+//------------------------------------------------------------------------
+// BaseStream
+//
+// This is the base class for all streams that read directly from a file.
+//------------------------------------------------------------------------
+
+class BaseStream: public Stream {
+public:
+
+ BaseStream(Object *dictA);
+ virtual ~BaseStream();
+ virtual Stream *makeSubStream(Guint start, GBool limited,
+ Guint length, Object *dict) = 0;
+ virtual void setPos(Guint pos, int dir = 0) = 0;
+ virtual GBool isBinary(GBool last = gTrue) { return last; }
+ virtual BaseStream *getBaseStream() { return this; }
+ virtual Dict *getDict() { return dict.getDict(); }
+
+ // Get/set position of first byte of stream within the file.
+ virtual Guint getStart() = 0;
+ virtual void moveStart(int delta) = 0;
+
+#ifndef NO_DECRYPTION
+ // Set decryption for this stream.
+ virtual void doDecryption(Guchar *fileKey, int keyLength,
+ int objNum, int objGen);
+#endif
+
+#ifndef NO_DECRYPTION
+protected:
+
+ Decrypt *decrypt;
+#endif
+
+private:
+
+ Object dict;
+};
+
+//------------------------------------------------------------------------
+// FilterStream
+//
+// This is the base class for all streams that filter another stream.
+//------------------------------------------------------------------------
+
+class FilterStream: public Stream {
+public:
+
+ FilterStream(Stream *strA);
+ virtual ~FilterStream();
+ virtual void close();
+ virtual int getPos() { return str->getPos(); }
+ virtual void setPos(Guint pos, int dir = 0);
+ virtual BaseStream *getBaseStream() { return str->getBaseStream(); }
+ virtual Dict *getDict() { return str->getDict(); }
+ virtual void ignoreLength() { str->ignoreLength(); }
+
+protected:
+
+ Stream *str;
+};
+