+
+private:
+ // UTF-7 decoder/encoder may be in direct mode or in shifted mode after a
+ // '+' (and until the '-' or any other non-base64 character)
+ struct StateMode
+ {
+ enum Mode
+ {
+ Direct, // pass through state
+ Shifted // after a '+' (and before '-')
+ };
+ };
+
+ // the current decoder state: this is only used by ToWChar() if srcLen
+ // parameter is not wxNO_LEN, when working on the entire NUL-terminated
+ // strings we neither update nor use the state
+ class DecoderState : StateMode
+ {
+ private:
+ // current state: this one is private as we want to enforce the use of
+ // ToDirect/ToShifted() methods below
+ Mode mode;
+
+ public:
+ // the initial state is direct
+ DecoderState() { mode = Direct; }
+
+ // switch to/from shifted mode
+ void ToDirect() { mode = Direct; }
+ void ToShifted() { mode = Shifted; accum = bit = 0; isLSB = false; }
+
+ bool IsDirect() const { return mode == Direct; }
+ bool IsShifted() const { return mode == Shifted; }
+
+
+ // these variables are only used in shifted mode
+
+ unsigned int accum; // accumulator of the bit we've already got
+ unsigned int bit; // the number of bits consumed mod 8
+ unsigned char msb; // the high byte of UTF-16 word
+ bool isLSB; // whether we're decoding LSB or MSB of UTF-16 word
+ };
+
+ DecoderState m_stateDecoder;
+
+
+ // encoder state is simpler as we always receive entire Unicode characters
+ // on input
+ class EncoderState : StateMode
+ {
+ private:
+ Mode mode;
+
+ public:
+ EncoderState() { mode = Direct; }
+
+ void ToDirect() { mode = Direct; }
+ void ToShifted() { mode = Shifted; accum = bit = 0; }
+
+ bool IsDirect() const { return mode == Direct; }
+ bool IsShifted() const { return mode == Shifted; }
+
+ unsigned int accum;
+ unsigned int bit;
+ };
+
+ EncoderState m_stateEncoder;