Remove CFX_PtrList from renderer main loop.

Exposes an iterator over the object list, but not the object
holder, since pages and forms inherit from object holder, and
we don't want to imply that there's only one thing that might
be iterated over for those classes.

R=thestig@chromium.org

Review URL: https://codereview.chromium.org/1700183002 .

1 files changed, 22 insertions, 29 deletions

diff --git a/core/src/fpdfapi/fpdf_render/fpdf_render.cpp b/core/src/fpdfapi/fpdf_render/fpdf_render.cpp
index 0023ee92de..147de51f4d 100644
--- a/core/src/fpdfapi/fpdf_render/fpdf_render.cpp
+++ b/core/src/fpdfapi/fpdf_render/fpdf_render.cpp
@@ -244,29 +244,24 @@ void CPDF_RenderStatus::RenderObjectList(
   CFX_Matrix device2object;
   device2object.SetReverse(*pObj2Device);
   device2object.TransformRect(clip_rect);
-  int index = 0;
-  FX_POSITION pos = pObjectHolder->GetPageObjectList()->GetHeadPosition();
-  while (pos) {
-    index++;
-    CPDF_PageObject* pCurObj =
-        pObjectHolder->GetPageObjectList()->GetNextObject(pos);
-    if (pCurObj == m_pStopObj) {
+
+  for (const auto& pCurObj : *pObjectHolder->GetPageObjectList()) {
+    if (pCurObj.get() == m_pStopObj) {
       m_bStopped = TRUE;
       return;
     }
-    if (!pCurObj) {
+    if (!pCurObj)
       continue;
-    }
-    if (!pCurObj || pCurObj->m_Left > clip_rect.right ||
+
+    if (pCurObj->m_Left > clip_rect.right ||
         pCurObj->m_Right < clip_rect.left ||
         pCurObj->m_Bottom > clip_rect.top ||
         pCurObj->m_Top < clip_rect.bottom) {
       continue;
     }
-    RenderSingleObject(pCurObj, pObj2Device);
-    if (m_bStopped) {
+    RenderSingleObject(pCurObj.get(), pObj2Device);
+    if (m_bStopped)
       return;
-    }
   }
 }
 void CPDF_RenderStatus::RenderSingleObject(const CPDF_PageObject* pObj,
@@ -1037,8 +1032,7 @@ CPDF_ProgressiveRenderer::CPDF_ProgressiveRenderer(
       m_pDevice(pDevice),
       m_pOptions(pOptions),
       m_LayerIndex(0),
-      m_pCurrentLayer(nullptr),
-      m_LastObjectRendered(nullptr) {}
+      m_pCurrentLayer(nullptr) {}
 
 CPDF_ProgressiveRenderer::~CPDF_ProgressiveRenderer() {
   if (m_pRenderStatus)
@@ -1062,7 +1056,8 @@ void CPDF_ProgressiveRenderer::Continue(IFX_Pause* pPause) {
         return;
       }
       m_pCurrentLayer = m_pContext->GetLayer(m_LayerIndex);
-      m_LastObjectRendered = nullptr;
+      m_LastObjectRendered =
+          m_pCurrentLayer->m_pObjectHolder->GetPageObjectList()->end();
       m_pRenderStatus.reset(new CPDF_RenderStatus());
       m_pRenderStatus->Initialize(
           m_pContext, m_pDevice, NULL, NULL, NULL, NULL, m_pOptions,
@@ -1073,19 +1068,18 @@ void CPDF_ProgressiveRenderer::Continue(IFX_Pause* pPause) {
       device2object.SetReverse(m_pCurrentLayer->m_Matrix);
       device2object.TransformRect(m_ClipRect);
     }
-    FX_POSITION pos;
-    if (m_LastObjectRendered) {
-      pos = m_LastObjectRendered;
-      m_pCurrentLayer->m_pObjectHolder->GetPageObjectList()->GetNextObject(pos);
+    CPDF_PageObjectList::iterator iter;
+    CPDF_PageObjectList::iterator iterEnd =
+        m_pCurrentLayer->m_pObjectHolder->GetPageObjectList()->end();
+    if (m_LastObjectRendered != iterEnd) {
+      iter = m_LastObjectRendered;
+      ++iter;
     } else {
-      pos = m_pCurrentLayer->m_pObjectHolder->GetPageObjectList()
-                ->GetHeadPosition();
+      iter = m_pCurrentLayer->m_pObjectHolder->GetPageObjectList()->begin();
     }
     int nObjsToGo = kStepLimit;
-    while (pos) {
-      CPDF_PageObject* pCurObj =
-          m_pCurrentLayer->m_pObjectHolder->GetPageObjectList()->GetObjectAt(
-              pos);
+    while (iter != iterEnd) {
+      CPDF_PageObject* pCurObj = iter->get();
       if (pCurObj && pCurObj->m_Left <= m_ClipRect.right &&
           pCurObj->m_Right >= m_ClipRect.left &&
           pCurObj->m_Bottom <= m_ClipRect.top &&
@@ -1106,19 +1100,18 @@ void CPDF_ProgressiveRenderer::Continue(IFX_Pause* pPause) {
           --nObjsToGo;
         }
       }
-      m_LastObjectRendered = pos;
+      m_LastObjectRendered = iter;
       if (nObjsToGo == 0) {
         if (pPause && pPause->NeedToPauseNow())
           return;
         nObjsToGo = kStepLimit;
       }
-      m_pCurrentLayer->m_pObjectHolder->GetPageObjectList()->GetNextObject(pos);
+      ++iter;
     }
     if (m_pCurrentLayer->m_pObjectHolder->IsParsed()) {
       m_pRenderStatus.reset();
       m_pDevice->RestoreState();
       m_pCurrentLayer = nullptr;
-      m_LastObjectRendered = nullptr;
       m_LayerIndex++;
       if (pPause && pPause->NeedToPauseNow()) {
         return;