Introduce CPDFPageFromFPDFPage()

fpdfsdk/src/fpdf_progressive.cpp

 // 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
 
 #include "../../public/fpdf_progressive.h"
 #include "../../public/fpdfview.h"
 #include "../include/fsdk_define.h"
 #include "../include/fsdk_rendercontext.h"
 
 DLLEXPORT int STDCALL FPDF_RenderPageBitmap_Start(FPDF_BITMAP bitmap,
                                                   FPDF_PAGE page,
                                                   int start_x,
                                                   int start_y,
                                                   int size_x,
                                                   int size_y,
                                                   int rotate,
                                                   int flags,
                                                   IFSDK_PAUSE* pause) {
-  if (bitmap == NULL || page == NULL)
+  if (!bitmap || !pause || pause->version != 1)
     return FPDF_RENDER_FAILED;
 
-  if (!pause)
+  CPDF_Page* pPage = CPDFPageFromFPDFPage(page);
+  if (!pPage)
     return FPDF_RENDER_FAILED;
 
-  if (pause->version != 1)
-    return FPDF_RENDER_FAILED;
-
-  CPDF_Page* pPage = (CPDF_Page*)page;
   CRenderContext* pContext = new CRenderContext;
   pPage->SetPrivateData((void*)1, pContext, DropContext);
 #ifdef _SKIA_SUPPORT_
   pContext->m_pDevice = new CFX_SkiaDevice;
   if (flags & FPDF_REVERSE_BYTE_ORDER)
     ((CFX_SkiaDevice*)pContext->m_pDevice)
         ->Attach((CFX_DIBitmap*)bitmap, 0, TRUE);
   else
     ((CFX_SkiaDevice*)pContext->m_pDevice)->Attach((CFX_DIBitmap*)bitmap);
 #else
@@ skipping 11 matching lines @@
 
   if (pContext->m_pRenderer)
     return CPDF_ProgressiveRenderer::ToFPDFStatus(
         pContext->m_pRenderer->GetStatus());
 
   return FPDF_RENDER_FAILED;
 }
 
 DLLEXPORT int STDCALL FPDF_RenderPage_Continue(FPDF_PAGE page,
                                                IFSDK_PAUSE* pause) {
-  if (page == NULL)
+  if (!pause || pause->version != 1)
     return FPDF_RENDER_FAILED;
 
-  if (!pause)
+  CPDF_Page* pPage = CPDFPageFromFPDFPage(page);
+  if (!pPage)
     return FPDF_RENDER_FAILED;
 
-  if (pause->version != 1)
-    return FPDF_RENDER_FAILED;
-
-  CPDF_Page* pPage = (CPDF_Page*)page;
   CRenderContext* pContext = (CRenderContext*)pPage->GetPrivateData((void*)1);
   if (pContext && pContext->m_pRenderer) {
     IFSDK_PAUSE_Adapter IPauseAdapter(pause);
     pContext->m_pRenderer->Continue(&IPauseAdapter);
     return CPDF_ProgressiveRenderer::ToFPDFStatus(
         pContext->m_pRenderer->GetStatus());
   }
   return FPDF_RENDER_FAILED;
 }
 
 DLLEXPORT void STDCALL FPDF_RenderPage_Close(FPDF_PAGE page) {
-  if (!page)
+  CPDF_Page* pPage = CPDFPageFromFPDFPage(page);
+  if (!pPage)
     return;
 
-  CPDF_Page* pPage = (CPDF_Page*)page;
   CRenderContext* pContext = (CRenderContext*)pPage->GetPrivateData((void*)1);
   if (!pContext)
     return;
 
   pContext->m_pDevice->RestoreState();
   delete pContext;
   pPage->RemovePrivateData((void*)1);
 }