Changes for mingw32/gcc-2.95

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

diff --git a/src/common/imagpng.cpp b/src/common/imagpng.cpp
index 1a27982b129883f96f860bfce63de5d2fd12f2c0..1815bcb1bab4f3e866f83d110d9893dc2e9a92c6 100644 (file)
--- a/src/common/imagpng.cpp
+++ b/src/common/imagpng.cpp
@@ -57,7 +57,7 @@
 IMPLEMENT_DYNAMIC_CLASS(wxPNGHandler,wxImageHandler)
 #endif
 
-#if wxUSE_STREAMS
+#if wxUSE_LIBPNG
 
 #if defined(__VISAGECPP__)
 #define LINKAGEMODE _Optlink
@@ -78,7 +78,7 @@ static void LINKAGEMODE _PNG_stream_writer( png_structp png_ptr, png_bytep data,
 // 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))
+LINKAGEMODE png_silent_error(png_structp png_ptr, png_const_charp WXUNUSED(message))
 {
 #ifdef USE_FAR_KEYWORD
    {
@@ -92,7 +92,7 @@ png_silent_error(png_structp png_ptr, png_const_charp WXUNUSED(message))
 }
 
 void
-png_silent_warning(png_structp WXUNUSED(png_ptr), png_const_charp WXUNUSED(message))
+LINKAGEMODE png_silent_warning(png_structp WXUNUSED(png_ptr), png_const_charp WXUNUSED(message))
 {
 }
 
@@ -346,9 +346,15 @@ bool wxPNGHandler::SaveFile( wxImage *image, wxOutputStream& stream, bool verbos
     return TRUE;
 }
 
-#endif
-  // wxUSE_STREAMS
+bool wxPNGHandler::CanRead( wxInputStream& stream )
+{
+    unsigned char hdr[4];
 
-#endif
-  // wxUSE_LIBPNG
+    stream.Read(&hdr, 4);
+    stream.SeekI(-4, wxFromCurrent);
+    return (hdr[0] == 0x89 && hdr[1] == 'P' && hdr[2] == 'N' && hdr[3] == 'G');
+}
+
+#endif  // wxUSE_STREAMS
 
+#endif  // wxUSE_LIBPNG