Move generated graphics and font maps to CPDF_Page

A new CPDF_PageContentGenerator is created for every call of
FPDFPage_GenerateContent, so having the maps there will cause duplicated
resources to be created every time this method is called. Thus it is better
to move these to the page.

Change-Id: I47804f79790fc5354f8a94b6387d66b65eda5a20
Reviewed-on: https://pdfium-review.googlesource.com/2717
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Nicolás Peña <npm@chromium.org>

5 files changed, 95 insertions, 32 deletions

diff --git a/core/fpdfapi/edit/cpdf_pagecontentgenerator.cpp b/core/fpdfapi/edit/cpdf_pagecontentgenerator.cpp
index ff8b676de1..b5fe4c0f35 100644
--- a/core/fpdfapi/edit/cpdf_pagecontentgenerator.cpp
+++ b/core/fpdfapi/edit/cpdf_pagecontentgenerator.cpp
@@ -222,8 +222,8 @@ void CPDF_PageContentGenerator::ProcessGraphics(CFX_ByteTextBuf* buf,
     return;
 
   CFX_ByteString name;
-  auto it = m_GraphicsMap.find(graphD);
-  if (it != m_GraphicsMap.end()) {
+  auto it = m_pPage->m_GraphicsMap.find(graphD);
+  if (it != m_pPage->m_GraphicsMap.end()) {
     name = it->second;
   } else {
     auto gsDict = pdfium::MakeUnique<CPDF_Dictionary>();
@@ -232,23 +232,11 @@ void CPDF_PageContentGenerator::ProcessGraphics(CFX_ByteTextBuf* buf,
     CPDF_Object* pDict = m_pDocument->AddIndirectObject(std::move(gsDict));
     uint32_t dwObjNum = pDict->GetObjNum();
     name = RealizeResource(dwObjNum, "ExtGState");
-    m_GraphicsMap[graphD] = name;
+    m_pPage->m_GraphicsMap[graphD] = name;
   }
   *buf << "/" << PDF_NameEncode(name) << " gs ";
 }
 
-bool CPDF_PageContentGenerator::GraphicsData::operator<(
-    const GraphicsData& other) const {
-  if (fillAlpha != other.fillAlpha)
-    return fillAlpha < other.fillAlpha;
-  return strokeAlpha < other.strokeAlpha;
-}
-
-bool CPDF_PageContentGenerator::FontData::operator<(
-    const FontData& other) const {
-  return baseFont < other.baseFont;
-}
-
 // This method adds text to the buffer, BT begins the text object, ET ends it.
 // Tm sets the text matrix (allows positioning and transforming text).
 // Tf sets the font name (from Font in Resources) and font size.
@@ -262,9 +250,9 @@ void CPDF_PageContentGenerator::ProcessText(CFX_ByteTextBuf* buf,
     pFont = CPDF_Font::GetStockFont(m_pDocument, "Helvetica");
   FontData fontD;
   fontD.baseFont = pFont->GetBaseFont();
-  auto it = m_FontsMap.find(fontD);
+  auto it = m_pPage->m_FontsMap.find(fontD);
   CFX_ByteString dictName;
-  if (it != m_FontsMap.end()) {
+  if (it != m_pPage->m_FontsMap.end()) {
     dictName = it->second;
   } else {
     auto fontDict = pdfium::MakeUnique<CPDF_Dictionary>();
@@ -274,7 +262,7 @@ void CPDF_PageContentGenerator::ProcessText(CFX_ByteTextBuf* buf,
     CPDF_Object* pDict = m_pDocument->AddIndirectObject(std::move(fontDict));
     uint32_t dwObjNum = pDict->GetObjNum();
     dictName = RealizeResource(dwObjNum, "Font");
-    m_FontsMap[fontD] = dictName;
+    m_pPage->m_FontsMap[fontD] = dictName;
   }
   *buf << "/" << PDF_NameEncode(dictName) << " " << pTextObj->GetFontSize()
        << " Tf ";
diff --git a/core/fpdfapi/edit/cpdf_pagecontentgenerator.h b/core/fpdfapi/edit/cpdf_pagecontentgenerator.h
index fd80bd8f44..73e75187e4 100644
--- a/core/fpdfapi/edit/cpdf_pagecontentgenerator.h
+++ b/core/fpdfapi/edit/cpdf_pagecontentgenerator.h
@@ -7,7 +7,6 @@
 #ifndef CORE_FPDFAPI_EDIT_CPDF_PAGECONTENTGENERATOR_H_
 #define CORE_FPDFAPI_EDIT_CPDF_PAGECONTENTGENERATOR_H_
 
-#include <map>
 #include <vector>
 
 #include "core/fxcrt/fx_basic.h"
@@ -37,19 +36,6 @@ class CPDF_PageContentGenerator {
   CFX_ByteString RealizeResource(uint32_t dwResourceObjNum,
                                  const CFX_ByteString& bsType);
 
-  struct GraphicsData {
-    FX_FLOAT fillAlpha;
-    FX_FLOAT strokeAlpha;
-    bool operator<(const GraphicsData& other) const;
-  };
-
-  struct FontData {
-    CFX_ByteString baseFont;
-    bool operator<(const FontData& other) const;
-  };
-
-  std::map<GraphicsData, CFX_ByteString> m_GraphicsMap;
-  std::map<FontData, CFX_ByteString> m_FontsMap;
   CPDF_Page* const m_pPage;
   CPDF_Document* const m_pDocument;
   std::vector<CPDF_PageObject*> m_pageObjects;
diff --git a/core/fpdfapi/page/cpdf_page.cpp b/core/fpdfapi/page/cpdf_page.cpp
index ba30ce57c3..46123ab42e 100644
--- a/core/fpdfapi/page/cpdf_page.cpp
+++ b/core/fpdfapi/page/cpdf_page.cpp
@@ -175,3 +175,13 @@ CFX_Matrix CPDF_Page::GetDisplayMatrix(int xPos,
                            x0, y0));
   return matrix;
 }
+
+bool GraphicsData::operator<(const GraphicsData& other) const {
+  if (fillAlpha != other.fillAlpha)
+    return fillAlpha < other.fillAlpha;
+  return strokeAlpha < other.strokeAlpha;
+}
+
+bool FontData::operator<(const FontData& other) const {
+  return baseFont < other.baseFont;
+}
diff --git a/core/fpdfapi/page/cpdf_page.h b/core/fpdfapi/page/cpdf_page.h
index 6d29a8f34e..9e303562c6 100644
--- a/core/fpdfapi/page/cpdf_page.h
+++ b/core/fpdfapi/page/cpdf_page.h
@@ -7,6 +7,7 @@
 #ifndef CORE_FPDFAPI_PAGE_CPDF_PAGE_H_
 #define CORE_FPDFAPI_PAGE_CPDF_PAGE_H_
 
+#include <map>
 #include <memory>
 
 #include "core/fpdfapi/page/cpdf_pageobjectholder.h"
@@ -20,6 +21,19 @@ class CPDF_Object;
 class CPDF_PageRenderCache;
 class CPDF_PageRenderContext;
 
+// These structs are used to keep track of resources that have already been
+// generated in the page.
+struct GraphicsData {
+  FX_FLOAT fillAlpha;
+  FX_FLOAT strokeAlpha;
+  bool operator<(const GraphicsData& other) const;
+};
+
+struct FontData {
+  CFX_ByteString baseFont;
+  bool operator<(const FontData& other) const;
+};
+
 class CPDF_Page : public CPDF_PageObjectHolder {
  public:
   class View {};  // Caller implements as desired, empty here due to layering.
@@ -52,6 +66,9 @@ class CPDF_Page : public CPDF_PageObjectHolder {
   View* GetView() const { return m_pView; }
   void SetView(View* pView) { m_pView = pView; }
 
+  std::map<GraphicsData, CFX_ByteString> m_GraphicsMap;
+  std::map<FontData, CFX_ByteString> m_FontsMap;
+
  protected:
   void StartParse();
 
diff --git a/fpdfsdk/fpdfedit_embeddertest.cpp b/fpdfsdk/fpdfedit_embeddertest.cpp
index fb561967ec..f877617b49 100644
--- a/fpdfsdk/fpdfedit_embeddertest.cpp
+++ b/fpdfsdk/fpdfedit_embeddertest.cpp
@@ -5,7 +5,10 @@
 #include <memory>
 #include <string>
 
+#include "core/fpdfapi/page/cpdf_page.h"
+#include "core/fpdfapi/parser/cpdf_dictionary.h"
 #include "core/fxcrt/fx_system.h"
+#include "fpdfsdk/fsdk_define.h"
 #include "public/fpdf_edit.h"
 #include "public/fpdfview.h"
 #include "testing/embedder_test.h"
@@ -378,3 +381,62 @@ TEST_F(FPDFEditEmbeddertest, AddStandardFontText) {
   FPDF_ClosePage(page);
   FPDF_CloseDocument(doc);
 }
+
+TEST_F(FPDFEditEmbeddertest, DoubleGenerating) {
+  // Start with a blank page
+  FPDF_DOCUMENT doc = FPDF_CreateNewDocument();
+  FPDF_PAGE page = FPDFPage_New(doc, 0, 612, 792);
+
+  // Add a red rectangle with some non-default alpha
+  FPDF_PAGEOBJECT rect = FPDFPageObj_CreateNewRect(10, 10, 100, 100);
+  EXPECT_TRUE(FPDFPath_SetFillColor(rect, 255, 0, 0, 128));
+  EXPECT_TRUE(FPDFPath_SetDrawMode(rect, FPDF_FILLMODE_WINDING, 0));
+  FPDFPage_InsertObject(page, rect);
+  EXPECT_TRUE(FPDFPage_GenerateContent(page));
+
+  // Check the ExtGState
+  CPDF_Page* the_page = CPDFPageFromFPDFPage(page);
+  CPDF_Dictionary* graphics_dict =
+      the_page->m_pResources->GetDictFor("ExtGState");
+  ASSERT_TRUE(graphics_dict);
+  EXPECT_EQ(1, static_cast<int>(graphics_dict->GetCount()));
+
+  // Check the bitmap
+  FPDF_BITMAP page_bitmap = RenderPage(page);
+  CompareBitmap(page_bitmap, 612, 792, "5384da3406d62360ffb5cac4476fff1c");
+  FPDFBitmap_Destroy(page_bitmap);
+
+  // Never mind, my new favorite color is blue, increase alpha
+  EXPECT_TRUE(FPDFPath_SetFillColor(rect, 0, 0, 255, 180));
+  EXPECT_TRUE(FPDFPage_GenerateContent(page));
+  EXPECT_EQ(2, static_cast<int>(graphics_dict->GetCount()));
+
+  // Check that bitmap displays changed content
+  page_bitmap = RenderPage(page);
+  CompareBitmap(page_bitmap, 612, 792, "2e51656f5073b0bee611d9cd086aa09c");
+  FPDFBitmap_Destroy(page_bitmap);
+
+  // And now generate, without changes
+  EXPECT_TRUE(FPDFPage_GenerateContent(page));
+  EXPECT_EQ(2, static_cast<int>(graphics_dict->GetCount()));
+  page_bitmap = RenderPage(page);
+  CompareBitmap(page_bitmap, 612, 792, "2e51656f5073b0bee611d9cd086aa09c");
+  FPDFBitmap_Destroy(page_bitmap);
+
+  // Add some text to the page
+  FPDF_PAGEOBJECT text = FPDFPageObj_NewTextObj(doc, "Arial", 12.0f);
+  EXPECT_TRUE(FPDFText_SetText(text, "Something something #text# something"));
+  FPDFPageObj_Transform(text, 1, 0, 0, 1, 300, 300);
+  FPDFPage_InsertObject(page, text);
+  EXPECT_TRUE(FPDFPage_GenerateContent(page));
+  CPDF_Dictionary* font_dict = the_page->m_pResources->GetDictFor("Font");
+  ASSERT_TRUE(font_dict);
+  EXPECT_EQ(1, static_cast<int>(font_dict->GetCount()));
+
+  // Generate yet again, check dicts are reasonably sized
+  EXPECT_TRUE(FPDFPage_GenerateContent(page));
+  EXPECT_EQ(2, static_cast<int>(graphics_dict->GetCount()));
+  EXPECT_EQ(1, static_cast<int>(font_dict->GetCount()));
+  FPDF_ClosePage(page);
+  FPDF_CloseDocument(doc);
+}