Change return types for some rendering Start/Continue methods.

Either return a bool or a CPDF_DIBSource::LoadState. Explain what the
bool return value means.

Change-Id: I6346d0cd61d5faee5290df181cfff3b9e4d5d84e
Reviewed-on: https://pdfium-review.googlesource.com/27851
Commit-Queue: dsinclair <dsinclair@chromium.org>
Reviewed-by: dsinclair <dsinclair@chromium.org>

5 files changed, 51 insertions, 44 deletions

diff --git a/core/fpdfapi/page/cpdf_image.cpp b/core/fpdfapi/page/cpdf_image.cpp
index 5f82886a9b..24f58dfeff 100644
--- a/core/fpdfapi/page/cpdf_image.cpp
+++ b/core/fpdfapi/page/cpdf_image.cpp
@@ -351,7 +351,7 @@ bool CPDF_Image::StartLoadDIBSource(CPDF_Dictionary* pFormResource,
   int ret = source->StartLoadDIBSource(m_pDocument.Get(), m_pStream.Get(), true,
                                        pFormResource, pPageResource, bStdCS,
                                        GroupFamily, bLoadMask);
-  if (!ret) {
+  if (ret == 0) {
     m_pDIBSource.Reset();
     return false;
   }
@@ -367,14 +367,14 @@ bool CPDF_Image::StartLoadDIBSource(CPDF_Dictionary* pFormResource,
 bool CPDF_Image::Continue(IFX_PauseIndicator* pPause) {
   RetainPtr<CPDF_DIBSource> pSource = m_pDIBSource.As<CPDF_DIBSource>();
   int ret = pSource->ContinueLoadDIBSource(pPause);
-  if (!ret) {
-    m_pDIBSource.Reset();
-    return false;
-  }
   if (ret == 2)
     return true;
 
-  m_pMask = pSource->DetachMask();
-  m_MatteColor = pSource->GetMatteColor();
+  if (ret == 1) {
+    m_pMask = pSource->DetachMask();
+    m_MatteColor = pSource->GetMatteColor();
+  } else {
+    m_pDIBSource.Reset();
+  }
   return false;
 }
diff --git a/core/fpdfapi/page/cpdf_image.h b/core/fpdfapi/page/cpdf_image.h
index 57cbe94ca2..43011f8822 100644
--- a/core/fpdfapi/page/cpdf_image.h
+++ b/core/fpdfapi/page/cpdf_image.h
@@ -48,12 +48,17 @@ class CPDF_Image : public Retainable {
   void SetJpegImageInline(const RetainPtr<IFX_SeekableReadStream>& pFile);
 
   void ResetCache(CPDF_Page* pPage, const RetainPtr<CFX_DIBitmap>& pDIBitmap);
+
+  // Returns whether to Continue() or not.
   bool StartLoadDIBSource(CPDF_Dictionary* pFormResource,
                           CPDF_Dictionary* pPageResource,
                           bool bStdCS = false,
                           uint32_t GroupFamily = 0,
                           bool bLoadMask = false);
+
+  // Returns whether to Continue() or not.
   bool Continue(IFX_PauseIndicator* pPause);
+
   RetainPtr<CFX_DIBSource> DetachBitmap();
   RetainPtr<CFX_DIBSource> DetachMask();
 
diff --git a/core/fpdfapi/render/cpdf_imagecacheentry.cpp b/core/fpdfapi/render/cpdf_imagecacheentry.cpp
index f69bfdae68..f4be2af12c 100644
--- a/core/fpdfapi/render/cpdf_imagecacheentry.cpp
+++ b/core/fpdfapi/render/cpdf_imagecacheentry.cpp
@@ -52,7 +52,7 @@ RetainPtr<CFX_DIBSource> CPDF_ImageCacheEntry::DetachMask() {
   return std::move(m_pCurMask);
 }
 
-int CPDF_ImageCacheEntry::StartGetCachedBitmap(
+CPDF_DIBSource::LoadState CPDF_ImageCacheEntry::StartGetCachedBitmap(
     CPDF_Dictionary* pFormResources,
     CPDF_Dictionary* pPageResources,
     bool bStdCS,
@@ -64,7 +64,7 @@ int CPDF_ImageCacheEntry::StartGetCachedBitmap(
   if (m_pCachedBitmap) {
     m_pCurBitmap = m_pCachedBitmap;
     m_pCurMask = m_pCachedMask;
-    return 1;
+    return CPDF_DIBSource::LoadState::kSuccess;
   }
 
   m_pCurBitmap = pdfium::MakeRetain<CPDF_DIBSource>();
@@ -72,14 +72,26 @@ int CPDF_ImageCacheEntry::StartGetCachedBitmap(
       m_pDocument.Get(), m_pImage->GetStream(), true, pFormResources,
       pPageResources, bStdCS, GroupFamily, bLoadMask);
   if (ret == 2)
-    return ret;
+    return CPDF_DIBSource::LoadState::kContinue;
 
-  if (!ret) {
+  if (ret == 1)
+    ContinueGetCachedBitmap(pRenderStatus);
+  else
     m_pCurBitmap.Reset();
-    return 0;
-  }
-  ContinueGetCachedBitmap(pRenderStatus);
-  return 0;
+  return CPDF_DIBSource::LoadState::kFail;
+}
+
+bool CPDF_ImageCacheEntry::Continue(IFX_PauseIndicator* pPause,
+                                    CPDF_RenderStatus* pRenderStatus) {
+  int ret = m_pCurBitmap.As<CPDF_DIBSource>()->ContinueLoadDIBSource(pPause);
+  if (ret == 2)
+    return true;
+
+  if (ret == 1)
+    ContinueGetCachedBitmap(pRenderStatus);
+  else
+    m_pCurBitmap.Reset();
+  return false;
 }
 
 void CPDF_ImageCacheEntry::ContinueGetCachedBitmap(
@@ -105,20 +117,6 @@ void CPDF_ImageCacheEntry::ContinueGetCachedBitmap(
   CalcSize();
 }
 
-int CPDF_ImageCacheEntry::Continue(IFX_PauseIndicator* pPause,
-                                   CPDF_RenderStatus* pRenderStatus) {
-  int ret = m_pCurBitmap.As<CPDF_DIBSource>()->ContinueLoadDIBSource(pPause);
-  if (!ret) {
-    m_pCurBitmap.Reset();
-    return 0;
-  }
-  if (ret == 2)
-    return ret;
-
-  ContinueGetCachedBitmap(pRenderStatus);
-  return 0;
-}
-
 void CPDF_ImageCacheEntry::CalcSize() {
   m_dwCacheSize = FPDF_ImageCache_EstimateImageSize(m_pCachedBitmap) +
                   FPDF_ImageCache_EstimateImageSize(m_pCachedMask);
diff --git a/core/fpdfapi/render/cpdf_imagecacheentry.h b/core/fpdfapi/render/cpdf_imagecacheentry.h
index 2bede23e62..dfeeddf408 100644
--- a/core/fpdfapi/render/cpdf_imagecacheentry.h
+++ b/core/fpdfapi/render/cpdf_imagecacheentry.h
@@ -9,11 +9,11 @@
 
 #include <memory>
 
+#include "core/fpdfapi/render/cpdf_dibsource.h"
 #include "core/fxcrt/fx_system.h"
 #include "core/fxcrt/retain_ptr.h"
 #include "core/fxcrt/unowned_ptr.h"
 
-class CFX_DIBSource;
 class CFX_DIBitmap;
 class CPDF_Dictionary;
 class CPDF_Document;
@@ -31,13 +31,18 @@ class CPDF_ImageCacheEntry {
   uint32_t EstimateSize() const { return m_dwCacheSize; }
   uint32_t GetTimeCount() const { return m_dwTimeCount; }
   CPDF_Image* GetImage() const { return m_pImage.Get(); }
-  int StartGetCachedBitmap(CPDF_Dictionary* pFormResources,
-                           CPDF_Dictionary* pPageResources,
-                           bool bStdCS,
-                           uint32_t GroupFamily,
-                           bool bLoadMask,
-                           CPDF_RenderStatus* pRenderStatus);
-  int Continue(IFX_PauseIndicator* pPause, CPDF_RenderStatus* pRenderStatus);
+
+  CPDF_DIBSource::LoadState StartGetCachedBitmap(
+      CPDF_Dictionary* pFormResources,
+      CPDF_Dictionary* pPageResources,
+      bool bStdCS,
+      uint32_t GroupFamily,
+      bool bLoadMask,
+      CPDF_RenderStatus* pRenderStatus);
+
+  // Returns whether to Continue() or not.
+  bool Continue(IFX_PauseIndicator* pPause, CPDF_RenderStatus* pRenderStatus);
+
   RetainPtr<CFX_DIBSource> DetachBitmap();
   RetainPtr<CFX_DIBSource> DetachMask();
 
diff --git a/core/fpdfapi/render/cpdf_pagerendercache.cpp b/core/fpdfapi/render/cpdf_pagerendercache.cpp
index 0d01589af3..781f18f0e0 100644
--- a/core/fpdfapi/render/cpdf_pagerendercache.cpp
+++ b/core/fpdfapi/render/cpdf_pagerendercache.cpp
@@ -94,17 +94,17 @@ bool CPDF_PageRenderCache::StartGetCachedBitmap(
     m_pCurImageCacheEntry =
         new CPDF_ImageCacheEntry(m_pPage->m_pDocument.Get(), pImage);
   }
-  int ret = m_pCurImageCacheEntry->StartGetCachedBitmap(
+  CPDF_DIBSource::LoadState ret = m_pCurImageCacheEntry->StartGetCachedBitmap(
       pRenderStatus->GetFormResource(), m_pPage->m_pPageResources.Get(), bStdCS,
       GroupFamily, bLoadMask, pRenderStatus);
-  if (ret == 2)
+  if (ret == CPDF_DIBSource::LoadState::kContinue)
     return true;
 
   m_nTimeCount++;
   if (!m_bCurFindCache)
     m_ImageCache[pStream] = m_pCurImageCacheEntry;
 
-  if (!ret)
+  if (ret == CPDF_DIBSource::LoadState::kFail)
     m_nCacheSize += m_pCurImageCacheEntry->EstimateSize();
 
   return false;
@@ -112,8 +112,8 @@ bool CPDF_PageRenderCache::StartGetCachedBitmap(
 
 bool CPDF_PageRenderCache::Continue(IFX_PauseIndicator* pPause,
                                     CPDF_RenderStatus* pRenderStatus) {
-  int ret = m_pCurImageCacheEntry->Continue(pPause, pRenderStatus);
-  if (ret == 2)
+  bool ret = m_pCurImageCacheEntry->Continue(pPause, pRenderStatus);
+  if (ret)
     return true;
 
   m_nTimeCount++;
@@ -121,8 +121,7 @@ bool CPDF_PageRenderCache::Continue(IFX_PauseIndicator* pPause,
     m_ImageCache[m_pCurImageCacheEntry->GetImage()->GetStream()] =
         m_pCurImageCacheEntry;
   }
-  if (!ret)
-    m_nCacheSize += m_pCurImageCacheEntry->EstimateSize();
+  m_nCacheSize += m_pCurImageCacheEntry->EstimateSize();
   return false;
 }