implement format detection

1 files changed, 16 insertions, 0 deletions

diff --git a/src/lib/SDFDocument.cpp b/src/lib/SDFDocument.cpp
index d253c21..07743fd 100644
--- a/src/lib/SDFDocument.cpp
+++ b/src/lib/SDFDocument.cpp
@@ -25,8 +25,24 @@ using boost::shared_ptr;
 namespace libsdf
 {
 
+static const unsigned char SDF_MIMETYPE[] = "application/x-sdf";
+
 SDFAPI bool SDFDocument::isSupported(librevenge::RVNGInputStream *const input) try
 {
+  if (input->isStructured() && input->existsSubStream("mimetype"))
+  {
+    RVNGInputStreamPtr_t mimetypeInput(input->getSubStreamByName("mimetype"));
+
+    const unsigned long len = SDF_NUM_ELEMENTS(SDF_MIMETYPE) - 1; // ignore the trailing 0
+    unsigned long readBytes = 0;
+    const unsigned char *const mimetype = mimetypeInput->read(len, readBytes);
+    if (readBytes == len)
+    {
+      unsigned char c = readU8(mimetypeInput);
+      return mimetypeInput->isEnd() && std::equal(mimetype, mimetype + len, SDF_MIMETYPE) && ('\n' == c);
+    }
+  }
+
   return false;
 }
 catch (...)