add wxScrollHelper::ShowScrollbars() (implemented for GTK only right now, generic...

[wxWidgets.git] / src / common / gifdecod.cpp

diff --git a/src/common/gifdecod.cpp b/src/common/gifdecod.cpp
index 3ca73d91a6ce0df85062050b4f8714d7cc2e49df..9d8cc1dd71d9a7a1a8bf94ff5c56f9a917b81407 100644 (file)
--- a/src/common/gifdecod.cpp
+++ b/src/common/gifdecod.cpp
@@ -24,6 +24,8 @@
 #include <stdlib.h>
 #include <string.h>
 #include "wx/gifdecod.h"
 #include <stdlib.h>
 #include <string.h>
 #include "wx/gifdecod.h"

+#include "wx/ptr_scpd.h"
+#include "wx/scopeguard.h"

 
 
 
 
 
 


@@ -38,20 +40,22 @@ public:
     // def ctor
     GIFImage();
 
     // def ctor
     GIFImage();
 

-    unsigned int w;                 /* width */
-    unsigned int h;                 /* height */
-    unsigned int left;              /* x coord (in logical screen) */
-    unsigned int top;               /* y coord (in logical screen) */
-    int transparent;                /* transparent color index (-1 = none) */
-    wxAnimationDisposal disposal;   /* disposal method */
-    long delay;                     /* delay in ms (-1 = unused) */
-    unsigned char *p;               /* bitmap */
-    unsigned char *pal;             /* palette */
-    unsigned int ncolours;          /* number of colours */
+    unsigned int w;                 // width
+    unsigned int h;                 // height
+    unsigned int left;              // x coord (in logical screen)
+    unsigned int top;               // y coord (in logical screen)
+    int transparent;                // transparent color index (-1 = none)
+    wxAnimationDisposal disposal;   // disposal method
+    long delay;                     // delay in ms (-1 = unused)
+    unsigned char *p;               // bitmap
+    unsigned char *pal;             // palette
+    unsigned int ncolours;          // number of colours

 
     DECLARE_NO_COPY_CLASS(GIFImage)
 };
 
 
     DECLARE_NO_COPY_CLASS(GIFImage)
 };
 

+wxDECLARE_SCOPED_PTR(GIFImage, GIFImagePtr)
+wxDEFINE_SCOPED_PTR(GIFImage, GIFImagePtr)

 
 
 //---------------------------------------------------------------------------
 
 
 //---------------------------------------------------------------------------


@@ -87,7 +91,7 @@ wxGIFDecoder::~wxGIFDecoder()
 void wxGIFDecoder::Destroy()
 {
     wxASSERT(m_nFrames==m_frames.GetCount());
 void wxGIFDecoder::Destroy()
 {
     wxASSERT(m_nFrames==m_frames.GetCount());

-    for (size_t i=0; i<m_nFrames; i++)
+    for (unsigned int i=0; i<m_nFrames; i++)

     {
         GIFImage *f = (GIFImage*)m_frames[i];
         free(f->p);
     {
         GIFImage *f = (GIFImage*)m_frames[i];
         free(f->p);


@@ -106,18 +110,19 @@ void wxGIFDecoder::Destroy()
 
 // This function was designed by Vaclav Slavik
 
 
 // This function was designed by Vaclav Slavik
 

-bool wxGIFDecoder::ConvertToImage(size_t frame, wxImage *image) const
+bool wxGIFDecoder::ConvertToImage(unsigned int frame, wxImage *image) const

 {
     unsigned char *src, *dst, *pal;
     unsigned long i;
     int      transparent;
 
 {
     unsigned char *src, *dst, *pal;
     unsigned long i;
     int      transparent;
 

-    /* just in case... */
+    // just in case...

     image->Destroy();
 
     image->Destroy();
 

-    /* create the image */
+    // create the image

     wxSize sz = GetFrameSize(frame);
     image->Create(sz.GetWidth(), sz.GetHeight());
     wxSize sz = GetFrameSize(frame);
     image->Create(sz.GetWidth(), sz.GetHeight());

+    image->SetType(wxBITMAP_TYPE_GIF);

 
     if (!image->Ok())
         return false;
 
     if (!image->Ok())
         return false;


@@ -127,7 +132,7 @@ bool wxGIFDecoder::ConvertToImage(size_t frame, wxImage *image) const
     dst = image->GetData();
     transparent = GetTransparentColourIndex(frame);
 
     dst = image->GetData();
     transparent = GetTransparentColourIndex(frame);
 

-    /* set transparent colour mask */
+    // set transparent colour mask

     if (transparent != -1)
     {
         for (i = 0; i < GetNcolours(frame); i++)
     if (transparent != -1)
     {
         for (i = 0; i < GetNcolours(frame); i++)


@@ -164,7 +169,7 @@ bool wxGIFDecoder::ConvertToImage(size_t frame, wxImage *image) const
     image->SetPalette(wxPalette(GetNcolours(frame), r, g, b));
 #endif // wxUSE_PALETTE
 
     image->SetPalette(wxPalette(GetNcolours(frame), r, g, b));
 #endif // wxUSE_PALETTE
 

-    /* copy image data */
+    // copy image data

     unsigned long npixel = sz.GetWidth() * sz.GetHeight();
     for (i = 0; i < npixel; i++, src++)
     {
     unsigned long npixel = sz.GetWidth() * sz.GetHeight();
     for (i = 0; i < npixel; i++, src++)
     {


@@ -186,27 +191,27 @@ bool wxGIFDecoder::ConvertToImage(size_t frame, wxImage *image) const
 
 // Get data for current frame
 
 
 // Get data for current frame
 

-wxSize wxGIFDecoder::GetFrameSize(size_t frame) const 
+wxSize wxGIFDecoder::GetFrameSize(unsigned int frame) const

 {
     return wxSize(GetFrame(frame)->w, GetFrame(frame)->h);
 }
 
 {
     return wxSize(GetFrame(frame)->w, GetFrame(frame)->h);
 }
 

-wxPoint wxGIFDecoder::GetFramePosition(size_t frame) const
+wxPoint wxGIFDecoder::GetFramePosition(unsigned int frame) const

 {
     return wxPoint(GetFrame(frame)->left, GetFrame(frame)->top);
 }
 
 {
     return wxPoint(GetFrame(frame)->left, GetFrame(frame)->top);
 }
 

-wxAnimationDisposal wxGIFDecoder::GetDisposalMethod(size_t frame) const
+wxAnimationDisposal wxGIFDecoder::GetDisposalMethod(unsigned int frame) const

 {
     return GetFrame(frame)->disposal;
 }
 
 {
     return GetFrame(frame)->disposal;
 }
 

-long wxGIFDecoder::GetDelay(size_t frame) const
+long wxGIFDecoder::GetDelay(unsigned int frame) const

 {
     return GetFrame(frame)->delay;
 }
 
 {
     return GetFrame(frame)->delay;
 }
 

-wxColour wxGIFDecoder::GetTransparentColour(size_t frame) const
+wxColour wxGIFDecoder::GetTransparentColour(unsigned int frame) const

 {
     unsigned char *pal = GetFrame(frame)->pal;
     int n = GetFrame(frame)->transparent;
 {
     unsigned char *pal = GetFrame(frame)->pal;
     int n = GetFrame(frame)->transparent;


@@ -218,10 +223,10 @@ wxColour wxGIFDecoder::GetTransparentColour(size_t frame) const
                     pal[n*3 + 2]);
 }
 
                     pal[n*3 + 2]);
 }
 

-unsigned char* wxGIFDecoder::GetData(size_t frame) const    { return (GetFrame(frame)->p); }
-unsigned char* wxGIFDecoder::GetPalette(size_t frame) const { return (GetFrame(frame)->pal); }
-unsigned int wxGIFDecoder::GetNcolours(size_t frame) const  { return (GetFrame(frame)->ncolours); }
-int wxGIFDecoder::GetTransparentColourIndex(size_t frame) const  { return (GetFrame(frame)->transparent); }
+unsigned char* wxGIFDecoder::GetData(unsigned int frame) const    { return (GetFrame(frame)->p); }
+unsigned char* wxGIFDecoder::GetPalette(unsigned int frame) const { return (GetFrame(frame)->pal); }
+unsigned int wxGIFDecoder::GetNcolours(unsigned int frame) const  { return (GetFrame(frame)->ncolours); }
+int wxGIFDecoder::GetTransparentColourIndex(unsigned int frame) const  { return (GetFrame(frame)->transparent); }

 
 
 
 
 
 


@@ -234,17 +239,17 @@ int wxGIFDecoder::GetTransparentColourIndex(size_t frame) const  { return (GetFr
 //
 int wxGIFDecoder::getcode(wxInputStream& stream, int bits, int ab_fin)
 {
 //
 int wxGIFDecoder::getcode(wxInputStream& stream, int bits, int ab_fin)
 {

-    unsigned int mask;          /* bit mask */
-    unsigned int code;          /* code (result) */
+    unsigned int mask;          // bit mask
+    unsigned int code;          // code (result)

 
 

-    /* get remaining bits from last byte read */
+    // get remaining bits from last byte read

     mask = (1 << bits) - 1;
     code = (m_lastbyte >> (8 - m_restbits)) & mask;
 
     mask = (1 << bits) - 1;
     code = (m_lastbyte >> (8 - m_restbits)) & mask;
 

-    /* keep reading new bytes while needed */
+    // keep reading new bytes while needed

     while (bits > m_restbits)
     {
     while (bits > m_restbits)
     {

-        /* if no bytes left in this block, read the next block */
+        // if no bytes left in this block, read the next block

         if (m_restbyte == 0)
         {
             m_restbyte = (unsigned char)stream.GetC();
         if (m_restbyte == 0)
         {
             m_restbyte = (unsigned char)stream.GetC();


@@ -260,7 +265,7 @@ int wxGIFDecoder::getcode(wxInputStream& stream, int bits, int ab_fin)
                 break;
             }
 
                 break;
             }
 

-            /* prefetch data */
+            // prefetch data

             stream.Read((void *) m_buffer, m_restbyte);
             if (stream.LastRead() != m_restbyte)
             {
             stream.Read((void *) m_buffer, m_restbyte);
             if (stream.LastRead() != m_restbyte)
             {


@@ -270,17 +275,17 @@ int wxGIFDecoder::getcode(wxInputStream& stream, int bits, int ab_fin)
             m_bufp = m_buffer;
         }
 
             m_bufp = m_buffer;
         }
 

-        /* read next byte and isolate the bits we need */
+        // read next byte and isolate the bits we need

         m_lastbyte = (unsigned char) (*m_bufp++);
         mask       = (1 << (bits - m_restbits)) - 1;
         code       = code + ((m_lastbyte & mask) << m_restbits);
         m_restbyte--;
 
         m_lastbyte = (unsigned char) (*m_bufp++);
         mask       = (1 << (bits - m_restbits)) - 1;
         code       = code + ((m_lastbyte & mask) << m_restbits);
         m_restbyte--;
 

-        /* adjust total number of bits extracted from the buffer */
+        // adjust total number of bits extracted from the buffer

         m_restbits = m_restbits + 8;
     }
 
         m_restbits = m_restbits + 8;
     }
 

-    /* find number of bits remaining for next code */
+    // find number of bits remaining for next code

     m_restbits = (m_restbits - bits);
 
     return code;
     m_restbits = (m_restbits - bits);
 
     return code;


@@ -292,23 +297,24 @@ int wxGIFDecoder::getcode(wxInputStream& stream, int bits, int ab_fin)
 //  is 'bits'. Supports interlaced images (interl == 1).
 //  Returns wxGIF_OK (== 0) on success, or an error code if something
 // fails (see header file for details)
 //  is 'bits'. Supports interlaced images (interl == 1).
 //  Returns wxGIF_OK (== 0) on success, or an error code if something
 // fails (see header file for details)

-wxGIFErrorCode wxGIFDecoder::dgif(wxInputStream& stream, GIFImage *img, int interl, int bits)
+wxGIFErrorCode
+wxGIFDecoder::dgif(wxInputStream& stream, GIFImage *img, int interl, int bits)

 {
     static const int allocSize = 4096 + 1;
 {
     static const int allocSize = 4096 + 1;

-    int *ab_prefix = new int[allocSize]; /* alphabet (prefixes) */
+    int *ab_prefix = new int[allocSize]; // alphabet (prefixes)

     if (ab_prefix == NULL)
     {
         return wxGIF_MEMERR;
     }
 
     if (ab_prefix == NULL)
     {
         return wxGIF_MEMERR;
     }
 

-    int *ab_tail = new int[allocSize];   /* alphabet (tails) */
+    int *ab_tail = new int[allocSize];   // alphabet (tails)

     if (ab_tail == NULL)
     {
         delete[] ab_prefix;
         return wxGIF_MEMERR;
     }
 
     if (ab_tail == NULL)
     {
         delete[] ab_prefix;
         return wxGIF_MEMERR;
     }
 

-    int *stack = new int[allocSize];     /* decompression stack */
+    int *stack = new int[allocSize];     // decompression stack

     if (stack == NULL)
     {
         delete[] ab_prefix;
     if (stack == NULL)
     {
         delete[] ab_prefix;


@@ -316,22 +322,22 @@ wxGIFErrorCode wxGIFDecoder::dgif(wxInputStream& stream, GIFImage *img, int inte
         return wxGIF_MEMERR;
     }
 
         return wxGIF_MEMERR;
     }
 

-    int ab_clr;                     /* clear code */
-    int ab_fin;                     /* end of info code */
-    int ab_bits;                    /* actual symbol width, in bits */
-    int ab_free;                    /* first free position in alphabet */
-    int ab_max;                     /* last possible character in alphabet */
-    int pass;                       /* pass number in interlaced images */
-    int pos;                        /* index into decompresion stack */
-    unsigned int x, y;              /* position in image buffer */
+    int ab_clr;                     // clear code
+    int ab_fin;                     // end of info code
+    int ab_bits;                    // actual symbol width, in bits
+    int ab_free;                    // first free position in alphabet
+    int ab_max;                     // last possible character in alphabet
+    int pass;                       // pass number in interlaced images
+    int pos;                        // index into decompresion stack
+    unsigned int x, y;              // position in image buffer

 
     int code, readcode, lastcode, abcabca;
 
 
     int code, readcode, lastcode, abcabca;
 

-    /* these won't change */
+    // these won't change

     ab_clr = (1 << bits);
     ab_fin = (1 << bits) + 1;
 
     ab_clr = (1 << bits);
     ab_fin = (1 << bits) + 1;
 

-    /* these will change through the decompression proccess */
+    // these will change through the decompression proccess

     ab_bits  = bits + 1;
     ab_free  = (1 << bits) + 2;
     ab_max   = (1 << ab_bits) - 1;
     ab_bits  = bits + 1;
     ab_free  = (1 << bits) + 2;
     ab_max   = (1 << ab_bits) - 1;


@@ -340,41 +346,41 @@ wxGIFErrorCode wxGIFDecoder::dgif(wxInputStream& stream, GIFImage *img, int inte
     pass     = 1;
     pos = x = y = 0;
 
     pass     = 1;
     pos = x = y = 0;
 

-    /* reset decoder vars */
+    // reset decoder vars

     m_restbits = 0;
     m_restbyte = 0;
     m_lastbyte = 0;
 
     do
     {
     m_restbits = 0;
     m_restbyte = 0;
     m_lastbyte = 0;
 
     do
     {

-        /* get next code */
+        // get next code

         readcode = code = getcode(stream, ab_bits, ab_fin);
 
         readcode = code = getcode(stream, ab_bits, ab_fin);
 

-        /* end of image? */
+        // end of image?

         if (code == ab_fin) break;
 
         if (code == ab_fin) break;
 

-        /* reset alphabet? */
+        // reset alphabet?

         if (code == ab_clr)
         {
         if (code == ab_clr)
         {

-            /* reset main variables */
+            // reset main variables

             ab_bits  = bits + 1;
             ab_free  = (1 << bits) + 2;
             ab_max   = (1 << ab_bits) - 1;
             lastcode = -1;
             abcabca  = -1;
 
             ab_bits  = bits + 1;
             ab_free  = (1 << bits) + 2;
             ab_max   = (1 << ab_bits) - 1;
             lastcode = -1;
             abcabca  = -1;
 

-            /* skip to next code */
+            // skip to next code

             continue;
         }
 
             continue;
         }
 

-        /* unknown code: special case (like in ABCABCA) */
+        // unknown code: special case (like in ABCABCA)

         if (code >= ab_free)
         {
         if (code >= ab_free)
         {

-            code = lastcode;            /* take last string */
-            stack[pos++] = abcabca;     /* add first character */
+            code = lastcode;            // take last string
+            stack[pos++] = abcabca;     // add first character

         }
 
         }
 

-        /* build the string for this code in the stack */
+        // build the string for this code in the stack

         while (code > ab_clr)
         {
             stack[pos++] = ab_tail[code];
         while (code > ab_clr)
         {
             stack[pos++] = ab_tail[code];


@@ -400,10 +406,10 @@ wxGIFErrorCode wxGIFDecoder::dgif(wxInputStream& stream, GIFImage *img, int inte
             return wxGIF_INVFORMAT;
         }
 
             return wxGIF_INVFORMAT;
         }
 

-        stack[pos] = code;              /* push last code into the stack */
-        abcabca    = code;              /* save for special case */
+        stack[pos] = code;              // push last code into the stack
+        abcabca    = code;              // save for special case

 
 

-        /* make new entry in alphabet (only if NOT just cleared) */
+        // make new entry in alphabet (only if NOT just cleared)

         if (lastcode != -1)
         {
             // Normally, after the alphabet is full and can't grow any
         if (lastcode != -1)
         {
             // Normally, after the alphabet is full and can't grow any


@@ -436,7 +442,7 @@ wxGIFErrorCode wxGIFDecoder::dgif(wxInputStream& stream, GIFImage *img, int inte
             }
         }
 
             }
         }
 

-        /* dump stack data to the image buffer */
+        // dump stack data to the image buffer

         while (pos >= 0)
         {
             (img->p)[x + (y * (img->w))] = (char) stack[pos];
         while (pos >= 0)
         {
             (img->p)[x + (y * (img->w))] = (char) stack[pos];


@@ -448,7 +454,7 @@ wxGIFErrorCode wxGIFDecoder::dgif(wxInputStream& stream, GIFImage *img, int inte
 
                 if (interl)
                 {
 
                 if (interl)
                 {

-                    /* support for interlaced images */
+                    // support for interlaced images

                     switch (pass)
                     {
                         case 1: y += 8; break;
                     switch (pass)
                     {
                         case 1: y += 8; break;


@@ -505,7 +511,7 @@ wxGIFErrorCode wxGIFDecoder::dgif(wxInputStream& stream, GIFImage *img, int inte
                 }
                 else
                 {
                 }
                 else
                 {

-                    /* non-interlaced */
+                    // non-interlaced

                     y++;
 /*
 Normally image decoding is finished when an End of Information code is
                     y++;
 /*
 Normally image decoding is finished when an End of Information code is


@@ -592,7 +598,7 @@ bool wxGIFDecoder::CanRead(wxInputStream &stream) const
 wxGIFErrorCode wxGIFDecoder::LoadGIF(wxInputStream& stream)
 {
     unsigned int  global_ncolors = 0;
 wxGIFErrorCode wxGIFDecoder::LoadGIF(wxInputStream& stream)
 {
     unsigned int  global_ncolors = 0;

-    int           bits, interl, transparent, i;
+    int           bits, interl, i;

     wxAnimationDisposal disposal;
     long          size;
     long          delay;
     wxAnimationDisposal disposal;
     long          size;
     long          delay;


@@ -601,13 +607,13 @@ wxGIFErrorCode wxGIFDecoder::LoadGIF(wxInputStream& stream)
     unsigned char buf[16];
     bool anim = true;
 
     unsigned char buf[16];
     bool anim = true;
 

-    /* check GIF signature */
+    // check GIF signature

     if (!CanRead(stream))
         return wxGIF_INVFORMAT;
 
     if (!CanRead(stream))
         return wxGIF_INVFORMAT;
 

-    /* check for animated GIF support (ver. >= 89a) */
+    // check for animated GIF support (ver. >= 89a)

 
 

-    static const size_t headerSize = (3 + 3);
+    static const unsigned int headerSize = (3 + 3);

     stream.Read(buf, headerSize);
     if (stream.LastRead() != headerSize)
     {
     stream.Read(buf, headerSize);
     if (stream.LastRead() != headerSize)
     {


@@ -619,8 +625,8 @@ wxGIFErrorCode wxGIFDecoder::LoadGIF(wxInputStream& stream)
         anim = false;
     }
 
         anim = false;
     }
 

-    /* read logical screen descriptor block (LSDB) */
-    static const size_t lsdbSize = (2 + 2 + 1 + 1 + 1);
+    // read logical screen descriptor block (LSDB)
+    static const unsigned int lsdbSize = (2 + 2 + 1 + 1 + 1);

     stream.Read(buf, lsdbSize);
     if (stream.LastRead() != lsdbSize)
     {
     stream.Read(buf, lsdbSize);
     if (stream.LastRead() != lsdbSize)
     {


@@ -635,13 +641,13 @@ wxGIFErrorCode wxGIFDecoder::LoadGIF(wxInputStream& stream)
         return wxGIF_INVFORMAT;
     }
 
         return wxGIF_INVFORMAT;
     }
 

-    /* load global color map if available */
+    // load global color map if available

     if ((buf[4] & 0x80) == 0x80)
     {
         int backgroundColIndex = buf[5];
 
         global_ncolors = 2 << (buf[4] & 0x07);
     if ((buf[4] & 0x80) == 0x80)
     {
         int backgroundColIndex = buf[5];
 
         global_ncolors = 2 << (buf[4] & 0x07);

-        size_t numBytes = 3 * global_ncolors;
+        unsigned int numBytes = 3 * global_ncolors;

         stream.Read(pal, numBytes);
         if (stream.LastRead() != numBytes)
         {
         stream.Read(pal, numBytes);
         if (stream.LastRead() != numBytes)
         {


@@ -653,8 +659,8 @@ wxGIFErrorCode wxGIFDecoder::LoadGIF(wxInputStream& stream)
                          pal[backgroundColIndex*3 + 2]);
     }
 
                          pal[backgroundColIndex*3 + 2]);
     }
 

-    /* transparent colour, disposal method and delay default to unused */
-    transparent = -1;
+    // transparent colour, disposal method and delay default to unused
+    int transparent = -1;

     disposal = wxANIM_UNSPECIFIED;
     delay = -1;
 
     disposal = wxANIM_UNSPECIFIED;
     delay = -1;
 


@@ -680,19 +686,19 @@ wxGIFErrorCode wxGIFDecoder::LoadGIF(wxInputStream& stream)
             break; // Alternative : "return wxGIF_INVFORMAT;"
         }
 
             break; // Alternative : "return wxGIF_INVFORMAT;"
         }
 

-        /* end of data? */
+        // end of data?

         if (type == 0x3B)
         {
             done = true;
         }
         else
         if (type == 0x3B)
         {
             done = true;
         }
         else

-        /* extension block? */
+        // extension block?

         if (type == 0x21)
         {
             if (((unsigned char)stream.GetC()) == 0xF9)
         if (type == 0x21)
         {
             if (((unsigned char)stream.GetC()) == 0xF9)

-            /* graphics control extension, parse it */
+            // graphics control extension, parse it

             {
             {

-                static const size_t gceSize = 6;
+                static const unsigned int gceSize = 6;

                 stream.Read(buf, gceSize);
                 if (stream.LastRead() != gceSize)
                 {
                 stream.Read(buf, gceSize);
                 if (stream.LastRead() != gceSize)
                 {


@@ -700,18 +706,17 @@ wxGIFErrorCode wxGIFDecoder::LoadGIF(wxInputStream& stream)
                     return wxGIF_INVFORMAT;
                 }
 
                     return wxGIF_INVFORMAT;
                 }
 

-                /* read delay and convert from 1/100 of a second to ms */
+                // read delay and convert from 1/100 of a second to ms

                 delay = 10 * (buf[2] + 256 * buf[3]);
 
                 delay = 10 * (buf[2] + 256 * buf[3]);
 

-                /* read transparent colour index, if used */
-                if (buf[1] & 0x01)
-                    transparent = buf[4];
+                // read transparent colour index, if used
+                transparent = buf[1] & 0x01 ? buf[4] : -1;

 
 

-                /* read disposal method */
+                // read disposal method

                 disposal = (wxAnimationDisposal)(((buf[1] & 0x1C) >> 2) - 1);
             }
             else
                 disposal = (wxAnimationDisposal)(((buf[1] & 0x1C) >> 2) - 1);
             }
             else

-            /* other extension, skip */
+            // other extension, skip

             {
                 while ((i = (unsigned char)stream.GetC()) != 0)
                 {
             {
                 while ((i = (unsigned char)stream.GetC()) != 0)
                 {


@@ -725,26 +730,22 @@ wxGIFErrorCode wxGIFDecoder::LoadGIF(wxInputStream& stream)
             }
         }
         else
             }
         }
         else

-        /* image descriptor block? */
+        // image descriptor block?

         if (type == 0x2C)
         {
         if (type == 0x2C)
         {

-            /* allocate memory for IMAGEN struct */
-            GIFImage *pimg = new GIFImage();
+            // allocate memory for IMAGEN struct
+            GIFImagePtr pimg(new GIFImage());

 
 

-            if (pimg == NULL)
-            {
-                Destroy();
+            wxScopeGuard guardDestroy = wxMakeObjGuard(*this, &wxGIFDecoder::Destroy);
+
+            if ( !pimg.get() )

                 return wxGIF_MEMERR;
                 return wxGIF_MEMERR;

-            }

 
 

-            /* fill in the data */
-            static const size_t idbSize = (2 + 2 + 2 + 2 + 1);
+            // fill in the data
+            static const unsigned int idbSize = (2 + 2 + 2 + 2 + 1);

             stream.Read(buf, idbSize);
             if (stream.LastRead() != idbSize)
             stream.Read(buf, idbSize);
             if (stream.LastRead() != idbSize)

-            {
-                Destroy();

                 return wxGIF_INVFORMAT;
                 return wxGIF_INVFORMAT;

-            }

 
             pimg->left = buf[0] + 256 * buf[1];
             pimg->top = buf[2] + 256 * buf[3];
 
             pimg->left = buf[0] + 256 * buf[1];
             pimg->top = buf[2] + 256 * buf[3];


@@ -755,12 +756,9 @@ wxGIFErrorCode wxGIFDecoder::LoadGIF(wxInputStream& stream)
             pimg->w = buf[4] + 256 * buf[5];
             pimg->h = buf[6] + 256 * buf[7];
 
             pimg->w = buf[4] + 256 * buf[5];
             pimg->h = buf[6] + 256 * buf[7];
 

-            if (anim && ((pimg->w == 0) || (pimg->w > (unsigned int)m_szAnimation.GetWidth()) || 
-                        (pimg->h == 0) || (pimg->h > (unsigned int)m_szAnimation.GetHeight())))
-            {
-                Destroy();
+            if ( anim && ((pimg->w == 0) || (pimg->w > (unsigned int)m_szAnimation.GetWidth()) ||
+                  (pimg->h == 0) || (pimg->h > (unsigned int)m_szAnimation.GetHeight())) )

                 return wxGIF_INVFORMAT;
                 return wxGIF_INVFORMAT;

-            }

 
             interl = ((buf[8] & 0x40)? 1 : 0);
             size = pimg->w * pimg->h;
 
             interl = ((buf[8] & 0x40)? 1 : 0);
             size = pimg->w * pimg->h;


@@ -769,28 +767,22 @@ wxGIFErrorCode wxGIFDecoder::LoadGIF(wxInputStream& stream)
             pimg->disposal = disposal;
             pimg->delay = delay;
 
             pimg->disposal = disposal;
             pimg->delay = delay;
 

-            /* allocate memory for image and palette */
-            pimg->p   = (unsigned char *) malloc((size_t)size);
+            // allocate memory for image and palette
+            pimg->p   = (unsigned char *) malloc((unsigned int)size);

             pimg->pal = (unsigned char *) malloc(768);
 
             if ((!pimg->p) || (!pimg->pal))
             pimg->pal = (unsigned char *) malloc(768);
 
             if ((!pimg->p) || (!pimg->pal))

-            {
-                Destroy();

                 return wxGIF_MEMERR;
                 return wxGIF_MEMERR;

-            }

 
 

-            /* load local color map if available, else use global map */
+            // load local color map if available, else use global map

             if ((buf[8] & 0x80) == 0x80)
             {
                 unsigned int local_ncolors = 2 << (buf[8] & 0x07);
             if ((buf[8] & 0x80) == 0x80)
             {
                 unsigned int local_ncolors = 2 << (buf[8] & 0x07);

-                size_t numBytes = 3 * local_ncolors;
+                unsigned int numBytes = 3 * local_ncolors;

                 stream.Read(pimg->pal, numBytes);
                 pimg->ncolours = local_ncolors;
                 if (stream.LastRead() != numBytes)
                 stream.Read(pimg->pal, numBytes);
                 pimg->ncolours = local_ncolors;
                 if (stream.LastRead() != numBytes)

-                {
-                    Destroy();

                     return wxGIF_INVFORMAT;
                     return wxGIF_INVFORMAT;

-                }

             }
             else
             {
             }
             else
             {


@@ -798,27 +790,23 @@ wxGIFErrorCode wxGIFDecoder::LoadGIF(wxInputStream& stream)
                 pimg->ncolours = global_ncolors;
             }
 
                 pimg->ncolours = global_ncolors;
             }
 

-            /* get initial code size from first byte in raster data */
+            // get initial code size from first byte in raster data

             bits = (unsigned char)stream.GetC();
             if (bits == 0)
             bits = (unsigned char)stream.GetC();
             if (bits == 0)

-            {
-                Destroy();

                 return wxGIF_INVFORMAT;
                 return wxGIF_INVFORMAT;

-            }

 
 

-            /* decode image */
-            wxGIFErrorCode result = dgif(stream, pimg, interl, bits);
+            // decode image
+            wxGIFErrorCode result = dgif(stream, pimg.get(), interl, bits);

             if (result != wxGIF_OK)
             if (result != wxGIF_OK)

-            {
-                Destroy();

                 return result;
                 return result;

-            }

 
 

-            /* add the image to our frame array */
-            m_frames.Add((void*)pimg);
+            guardDestroy.Dismiss();
+
+            // add the image to our frame array
+            m_frames.Add(pimg.release());

             m_nFrames++;
 
             m_nFrames++;
 

-            /* if this is not an animated GIF, exit after first image */
+            // if this is not an animated GIF, exit after first image

             if (!anim)
                 done = true;
         }
             if (!anim)
                 done = true;
         }


@@ -830,7 +818,7 @@ wxGIFErrorCode wxGIFDecoder::LoadGIF(wxInputStream& stream)
         return wxGIF_INVFORMAT;
     }
 
         return wxGIF_INVFORMAT;
     }
 

-    /* try to read to the end of the stream */
+    // try to read to the end of the stream

     while (type != 0x3B)
     {
         if (!stream.IsOk())
     while (type != 0x3B)
     {
         if (!stream.IsOk())


@@ -840,10 +828,10 @@ wxGIFErrorCode wxGIFDecoder::LoadGIF(wxInputStream& stream)
 
         if (type == 0x21)
         {
 
         if (type == 0x21)
         {

-            /* extension type */
+            // extension type

             (void) stream.GetC();
 
             (void) stream.GetC();
 

-            /* skip all data */
+            // skip all data

             while ((i = (unsigned char)stream.GetC()) != 0)
             {
                 if (stream.Eof() || (stream.LastRead() == 0))
             while ((i = (unsigned char)stream.GetC()) != 0)
             {
                 if (stream.Eof() || (stream.LastRead() == 0))


@@ -856,8 +844,8 @@ wxGIFErrorCode wxGIFDecoder::LoadGIF(wxInputStream& stream)
         }
         else if (type == 0x2C)
         {
         }
         else if (type == 0x2C)
         {

-            /* image descriptor block */
-            static const size_t idbSize = (2 + 2 + 2 + 2 + 1);
+            // image descriptor block
+            static const unsigned int idbSize = (2 + 2 + 2 + 2 + 1);

             stream.Read(buf, idbSize);
             if (stream.LastRead() != idbSize)
             {
             stream.Read(buf, idbSize);
             if (stream.LastRead() != idbSize)
             {


@@ -865,7 +853,7 @@ wxGIFErrorCode wxGIFDecoder::LoadGIF(wxInputStream& stream)
                 return wxGIF_INVFORMAT;
             }
 
                 return wxGIF_INVFORMAT;
             }
 

-            /* local color map */
+            // local color map

             if ((buf[8] & 0x80) == 0x80)
             {
                 unsigned int local_ncolors = 2 << (buf[8] & 0x07);
             if ((buf[8] & 0x80) == 0x80)
             {
                 unsigned int local_ncolors = 2 << (buf[8] & 0x07);


@@ -873,7 +861,7 @@ wxGIFErrorCode wxGIFDecoder::LoadGIF(wxInputStream& stream)
                 stream.SeekI(numBytes, wxFromCurrent);
             }
 
                 stream.SeekI(numBytes, wxFromCurrent);
             }
 

-            /* initial code size */
+            // initial code size

             (void) stream.GetC();
             if (stream.Eof() || (stream.LastRead() == 0))
             {
             (void) stream.GetC();
             if (stream.Eof() || (stream.LastRead() == 0))
             {


@@ -881,7 +869,7 @@ wxGIFErrorCode wxGIFDecoder::LoadGIF(wxInputStream& stream)
                 return wxGIF_INVFORMAT;
             }
 
                 return wxGIF_INVFORMAT;
             }
 

-            /* skip all data */
+            // skip all data

             while ((i = (unsigned char)stream.GetC()) != 0)
             {
                 if (stream.Eof() || (stream.LastRead() == 0))
             while ((i = (unsigned char)stream.GetC()) != 0)
             {
                 if (stream.Eof() || (stream.LastRead() == 0))


@@ -892,9 +880,9 @@ wxGIFErrorCode wxGIFDecoder::LoadGIF(wxInputStream& stream)
                 stream.SeekI(i, wxFromCurrent);
             }
         }
                 stream.SeekI(i, wxFromCurrent);
             }
         }

-        else if ((type != 0x3B) && (type != 00)) /* testing */
+        else if ((type != 0x3B) && (type != 00)) // testing

         {
         {

-            /* images are OK, but couldn't read to the end of the stream */
+            // images are OK, but couldn't read to the end of the stream

             return wxGIF_TRUNCATED;
         }
     }
             return wxGIF_TRUNCATED;
         }
     }