Rewind the input stream after failing to load image from it.

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

diff --git a/src/common/imagpnm.cpp b/src/common/imagpnm.cpp
index 3646d49e8205beff3b0eb7bbabe1fe626e07fdab..731220450b67e54121d9216ecd872b9528666191 100644 (file)
--- a/src/common/imagpnm.cpp
+++ b/src/common/imagpnm.cpp
@@ -1,5 +1,5 @@
 /////////////////////////////////////////////////////////////////////////////
-// Name:        imagpnm.cpp
+// Name:        src/common/imagpnm.cpp
 // Purpose:     wxImage PNM handler
 // Author:      Sylvain Bougnoux
 // RCS-ID:      $Id$
@@ -7,26 +7,22 @@
 // Licence:     wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
 
-#ifdef __GNUG__
-#pragma implementation "imagpnm.h"
-#endif
-
 // For compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"
 
 #ifdef __BORLANDC__
-#pragma hdrstop
+    #pragma hdrstop
 #endif
 
+#if wxUSE_IMAGE && wxUSE_PNM
+
+#include "wx/imagpnm.h"
+
 #ifndef WX_PRECOMP
-#  include "wx/setup.h"
+    #include "wx/intl.h"
+    #include "wx/log.h"
 #endif
 
-#if wxUSE_PNM
-
-#include "wx/imagpnm.h"
-#include "wx/log.h"
-#include "wx/intl.h"
 #include "wx/txtstrm.h"
 
 //-----------------------------------------------------------------------------
@@ -39,12 +35,12 @@ IMPLEMENT_DYNAMIC_CLASS(wxPNMHandler,wxImageHandler)
 
 void Skip_Comment(wxInputStream &stream)
 {
-  wxTextInputStream text_stream(stream);
+    wxTextInputStream text_stream(stream);
 
-  if (stream.Peek()==wxT('#'))
+    if (stream.Peek()==wxT('#'))
     {
-      text_stream.ReadLine();
-      Skip_Comment(stream);
+        text_stream.ReadLine();
+        Skip_Comment(stream);
     }
 }
 
@@ -68,17 +64,16 @@ bool wxPNMHandler::LoadFile( wxImage *image, wxInputStream& stream, bool verbose
 
     switch (c)
     {
-        case wxT('2'):
-            if (verbose) wxLogError(_("Loading Grey Ascii PNM image is not yet implemented."));
-            return FALSE;
-        case wxT('5'):
-            if (verbose) wxLogError(_("Loading Grey Raw PNM image is not yet implemented."));
-            return FALSE;
-        case wxT('3'): 
-       case wxT('6'): break;
+        case wxT('2'): // ASCII Grey
+        case wxT('3'): // ASCII RGB
+        case wxT('5'): // RAW Grey
+        case wxT('6'): break;
         default:
-            if (verbose) wxLogError(_("PNM: File format is not recognized."));
-            return FALSE;
+            if (verbose)
+            {
+                wxLogError(_("PNM: File format is not recognized."));
+            }
+            return false;
     }
 
     text_stream.ReadLine(); // for the \n
@@ -93,33 +88,93 @@ bool wxPNMHandler::LoadFile( wxImage *image, wxInputStream& stream, bool verbose
     if (!ptr)
     {
         if (verbose)
+        {
            wxLogError( _("PNM: Couldn't allocate memory.") );
-        return FALSE;
+        }
+        return false;
     }
 
-   if (c=='3') // Ascii RBG
-      {
+
+    if (c=='2') // Ascii GREY
+    {
+        wxUint32 value, size=width*height;
+        for (wxUint32 i=0; i<size; ++i)
+        {
+            value=text_stream.Read32();
+            if ( maxval != 255 )
+                value = (255 * value)/maxval;
+            *ptr++=(unsigned char)value; // R
+            *ptr++=(unsigned char)value; // G
+            *ptr++=(unsigned char)value; // B
+            if ( !buf_stream )
+            {
+                if (verbose)
+                {
+                    wxLogError(_("PNM: File seems truncated."));
+                }
+                return false;
+            }
+        }
+    }
+    if (c=='3') // Ascii RBG
+    {
         wxUint32 value, size=3*width*height;
         for (wxUint32 i=0; i<size; ++i)
           {
             //this is very slow !!!
             //I wonder how we can make any better ?
             value=text_stream.Read32();
+            if ( maxval != 255 )
+                value = (255 * value)/maxval;
             *ptr++=(unsigned char)value;
 
-            if (buf_stream.LastError()!=wxSTREAM_NOERROR)
+            if ( !buf_stream )
               {
-                if (verbose) wxLogError(_("PNM: File seems truncated."));
-                return FALSE;
+                if (verbose)
+                {
+                    wxLogError(_("PNM: File seems truncated."));
+                }
+                return false;
               }
           }
-      }
-    if (c=='6') // Raw RGB
-      buf_stream.Read( ptr, 3*width*height );
+    }
+    if (c=='5') // Raw GREY
+    {
+        wxUint32 size=width*height;
+        unsigned char value;
+        for (wxUint32 i=0; i<size; ++i)
+        {
+            buf_stream.Read(&value,1);
+            if ( maxval != 255 )
+                value = (255 * value)/maxval;
+            *ptr++=value; // R
+            *ptr++=value; // G
+            *ptr++=value; // B
+            if ( !buf_stream )
+            {
+                if (verbose)
+                {
+                    wxLogError(_("PNM: File seems truncated."));
+                }
+                return false;
+            }
+        }
+    }
 
-    image->SetMask( FALSE );
+    if ( c=='6' ) // Raw RGB
+    {
+        buf_stream.Read(ptr, 3*width*height);
+        if ( maxval != 255 )
+        {
+            for ( unsigned i = 0; i < 3*width*height; i++ )
+                ptr[i] = (255 * ptr[i])/maxval;
+        }
+    }
+
+    image->SetMask( false );
 
-    return (buf_stream.LastError()==wxStream_NOERROR || buf_stream.LastError()==wxStream_EOF);
+    const wxStreamError err = buf_stream.GetLastError();
+    return err == wxSTREAM_NO_ERROR || err == wxSTREAM_EOF;
 }
 
 bool wxPNMHandler::SaveFile( wxImage *image, wxOutputStream& stream, bool WXUNUSED(verbose) )
@@ -129,34 +184,33 @@ bool wxPNMHandler::SaveFile( wxImage *image, wxOutputStream& stream, bool WXUNUS
     //text_stream << "P6" << endl
     //<< image->GetWidth() << " " << image->GetHeight() << endl
     //<< "255" << endl;
-    text_stream << "P6\n" << image->GetWidth() << " " << image->GetHeight() << "\n255\n";
+    text_stream << wxT("P6\n") << image->GetWidth() << wxT(" ") << image->GetHeight() << wxT("\n255\n");
     stream.Write(image->GetData(),3*image->GetWidth()*image->GetHeight());
 
-    return (stream.LastError()==wxStream_NOERROR);
+    return stream.IsOk();
 }
 
 bool wxPNMHandler::DoCanRead( wxInputStream& stream )
 {
-    off_t pos = stream.TellI();
-
     Skip_Comment(stream);
 
+    // it's ok to modify the stream position here
     if ( stream.GetC() == 'P' )
     {
-        switch (stream.GetC())
+        switch ( stream.GetC() )
         {
-            case '3':
-            case '6':
-                stream.SeekI(pos);
-                return TRUE;
+            case '2': // ASCII Grey
+            case '3': // ASCII RGB
+            case '5': // RAW Grey
+            case '6': // RAW RGB
+                return true;
         }
     }
 
-    stream.SeekI(pos);
-    return FALSE;
+    return false;
 }
 
 
 #endif // wxUSE_STREAMS
 
-#endif // wxUSE_PNM
+#endif // wxUSE_IMAGE && wxUSE_PNM