X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/717b9bf234a20c491e0c9ee8f2c1bffad56a59c5..c60fc26d5522510e50de8b9b83cf586066781811:/src/common/imagpng.cpp

diff --git a/src/common/imagpng.cpp b/src/common/imagpng.cpp
index 1b3a066639..7609aae068 100644
--- a/src/common/imagpng.cpp
+++ b/src/common/imagpng.cpp
@@ -75,7 +75,28 @@ static void LINKAGEMODE _PNG_stream_writer( png_structp png_ptr, png_bytep data,
     ((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...)
@@ -93,6 +114,9 @@ bool wxPNGHandler::LoadFile( wxImage *image, wxInputStream& stream )
     if (!png_ptr)
         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)
         goto error_nolines;
@@ -245,7 +269,7 @@ bool wxPNGHandler::LoadFile( wxImage *image, wxInputStream& stream )
 }
 
 
-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);
@@ -254,6 +278,8 @@ bool wxPNGHandler::SaveFile( wxImage *image, wxOutputStream& stream )
             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)
         {
@@ -320,6 +346,15 @@ bool wxPNGHandler::SaveFile( wxImage *image, wxOutputStream& stream )
     return TRUE;
 }
 
+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
   // wxUSE_STREAMS