Add public method FPDFPath_CountPoint to get # of points of a path object.

It was already possible to get the fill color, this exposes the number of
points. Naming attempts to be consistent with existing
FPDFPage_CountObject().

Change-Id: I79e8dd9f0c077de84ce9017a01d239e48e58174a
Reviewed-on: https://pdfium-review.googlesource.com/13592
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>

4 files changed, 39 insertions, 0 deletions

diff --git a/fpdfsdk/fpdfedit_embeddertest.cpp b/fpdfsdk/fpdfedit_embeddertest.cpp
index 71933fea43..faf6d97adf 100644
--- a/fpdfsdk/fpdfedit_embeddertest.cpp
+++ b/fpdfsdk/fpdfedit_embeddertest.cpp
@@ -256,6 +256,10 @@ TEST_F(FPDFEditEmbeddertest, AddPaths) {
   EXPECT_EQ(0U, B);
   EXPECT_EQ(128U, A);
 
+  // Make sure the path has 5 points (1 FXPT_TYPE::MoveTo and 4
+  // FXPT_TYPE::LineTo).
+  ASSERT_EQ(5, FPDFPath_CountPoint(green_rect));
+
   EXPECT_TRUE(FPDFPath_SetDrawMode(green_rect, FPDF_FILLMODE_WINDING, 0));
   FPDFPage_InsertObject(page, green_rect);
   page_bitmap = RenderPage(page);
@@ -269,6 +273,11 @@ TEST_F(FPDFEditEmbeddertest, AddPaths) {
   EXPECT_TRUE(FPDFPath_LineTo(black_path, 400, 200));
   EXPECT_TRUE(FPDFPath_LineTo(black_path, 300, 100));
   EXPECT_TRUE(FPDFPath_Close(black_path));
+
+  // Make sure the path has 3 points (1 FXPT_TYPE::MoveTo and 2
+  // FXPT_TYPE::LineTo).
+  ASSERT_EQ(3, FPDFPath_CountPoint(black_path));
+
   FPDFPage_InsertObject(page, black_path);
   page_bitmap = RenderPage(page);
   CompareBitmap(page_bitmap, 612, 792, "eadc8020a14dfcf091da2688733d8806");
@@ -299,6 +308,18 @@ TEST_F(FPDFEditEmbeddertest, AddPaths) {
   TestAndCloseSaved(612, 792, last_md5);
 }
 
+TEST_F(FPDFEditEmbeddertest, PathsPoints) {
+  CreateNewDocument();
+  FPDF_PAGEOBJECT img = FPDFPageObj_NewImageObj(document_);
+  // This should fail gracefully, even if img is not a path.
+  ASSERT_EQ(-1, FPDFPath_CountPoint(img));
+
+  // This should fail gracefully, even if path is NULL.
+  ASSERT_EQ(-1, FPDFPath_CountPoint(nullptr));
+
+  FPDFPageObj_Destroy(img);
+}
+
 TEST_F(FPDFEditEmbeddertest, PathOnTopOfText) {
   // Load document with some text
   EXPECT_TRUE(OpenDocument("hello_world.pdf"));
diff --git a/fpdfsdk/fpdfeditpath.cpp b/fpdfsdk/fpdfeditpath.cpp
index 2b33dee934..164ab7015f 100644
--- a/fpdfsdk/fpdfeditpath.cpp
+++ b/fpdfsdk/fpdfeditpath.cpp
@@ -118,6 +118,13 @@ FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FPDFPath_GetFillColor(FPDF_PAGEOBJECT path,
   return true;
 }
 
+FPDF_EXPORT int FPDF_CALLCONV FPDFPath_CountPoint(FPDF_PAGEOBJECT path) {
+  auto* pPathObj = CPDFPathObjectFromFPDFPageObject(path);
+  if (!pPathObj)
+    return -1;
+  return pdfium::CollectionSize<int>(pPathObj->m_Path.GetPoints());
+}
+
 FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FPDFPath_MoveTo(FPDF_PAGEOBJECT path,
                                                     float x,
                                                     float y) {
diff --git a/fpdfsdk/fpdfview_c_api_test.c b/fpdfsdk/fpdfview_c_api_test.c
index 6f84f353aa..415543dbe2 100644
--- a/fpdfsdk/fpdfview_c_api_test.c
+++ b/fpdfsdk/fpdfview_c_api_test.c
@@ -148,6 +148,7 @@ int CheckPDFiumCApi() {
     CHK(FPDFPath_SetStrokeWidth);
     CHK(FPDFPath_SetFillColor);
     CHK(FPDFPath_GetFillColor);
+    CHK(FPDFPath_CountPoint);
     CHK(FPDFPath_MoveTo);
     CHK(FPDFPath_LineTo);
     CHK(FPDFPath_BezierTo);
diff --git a/public/fpdf_edit.h b/public/fpdf_edit.h
index 22582674ea..9ee11cb5ec 100644
--- a/public/fpdf_edit.h
+++ b/public/fpdf_edit.h
@@ -552,6 +552,16 @@ FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FPDFPath_GetFillColor(FPDF_PAGEOBJECT path,
                                                           unsigned int* B,
                                                           unsigned int* A);
 
+// Get number of point objects inside |path|.
+//
+//   path - handle to a path.
+//
+// A point object is a command, created by e.g. FPDFPath_MoveTo() or
+// FPDFPath_LineTo().
+//
+// Returns the number of objects in |path| or -1 on failure.
+FPDF_EXPORT int FPDF_CALLCONV FPDFPath_CountPoint(FPDF_PAGEOBJECT path);
+
 // Move a path's current point.
 //
 // path   - the handle to the path object.