Add FPDFPage_SetRotation function

R=jam@chromium.org

Review URL: https://codereview.chromium.org/336563004

fpdfsdk/include/fpdfedit.h

diff --git a/fpdfsdk/include/fpdfedit.h b/fpdfsdk/include/fpdfedit.h
index c7d8b01..18b8168 100644
--- a/fpdfsdk/include/fpdfedit.h
+++ b/fpdfsdk/include/fpdfedit.h
@@ -67,17 +67,29 @@
 // Function: FPDFPage_GetRotation
 //			Get the page rotation. One of following values will be returned: 0(0), 1(90), 2(180), 3(270).
 // Parameters:	
-//			page		-	Handle to a page. Returned by FPDFPage_New.
+//			page		-	Handle to a page. Returned by FPDFPage_New or FPDF_LoadPage.
 // Return value:
 //			The PDF page rotation.
 // Comment:
 //			The PDF page rotation is rotated clockwise.
 DLLEXPORT int STDCALL FPDFPage_GetRotation(FPDF_PAGE page);
 
+// Function: FPDFPage_SetRotation
+//			Set page rotation. One of following values will be set: 0(0), 1(90), 2(180), 3(270).
+// Parameters:	
+//			page		-	Handle to a page. Returned by FPDFPage_New or FPDF_LoadPage.
+//			rotate		-	The value of the PDF page rotation.
+// Return value:
+//			None.
+// Comment:
+//			The PDF page rotation is rotated clockwise.
+// 
+DLLEXPORT void STDCALL FPDFPage_SetRotation(FPDF_PAGE page, int rotate);
+
 // Function: FPDFPage_InsertObject
 //			Insert an object to the page. The page object is automatically freed.
 // Parameters:	
-//			page		-	Handle to a page. Returned by FPDFPage_New.
+//			page		-	Handle to a page. Returned by FPDFPage_New or FPDF_LoadPage.
 //			page_obj	-	Handle to a page object. Returned by FPDFPageObj_NewTextObj,FPDFPageObj_NewTextObjEx and
 //							FPDFPageObj_NewPathObj.
 // Return value:
@@ -87,7 +99,7 @@
 // Function: FPDFPage_CountObject
 //			Get number of page objects inside the page.
 // Parameters:	
-//			page		-	Handle to a page. Returned by FPDFPage_New.
+//			page		-	Handle to a page. Returned by FPDFPage_New or FPDF_LoadPage.
 // Return value:
 //			The number of the page object.
 DLLEXPORT int STDCALL FPDFPage_CountObject(FPDF_PAGE page);
@@ -95,7 +107,7 @@
 // Function: FPDFPage_GetObject
 //			Get page object by index.
 // Parameters:	
-//			page		-	Handle to a page. Returned by FPDFPage_New.
+//			page		-	Handle to a page. Returned by FPDFPage_New or FPDF_LoadPage.
 //			index		-	The index of a page object.
 // Return value:
 //			The handle of the page object. Null for failed.
@@ -113,7 +125,7 @@
 // Function: FPDFPage_GenerateContent
 //			Generate PDF Page content.
 // Parameters:	
-//			page		-	Handle to a page. Returned by FPDFPage_New.
+//			page		-	Handle to a page. Returned by FPDFPage_New or FPDF_LoadPage.
 // Return value:
 //			True if successful, false otherwise.
 // Comment:

fpdfsdk/src/fpdfeditpage.cpp

diff --git a/fpdfsdk/src/fpdfeditpage.cpp b/fpdfsdk/src/fpdfeditpage.cpp
index 3f22b56..4c9fd35 100644
--- a/fpdfsdk/src/fpdfeditpage.cpp
+++ b/fpdfsdk/src/fpdfeditpage.cpp
@@ -314,3 +314,17 @@
 	}
 
 }
+
+DLLEXPORT void STDCALL FPDFPage_SetRotation(FPDF_PAGE page, int rotate)
+{
+	CPDF_Page* pPage = (CPDF_Page*)page;
+	if (!pPage || !pPage->m_pFormDict || !pPage->m_pFormDict->KeyExist("Type")
+		|| pPage->m_pFormDict->GetElement("Type")->GetDirect()->GetString().Compare("Page"))
+	{
+		return;
+	}
+	CPDF_Dictionary* pDict = pPage->m_pFormDict;
+	rotate %=4;
+
+	pDict->SetAt("Rotate", FX_NEW CPDF_Number(rotate * 90));
+}
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