Add opaque "layout item" to widgets for caller's use.

xfa/fwl/core/fwl_widgetimp.h

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #ifndef XFA_FWL_CORE_FWL_WIDGETIMP_H_
 #define XFA_FWL_CORE_FWL_WIDGETIMP_H_
 
 #include "core/fxcrt/include/fx_coordinates.h"
@@ skipping 62 matching lines @@
   virtual FWL_Error SetDataProvider(IFWL_DataProvider* pDataProvider);
   virtual IFWL_WidgetDelegate* SetDelegate(IFWL_WidgetDelegate* pDelegate);
   virtual IFWL_App* GetOwnerApp() const;
 
   FWL_Error SetOwnerApp(CFWL_AppImp* pOwnerApp);
   IFWL_Widget* GetInterface() const;
   void SetInterface(IFWL_Widget* pInterface);
   CFX_SizeF GetOffsetFromParent(IFWL_Widget* pParent);
   uint32_t GetEventKey() const;
   void SetEventKey(uint32_t key);
+  void* GetLayoutItem() const;
+  void SetLayoutItem(void* pItem);
 
  protected:
   friend class CFWL_WidgetImpDelegate;
 
   CFWL_WidgetImp(const CFWL_WidgetImpProperties& properties,
                  IFWL_Widget* pOuter);
 
   FX_BOOL IsEnabled() const;
   FX_BOOL IsVisible() const;
   FX_BOOL IsActive() const;
@@ skipping 62 matching lines @@
   FX_BOOL IsParent(IFWL_Widget* pParent);
 
   CFWL_WidgetMgr* m_pWidgetMgr;
   CFWL_AppImp* m_pOwnerApp;
   CFWL_WidgetImpProperties* m_pProperties;
   CFX_PrivateData* m_pPrivateData;
   IFWL_WidgetDelegate* m_pDelegate;
   IFWL_WidgetDelegate* m_pCurDelegate;
   IFWL_Widget* m_pOuter;
   IFWL_Widget* m_pInterface;
+  void* m_pLayoutItem;
   int32_t m_iLock;
   uint32_t m_nEventKey;
 };
 
 class CFWL_WidgetImpDelegate : public IFWL_WidgetDelegate {
  public:
   CFWL_WidgetImpDelegate();
   ~CFWL_WidgetImpDelegate() override {}
   void OnProcessMessage(CFWL_Message* pMessage) override;
   void OnProcessEvent(CFWL_Event* pEvent) override;
   void OnDrawWidget(CFX_Graphics* pGraphics,
                     const CFX_Matrix* pMatrix = NULL) override;
 };
 
 #endif  // XFA_FWL_CORE_FWL_WIDGETIMP_H_