Add FPDFAnnot_GetAP to public API.

The matching FPDFAnnot_SetAP will be added in a subsequent CL.

Change-Id: If567e02c6c56138d218498879cb4a8ee91dff080
Reviewed-on: https://pdfium-review.googlesource.com/22450
Reviewed-by: dsinclair <dsinclair@chromium.org>
Commit-Queue: Henrique Nakashima <hnakashima@chromium.org>

3 files changed, 114 insertions, 17 deletions

diff --git a/fpdfsdk/fpdfannot.cpp b/fpdfsdk/fpdfannot.cpp
index ec541f55d0..c7433d03d8 100644
--- a/fpdfsdk/fpdfannot.cpp
+++ b/fpdfsdk/fpdfannot.cpp
@@ -104,6 +104,18 @@ static_assert(static_cast<int>(CPDF_Annot::Subtype::XFAWIDGET) ==
                   FPDF_ANNOT_XFAWIDGET,
               "CPDF_Annot::XFAWIDGET value mismatch");
 
+// These checks ensure the consistency of annotation appearance mode values
+// across core/ and public.
+static_assert(static_cast<int>(CPDF_Annot::AppearanceMode::Normal) ==
+                  FPDF_ANNOT_APPEARANCEMODE_NORMAL,
+              "CPDF_Annot::AppearanceMode::Normal value mismatch");
+static_assert(static_cast<int>(CPDF_Annot::AppearanceMode::Rollover) ==
+                  FPDF_ANNOT_APPEARANCEMODE_ROLLOVER,
+              "CPDF_Annot::AppearanceMode::Rollover value mismatch");
+static_assert(static_cast<int>(CPDF_Annot::AppearanceMode::Down) ==
+                  FPDF_ANNOT_APPEARANCEMODE_DOWN,
+              "CPDF_Annot::AppearanceMode::Down value mismatch");
+
 // These checks ensure the consistency of dictionary value types across core/
 // and public/.
 static_assert(static_cast<int>(CPDF_Object::Type::BOOLEAN) ==
@@ -735,6 +747,33 @@ FPDFAnnot_GetStringValue(FPDF_ANNOTATION annot,
                                              buffer, buflen);
 }
 
+FPDF_EXPORT unsigned long FPDF_CALLCONV
+FPDFAnnot_GetAP(FPDF_ANNOTATION annot,
+                FPDF_ANNOT_APPEARANCEMODE appearanceMode,
+                void* buffer,
+                unsigned long buflen) {
+  if (appearanceMode < 0 || appearanceMode >= FPDF_ANNOT_APPEARANCEMODE_COUNT)
+    return 0;
+
+  if (!annot)
+    return 0;
+
+  CPDF_Dictionary* pAnnotDict =
+      CPDFAnnotContextFromFPDFAnnotation(annot)->GetAnnotDict();
+  if (!pAnnotDict)
+    return 0;
+
+  CPDF_Annot::AppearanceMode mode =
+      static_cast<CPDF_Annot::AppearanceMode>(appearanceMode);
+
+  CPDF_Stream* pStream = FPDFDOC_GetAnnotAPNoFallback(pAnnotDict, mode);
+  if (!pStream)
+    return Utf16EncodeMaybeCopyAndReturnLength(L"", buffer, buflen);
+
+  return Utf16EncodeMaybeCopyAndReturnLength(pStream->GetUnicodeText(), buffer,
+                                             buflen);
+}
+
 FPDF_EXPORT FPDF_ANNOTATION FPDF_CALLCONV
 FPDFAnnot_GetLinkedAnnot(FPDF_ANNOTATION annot, FPDF_BYTESTRING key) {
   CPDF_AnnotContext* pAnnot = CPDFAnnotContextFromFPDFAnnotation(annot);
diff --git a/fpdfsdk/fpdfannot_embeddertest.cpp b/fpdfsdk/fpdfannot_embeddertest.cpp
index dce658201c..6d4521f26e 100644
--- a/fpdfsdk/fpdfannot_embeddertest.cpp
+++ b/fpdfsdk/fpdfannot_embeddertest.cpp
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include <cwchar>
 #include <memory>
 #include <string>
 #include <vector>
@@ -11,12 +12,21 @@
 #include "public/fpdf_edit.h"
 #include "public/fpdfview.h"
 #include "testing/embedder_test.h"
+#include "testing/gmock/include/gmock/gmock-matchers.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 static constexpr char kContentsKey[] = "Contents";
 
 class FPDFAnnotEmbeddertest : public EmbedderTest {};
 
+const std::wstring BufferToWString(std::vector<char>& buf) {
+  return GetPlatformWString(reinterpret_cast<unsigned short*>(buf.data()));
+}
+
+const std::string BufferToString(std::vector<char>& buf) {
+  return GetPlatformString(reinterpret_cast<unsigned short*>(buf.data()));
+}
+
 TEST_F(FPDFAnnotEmbeddertest, RenderAnnotWithOnlyRolloverAP) {
   // Open a file with one annotation and load its first page.
   ASSERT_TRUE(OpenDocument("annotation_highlight_rollover_ap.pdf"));
@@ -66,9 +76,7 @@ TEST_F(FPDFAnnotEmbeddertest, ExtractHighlightLongContent) {
   unsigned long len = FPDFAnnot_GetStringValue(annot, kAuthorKey, nullptr, 0);
   std::vector<char> buf(len);
   EXPECT_EQ(28u, FPDFAnnot_GetStringValue(annot, kAuthorKey, buf.data(), len));
-  EXPECT_STREQ(L"Jae Hyun Park",
-               GetPlatformWString(reinterpret_cast<unsigned short*>(buf.data()))
-                   .c_str());
+  EXPECT_STREQ(L"Jae Hyun Park", BufferToWString(buf).c_str());
 
   // Check that the content is correct.
   EXPECT_EQ(FPDF_OBJECT_STRING, FPDFAnnot_GetValueType(annot, kContentsKey));
@@ -98,9 +106,7 @@ TEST_F(FPDFAnnotEmbeddertest, ExtractHighlightLongContent) {
       "longLong long longLong long longLong long longLong long longLong long "
       "longLong long longLong long longLong long longLong long longLong long "
       "longLong long long. END";
-  EXPECT_STREQ(contents,
-               GetPlatformWString(reinterpret_cast<unsigned short*>(buf.data()))
-                   .c_str());
+  EXPECT_STREQ(contents, BufferToWString(buf).c_str());
 
   // Check that the quadpoints are correct.
   FS_QUADPOINTSF quadpoints;
@@ -243,9 +249,7 @@ TEST_F(FPDFAnnotEmbeddertest, AddFirstTextAnnotation) {
   std::vector<char> buf(len);
   EXPECT_EQ(74u,
             FPDFAnnot_GetStringValue(annot, kContentsKey, buf.data(), len));
-  EXPECT_STREQ(contents,
-               GetPlatformWString(reinterpret_cast<unsigned short*>(buf.data()))
-                   .c_str());
+  EXPECT_STREQ(contents, BufferToWString(buf).c_str());
 
   FPDFPage_CloseAnnot(annot);
   UnloadPage(page);
@@ -838,8 +842,7 @@ TEST_F(FPDFAnnotEmbeddertest, GetSetStringValue) {
   std::vector<char> buf(len);
   EXPECT_EQ(66u, FPDFAnnot_GetStringValue(annot, kHashKey, buf.data(), len));
   EXPECT_STREQ(L"395fbcb98d558681742f30683a62a2ad",
-               GetPlatformWString(reinterpret_cast<unsigned short*>(buf.data()))
-                   .c_str());
+               BufferToWString(buf).c_str());
 
   // Check that the string value of the modified date is correct.
   static constexpr char kDateKey[] = "M";
@@ -848,9 +851,7 @@ TEST_F(FPDFAnnotEmbeddertest, GetSetStringValue) {
   buf.clear();
   buf.resize(len);
   EXPECT_EQ(44u, FPDFAnnot_GetStringValue(annot, kDateKey, buf.data(), len));
-  EXPECT_STREQ(L"D:201706071721Z00'00'",
-               GetPlatformWString(reinterpret_cast<unsigned short*>(buf.data()))
-                   .c_str());
+  EXPECT_STREQ(L"D:201706071721Z00'00'", BufferToWString(buf).c_str());
 
   // Update the date entry for the annotation.
   const wchar_t new_date[] = L"D:201706282359Z00'00'";
@@ -881,15 +882,71 @@ TEST_F(FPDFAnnotEmbeddertest, GetSetStringValue) {
   buf.resize(len);
   EXPECT_EQ(44u,
             FPDFAnnot_GetStringValue(new_annot, kDateKey, buf.data(), len));
-  EXPECT_STREQ(new_date,
-               GetPlatformWString(reinterpret_cast<unsigned short*>(buf.data()))
-                   .c_str());
+  EXPECT_STREQ(new_date, BufferToWString(buf).c_str());
 
   FPDFPage_CloseAnnot(new_annot);
   CloseSavedPage(page);
   CloseSavedDocument();
 }
 
+TEST_F(FPDFAnnotEmbeddertest, GetAP) {
+  // Open a file with four annotations and load its first page.
+  ASSERT_TRUE(OpenDocument("annotation_stamp_with_ap.pdf"));
+  FPDF_PAGE page = FPDF_LoadPage(document(), 0);
+  ASSERT_TRUE(page);
+
+  // Retrieve the first annotation.
+  FPDF_ANNOTATION annot = FPDFPage_GetAnnot(page, 0);
+  ASSERT_TRUE(annot);
+
+  // Check that the string value of an AP returns the expected length.
+  unsigned long len =
+      FPDFAnnot_GetAP(annot, FPDF_ANNOT_APPEARANCEMODE_NORMAL, nullptr, 0);
+  EXPECT_EQ(73970u, len);
+
+  // Check that the string value of an AP is not returned if the buffer is too
+  // small. The result buffer should be overwritten with an empty string.
+  std::vector<char> buf(len - 1);
+  // Write L"z" in the buffer to verify it's not overwritten.
+  wcscpy(reinterpret_cast<wchar_t*>(buf.data()), L"z");
+  EXPECT_EQ(73970u, FPDFAnnot_GetAP(annot, FPDF_ANNOT_APPEARANCEMODE_NORMAL,
+                                    buf.data(), len - 1));
+  std::string ap = BufferToString(buf);
+  EXPECT_STREQ("z", ap.c_str());
+
+  // Check that the string value of an AP is returned through a buffer that is
+  // the right size.
+  buf.clear();
+  buf.resize(len);
+  EXPECT_EQ(73970u, FPDFAnnot_GetAP(annot, FPDF_ANNOT_APPEARANCEMODE_NORMAL,
+                                    buf.data(), len));
+  ap = BufferToString(buf);
+  EXPECT_THAT(ap, testing::StartsWith("q Q q 7.442786 w 2 J"));
+  EXPECT_THAT(ap, testing::EndsWith("c 716.5381 327.7156 l S Q Q"));
+
+  // Check that the string value of an AP is returned through a buffer that is
+  // larger than necessary.
+  buf.clear();
+  buf.resize(len + 1);
+  EXPECT_EQ(73970u, FPDFAnnot_GetAP(annot, FPDF_ANNOT_APPEARANCEMODE_NORMAL,
+                                    buf.data(), len + 1));
+  ap = BufferToString(buf);
+  EXPECT_THAT(ap, testing::StartsWith("q Q q 7.442786 w 2 J"));
+  EXPECT_THAT(ap, testing::EndsWith("c 716.5381 327.7156 l S Q Q"));
+
+  // Check that getting an AP for a mode that does not have an AP returns an
+  // empty string.
+  buf.clear();
+  buf.resize(len);
+  EXPECT_EQ(2u, FPDFAnnot_GetAP(annot, FPDF_ANNOT_APPEARANCEMODE_ROLLOVER,
+                                buf.data(), len));
+  ap = BufferToString(buf);
+  EXPECT_STREQ("", ap.c_str());
+
+  FPDFPage_CloseAnnot(annot);
+  FPDF_ClosePage(page);
+}
+
 TEST_F(FPDFAnnotEmbeddertest, ExtractLinkedAnnotations) {
   // Open a file with annotations and load its first page.
   ASSERT_TRUE(OpenDocument("annotation_highlight_square_with_ap.pdf"));
diff --git a/fpdfsdk/fpdfview_c_api_test.c b/fpdfsdk/fpdfview_c_api_test.c
index 5f935fc665..08696c2e27 100644
--- a/fpdfsdk/fpdfview_c_api_test.c
+++ b/fpdfsdk/fpdfview_c_api_test.c
@@ -62,6 +62,7 @@ int CheckPDFiumCApi() {
     CHK(FPDFAnnot_GetValueType);
     CHK(FPDFAnnot_SetStringValue);
     CHK(FPDFAnnot_GetStringValue);
+    CHK(FPDFAnnot_GetAP);
     CHK(FPDFAnnot_GetLinkedAnnot);
     CHK(FPDFAnnot_GetFlags);
     CHK(FPDFAnnot_SetFlags);