Replaced an old ifndef FWD_ONLY_CURSORS with the new wxODBC_FWD_ONLY_CURSORS setup...

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

diff --git a/src/common/imagpng.cpp b/src/common/imagpng.cpp
index 1b3a06663955197325bcd50795226113c0b2018f..132655980c64e0e38e6f08eedc30e726491fa890 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
@@ -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
+LINKAGEMODE 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
+LINKAGEMODE 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)
         {
@@ -298,15 +324,16 @@ bool wxPNGHandler::SaveFile( wxImage *image, wxOutputStream& stream )
                 data[(x << 2) + 0] = *ptr++;
                 data[(x << 2) + 1] = *ptr++;
                 data[(x << 2) + 2] = *ptr++;
-                if ((data[(x << 2) + 0] == image->GetMaskRed()) &&
-                    (data[(x << 2) + 1] == image->GetMaskGreen()) &&
-                    (data[(x << 2) + 2] == image->GetMaskBlue()))
+                if (( !image->HasMask() ) || \
+                    (data[(x << 2) + 0] != image->GetMaskRed()) || \
+                    (data[(x << 2) + 1] != image->GetMaskGreen()) || \
+                    (data[(x << 2) + 2] != image->GetMaskBlue()))
                 {
-                    data[(x << 2) + 3] = 0;
+                    data[(x << 2) + 3] = 255;
                 }
                 else
                 {
-                    data[(x << 2) + 3] = 255;
+                    data[(x << 2) + 3] = 0;
                 }
             }
             png_bytep row_ptr = data;
@@ -320,9 +347,15 @@ bool wxPNGHandler::SaveFile( wxImage *image, wxOutputStream& stream )
     return TRUE;
 }
 
-#endif
-  // wxUSE_STREAMS
+bool wxPNGHandler::DoCanRead( 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