Generalized annotation APIs to support image and text objects

Generalized the following annotation APIs to support working with image
and text objects:
FPDFAnnot_AppendPathObject()   -> FPDFAnnot_AppendObject()
FPDFAnnot_UpdatePathObject()   -> FPDFAnnot_UpdateObject()
FPDFAnnot_GetPathObjectCount() -> FPDFAnnot_GetObjectCount()
FPDFAnnot_GetPathObject()      -> FPDFAnnot_GetObject()

Also added two embeddertests to test appending, retrieving, editting,
and updating image and text objects in annotations.

Bug=pdfium:737

Change-Id: If3ea5846d5abec7dc195291bb1a0ef4b17f0d604
Reviewed-on: https://pdfium-review.googlesource.com/7210
Commit-Queue: Jane Liu <janeliulwq@google.com>
Reviewed-by: dsinclair <dsinclair@chromium.org>

4 files changed, 248 insertions, 89 deletions

diff --git a/fpdfsdk/fpdfannot.cpp b/fpdfsdk/fpdfannot.cpp
index d7ab8abac1..024c52bc10 100644
--- a/fpdfsdk/fpdfannot.cpp
+++ b/fpdfsdk/fpdfannot.cpp
@@ -236,12 +236,11 @@ FPDFAnnot_GetSubtype(FPDF_ANNOTATION annot) {
       CPDF_Annot::StringToAnnotSubtype(pAnnotDict->GetStringFor("Subtype")));
 }
 
-DLLEXPORT FPDF_BOOL STDCALL FPDFAnnot_UpdatePathObject(FPDF_ANNOTATION annot,
-                                                       FPDF_PAGEOBJECT path) {
+DLLEXPORT FPDF_BOOL STDCALL FPDFAnnot_UpdateObject(FPDF_ANNOTATION annot,
+                                                   FPDF_PAGEOBJECT obj) {
   CPDF_AnnotContext* pAnnot = CPDFAnnotContextFromFPDFAnnotation(annot);
-  CPDF_PageObject* pPathObj = CPDFPageObjectFromFPDFPageObject(path);
-  if (!pAnnot || !pAnnot->GetAnnotDict() || !pAnnot->HasForm() || !pPathObj ||
-      !pPathObj->IsPath())
+  CPDF_PageObject* pObj = CPDFPageObjectFromFPDFPageObject(obj);
+  if (!pAnnot || !pAnnot->GetAnnotDict() || !pAnnot->HasForm() || !pObj)
     return false;
 
   // Check that the annotation type is supported by this method.
@@ -250,19 +249,19 @@ DLLEXPORT FPDF_BOOL STDCALL FPDFAnnot_UpdatePathObject(FPDF_ANNOTATION annot,
     return false;
 
   // Check that the annotation already has an appearance stream, since an
-  // existing path object is to be updated.
+  // existing object is to be updated.
   CPDF_Stream* pStream = FPDFDOC_GetAnnotAP(pAnnot->GetAnnotDict(),
                                             CPDF_Annot::AppearanceMode::Normal);
   if (!pStream)
     return false;
 
-  // Check that the path object is already in this annotation's object list.
+  // Check that the object is already in this annotation's object list.
   CPDF_PageObjectList* pObjList = pAnnot->GetForm()->GetPageObjectList();
-  auto it = std::find_if(
-      pObjList->begin(), pObjList->end(),
-      [pPathObj](const std::unique_ptr<CPDF_PageObject>& candidate) {
-        return candidate.get() == pPathObj;
-      });
+  auto it =
+      std::find_if(pObjList->begin(), pObjList->end(),
+                   [pObj](const std::unique_ptr<CPDF_PageObject>& candidate) {
+                     return candidate.get() == pObj;
+                   });
   if (it == pObjList->end())
     return false;
 
@@ -275,11 +274,11 @@ DLLEXPORT FPDF_BOOL STDCALL FPDFAnnot_UpdatePathObject(FPDF_ANNOTATION annot,
   return true;
 }
 
-DLLEXPORT FPDF_BOOL STDCALL FPDFAnnot_AppendPathObject(FPDF_ANNOTATION annot,
-                                                       FPDF_PAGEOBJECT path) {
+DLLEXPORT FPDF_BOOL STDCALL FPDFAnnot_AppendObject(FPDF_ANNOTATION annot,
+                                                   FPDF_PAGEOBJECT obj) {
   CPDF_AnnotContext* pAnnot = CPDFAnnotContextFromFPDFAnnotation(annot);
-  CPDF_PageObject* pPathObj = CPDFPageObjectFromFPDFPageObject(path);
-  if (!pAnnot || !pPathObj || !pPathObj->IsPath())
+  CPDF_PageObject* pObj = CPDFPageObjectFromFPDFPageObject(obj);
+  if (!pAnnot || !pObj)
     return false;
 
   CPDF_Dictionary* pAnnotDict = pAnnot->GetAnnotDict();
@@ -316,22 +315,22 @@ DLLEXPORT FPDF_BOOL STDCALL FPDFAnnot_AppendPathObject(FPDF_ANNOTATION annot,
 
   CPDF_Form* pForm = pAnnot->GetForm();
 
-  // Check that the path object did not come from the same annotation. If this
-  // check succeeds, then it is assumed that the path object came from
-  // FPDFPageObj_CreateNewPath(). Note that a path object that came from a
-  // different annotation must not be passed here, since a path object cannot
-  // belong to more than one annotation.
+  // Check that the object did not come from the same annotation. If this check
+  // succeeds, then it is assumed that the object came from
+  // FPDFPageObj_CreateNew{Path|Rect}() or FPDFPageObj_New{Text|Image}Obj().
+  // Note that an object that came from a different annotation must not be
+  // passed here, since an object cannot belong to more than one annotation.
   CPDF_PageObjectList* pObjList = pForm->GetPageObjectList();
-  auto it = std::find_if(
-      pObjList->begin(), pObjList->end(),
-      [pPathObj](const std::unique_ptr<CPDF_PageObject>& candidate) {
-        return candidate.get() == pPathObj;
-      });
+  auto it =
+      std::find_if(pObjList->begin(), pObjList->end(),
+                   [pObj](const std::unique_ptr<CPDF_PageObject>& candidate) {
+                     return candidate.get() == pObj;
+                   });
   if (it != pObjList->end())
     return false;
 
-  // Append the path object to the object list.
-  std::unique_ptr<CPDF_PageObject> pPageObjHolder(pPathObj);
+  // Append the object to the object list.
+  std::unique_ptr<CPDF_PageObject> pPageObjHolder(pObj);
   pObjList->push_back(std::move(pPageObjHolder));
 
   // Set the content stream data in the annotation's AP stream.
@@ -343,9 +342,9 @@ DLLEXPORT FPDF_BOOL STDCALL FPDFAnnot_AppendPathObject(FPDF_ANNOTATION annot,
   return true;
 }
 
-DLLEXPORT int STDCALL FPDFAnnot_GetPathObjectCount(FPDF_ANNOTATION annot) {
+DLLEXPORT int STDCALL FPDFAnnot_GetObjectCount(FPDF_ANNOTATION annot) {
   CPDF_AnnotContext* pAnnot = CPDFAnnotContextFromFPDFAnnotation(annot);
-  if (!pAnnot)
+  if (!pAnnot || !pAnnot->GetAnnotDict())
     return 0;
 
   if (!pAnnot->HasForm()) {
@@ -356,19 +355,13 @@ DLLEXPORT int STDCALL FPDFAnnot_GetPathObjectCount(FPDF_ANNOTATION annot) {
 
     pAnnot->SetForm(pStream);
   }
-
-  int pathCount = 0;
-  for (const auto& pObj : *pAnnot->GetForm()->GetPageObjectList()) {
-    if (pObj && pObj->IsPath())
-      ++pathCount;
-  }
-  return pathCount;
+  return pAnnot->GetForm()->GetPageObjectList()->size();
 }
 
-DLLEXPORT FPDF_PAGEOBJECT STDCALL FPDFAnnot_GetPathObject(FPDF_ANNOTATION annot,
-                                                          int index) {
+DLLEXPORT FPDF_PAGEOBJECT STDCALL FPDFAnnot_GetObject(FPDF_ANNOTATION annot,
+                                                      int index) {
   CPDF_AnnotContext* pAnnot = CPDFAnnotContextFromFPDFAnnotation(annot);
-  if (!pAnnot || index < 0)
+  if (!pAnnot || !pAnnot->GetAnnotDict() || index < 0)
     return nullptr;
 
   if (!pAnnot->HasForm()) {
@@ -380,22 +373,7 @@ DLLEXPORT FPDF_PAGEOBJECT STDCALL FPDFAnnot_GetPathObject(FPDF_ANNOTATION annot,
     pAnnot->SetForm(pStream);
   }
 
-  const CPDF_PageObjectList* pObjList = pAnnot->GetForm()->GetPageObjectList();
-  if (static_cast<size_t>(index) >= pObjList->size())
-    return nullptr;
-
-  // Retrieve the path object located at |index| in the list of path objects.
-  // Note that the list of path objects is a sublist of the page object list,
-  // consisting of only path objects specifically.
-  int pathCount = -1;
-  for (const auto& pObj : *pObjList) {
-    if (pObj && pObj->IsPath()) {
-      ++pathCount;
-      if (pathCount == index)
-        return pObj.get();
-    }
-  }
-  return nullptr;
+  return pAnnot->GetForm()->GetPageObjectList()->GetPageObjectByIndex(index);
 }
 
 DLLEXPORT FPDF_BOOL STDCALL FPDFAnnot_SetColor(FPDF_ANNOTATION annot,
diff --git a/fpdfsdk/fpdfannot_embeddertest.cpp b/fpdfsdk/fpdfannot_embeddertest.cpp
index beaedf91af..7d174ff11d 100644
--- a/fpdfsdk/fpdfannot_embeddertest.cpp
+++ b/fpdfsdk/fpdfannot_embeddertest.cpp
@@ -486,15 +486,16 @@ TEST_F(FPDFAnnotEmbeddertest, AddAndModifyPath) {
   ASSERT_TRUE(annot);
 
   // Check that this annotation has one path object and retrieve it.
-  EXPECT_EQ(1, FPDFAnnot_GetPathObjectCount(annot));
-  FPDF_PAGEOBJECT path = FPDFAnnot_GetPathObject(annot, 1);
+  EXPECT_EQ(1, FPDFAnnot_GetObjectCount(annot));
+  FPDF_PAGEOBJECT path = FPDFAnnot_GetObject(annot, 1);
   EXPECT_FALSE(path);
-  path = FPDFAnnot_GetPathObject(annot, 0);
+  path = FPDFAnnot_GetObject(annot, 0);
+  EXPECT_EQ(FPDF_PAGEOBJ_PATH, FPDFPageObj_GetType(path));
   EXPECT_TRUE(path);
 
   // Modify the color of the path object.
   EXPECT_TRUE(FPDFPath_SetStrokeColor(path, 0, 0, 0, 255));
-  EXPECT_TRUE(FPDFAnnot_UpdatePathObject(annot, path));
+  EXPECT_TRUE(FPDFAnnot_UpdateObject(annot, path));
   FPDFPage_CloseAnnot(annot);
 
   // Check that the page with the modified annotation renders correctly.
@@ -521,8 +522,8 @@ TEST_F(FPDFAnnotEmbeddertest, AddAndModifyPath) {
   EXPECT_TRUE(FPDFPath_SetStrokeColor(check, 0, 255, 255, 180));
   EXPECT_TRUE(FPDFPath_SetStrokeWidth(check, 8.35f));
   EXPECT_TRUE(FPDFPath_SetDrawMode(check, 0, 1));
-  EXPECT_TRUE(FPDFAnnot_AppendPathObject(annot, check));
-  EXPECT_EQ(1, FPDFAnnot_GetPathObjectCount(annot));
+  EXPECT_TRUE(FPDFAnnot_AppendObject(annot, check));
+  EXPECT_EQ(1, FPDFAnnot_GetObjectCount(annot));
 
   // Check that the annotation's bounding box came from its rectangle.
   FS_RECTF new_rect = FPDFAnnot_GetRect(annot);
@@ -539,11 +540,11 @@ TEST_F(FPDFAnnotEmbeddertest, AddAndModifyPath) {
   // Open the saved document.
   TestSaved(595, 842, md5_3);
 
-  // Check that the saved document has a correct count of annotations and paths.
+  // Check that the document has a correct count of annotations and objects.
   EXPECT_EQ(3, FPDFPage_GetAnnotCount(m_SavedPage));
   annot = FPDFPage_GetAnnot(m_SavedPage, 2);
   ASSERT_TRUE(annot);
-  EXPECT_EQ(1, FPDFAnnot_GetPathObjectCount(annot));
+  EXPECT_EQ(1, FPDFAnnot_GetObjectCount(annot));
 
   // Check that the new annotation's rectangle is as defined.
   new_rect = FPDFAnnot_GetRect(annot);
@@ -605,3 +606,163 @@ TEST_F(FPDFAnnotEmbeddertest, ModifyAnnotationFlags) {
   FPDFPage_CloseAnnot(annot);
   UnloadPage(page);
 }
+
+TEST_F(FPDFAnnotEmbeddertest, AddAndModifyImage) {
+#if _FXM_PLATFORM_ == _FXM_PLATFORM_APPLE_
+  const char md5[] = "c35408717759562d1f8bf33d317483d2";
+  const char md5_2[] = "ff012f5697436dfcaec25b32d1333596";
+  const char md5_3[] = "86cf8cb2755a7a2046a543e66d9c1e61";
+#elif _FXM_PLATFORM_ == _FXM_PLATFORM_WINDOWS_
+  const char md5[] = "bdf96279ab82d9f484874db3f0c03429";
+  const char md5_2[] = "048a9af8b6239b59a19dacd8e1688e0a";
+  const char md5_3[] = "3be8aa2ebc927e32060e7116dd937a14";
+#else
+  const char md5[] = "07d4168715553b4294525f840c40aa1c";
+  const char md5_2[] = "9685b2a0cf11ee730125f88ab10ff1d0";
+  const char md5_3[] = "0763407baf3656b8061bbbe698e9fd89";
+#endif
+
+  // Open a file with two annotations and load its first page.
+  ASSERT_TRUE(OpenDocument("annotation_stamp_with_ap.pdf"));
+  FPDF_PAGE page = FPDF_LoadPage(document(), 0);
+  ASSERT_TRUE(page);
+  EXPECT_EQ(2, FPDFPage_GetAnnotCount(page));
+
+  // Check that the page renders correctly.
+  FPDF_BITMAP bitmap = RenderPageWithFlags(page, form_handle_, FPDF_ANNOT);
+  CompareBitmap(bitmap, 595, 842, md5);
+  FPDFBitmap_Destroy(bitmap);
+
+  // Create a stamp annotation and set its annotation rectangle.
+  FPDF_ANNOTATION annot = FPDFPage_CreateAnnot(page, FPDF_ANNOT_STAMP);
+  ASSERT_TRUE(annot);
+  FS_RECTF rect;
+  rect.left = 200.f;
+  rect.bottom = 600.f;
+  rect.right = 400.f;
+  rect.top = 800.f;
+  EXPECT_TRUE(FPDFAnnot_SetRect(annot, &rect));
+
+  // Add a solid-color translucent image object to the new annotation.
+  constexpr int kBitmapSize = 200;
+  FPDF_BITMAP image_bitmap = FPDFBitmap_Create(kBitmapSize, kBitmapSize, 1);
+  FPDFBitmap_FillRect(image_bitmap, 0, 0, kBitmapSize, kBitmapSize, 0xeeeecccc);
+  EXPECT_EQ(kBitmapSize, FPDFBitmap_GetWidth(image_bitmap));
+  EXPECT_EQ(kBitmapSize, FPDFBitmap_GetHeight(image_bitmap));
+  FPDF_PAGEOBJECT image_object = FPDFPageObj_NewImageObj(document());
+  ASSERT_TRUE(FPDFImageObj_SetBitmap(&page, 0, image_object, image_bitmap));
+  ASSERT_TRUE(FPDFImageObj_SetMatrix(image_object, kBitmapSize, 0, 0,
+                                     kBitmapSize, 0, 0));
+  FPDFPageObj_Transform(image_object, 1, 0, 0, 1, 200, 600);
+  EXPECT_TRUE(FPDFAnnot_AppendObject(annot, image_object));
+  FPDFPage_CloseAnnot(annot);
+
+  // Check that the page renders correctly with the new image object.
+  bitmap = RenderPageWithFlags(page, form_handle_, FPDF_ANNOT);
+  CompareBitmap(bitmap, 595, 842, md5_2);
+  FPDFBitmap_Destroy(bitmap);
+
+  // Retrieve the newly added stamp annotation and its image object.
+  annot = FPDFPage_GetAnnot(page, 2);
+  ASSERT_TRUE(annot);
+  EXPECT_EQ(1, FPDFAnnot_GetObjectCount(annot));
+  image_object = FPDFAnnot_GetObject(annot, 0);
+  EXPECT_EQ(FPDF_PAGEOBJ_IMAGE, FPDFPageObj_GetType(image_object));
+
+  // Modify the image in the new annotation.
+  FPDFBitmap_FillRect(image_bitmap, 0, 0, kBitmapSize, kBitmapSize, 0xff000000);
+  ASSERT_TRUE(FPDFImageObj_SetBitmap(&page, 0, image_object, image_bitmap));
+  EXPECT_TRUE(FPDFAnnot_UpdateObject(annot, image_object));
+  FPDFPage_CloseAnnot(annot);
+
+  // Save the document, closing the page and document.
+  EXPECT_TRUE(FPDF_SaveAsCopy(document(), this, 0));
+  FPDF_ClosePage(page);
+
+  // Test that the saved document renders the modified image object correctly.
+  TestSaved(595, 842, md5_3);
+
+  FPDFBitmap_Destroy(image_bitmap);
+  CloseSaved();
+}
+
+TEST_F(FPDFAnnotEmbeddertest, AddAndModifyText) {
+#if _FXM_PLATFORM_ == _FXM_PLATFORM_APPLE_
+  const char md5[] = "c35408717759562d1f8bf33d317483d2";
+  const char md5_2[] = "e5680ed048c2cfd9a1d27212cdf41286";
+  const char md5_3[] = "79f5cfb0b07caaf936f65f6a7a57ce77";
+#elif _FXM_PLATFORM_ == _FXM_PLATFORM_WINDOWS_
+  const char md5[] = "bdf96279ab82d9f484874db3f0c03429";
+  const char md5_2[] = "fa5709c115d4ebd502df91841b44b3ef";
+  const char md5_3[] = "9f6fa52dc477ccf52be4184d8589ef3f";
+#else
+  const char md5[] = "07d4168715553b4294525f840c40aa1c";
+  const char md5_2[] = "40a4c5e0561b062882b47253be3393ef";
+  const char md5_3[] = "f8ce0682add01f6d273890ac64d90fa6";
+#endif
+
+  // Open a file with two annotations and load its first page.
+  ASSERT_TRUE(OpenDocument("annotation_stamp_with_ap.pdf"));
+  FPDF_PAGE page = FPDF_LoadPage(document(), 0);
+  ASSERT_TRUE(page);
+  EXPECT_EQ(2, FPDFPage_GetAnnotCount(page));
+
+  // Check that the page renders correctly.
+  FPDF_BITMAP bitmap = RenderPageWithFlags(page, form_handle_, FPDF_ANNOT);
+  CompareBitmap(bitmap, 595, 842, md5);
+  FPDFBitmap_Destroy(bitmap);
+
+  // Create a stamp annotation and set its annotation rectangle.
+  FPDF_ANNOTATION annot = FPDFPage_CreateAnnot(page, FPDF_ANNOT_STAMP);
+  ASSERT_TRUE(annot);
+  FS_RECTF rect;
+  rect.left = 200.f;
+  rect.bottom = 550.f;
+  rect.right = 450.f;
+  rect.top = 650.f;
+  EXPECT_TRUE(FPDFAnnot_SetRect(annot, &rect));
+
+  // Add a translucent text object to the new annotation.
+  FPDF_PAGEOBJECT text_object =
+      FPDFPageObj_NewTextObj(document(), "Arial", 12.0f);
+  EXPECT_TRUE(text_object);
+  std::unique_ptr<unsigned short, pdfium::FreeDeleter> text =
+      GetFPDFWideString(L"I'm a translucent text laying on other text.");
+  EXPECT_TRUE(FPDFText_SetText(text_object, text.get()));
+  EXPECT_TRUE(FPDFText_SetFillColor(text_object, 0, 0, 255, 150));
+  FPDFPageObj_Transform(text_object, 1, 0, 0, 1, 200, 600);
+  EXPECT_TRUE(FPDFAnnot_AppendObject(annot, text_object));
+  FPDFPage_CloseAnnot(annot);
+
+  // Check that the page renders correctly with the new text object.
+  bitmap = RenderPageWithFlags(page, form_handle_, FPDF_ANNOT);
+  CompareBitmap(bitmap, 595, 842, md5_2);
+  FPDFBitmap_Destroy(bitmap);
+
+  // Retrieve the newly added stamp annotation and its text object.
+  annot = FPDFPage_GetAnnot(page, 2);
+  ASSERT_TRUE(annot);
+  EXPECT_EQ(1, FPDFAnnot_GetObjectCount(annot));
+  text_object = FPDFAnnot_GetObject(annot, 0);
+  EXPECT_EQ(FPDF_PAGEOBJ_TEXT, FPDFPageObj_GetType(text_object));
+
+  // Modify the text in the new annotation.
+  std::unique_ptr<unsigned short, pdfium::FreeDeleter> new_text =
+      GetFPDFWideString(L"New text!");
+  EXPECT_TRUE(FPDFText_SetText(text_object, new_text.get()));
+  EXPECT_TRUE(FPDFAnnot_UpdateObject(annot, text_object));
+  FPDFPage_CloseAnnot(annot);
+
+  // Check that the page renders correctly with the modified text object.
+  bitmap = RenderPageWithFlags(page, form_handle_, FPDF_ANNOT);
+  CompareBitmap(bitmap, 595, 842, md5_3);
+  FPDFBitmap_Destroy(bitmap);
+
+  // Remove the new annotation, and check that the page renders as before.
+  EXPECT_TRUE(FPDFPage_RemoveAnnot(page, 2));
+  bitmap = RenderPageWithFlags(page, form_handle_, FPDF_ANNOT);
+  CompareBitmap(bitmap, 595, 842, md5);
+  FPDFBitmap_Destroy(bitmap);
+
+  UnloadPage(page);
+}
diff --git a/fpdfsdk/fpdfview_c_api_test.c b/fpdfsdk/fpdfview_c_api_test.c
index 01c318912f..0027aa4b52 100644
--- a/fpdfsdk/fpdfview_c_api_test.c
+++ b/fpdfsdk/fpdfview_c_api_test.c
@@ -42,10 +42,10 @@ int CheckPDFiumCApi() {
     CHK(FPDFPage_CloseAnnot);
     CHK(FPDFPage_RemoveAnnot);
     CHK(FPDFAnnot_GetSubtype);
-    CHK(FPDFAnnot_UpdatePathObject);
-    CHK(FPDFAnnot_AppendPathObject);
-    CHK(FPDFAnnot_GetPathObjectCount);
-    CHK(FPDFAnnot_GetPathObject);
+    CHK(FPDFAnnot_UpdateObject);
+    CHK(FPDFAnnot_AppendObject);
+    CHK(FPDFAnnot_GetObjectCount);
+    CHK(FPDFAnnot_GetObject);
     CHK(FPDFAnnot_SetColor);
     CHK(FPDFAnnot_GetColor);
     CHK(FPDFAnnot_HasAttachmentPoints);
diff --git a/public/fpdf_annot.h b/public/fpdf_annot.h
index 971662f8e8..7c3b7247c8 100644
--- a/public/fpdf_annot.h
+++ b/public/fpdf_annot.h
@@ -67,6 +67,7 @@ typedef enum FPDFANNOT_TEXTTYPE {
   FPDFANNOT_TEXTTYPE_Author
 } FPDFANNOT_TEXTTYPE;
 
+// Experimental API.
 // Check if an annotation subtype is currently supported for creation.
 // Currently supported subtypes: circle, highlight, ink, popup, square,
 // squiggly, stamp, strikeout, text, and underline.
@@ -77,6 +78,7 @@ typedef enum FPDFANNOT_TEXTTYPE {
 DLLEXPORT FPDF_BOOL STDCALL
 FPDFAnnot_IsSupportedSubtype(FPDF_ANNOTATION_SUBTYPE subtype);
 
+// Experimental API.
 // Create an annotation in |page| of the subtype |subtype|. If the specified
 // subtype is illegal or unsupported, then a new annotation will not be created.
 // Must call FPDFPage_CloseAnnot() when the annotation returned by this
@@ -89,6 +91,7 @@ FPDFAnnot_IsSupportedSubtype(FPDF_ANNOTATION_SUBTYPE subtype);
 DLLEXPORT FPDF_ANNOTATION STDCALL
 FPDFPage_CreateAnnot(FPDF_PAGE page, FPDF_ANNOTATION_SUBTYPE subtype);
 
+// Experimental API.
 // Get the number of annotations in |page|.
 //
 //   page   - handle to a page.
@@ -96,6 +99,7 @@ FPDFPage_CreateAnnot(FPDF_PAGE page, FPDF_ANNOTATION_SUBTYPE subtype);
 // Returns the number of annotations in |page|.
 DLLEXPORT int STDCALL FPDFPage_GetAnnotCount(FPDF_PAGE page);
 
+// Experimental API.
 // Get annotation in |page| at |index|. Must call FPDFPage_CloseAnnot() when the
 // annotation returned by this function is no longer needed.
 //
@@ -105,6 +109,7 @@ DLLEXPORT int STDCALL FPDFPage_GetAnnotCount(FPDF_PAGE page);
 // Returns a handle to the annotation object, or NULL on failure.
 DLLEXPORT FPDF_ANNOTATION STDCALL FPDFPage_GetAnnot(FPDF_PAGE page, int index);
 
+// Experimental API.
 // Close an annotation. Must be called when the annotation returned by
 // FPDFPage_CreateAnnot() or FPDFPage_GetAnnot() is no longer needed. This
 // function does not remove the annotation from the document.
@@ -112,6 +117,7 @@ DLLEXPORT FPDF_ANNOTATION STDCALL FPDFPage_GetAnnot(FPDF_PAGE page, int index);
 //   annot  - handle to an annotation.
 DLLEXPORT void STDCALL FPDFPage_CloseAnnot(FPDF_ANNOTATION annot);
 
+// Experimental API.
 // Remove the annotation in |page| at |index|.
 //
 //   page  - handle to a page.
@@ -120,6 +126,7 @@ DLLEXPORT void STDCALL FPDFPage_CloseAnnot(FPDF_ANNOTATION annot);
 // Returns true if successful.
 DLLEXPORT FPDF_BOOL STDCALL FPDFPage_RemoveAnnot(FPDF_PAGE page, int index);
 
+// Experimental API.
 // Get the subtype of an annotation.
 //
 //   annot  - handle to an annotation.
@@ -129,48 +136,53 @@ DLLEXPORT FPDF_ANNOTATION_SUBTYPE STDCALL
 FPDFAnnot_GetSubtype(FPDF_ANNOTATION annot);
 
 // Experimental API.
-// Update |path| in |annot|. |path| must be in |annot| already and must have
-// been retrieved by FPDFAnnot_GetPathObject(). Only ink and stamp annotations
-// are supported currently.
+// Update |obj| in |annot|. |obj| must be in |annot| already and must have
+// been retrieved by FPDFAnnot_GetObject(). Currently, only ink and stamp
+// annotations are supported by this API. Also note that only path, image, and
+// text objects have APIs for modification; see FPDFPath_*(), FPDFText_*(), and
+// FPDFImageObj_*().
 //
 //   annot  - handle to an annotation.
-//   path   - handle to the path that |annot| needs to update.
+//   obj    - handle to the object that |annot| needs to update.
 //
 // Return true if successful.
-DLLEXPORT FPDF_BOOL STDCALL FPDFAnnot_UpdatePathObject(FPDF_ANNOTATION annot,
-                                                       FPDF_PAGEOBJECT path);
+DLLEXPORT FPDF_BOOL STDCALL FPDFAnnot_UpdateObject(FPDF_ANNOTATION annot,
+                                                   FPDF_PAGEOBJECT obj);
 
 // Experimental API.
-// Add |path| to |annot|. |path| must have been created by
-// FPDFPageObj_CreateNewPath(), and will be owned by |annot|. Note that a |path|
-// cannot belong to more than one |annot|. Only ink and stamp annotations
-// are supported currently.
+// Add |obj| to |annot|. |obj| must have been created by
+// FPDFPageObj_CreateNew{Path|Rect}() or FPDFPageObj_New{Text|Image}Obj(), and
+// will be owned by |annot|. Note that an |obj| cannot belong to more than one
+// |annot|. Currently, only ink and stamp annotations are supported by this API.
+// Also note that only path, image, and text objects have APIs for creation.
 //
 //   annot  - handle to an annotation.
-//   path   - handle to the path that is to be added to |annot|.
+//   obj    - handle to the object that is to be added to |annot|.
 //
 // Return true if successful.
-DLLEXPORT FPDF_BOOL STDCALL FPDFAnnot_AppendPathObject(FPDF_ANNOTATION annot,
-                                                       FPDF_PAGEOBJECT path);
+DLLEXPORT FPDF_BOOL STDCALL FPDFAnnot_AppendObject(FPDF_ANNOTATION annot,
+                                                   FPDF_PAGEOBJECT obj);
 
 // Experimental API.
-// Get the number of path objects in |annot|.
+// Get the total number of objects in |annot|, including path objects, text
+// objects, external objects, image objects, and shading objects.
 //
 //   annot  - handle to an annotation.
 //
-// Returns the number of path objects in |annot|.
-DLLEXPORT int STDCALL FPDFAnnot_GetPathObjectCount(FPDF_ANNOTATION annot);
+// Returns the number of objects in |annot|.
+DLLEXPORT int STDCALL FPDFAnnot_GetObjectCount(FPDF_ANNOTATION annot);
 
 // Experimental API.
-// Get the path object in |annot| at |index|.
+// Get the object in |annot| at |index|.
 //
 //   annot  - handle to an annotation.
-//   index  - the index of the path object.
+//   index  - the index of the object.
 //
-// Return a handle to the path object, or NULL on failure.
-DLLEXPORT FPDF_PAGEOBJECT STDCALL FPDFAnnot_GetPathObject(FPDF_ANNOTATION annot,
-                                                          int index);
+// Return a handle to the object, or NULL on failure.
+DLLEXPORT FPDF_PAGEOBJECT STDCALL FPDFAnnot_GetObject(FPDF_ANNOTATION annot,
+                                                      int index);
 
+// Experimental API.
 // Set the color of an annotation. Fails when called on annotations with
 // appearance streams already defined; instead use
 // FPDFPath_Set{Stroke|Fill}Color().
@@ -188,6 +200,7 @@ DLLEXPORT FPDF_BOOL STDCALL FPDFAnnot_SetColor(FPDF_ANNOTATION annot,
                                                unsigned int B,
                                                unsigned int A);
 
+// Experimental API.
 // Get the color of an annotation. If no color is specified, default to yellow
 // for highlight annotation, black for all else. Fails when called on
 // annotations with appearance streams already defined; instead use
@@ -206,6 +219,7 @@ DLLEXPORT FPDF_BOOL STDCALL FPDFAnnot_GetColor(FPDF_ANNOTATION annot,
                                                unsigned int* B,
                                                unsigned int* A);
 
+// Experimental API.
 // Check if the annotation is of a type that has attachment points
 // (i.e. quadpoints). Quadpoints are the vertices of the rectange that
 // encompasses the texts affected by the annotation. They provide the
@@ -220,6 +234,7 @@ DLLEXPORT FPDF_BOOL STDCALL FPDFAnnot_GetColor(FPDF_ANNOTATION annot,
 DLLEXPORT FPDF_BOOL STDCALL
 FPDFAnnot_HasAttachmentPoints(FPDF_ANNOTATION annot);
 
+// Experimental API.
 // Set the attachment points (i.e. quadpoints) of an annotation. If the
 // annotation's appearance stream is defined and this annotation is of a type
 // with quadpoints, then update the bounding box too.
@@ -232,6 +247,7 @@ DLLEXPORT FPDF_BOOL STDCALL
 FPDFAnnot_SetAttachmentPoints(FPDF_ANNOTATION annot,
                               const FS_QUADPOINTSF* quadPoints);
 
+// Experimental API.
 // Get the attachment points (i.e. quadpoints) of an annotation. If the
 // annotation's appearance stream is defined and this annotation is of a type
 // with quadpoints, then return the bounding box it specifies instead.
@@ -242,6 +258,7 @@ FPDFAnnot_SetAttachmentPoints(FPDF_ANNOTATION annot,
 DLLEXPORT FS_QUADPOINTSF STDCALL
 FPDFAnnot_GetAttachmentPoints(FPDF_ANNOTATION annot);
 
+// Experimental API.
 // Set the annotation rectangle defining the location of the annotation. If the
 // annotation's appearance stream is defined and this annotation is of a type
 // without quadpoints, then update the bounding box too.
@@ -253,6 +270,7 @@ FPDFAnnot_GetAttachmentPoints(FPDF_ANNOTATION annot);
 DLLEXPORT FPDF_BOOL STDCALL FPDFAnnot_SetRect(FPDF_ANNOTATION annot,
                                               const FS_RECTF* rect);
 
+// Experimental API.
 // Get the annotation rectangle defining the location of the annotation. If the
 // annotation's appearance stream is defined and this annotation is of a type
 // without quadpoints, then return the bounding box it specifies instead.
@@ -262,6 +280,7 @@ DLLEXPORT FPDF_BOOL STDCALL FPDFAnnot_SetRect(FPDF_ANNOTATION annot,
 // Returns a rectangle object, or an empty rectangle on failure.
 DLLEXPORT FS_RECTF STDCALL FPDFAnnot_GetRect(FPDF_ANNOTATION annot);
 
+// Experimental API.
 // Set the contents of an annotation.
 //
 //   annot  - handle to an annotation.
@@ -273,6 +292,7 @@ DLLEXPORT FPDF_BOOL STDCALL FPDFAnnot_SetText(FPDF_ANNOTATION annot,
                                               FPDFANNOT_TEXTTYPE type,
                                               FPDF_WIDESTRING text);
 
+// Experimental API.
 // Get the contents of an annotation. |buffer| is only modified if |buflen|
 // is longer than the length of contents.
 //