Remove DefaultAppearance HasColor and return an optional instead

This CL converts CPDF_DefaultAppearance to return
Optional<CFX_Color:Type> items instead of having a HasColor. This saves
the double parse of the appearance stream.

Change-Id: Ib3c136da6e2adfb559e495de1d299cce0b4ad25f
Reviewed-on: https://pdfium-review.googlesource.com/29630
Reviewed-by: Henrique Nakashima <hnakashima@chromium.org>
Commit-Queue: dsinclair <dsinclair@chromium.org>

2 files changed, 16 insertions, 28 deletions

diff --git a/core/fpdfdoc/cpdf_defaultappearance.cpp b/core/fpdfdoc/cpdf_defaultappearance.cpp
index 161f90e014..4efb0655b4 100644
--- a/core/fpdfdoc/cpdf_defaultappearance.cpp
+++ b/core/fpdfdoc/cpdf_defaultappearance.cpp
@@ -68,64 +68,53 @@ Optional<ByteString> CPDF_DefaultAppearance::GetFont(float* fFontSize) {
   return {PDF_NameDecode(csFontNameTag.AsStringView())};
 }
 
-bool CPDF_DefaultAppearance::HasColor() {
-  if (m_csDA.IsEmpty())
-    return false;
-
-  CPDF_SimpleParser syntax(m_csDA.AsStringView());
-  if (FindTagParamFromStart(&syntax, "g", 1))
-    return true;
-  if (FindTagParamFromStart(&syntax, "rg", 3))
-    return true;
-  return FindTagParamFromStart(&syntax, "k", 4);
-}
-
-CFX_Color::Type CPDF_DefaultAppearance::GetColor(float fc[4]) {
+Optional<CFX_Color::Type> CPDF_DefaultAppearance::GetColor(float fc[4]) {
   for (int c = 0; c < 4; c++)
     fc[c] = 0;
 
   if (m_csDA.IsEmpty())
-    return CFX_Color::kTransparent;
+    return {};
 
   CPDF_SimpleParser syntax(m_csDA.AsStringView());
   if (FindTagParamFromStart(&syntax, "g", 1)) {
     fc[0] = FX_atof(syntax.GetWord());
-    return CFX_Color::kGray;
+    return {CFX_Color::kGray};
   }
   if (FindTagParamFromStart(&syntax, "rg", 3)) {
     fc[0] = FX_atof(syntax.GetWord());
     fc[1] = FX_atof(syntax.GetWord());
     fc[2] = FX_atof(syntax.GetWord());
-    return CFX_Color::kRGB;
+    return {CFX_Color::kRGB};
   }
   if (FindTagParamFromStart(&syntax, "k", 4)) {
     fc[0] = FX_atof(syntax.GetWord());
     fc[1] = FX_atof(syntax.GetWord());
     fc[2] = FX_atof(syntax.GetWord());
     fc[3] = FX_atof(syntax.GetWord());
-    return CFX_Color::kCMYK;
+    return {CFX_Color::kCMYK};
   }
 
-  return CFX_Color::kTransparent;
+  return {};
 }
 
-std::pair<CFX_Color::Type, FX_ARGB> CPDF_DefaultAppearance::GetColor() {
+std::pair<Optional<CFX_Color::Type>, FX_ARGB>
+CPDF_DefaultAppearance::GetColor() {
   float values[4];
-  CFX_Color::Type type = GetColor(values);
-  if (type == CFX_Color::kTransparent)
+  Optional<CFX_Color::Type> type = GetColor(values);
+  if (!type)
     return {type, 0};
 
-  if (type == CFX_Color::kGray) {
+  if (*type == CFX_Color::kGray) {
     int g = static_cast<int>(values[0] * 255 + 0.5f);
     return {type, ArgbEncode(255, g, g, g)};
   }
-  if (type == CFX_Color::kRGB) {
+  if (*type == CFX_Color::kRGB) {
     int r = static_cast<int>(values[0] * 255 + 0.5f);
     int g = static_cast<int>(values[1] * 255 + 0.5f);
     int b = static_cast<int>(values[2] * 255 + 0.5f);
     return {type, ArgbEncode(255, r, g, b)};
   }
-  if (type == CFX_Color::kCMYK) {
+  if (*type == CFX_Color::kCMYK) {
     float r = 1.0f - std::min(1.0f, values[0] + values[3]);
     float g = 1.0f - std::min(1.0f, values[1] + values[3]);
     float b = 1.0f - std::min(1.0f, values[2] + values[3]);
@@ -134,7 +123,7 @@ std::pair<CFX_Color::Type, FX_ARGB> CPDF_DefaultAppearance::GetColor() {
                              static_cast<int>(b * 255 + 0.5f))};
   }
   NOTREACHED();
-  return {CFX_Color::kTransparent, 0};
+  return {{}, 0};
 }
 
 bool CPDF_DefaultAppearance::FindTagParamFromStartForTesting(
diff --git a/core/fpdfdoc/cpdf_defaultappearance.h b/core/fpdfdoc/cpdf_defaultappearance.h
index ae3c4f5517..73e35c7cd4 100644
--- a/core/fpdfdoc/cpdf_defaultappearance.h
+++ b/core/fpdfdoc/cpdf_defaultappearance.h
@@ -27,9 +27,8 @@ class CPDF_DefaultAppearance {
 
   Optional<ByteString> GetFont(float* fFontSize);
 
-  bool HasColor();
-  CFX_Color::Type GetColor(float fc[4]);
-  std::pair<CFX_Color::Type, FX_ARGB> GetColor();
+  Optional<CFX_Color::Type> GetColor(float fc[4]);
+  std::pair<Optional<CFX_Color::Type>, FX_ARGB> GetColor();
 
   bool FindTagParamFromStartForTesting(CPDF_SimpleParser* parser,
                                        const ByteStringView& token,