CanRead() now restores the stream to its previous state (potential

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

diff --git a/src/common/imagpng.cpp b/src/common/imagpng.cpp
index 4e487a7778cb6ae4c30a9dc7df44078802d5d41e..7609aae068ee107642818e0f51ef706f37a9739d 100644 (file)
--- a/src/common/imagpng.cpp
+++ b/src/common/imagpng.cpp
@@ -10,27 +10,27 @@
 /*
    We don't put pragma implement in this file because it is already present in
    src/common/image.cpp
 /*
    We don't put pragma implement in this file because it is already present in
    src/common/image.cpp

-
-#ifdef __GNUG__
-#pragma implementation "image.h"
-#endif

 */
 
 // For compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"
 
 #ifdef __BORLANDC__
 */
 
 // For compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"
 
 #ifdef __BORLANDC__

-#pragma hdrstop
+  #pragma hdrstop

 #endif
 
 #endif
 

+#ifndef WX_PRECOMP
+  #include "wx/defs.h"
+#endif
+
+#if wxUSE_LIBPNG
+

 #include "wx/image.h"
 #include "wx/bitmap.h"
 #include "wx/debug.h"
 #include "wx/log.h"
 #include "wx/app.h"
 #include "wx/image.h"
 #include "wx/bitmap.h"
 #include "wx/debug.h"
 #include "wx/log.h"
 #include "wx/app.h"

-#if wxUSE_LIBPNG
-#include "../png/png.h"
-#endif
+#include "png.h"

 #include "wx/filefn.h"
 #include "wx/wfstream.h"
 #include "wx/intl.h"
 #include "wx/filefn.h"
 #include "wx/wfstream.h"
 #include "wx/intl.h"


@@ -53,78 +53,106 @@
 // wxPNGHandler
 //-----------------------------------------------------------------------------
 
 // wxPNGHandler
 //-----------------------------------------------------------------------------
 

-#if wxUSE_LIBPNG
-

 #if !USE_SHARED_LIBRARIES
 IMPLEMENT_DYNAMIC_CLASS(wxPNGHandler,wxImageHandler)
 #endif
 
 #if !USE_SHARED_LIBRARIES
 IMPLEMENT_DYNAMIC_CLASS(wxPNGHandler,wxImageHandler)
 #endif
 

-

 #if wxUSE_STREAMS
 #if wxUSE_STREAMS

-static void _PNG_stream_reader( png_structp png_ptr, png_bytep data, png_size_t length )
+
+#if defined(__VISAGECPP__)
+#define LINKAGEMODE _Optlink
+#else
+#define LINKAGEMODE
+#endif
+
+static void LINKAGEMODE _PNG_stream_reader( png_structp png_ptr, png_bytep data, png_size_t length )

 {
     ((wxInputStream*) png_get_io_ptr( png_ptr )) -> Read(data, length);
 }
 
 {
     ((wxInputStream*) png_get_io_ptr( png_ptr )) -> Read(data, length);
 }
 

-static void _PNG_stream_writer( png_structp png_ptr, png_bytep data, png_size_t length )
+static void LINKAGEMODE _PNG_stream_writer( png_structp png_ptr, png_bytep data, png_size_t length )

 {
     ((wxOutputStream*) png_get_io_ptr( png_ptr )) -> Write(data, length);
 }
 
 {
     ((wxOutputStream*) png_get_io_ptr( png_ptr )) -> Write(data, length);
 }
 

-bool wxPNGHandler::LoadFile( wxImage *image, wxInputStream& stream )
+// from pngerror.c
+// so that the libpng doesn't send anything on stderr
+void
+png_silent_error(png_structp png_ptr, png_const_charp WXUNUSED(message))
+{
+#ifdef USE_FAR_KEYWORD
+   {
+      jmp_buf jmpbuf;
+      png_memcpy(jmpbuf,png_ptr->jmpbuf,sizeof(jmp_buf));
+      longjmp(jmpbuf, 1);
+   }
+#else
+   longjmp(png_ptr->jmpbuf, 1);
+#endif
+}
+
+void
+png_silent_warning(png_structp WXUNUSED(png_ptr), png_const_charp WXUNUSED(message))
+{
+}
+
+bool wxPNGHandler::LoadFile( wxImage *image, wxInputStream& stream, bool verbose)

 {
     // VZ: as this function uses setjmp() the only fool proof error handling
     //     method is to use goto (setjmp is not really C++ dtors friendly...)
 {
     // VZ: as this function uses setjmp() the only fool proof error handling
     //     method is to use goto (setjmp is not really C++ dtors friendly...)

-    
-    unsigned char **lines = (unsigned char **) NULL;
+
+    unsigned char **lines;

     unsigned int i;
     png_infop info_ptr = (png_infop) NULL;
     unsigned int i;
     png_infop info_ptr = (png_infop) NULL;

-    
+

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

-    
+

     png_structp png_ptr = png_create_read_struct( PNG_LIBPNG_VER_STRING,
         (voidp) NULL,
         (png_error_ptr) NULL,
         (png_error_ptr) NULL );
     if (!png_ptr)
     png_structp png_ptr = png_create_read_struct( PNG_LIBPNG_VER_STRING,
         (voidp) NULL,
         (png_error_ptr) NULL,
         (png_error_ptr) NULL );
     if (!png_ptr)

-        goto error;
-    
+        goto error_nolines;
+
+    // the file example.c explain how to guess if the stream is a png image
+    if (!verbose) png_set_error_fn(png_ptr, (png_voidp)NULL, png_silent_error, png_silent_warning);
+

     info_ptr = png_create_info_struct( png_ptr );
     if (!info_ptr)
     info_ptr = png_create_info_struct( png_ptr );
     if (!info_ptr)

-        goto error;
-    
+        goto error_nolines;
+

     if (setjmp(png_ptr->jmpbuf))
     if (setjmp(png_ptr->jmpbuf))

-        goto error;
-    
+        goto error_nolines;
+

     if (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
     if (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)

-        goto error;
-    
+        goto error_nolines;
+

     png_set_read_fn( png_ptr, &stream, _PNG_stream_reader);
     png_set_read_fn( png_ptr, &stream, _PNG_stream_reader);

-    
+

     png_uint_32 width,height;
     int bit_depth,color_type,interlace_type;
     png_uint_32 width,height;
     int bit_depth,color_type,interlace_type;

-    
+

     png_read_info( png_ptr, info_ptr );
     png_get_IHDR( png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, &interlace_type, (int*) NULL, (int*) NULL );
     png_read_info( png_ptr, info_ptr );
     png_get_IHDR( png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, &interlace_type, (int*) NULL, (int*) NULL );

-    
+

     if (color_type == PNG_COLOR_TYPE_PALETTE)
         png_set_expand( png_ptr );
     if (color_type == PNG_COLOR_TYPE_PALETTE)
         png_set_expand( png_ptr );

-    
+

     png_set_strip_16( png_ptr );
     png_set_packing( png_ptr );
     if (png_get_valid( png_ptr, info_ptr, PNG_INFO_tRNS))
         png_set_expand( png_ptr );
     png_set_filler( png_ptr, 0xff, PNG_FILLER_AFTER );
     png_set_strip_16( png_ptr );
     png_set_packing( png_ptr );
     if (png_get_valid( png_ptr, info_ptr, PNG_INFO_tRNS))
         png_set_expand( png_ptr );
     png_set_filler( png_ptr, 0xff, PNG_FILLER_AFTER );

-    
+

     image->Create( width, height );
     image->Create( width, height );

-    
+

     if (!image->Ok())
     if (!image->Ok())

-        goto error;
-    
+        goto error_nolines;
+

     lines = (unsigned char **)malloc( height * sizeof(unsigned char *) );
     if (lines == NULL)
     lines = (unsigned char **)malloc( height * sizeof(unsigned char *) );
     if (lines == NULL)

-        goto error;
-    
+        goto error_nolines;
+

     for (i = 0; i < height; i++)
     {
         if ((lines[i] = (unsigned char *)malloc(width * (sizeof(unsigned char) * 4))) == NULL)
     for (i = 0; i < height; i++)
     {
         if ((lines[i] = (unsigned char *)malloc(width * (sizeof(unsigned char) * 4))) == NULL)


@@ -134,7 +162,7 @@ bool wxPNGHandler::LoadFile( wxImage *image, wxInputStream& stream )
             goto error;
         }
     }
             goto error;
         }
     }

-    
+

     // loaded successfully!
     {
         int transp = 0;
     // loaded successfully!
     {
         int transp = 0;


@@ -195,11 +223,11 @@ bool wxPNGHandler::LoadFile( wxImage *image, wxInputStream& stream )
                 }
             }
         }
                 }
             }
         }

-        
+

         for ( unsigned int j = 0; j < height; j++ )
             free( lines[j] );
         free( lines );
         for ( unsigned int j = 0; j < height; j++ )
             free( lines[j] );
         free( lines );

-        
+

         if (transp)
         {
             image->SetMaskColour( 255, 0, 255 );
         if (transp)
         {
             image->SetMaskColour( 255, 0, 255 );


@@ -209,22 +237,24 @@ bool wxPNGHandler::LoadFile( wxImage *image, wxInputStream& stream )
             image->SetMask( FALSE );
         }
     }
             image->SetMask( FALSE );
         }
     }

-    
+

     return TRUE;
     return TRUE;

-    
-error:
+
+ error_nolines:
+    lines = NULL; // called from before it was set
+ error:

     wxLogError(_("Couldn't load a PNG image - probably file is corrupted."));
     wxLogError(_("Couldn't load a PNG image - probably file is corrupted."));

-    
+

     if ( image->Ok() )
     {
         image->Destroy();
     }
     if ( image->Ok() )
     {
         image->Destroy();
     }

-    
+

     if ( lines )
     {
         free( lines );
     }
     if ( lines )
     {
         free( lines );
     }

-    
+

     if ( png_ptr )
     {
         if ( info_ptr )
     if ( png_ptr )
     {
         if ( info_ptr )


@@ -239,7 +269,7 @@ error:
 }
 
 
 }
 
 

-bool wxPNGHandler::SaveFile( wxImage *image, wxOutputStream& stream )
+bool wxPNGHandler::SaveFile( wxImage *image, wxOutputStream& stream, bool verbose )

 {
     {
         png_structp png_ptr = png_create_write_struct( PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
 {
     {
         png_structp png_ptr = png_create_write_struct( PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);


@@ -247,26 +277,28 @@ bool wxPNGHandler::SaveFile( wxImage *image, wxOutputStream& stream )
         {
             return FALSE;
         }
         {
             return FALSE;
         }

-        
+
+       if (!verbose) png_set_error_fn(png_ptr, (png_voidp)NULL, png_silent_error, png_silent_warning);
+

         png_infop info_ptr = png_create_info_struct(png_ptr);
         if (info_ptr == NULL)
         {
             png_destroy_write_struct( &png_ptr, (png_infopp)NULL );
             return FALSE;
         }
         png_infop info_ptr = png_create_info_struct(png_ptr);
         if (info_ptr == NULL)
         {
             png_destroy_write_struct( &png_ptr, (png_infopp)NULL );
             return FALSE;
         }

-        
+

         if (setjmp(png_ptr->jmpbuf))
         {
             png_destroy_write_struct( &png_ptr, (png_infopp)NULL );
             return FALSE;
         }
         if (setjmp(png_ptr->jmpbuf))
         {
             png_destroy_write_struct( &png_ptr, (png_infopp)NULL );
             return FALSE;
         }

-        
+

         png_set_write_fn( png_ptr, &stream, _PNG_stream_writer, NULL);
         png_set_write_fn( png_ptr, &stream, _PNG_stream_writer, NULL);

-        
+

         png_set_IHDR( png_ptr, info_ptr, image->GetWidth(), image->GetHeight(), 8,
             PNG_COLOR_TYPE_RGB_ALPHA, PNG_INTERLACE_NONE,
             PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
         png_set_IHDR( png_ptr, info_ptr, image->GetWidth(), image->GetHeight(), 8,
             PNG_COLOR_TYPE_RGB_ALPHA, PNG_INTERLACE_NONE,
             PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);

-        
+

         png_color_8 sig_bit;
         sig_bit.red = 8;
         sig_bit.green = 8;
         png_color_8 sig_bit;
         sig_bit.red = 8;
         sig_bit.green = 8;


@@ -276,14 +308,14 @@ bool wxPNGHandler::SaveFile( wxImage *image, wxOutputStream& stream )
         png_write_info( png_ptr, info_ptr );
         png_set_shift( png_ptr, &sig_bit );
         png_set_packing( png_ptr );
         png_write_info( png_ptr, info_ptr );
         png_set_shift( png_ptr, &sig_bit );
         png_set_packing( png_ptr );

-        
+

         unsigned char *data = (unsigned char *)malloc( image->GetWidth()*4 );
         if (!data)
         {
             png_destroy_write_struct( &png_ptr, (png_infopp)NULL );
             return FALSE;
         }
         unsigned char *data = (unsigned char *)malloc( image->GetWidth()*4 );
         if (!data)
         {
             png_destroy_write_struct( &png_ptr, (png_infopp)NULL );
             return FALSE;
         }

-        
+

         for (int y = 0; y < image->GetHeight(); y++)
         {
             unsigned char *ptr = image->GetData() + (y * image->GetWidth() * 3);
         for (int y = 0; y < image->GetHeight(); y++)
         {
             unsigned char *ptr = image->GetData() + (y * image->GetWidth() * 3);


@@ -306,16 +338,26 @@ bool wxPNGHandler::SaveFile( wxImage *image, wxOutputStream& stream )
             png_bytep row_ptr = data;
             png_write_rows( png_ptr, &row_ptr, 1 );
         }
             png_bytep row_ptr = data;
             png_write_rows( png_ptr, &row_ptr, 1 );
         }

-        
+

         free(data);
         png_write_end( png_ptr, info_ptr );
         png_destroy_write_struct( &png_ptr, (png_infopp)&info_ptr );
     }
     return TRUE;
 }
         free(data);
         png_write_end( png_ptr, info_ptr );
         png_destroy_write_struct( &png_ptr, (png_infopp)&info_ptr );
     }
     return TRUE;
 }

-#endif // wxUSE_STREAMS
+
+bool wxPNGHandler::CanRead( wxInputStream& stream )
+{
+    unsigned char hdr[4];
+    
+    stream.Read(&hdr, 4);    
+    stream.SeekI(-4, wxFromCurrent);
+    return (hdr[0] == 0x89 && hdr[1] == 'P' && hdr[2] == 'N' && hdr[3] == 'G');
+}

 
 #endif
 
 #endif

+  // wxUSE_STREAMS

 
 

-// wxUSE_LIBPNG
+#endif
+  // wxUSE_LIBPNG