 100644
--- a/widget/src/windows/nsDeviceContextSpecWin.h
+++ b/widget/src/windows/nsDeviceContextSpecWin.h
@@ -42,10 +42,11 @@
 #include "nsIDeviceContextSpec.h"
 #include "nsIPrintOptions.h" // For nsIPrinterEnumerator
 #include "nsIPrintSettings.h"
-#include "nsIWidget.h"
 #include "nsISupportsPrimitives.h"
 #include <windows.h>
 
+class nsIWidget;
+
 class nsDeviceContextSpecWin : public nsIDeviceContextSpec
 {
 public:
diff --git a/widget/src/windows/nsNativeDragTarget.h b/widget/src/windows/nsNativeDragTarget.h
index 90b84c185974..42bdb110bff8 100644
--- a/widget/src/windows/nsNativeDragTarget.h
+++ b/widget/src/windows/nsNativeDragTarget.h
@@ -37,7 +37,6 @@
 #ifndef _nsNativeDragTarget_h_
 #define _nsNativeDragTarget_h_
 
-#include "nsGUIEvent.h"
 #include "nsCOMPtr.h"
 #include "nsIDragSession.h"
 #include <ole2.h>
diff --git a/widget/src/windows/nsWindow.h b/widget/src/windows/nsWindow.h
index 7805b2d57e7a..6a057f84498c 100644
--- a/widget/src/windows/nsWindow.h
+++ b/widget/src/windows/nsWindow.h
@@ -49,8 +49,6 @@
 #include "nsSwitchToUIThread.h"
 #include "nsToolkit.h"
 
-#include "nsIWidget.h"
-
 #include "nsIEventListener.h"
 #include "nsString.h"
 
diff --git a/widget/src/xpwidgets/nsBaseFilePicker.h b/widget/src/xpwidgets/nsBaseFilePicker.h
index edaa7646514a..145f95f89934 100644
--- a/widget/src/xpwidgets/nsBaseFilePicker.h
+++ b/widget/src/xpwidgets/nsBaseFilePicker.h
@@ -41,10 +41,13 @@
 #ifndef nsBaseFilePicker_h__
 #define nsBaseFilePicker_h__
 
+#include "nsISupports.h"
 #include "nsIFilePicker.h"
-#include "nsIWidget.h"
 #include "nsISimpleEnumerator.h"
 #include "nsArrayEnumerator.h"
+#include "nsCOMPtr.h"
+
+class nsIWidget;
 
 #define BASEFILEPICKER_HAS_DISPLAYDIRECTORY 1
 
diff --git a/widget/src/xpwidgets/nsNativeTheme.cpp b/widget/src/xpwidgets/nsNativeTheme.cpp
index 1bd56bc90577..2c4c9336cf00 100644
--- a/widget/src/xpwidgets/nsNativeTheme.cpp
+++ b/widget/src/xpwidgets/nsNativeTheme.cpp
@@ -37,6 +37,7 @@
  * ***** END LICENSE BLOCK ***** */
 
 #include "nsNativeTheme.h"
+#include "nsIWidget.h"
 #include "nsIDocument.h"
 #include "nsIContent.h"
 #include "nsIFrame.h"
diff --git a/xpfe/appshell/src/nsAppShellService.cpp b/xpfe/appshell/src/nsAppShellService.cpp
index c36f21f43a8c..3ffccd687f88 100644
--- a/xpfe/appshell/src/nsAppShellService.cpp
+++ b/xpfe/appshell/src/nsAppShellService.cpp
@@ -51,7 +51,6 @@
 #include "nsIPrefBranch.h"
 #include "nsIPrefService.h"
 
-#include "nsIWidget.h"
 #include "nsIWindowMediator.h"
 #include "nsIWindowWatcher.h"
 #include "nsPIWindowWatcher.h"
diff --git a/xpfe/appshell/src/nsWebShellWindow.h b/xpfe/appshell/src/nsWebShellWindow.h
index a12507cafc91..3fccada50c39 100644
--- a/xpfe/appshell/src/nsWebShellWindow.h
+++ b/xpfe/appshell/src/nsWebShellWindow.h
@@ -38,7 +38,7 @@
 #ifndef nsWebShellWindow_h__
 #define nsWebShellWindow_h__
 
-#include "nsGUIEvent.h"
+#include "nsEvent.h"
 #include "nsIWebProgressListener.h"
 #include "nsITimer.h"
 
diff --git a/xpfe/appshell/src/nsXULWindow.h b/xpfe/appshell/src/nsXULWindow.h
index d16b25c33d3a..21b2879add16 100644
--- a/xpfe/appshell/src/nsXULWindow.h
+++ b/xpfe/appshell/src/nsXULWindow.h
@@ -58,7 +58,6 @@
 #include "nsIDOMWindowInternal.h"
 #include "nsIInterfaceRequestor.h"
 #include "nsIInterfaceRequestorUtils.h"
-#include "nsIWidget.h"
 #include "nsIXULWindow.h"
 #include "nsIPrompt.h"
 #include "nsIAuthPrompt.h"