Refactor QPDFPageObjectHelper::removeUnreferencedResources()

Refactor removeUnreferencedResources to prepare for filtering form
XObjects.

2 files changed, 13 insertions, 0 deletions

diff --git a/include/qpdf/QPDFObjectHandle.hh b/include/qpdf/QPDFObjectHandle.hh
index 0e1a695a..9bf5f7f7 100644
--- a/include/qpdf/QPDFObjectHandle.hh
+++ b/include/qpdf/QPDFObjectHandle.hh
@@ -400,6 +400,12 @@ class QPDFObjectHandle
     void addContentTokenFilter(PointerHolder<TokenFilter> token_filter);
     // End legacy content stream helpers
 
+    // Called on a stream to filter the stream as if it were page
+    // contents. This can be used to apply a TokenFilter to a form
+    // XObject, whose data is in the same format as a content stream.
+    QPDF_DLL
+    void filterAsContents(TokenFilter* filter, Pipeline* next = 0);
+
     // Type-specific factories
     QPDF_DLL
     static QPDFObjectHandle newNull();
diff --git a/include/qpdf/QPDFPageObjectHelper.hh b/include/qpdf/QPDFPageObjectHelper.hh
index 96da35f4..e1409b56 100644
--- a/include/qpdf/QPDFPageObjectHelper.hh
+++ b/include/qpdf/QPDFPageObjectHelper.hh
@@ -28,6 +28,7 @@
 #include <qpdf/DLL.h>
 
 #include <qpdf/QPDFObjectHandle.hh>
+#include <functional>
 
 class QPDFPageObjectHelper: public QPDFObjectHelper
 {
@@ -231,6 +232,12 @@ class QPDFPageObjectHelper: public QPDFObjectHelper
         bool invert_transformations = true);
 
   private:
+    static void
+    removeUnreferencedResourcesHelper(
+        QPDFObjectHandle oh, std::set<QPDFObjGen>& seen,
+        std::function<QPDFObjectHandle()> get_resource,
+        std::function<void(QPDFObjectHandle::TokenFilter*)> filter_content);
+
     class Members
     {
         friend class QPDFPageObjectHelper;