Use virtual function to retrieve interface pointer

xfa/fwl/lightwidget/cfwl_barcode.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_LIGHTWIDGET_CFWL_BARCODE_H_
 #define XFA_FWL_LIGHTWIDGET_CFWL_BARCODE_H_
 
 #include "xfa/fwl/basewidget/ifwl_barcode.h"
 #include "xfa/fwl/core/fwl_error.h"
 #include "xfa/fwl/lightwidget/cfwl_edit.h"
 
 class CFWL_Widget;
 class CFWL_WidgetProperties;
 
 class CFWL_Barcode : public CFWL_Edit {
  public:
   static CFWL_Barcode* Create();
+
+  IFWL_Barcode* GetWidget() override;
+  const IFWL_Barcode* GetWidget() const override;
+
   FWL_Error Initialize(const CFWL_WidgetProperties* pProperties = nullptr);
   void SetType(BC_TYPE type);
   FX_BOOL IsProtectedType();
 
   void SetCharEncoding(BC_CHAR_ENCODING encoding) {
     m_barcodeData.m_dwAttributeMask |= FWL_BCDATTRIBUTE_CHARENCODING;
     m_barcodeData.m_eCharEncoding = encoding;
   }
   void SetModuleHeight(int32_t height) {
     m_barcodeData.m_dwAttributeMask |= FWL_BCDATTRIBUTE_MODULEHEIGHT;
     m_barcodeData.m_nModuleHeight = height;
   }
   void SetModuleWidth(int32_t width) {
     m_barcodeData.m_dwAttributeMask |= FWL_BCDATTRIBUTE_MODULEWIDTH;
     m_barcodeData.m_nModuleWidth = width;
   }
   void SetDataLength(int32_t dataLength) {
     m_barcodeData.m_dwAttributeMask |= FWL_BCDATTRIBUTE_DATALENGTH;
     m_barcodeData.m_nDataLength = dataLength;
-    static_cast<IFWL_Barcode*>(m_pIface)->SetLimit(dataLength);
+    GetWidget()->SetLimit(dataLength);
   }
   void SetCalChecksum(int32_t calChecksum) {
     m_barcodeData.m_dwAttributeMask |= FWL_BCDATTRIBUTE_CALCHECKSUM;
     m_barcodeData.m_nCalChecksum = calChecksum;
   }
   void SetPrintChecksum(FX_BOOL printChecksum) {
     m_barcodeData.m_dwAttributeMask |= FWL_BCDATTRIBUTE_PRINTCHECKSUM;
     m_barcodeData.m_bPrintChecksum = printChecksum;
   }
   void SetTextLocation(BC_TEXT_LOC location) {
@@ skipping 67 matching lines @@
     int32_t m_nVersion;
     int32_t m_nECLevel;
     FX_BOOL m_bTruncated;
     uint32_t m_dwAttributeMask;
   };
 
   CFWL_BarcodeDP m_barcodeData;
 };
 
 #endif  // XFA_FWL_LIGHTWIDGET_CFWL_BARCODE_H_