Add getTypeCode() and getTypeName()

Add virtual methods to QPDFObject, wrappers to QPDFObjectHandle, and
implementations to all the QPDF_Object types.

2 files changed, 41 insertions, 0 deletions

diff --git a/include/qpdf/QPDFObject.hh b/include/qpdf/QPDFObject.hh
index 8bb61022..4a5f2dec 100644
--- a/include/qpdf/QPDFObject.hh
+++ b/include/qpdf/QPDFObject.hh
@@ -18,9 +18,42 @@ class QPDFObjectHandle;
 class QPDFObject
 {
   public:
+
+    // Objects derived from QPDFObject are accessible through
+    // QPDFObjectHandle.  Each object returns a unique type code that
+    // has one of the values in the list below.  As new object types
+    // are added to qpdf, additional items may be added to the list,
+    // so code that switches on these values should take that into
+    // consideration.
+    enum object_type_e {
+        // Object types internal to qpdf
+        ot_uninitialized,
+        ot_reserved,
+        // Object types that can occur in the main document
+        ot_boolean,
+        ot_null,
+        ot_integer,
+        ot_real,
+        ot_name,
+        ot_string,
+        ot_array,
+        ot_dictionary,
+        ot_stream,
+        // Additional object types that can occur in content streams
+        ot_keyword,
+        ot_inlineimage,
+    };
+
     virtual ~QPDFObject() {}
     virtual std::string unparse() = 0;
 
+    // Return a unique type code for the object
+    virtual object_type_e getTypeCode() const = 0;
+
+    // Return a string literal that describes the type, useful for
+    // debugging and testing
+    virtual char const* getTypeName() const = 0;
+
     // Accessor to give specific access to non-public methods
     class ObjAccessor
     {
diff --git a/include/qpdf/QPDFObjectHandle.hh b/include/qpdf/QPDFObjectHandle.hh
index c4a922d1..a23d81df 100644
--- a/include/qpdf/QPDFObjectHandle.hh
+++ b/include/qpdf/QPDFObjectHandle.hh
@@ -91,6 +91,14 @@ class QPDFObjectHandle
     QPDF_DLL
     bool isInitialized() const;
 
+    // Return type code and type name of underlying object.  These are
+    // useful for doing rapid type tests (like switch statements) or
+    // for testing and debugging.
+    QPDF_DLL
+    QPDFObject::object_type_e getTypeCode() const;
+    QPDF_DLL
+    char const* getTypeName() const;
+
     // Exactly one of these will return true for any object.  Keyword
     // and InlineImage are only allowed in content streams.
     QPDF_DLL