1///////////////////////////////////////////////////////////////////////////// 2// Name: wx/gifdecod.h 3// Purpose: wxGIFDecoder, GIF reader for wxImage and wxAnimation 4// Author: Guillermo Rodriguez Garcia <guille@iies.es> 5// Version: 3.02 6// CVS-ID: $Id: gifdecod.h 45563 2007-04-21 18:17:50Z VZ $ 7// Copyright: (c) 1999 Guillermo Rodriguez Garcia 8// Licence: wxWindows licence 9///////////////////////////////////////////////////////////////////////////// 10 11#ifndef _WX_GIFDECOD_H_ 12#define _WX_GIFDECOD_H_ 13 14#include "wx/defs.h" 15 16#if wxUSE_STREAMS && wxUSE_GIF 17 18#include "wx/stream.h" 19#include "wx/image.h" 20#include "wx/animdecod.h" 21#include "wx/dynarray.h" 22 23// internal utility used to store a frame in 8bit-per-pixel format 24class GIFImage; 25 26 27// -------------------------------------------------------------------------- 28// Constants 29// -------------------------------------------------------------------------- 30 31// Error codes: 32// Note that the error code wxGIF_TRUNCATED means that the image itself 33// is most probably OK, but the decoder didn't reach the end of the data 34// stream; this means that if it was not reading directly from file, 35// the stream will not be correctly positioned. 36// 37enum wxGIFErrorCode 38{ 39 wxGIF_OK = 0, // everything was OK 40 wxGIF_INVFORMAT, // error in GIF header 41 wxGIF_MEMERR, // error allocating memory 42 wxGIF_TRUNCATED // file appears to be truncated 43}; 44 45// -------------------------------------------------------------------------- 46// wxGIFDecoder class 47// -------------------------------------------------------------------------- 48 49class WXDLLEXPORT wxGIFDecoder : public wxAnimationDecoder 50{ 51public: 52 // constructor, destructor, etc. 53 wxGIFDecoder(); 54 ~wxGIFDecoder(); 55 56 // get data of current frame 57 unsigned char* GetData(unsigned int frame) const; 58 unsigned char* GetPalette(unsigned int frame) const; 59 unsigned int GetNcolours(unsigned int frame) const; 60 int GetTransparentColourIndex(unsigned int frame) const; 61 wxColour GetTransparentColour(unsigned int frame) const; 62 63 virtual wxSize GetFrameSize(unsigned int frame) const; 64 virtual wxPoint GetFramePosition(unsigned int frame) const; 65 virtual wxAnimationDisposal GetDisposalMethod(unsigned int frame) const; 66 virtual long GetDelay(unsigned int frame) const; 67 68 // GIFs can contain both static images and animations 69 bool IsAnimation() const 70 { return m_nFrames > 1; } 71 72 // load function which returns more info than just Load(): 73 wxGIFErrorCode LoadGIF( wxInputStream& stream ); 74 75 // free all internal frames 76 void Destroy(); 77 78 // implementation of wxAnimationDecoder's pure virtuals 79 virtual bool CanRead( wxInputStream& stream ) const; 80 virtual bool Load( wxInputStream& stream ) 81 { return LoadGIF(stream) == wxGIF_OK; } 82 83 bool ConvertToImage(unsigned int frame, wxImage *image) const; 84 85 wxAnimationDecoder *Clone() const 86 { return new wxGIFDecoder; } 87 wxAnimationType GetType() const 88 { return wxANIMATION_TYPE_GIF; } 89 90private: 91 // array of all frames 92 wxArrayPtrVoid m_frames; 93 94 // decoder state vars 95 int m_restbits; // remaining valid bits 96 unsigned int m_restbyte; // remaining bytes in this block 97 unsigned int m_lastbyte; // last byte read 98 unsigned char m_buffer[256]; // buffer for reading 99 unsigned char *m_bufp; // pointer to next byte in buffer 100 101 int getcode(wxInputStream& stream, int bits, int abfin); 102 wxGIFErrorCode dgif(wxInputStream& stream, 103 GIFImage *img, int interl, int bits); 104 105 DECLARE_NO_COPY_CLASS(wxGIFDecoder) 106}; 107 108#endif // wxUSE_STREAM && wxUSE_GIF 109 110#endif // _WX_GIFDECOD_H_ 111