Remove PageObject's m_Type and add As<Type> functions

For CPDF_PageObject and its subclasses, remove m_Type and use GetType() instead. Also, add As<Type> functions to avoid casting all over the places.

BUG=pdfium:397
R=thestig@chromium.org

Review URL: https://codereview.chromium.org/1709393002 .

5 files changed, 60 insertions, 64 deletions

diff --git a/core/src/fpdfapi/fpdf_render/fpdf_render.cpp b/core/src/fpdfapi/fpdf_render/fpdf_render.cpp
index 8e205df281..a470e94b86 100644
--- a/core/src/fpdfapi/fpdf_render/fpdf_render.cpp
+++ b/core/src/fpdfapi/fpdf_render/fpdf_render.cpp
@@ -306,8 +306,8 @@ FX_BOOL CPDF_RenderStatus::ContinueSingleObject(const CPDF_PageObject* pObj,
   if (ProcessTransparency(pObj, pObj2Device))
     return FALSE;
 
-  if (pObj->m_Type == CPDF_PageObject::IMAGE) {
-    m_pObjectRenderer.reset(IPDF_ObjectRenderer::Create(pObj->m_Type));
+  if (pObj->IsImage()) {
+    m_pObjectRenderer.reset(IPDF_ObjectRenderer::Create());
     if (!m_pObjectRenderer->Start(this, pObj, pObj2Device, FALSE)) {
       if (!m_pObjectRenderer->m_Result)
         DrawObjWithBackground(pObj, pObj2Device);
@@ -321,12 +321,10 @@ FX_BOOL CPDF_RenderStatus::ContinueSingleObject(const CPDF_PageObject* pObj,
   return FALSE;
 }
 
-IPDF_ObjectRenderer* IPDF_ObjectRenderer::Create(int type) {
-  if (type != CPDF_PageObject::IMAGE) {
-    return NULL;
-  }
+IPDF_ObjectRenderer* IPDF_ObjectRenderer::Create() {
   return new CPDF_ImageRenderer;
 }
+
 FX_BOOL CPDF_RenderStatus::GetObjectClippedRect(const CPDF_PageObject* pObj,
                                                 const CFX_Matrix* pObj2Device,
                                                 FX_BOOL bLogical,
@@ -374,21 +372,21 @@ void CPDF_RenderStatus::DitherObjectArea(const CPDF_PageObject* pObj,
 void CPDF_RenderStatus::ProcessObjectNoClip(const CPDF_PageObject* pObj,
                                             const CFX_Matrix* pObj2Device) {
   FX_BOOL bRet = FALSE;
-  switch (pObj->m_Type) {
+  switch (pObj->GetType()) {
     case CPDF_PageObject::TEXT:
-      bRet = ProcessText((CPDF_TextObject*)pObj, pObj2Device, NULL);
+      bRet = ProcessText(pObj->AsText(), pObj2Device, NULL);
       break;
     case CPDF_PageObject::PATH:
-      bRet = ProcessPath((CPDF_PathObject*)pObj, pObj2Device);
+      bRet = ProcessPath(pObj->AsPath(), pObj2Device);
       break;
     case CPDF_PageObject::IMAGE:
-      bRet = ProcessImage((CPDF_ImageObject*)pObj, pObj2Device);
+      bRet = ProcessImage(pObj->AsImage(), pObj2Device);
       break;
     case CPDF_PageObject::SHADING:
-      bRet = ProcessShading((CPDF_ShadingObject*)pObj, pObj2Device);
+      bRet = ProcessShading(pObj->AsShading(), pObj2Device);
       break;
     case CPDF_PageObject::FORM:
-      bRet = ProcessForm((CPDF_FormObject*)pObj, pObj2Device);
+      bRet = ProcessForm(pObj->AsForm(), pObj2Device);
       break;
   }
   if (!bRet) {
@@ -398,15 +396,15 @@ void CPDF_RenderStatus::ProcessObjectNoClip(const CPDF_PageObject* pObj,
 FX_BOOL CPDF_RenderStatus::DrawObjWithBlend(const CPDF_PageObject* pObj,
                                             const CFX_Matrix* pObj2Device) {
   FX_BOOL bRet = FALSE;
-  switch (pObj->m_Type) {
+  switch (pObj->GetType()) {
     case CPDF_PageObject::PATH:
-      bRet = ProcessPath((CPDF_PathObject*)pObj, pObj2Device);
+      bRet = ProcessPath(pObj->AsPath(), pObj2Device);
       break;
     case CPDF_PageObject::IMAGE:
-      bRet = ProcessImage((CPDF_ImageObject*)pObj, pObj2Device);
+      bRet = ProcessImage(pObj->AsImage(), pObj2Device);
       break;
     case CPDF_PageObject::FORM:
-      bRet = ProcessForm((CPDF_FormObject*)pObj, pObj2Device);
+      bRet = ProcessForm(pObj->AsForm(), pObj2Device);
       break;
     default:
       break;
@@ -425,7 +423,7 @@ void CPDF_RenderStatus::DrawObjWithBackground(const CPDF_PageObject* pObj,
     return;
   }
   int res = 300;
-  if (pObj->m_Type == CPDF_PageObject::IMAGE &&
+  if (pObj->IsImage() &&
       m_pDevice->GetDeviceCaps(FXDC_DEVICE_CLASS) == FXDC_PRINTER) {
     res = 0;
   }
@@ -437,8 +435,8 @@ void CPDF_RenderStatus::DrawObjWithBackground(const CPDF_PageObject* pObj,
   matrix.Concat(*buffer.GetMatrix());
   GetScaledMatrix(matrix);
   CPDF_Dictionary* pFormResource = NULL;
-  if (pObj->m_Type == CPDF_PageObject::FORM) {
-    CPDF_FormObject* pFormObj = (CPDF_FormObject*)pObj;
+  if (pObj->IsForm()) {
+    const CPDF_FormObject* pFormObj = pObj->AsForm();
     if (pFormObj->m_pForm && pFormObj->m_pForm->m_pFormDict) {
       pFormResource = pFormObj->m_pForm->m_pFormDict->GetDictBy("Resources");
     }
@@ -450,7 +448,7 @@ void CPDF_RenderStatus::DrawObjWithBackground(const CPDF_PageObject* pObj,
   status.RenderSingleObject(pObj, &matrix);
   buffer.OutputToDevice();
 }
-FX_BOOL CPDF_RenderStatus::ProcessForm(CPDF_FormObject* pFormObj,
+FX_BOOL CPDF_RenderStatus::ProcessForm(const CPDF_FormObject* pFormObj,
                                        const CFX_Matrix* pObj2Device) {
   CPDF_Dictionary* pOC = pFormObj->m_pForm->m_pFormDict->GetDictBy("OC");
   if (pOC && m_Options.m_pOCContext &&
@@ -483,7 +481,7 @@ FX_BOOL IsAvailableMatrix(const CFX_Matrix& matrix) {
   }
   return TRUE;
 }
-FX_BOOL CPDF_RenderStatus::ProcessPath(CPDF_PathObject* pPathObj,
+FX_BOOL CPDF_RenderStatus::ProcessPath(const CPDF_PathObject* pPathObj,
                                        const CFX_Matrix* pObj2Device) {
   int FillType = pPathObj->m_FillType;
   FX_BOOL bStroke = pPathObj->m_bStroke;
@@ -691,7 +689,7 @@ void CPDF_RenderStatus::DrawClipPath(CPDF_ClipPath ClipPath,
                         fill_mode);
   }
 }
-FX_BOOL CPDF_RenderStatus::SelectClipPath(CPDF_PathObject* pPathObj,
+FX_BOOL CPDF_RenderStatus::SelectClipPath(const CPDF_PathObject* pPathObj,
                                           const CFX_Matrix* pObj2Device,
                                           FX_BOOL bStroke) {
   CFX_Matrix path_matrix = pPathObj->m_Matrix;
@@ -721,8 +719,8 @@ FX_BOOL CPDF_RenderStatus::ProcessTransparency(const CPDF_PageObject* pPageObj,
   CPDF_Dictionary* pSMaskDict =
       pGeneralState ? ToDictionary(pGeneralState->m_pSoftMask) : NULL;
   if (pSMaskDict) {
-    if (pPageObj->m_Type == CPDF_PageObject::IMAGE &&
-        ((CPDF_ImageObject*)pPageObj)->m_pImage->GetDict()->KeyExist("SMask")) {
+    if (pPageObj->IsImage() &&
+        pPageObj->AsImage()->m_pImage->GetDict()->KeyExist("SMask")) {
       pSMaskDict = NULL;
     }
   }
@@ -730,8 +728,8 @@ FX_BOOL CPDF_RenderStatus::ProcessTransparency(const CPDF_PageObject* pPageObj,
   FX_FLOAT group_alpha = 1.0f;
   int Transparency = m_Transparency;
   FX_BOOL bGroupTransparent = FALSE;
-  if (pPageObj->m_Type == CPDF_PageObject::FORM) {
-    CPDF_FormObject* pFormObj = (CPDF_FormObject*)pPageObj;
+  if (pPageObj->IsForm()) {
+    const CPDF_FormObject* pFormObj = pPageObj->AsForm();
     const CPDF_GeneralStateData* pStateData =
         pFormObj->m_GeneralState.GetObject();
     if (pStateData) {
@@ -749,22 +747,20 @@ FX_BOOL CPDF_RenderStatus::ProcessTransparency(const CPDF_PageObject* pPageObj,
       !(m_pDevice->GetDeviceCaps(FXDC_RENDER_CAPS) & FXRC_SOFT_CLIP)) {
     bTextClip = TRUE;
   }
-  if ((m_Options.m_Flags & RENDER_OVERPRINT) &&
-      pPageObj->m_Type == CPDF_PageObject::IMAGE && pGeneralState &&
-      pGeneralState->m_FillOP && pGeneralState->m_StrokeOP) {
+  if ((m_Options.m_Flags & RENDER_OVERPRINT) && pPageObj->IsImage() &&
+      pGeneralState && pGeneralState->m_FillOP && pGeneralState->m_StrokeOP) {
     CPDF_Document* pDocument = NULL;
     CPDF_Page* pPage = NULL;
     if (m_pContext->GetPageCache()) {
       pPage = m_pContext->GetPageCache()->GetPage();
       pDocument = pPage->m_pDocument;
     } else {
-      pDocument = ((CPDF_ImageObject*)pPageObj)->m_pImage->GetDocument();
+      pDocument = pPageObj->AsImage()->m_pImage->GetDocument();
     }
     CPDF_Dictionary* pPageResources = pPage ? pPage->m_pPageResources : NULL;
-    CPDF_Object* pCSObj = ((CPDF_ImageObject*)pPageObj)
-                              ->m_pImage->GetStream()
-                              ->GetDict()
-                              ->GetElementValue("ColorSpace");
+    CPDF_Object* pCSObj =
+        pPageObj->AsImage()->m_pImage->GetStream()->GetDict()->GetElementValue(
+            "ColorSpace");
     CPDF_ColorSpace* pColorSpace =
         pDocument->LoadColorSpace(pCSObj, pPageResources);
     if (pColorSpace) {
@@ -870,7 +866,7 @@ FX_BOOL CPDF_RenderStatus::ProcessTransparency(const CPDF_PageObject* pPageObj,
     bitmap->MultiplyAlpha((int32_t)(group_alpha * 255));
   }
   Transparency = m_Transparency;
-  if (pPageObj->m_Type == CPDF_PageObject::FORM) {
+  if (pPageObj->IsForm()) {
     Transparency |= PDFTRANS_GROUP;
   }
   CompositeDIBitmap(bitmap, rect.left, rect.top, 0, 255, blend_type,
@@ -1088,13 +1084,12 @@ void CPDF_ProgressiveRenderer::Continue(IFX_Pause* pPause) {
                 pCurObj, &m_pCurrentLayer->m_Matrix, pPause)) {
           return;
         }
-        if (pCurObj->m_Type == CPDF_PageObject::IMAGE &&
+        if (pCurObj->IsImage() &&
             m_pRenderStatus->m_Options.m_Flags & RENDER_LIMITEDIMAGECACHE) {
           m_pContext->GetPageCache()->CacheOptimization(
               m_pRenderStatus->m_Options.m_dwLimitCacheSize);
         }
-        if (pCurObj->m_Type == CPDF_PageObject::FORM ||
-            pCurObj->m_Type == CPDF_PageObject::SHADING) {
+        if (pCurObj->IsForm() || pCurObj->IsShading()) {
           nObjsToGo = 0;
         } else {
           --nObjsToGo;
diff --git a/core/src/fpdfapi/fpdf_render/fpdf_render_image.cpp b/core/src/fpdfapi/fpdf_render/fpdf_render_image.cpp
index 2bd3e91935..acfc083e0e 100644
--- a/core/src/fpdfapi/fpdf_render/fpdf_render_image.cpp
+++ b/core/src/fpdfapi/fpdf_render/fpdf_render_image.cpp
@@ -17,7 +17,7 @@
 #include "core/include/fxge/fx_ge.h"
 #include "core/src/fpdfapi/fpdf_page/pageint.h"
 
-FX_BOOL CPDF_RenderStatus::ProcessImage(CPDF_ImageObject* pImageObj,
+FX_BOOL CPDF_RenderStatus::ProcessImage(const CPDF_ImageObject* pImageObj,
                                         const CFX_Matrix* pObj2Device) {
   CPDF_ImageRenderer render;
   if (render.Start(this, pImageObj, pObj2Device, m_bStdCS, m_curBlend)) {
diff --git a/core/src/fpdfapi/fpdf_render/fpdf_render_pattern.cpp b/core/src/fpdfapi/fpdf_render/fpdf_render_pattern.cpp
index 7284b627b5..f4ade7d48d 100644
--- a/core/src/fpdfapi/fpdf_render/fpdf_render_pattern.cpp
+++ b/core/src/fpdfapi/fpdf_render/fpdf_render_pattern.cpp
@@ -912,19 +912,19 @@ void CPDF_RenderStatus::DrawShading(CPDF_ShadingPattern* pPattern,
   buffer.OutputToDevice();
 }
 void CPDF_RenderStatus::DrawShadingPattern(CPDF_ShadingPattern* pattern,
-                                           CPDF_PageObject* pPageObj,
+                                           const CPDF_PageObject* pPageObj,
                                            const CFX_Matrix* pObj2Device,
                                            FX_BOOL bStroke) {
   if (!pattern->Load()) {
     return;
   }
   m_pDevice->SaveState();
-  if (pPageObj->m_Type == CPDF_PageObject::PATH) {
-    if (!SelectClipPath((CPDF_PathObject*)pPageObj, pObj2Device, bStroke)) {
+  if (pPageObj->IsPath()) {
+    if (!SelectClipPath(pPageObj->AsPath(), pObj2Device, bStroke)) {
       m_pDevice->RestoreState();
       return;
     }
-  } else if (pPageObj->m_Type == CPDF_PageObject::IMAGE) {
+  } else if (pPageObj->IsImage()) {
     FX_RECT rect = pPageObj->GetBBox(pObj2Device);
     m_pDevice->SetClip_Rect(&rect);
   } else {
@@ -943,7 +943,7 @@ void CPDF_RenderStatus::DrawShadingPattern(CPDF_ShadingPattern* pattern,
               m_Options.m_ColorMode == RENDER_COLOR_ALPHA);
   m_pDevice->RestoreState();
 }
-FX_BOOL CPDF_RenderStatus::ProcessShading(CPDF_ShadingObject* pShadingObj,
+FX_BOOL CPDF_RenderStatus::ProcessShading(const CPDF_ShadingObject* pShadingObj,
                                           const CFX_Matrix* pObj2Device) {
   FX_RECT rect = pShadingObj->GetBBox(pObj2Device);
   FX_RECT clip_box = m_pDevice->GetClipBox();
@@ -994,19 +994,19 @@ static CFX_DIBitmap* DrawPatternBitmap(CPDF_Document* pDoc,
   return pBitmap;
 }
 void CPDF_RenderStatus::DrawTilingPattern(CPDF_TilingPattern* pPattern,
-                                          CPDF_PageObject* pPageObj,
+                                          const CPDF_PageObject* pPageObj,
                                           const CFX_Matrix* pObj2Device,
                                           FX_BOOL bStroke) {
   if (!pPattern->Load()) {
     return;
   }
   m_pDevice->SaveState();
-  if (pPageObj->m_Type == CPDF_PageObject::PATH) {
-    if (!SelectClipPath((CPDF_PathObject*)pPageObj, pObj2Device, bStroke)) {
+  if (pPageObj->IsPath()) {
+    if (!SelectClipPath(pPageObj->AsPath(), pObj2Device, bStroke)) {
       m_pDevice->RestoreState();
       return;
     }
-  } else if (pPageObj->m_Type == CPDF_PageObject::IMAGE) {
+  } else if (pPageObj->IsImage()) {
     FX_RECT rect = pPageObj->GetBBox(pObj2Device);
     m_pDevice->SetClip_Rect(&rect);
   } else {
@@ -1179,7 +1179,7 @@ void CPDF_RenderStatus::DrawTilingPattern(CPDF_TilingPattern* pPattern,
   m_pDevice->RestoreState();
   delete pPatternBitmap;
 }
-void CPDF_RenderStatus::DrawPathWithPattern(CPDF_PathObject* pPathObj,
+void CPDF_RenderStatus::DrawPathWithPattern(const CPDF_PathObject* pPathObj,
                                             const CFX_Matrix* pObj2Device,
                                             CPDF_Color* pColor,
                                             FX_BOOL bStroke) {
@@ -1195,7 +1195,7 @@ void CPDF_RenderStatus::DrawPathWithPattern(CPDF_PathObject* pPathObj,
                        pObj2Device, bStroke);
   }
 }
-void CPDF_RenderStatus::ProcessPathPattern(CPDF_PathObject* pPathObj,
+void CPDF_RenderStatus::ProcessPathPattern(const CPDF_PathObject* pPathObj,
                                            const CFX_Matrix* pObj2Device,
                                            int& filltype,
                                            FX_BOOL& bStroke) {
diff --git a/core/src/fpdfapi/fpdf_render/fpdf_render_text.cpp b/core/src/fpdfapi/fpdf_render/fpdf_render_text.cpp
index d2faac3b7e..769ee05dc9 100644
--- a/core/src/fpdfapi/fpdf_render/fpdf_render_text.cpp
+++ b/core/src/fpdfapi/fpdf_render/fpdf_render_text.cpp
@@ -318,10 +318,9 @@ FX_BOOL CPDF_Type3Char::LoadBitmap(CPDF_RenderContext* pContext) {
   }
   if (m_pForm->GetPageObjectList()->size() == 1 && !m_bColored) {
     auto& pPageObj = m_pForm->GetPageObjectList()->front();
-    if (pPageObj->m_Type == CPDF_PageObject::IMAGE) {
-      CPDF_ImageObject* pImage = static_cast<CPDF_ImageObject*>(pPageObj.get());
-      m_ImageMatrix = pImage->m_Matrix;
-      const CFX_DIBSource* pSource = pImage->m_pImage->LoadDIBSource();
+    if (pPageObj->IsImage()) {
+      const CFX_DIBSource* pSource =
+          pPageObj->AsImage()->m_pImage->LoadDIBSource();
       if (pSource) {
         m_pBitmap = pSource->Clone();
         delete pSource;
diff --git a/core/src/fpdfapi/fpdf_render/render_int.h b/core/src/fpdfapi/fpdf_render/render_int.h
index 9a262ea6fc..5af5909d2e 100644
--- a/core/src/fpdfapi/fpdf_render/render_int.h
+++ b/core/src/fpdfapi/fpdf_render/render_int.h
@@ -94,7 +94,7 @@ class CPDF_DocRenderData {
 
 class IPDF_ObjectRenderer {
  public:
-  static IPDF_ObjectRenderer* Create(int type);
+  static IPDF_ObjectRenderer* Create();
   virtual ~IPDF_ObjectRenderer() {}
   virtual FX_BOOL Start(CPDF_RenderStatus* pRenderStatus,
                         const CPDF_PageObject* pObj,
@@ -151,27 +151,28 @@ class CPDF_RenderStatus {
                              const CFX_Matrix* pObj2Device);
   FX_BOOL DrawObjWithBlend(const CPDF_PageObject* pObj,
                            const CFX_Matrix* pObj2Device);
-  FX_BOOL ProcessPath(CPDF_PathObject* pPathObj, const CFX_Matrix* pObj2Device);
-  void ProcessPathPattern(CPDF_PathObject* pPathObj,
+  FX_BOOL ProcessPath(const CPDF_PathObject* pPathObj,
+                      const CFX_Matrix* pObj2Device);
+  void ProcessPathPattern(const CPDF_PathObject* pPathObj,
                           const CFX_Matrix* pObj2Device,
                           int& filltype,
                           FX_BOOL& bStroke);
-  void DrawPathWithPattern(CPDF_PathObject* pPathObj,
+  void DrawPathWithPattern(const CPDF_PathObject* pPathObj,
                            const CFX_Matrix* pObj2Device,
                            CPDF_Color* pColor,
                            FX_BOOL bStroke);
   void DrawTilingPattern(CPDF_TilingPattern* pPattern,
-                         CPDF_PageObject* pPageObj,
+                         const CPDF_PageObject* pPageObj,
                          const CFX_Matrix* pObj2Device,
                          FX_BOOL bStroke);
   void DrawShadingPattern(CPDF_ShadingPattern* pPattern,
-                          CPDF_PageObject* pPageObj,
+                          const CPDF_PageObject* pPageObj,
                           const CFX_Matrix* pObj2Device,
                           FX_BOOL bStroke);
-  FX_BOOL SelectClipPath(CPDF_PathObject* pPathObj,
+  FX_BOOL SelectClipPath(const CPDF_PathObject* pPathObj,
                          const CFX_Matrix* pObj2Device,
                          FX_BOOL bStroke);
-  FX_BOOL ProcessImage(CPDF_ImageObject* pImageObj,
+  FX_BOOL ProcessImage(const CPDF_ImageObject* pImageObj,
                        const CFX_Matrix* pObj2Device);
   FX_BOOL OutputBitmapAlpha(CPDF_ImageObject* pImageObj,
                             const CFX_Matrix* pImage2Device);
@@ -190,7 +191,7 @@ class CPDF_RenderStatus {
                          int bitmap_alpha,
                          int blend_mode,
                          int bIsolated);
-  FX_BOOL ProcessShading(CPDF_ShadingObject* pShadingObj,
+  FX_BOOL ProcessShading(const CPDF_ShadingObject* pShadingObj,
                          const CFX_Matrix* pObj2Device);
   void DrawShading(CPDF_ShadingPattern* pPattern,
                    CFX_Matrix* pMatrix,
@@ -209,7 +210,8 @@ class CPDF_RenderStatus {
                                const CFX_Matrix* pTextMatrix,
                                FX_BOOL bFill,
                                FX_BOOL bStroke);
-  FX_BOOL ProcessForm(CPDF_FormObject* pFormObj, const CFX_Matrix* pObj2Device);
+  FX_BOOL ProcessForm(const CPDF_FormObject* pFormObj,
+                      const CFX_Matrix* pObj2Device);
   CFX_DIBitmap* GetBackdrop(const CPDF_PageObject* pObj,
                             const FX_RECT& rect,
                             int& left,