Basic APIs and tests for extracting attachments

1. Added API for extracting attachment properties and data.
  * Expanded the embedder test to cover all the new APIs.

Bug=pdfium:174

Change-Id: I09bffd412410e9aea45faca442d2b72eefafef4e
Reviewed-on: https://pdfium-review.googlesource.com/7790
Reviewed-by: dsinclair <dsinclair@chromium.org>
Commit-Queue: dsinclair <dsinclair@chromium.org>

1 files changed, 76 insertions, 9 deletions

diff --git a/public/fpdf_attachment.h b/public/fpdf_attachment.h
index 07fdff5a9e..2c40992760 100644
--- a/public/fpdf_attachment.h
+++ b/public/fpdf_attachment.h
@@ -21,21 +21,88 @@ extern "C" {
 DLLEXPORT int STDCALL FPDFDoc_GetAttachmentCount(FPDF_DOCUMENT document);
 
 // Experimental API.
-// Get the name of the embedded file at |index| in |document|. |buffer| is
-// only modified if |buflen| is longer than the length of the file name. On
-// errors, |buffer| is unmodified and the returned length is 0.
+// Get the embedded attachment at |index| in |document|. Note that the returned
+// attachment handle is only valid while |document| is open.
 //
 //   document - handle to a document.
 //   index    - the index of the requested embedded file.
-//   buffer   - buffer for holding the file name, encoded in UTF16-LE.
-//   buflen   - length of the buffer.
+//
+// Returns the handle to the attachment object, or NULL on failure.
+DLLEXPORT FPDF_ATTACHMENT STDCALL FPDFDoc_GetAttachment(FPDF_DOCUMENT document,
+                                                        int index);
+
+// Experimental API.
+// Get the name of the |attachment| file. |buffer| is only modified if |buflen|
+// is longer than the length of the file name. On errors, |buffer| is unmodified
+// and the returned length is 0.
+//
+//   attachment - handle to an attachment.
+//   buffer     - buffer for holding the file name, encoded in UTF16-LE.
+//   buflen     - length of the buffer.
 //
 // Returns the length of the file name.
 DLLEXPORT unsigned long STDCALL
-FPDFDoc_GetAttachmentName(FPDF_DOCUMENT document,
-                          int index,
-                          void* buffer,
-                          unsigned long buflen);
+FPDFAttachment_GetName(FPDF_ATTACHMENT attachment,
+                       void* buffer,
+                       unsigned long buflen);
+
+// Experimental API.
+// Check if the params dictionary of |attachment| has |key| as a key.
+//
+//   attachment - handle to an attachment.
+//   key        - the key to look for.
+//
+// Returns true if |key| exists.
+DLLEXPORT FPDF_BOOL STDCALL FPDFAttachment_HasKey(FPDF_ATTACHMENT attachment,
+                                                  FPDF_WIDESTRING key);
+
+// Experimental API.
+// Get the type of the value corresponding to |key| in the params dictionary of
+// the embedded |attachment|.
+//
+//   attachment - handle to an attachment.
+//   key        - the key to look for.
+//
+// Returns the type of the dictionary value.
+DLLEXPORT FPDF_OBJECT_TYPE STDCALL
+FPDFAttachment_GetValueType(FPDF_ATTACHMENT attachment, FPDF_WIDESTRING key);
+
+// Experimental API.
+// Get the string value corresponding to |key| in the params dictionary of the
+// embedded file |attachment|. |buffer| is only modified if |buflen| is longer
+// than the length of the string value. Note that if |key| does not exist in the
+// dictionary or if |key|'s corresponding value in the dictionary is not a
+// string (i.e. the value is not of type FPDF_OBJECT_STRING or
+// FPDF_OBJECT_NAME), then an empty string would be copied to |buffer| and the
+// return value would be 2. On other errors, nothing would be added to |buffer|
+// and the return value would be 0.
+//
+//   attachment - handle to an attachment.
+//   key        - the key to the requested string value.
+//   buffer     - buffer for holding the file's date string encoded in UTF16-LE.
+//   buflen     - length of the buffer.
+//
+// Returns the length of the dictionary value string.
+DLLEXPORT unsigned long STDCALL
+FPDFAttachment_GetStringValue(FPDF_ATTACHMENT attachment,
+                              FPDF_WIDESTRING key,
+                              void* buffer,
+                              unsigned long buflen);
+
+// Experimental API.
+// Get the file data of |attachment|. |buffer| is only modified if |buflen| is
+// longer than the length of the file. On errors, |buffer| is unmodified and the
+// returned length is 0.
+//
+//   attachment - handle to an attachment.
+//   buffer     - buffer for holding the file's data in raw bytes.
+//   buflen     - length of the buffer.
+//
+// Returns the length of the file.
+DLLEXPORT unsigned long STDCALL
+FPDFAttachment_GetFile(FPDF_ATTACHMENT attachment,
+                       void* buffer,
+                       unsigned long buflen);
 
 #ifdef __cplusplus
 }  // extern "C"