loop in wxInputStream::Read() while there is data to read

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

diff --git a/src/common/imagiff.cpp b/src/common/imagiff.cpp
index bd6fb87cfe957cf6916eeb309d74bc449e4c53b7..e852c4f645c3f1788995a6c3d9cd428fab297f4b 100644 (file)
--- a/src/common/imagiff.cpp
+++ b/src/common/imagiff.cpp
@@ -1,14 +1,16 @@
 /////////////////////////////////////////////////////////////////////////////
 // Name:        imagiff.h
 // Purpose:     wxImage handler for Amiga IFF images
-// Author:      Steffen Gutmann
+// Author:      Steffen Gutmann, Thomas Meyer
 // RCS-ID:      $Id$
 // Copyright:   (c) Steffen Gutmann, 2002
 // Licence:     wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
 
-//        parts of the source are based on xviff by Thomas Meyer
-//        Permission for use in wxWindows has been gratefully given.
+// Parts of this source are based on the iff loading algorithm found
+// in xviff.c.  Permission by the original author, Thomas Meyer, and
+// by the author of xv, John Bradley for using the iff loading part
+// in wxWindows has been gratefully given.
 
 #ifdef __GNUG__
 #pragma implementation "imagiff.h"
@@ -79,8 +81,8 @@ class WXDLLEXPORT wxIFFDecoder
 private:
     IFFImage *m_image;         // image data
     wxInputStream *m_f;        // input stream
-    unsigned char *databuf; 
-    unsigned char *picptr; 
+    unsigned char *databuf;
+    unsigned char *picptr;
     unsigned char *decomp_mem;
 
     void Destroy();
@@ -228,12 +230,14 @@ int wxIFFDecoder::GetTransparentColour() const { return m_image->transparent; }
 //
 bool wxIFFDecoder::CanRead()
 {
-    unsigned char buf[12] = "";
+    unsigned char buf[12];
 
-    m_f->Read(buf, 12);
-    m_f->SeekI(-12, wxFromCurrent);
+    if ( !m_f->Read(buf, WXSIZEOF(buf)) )
+        return FALSE;
+
+    m_f->SeekI(-(off_t)WXSIZEOF(buf), wxFromCurrent);
 
-    return (memcmp(buf, "FORM", 4) == 0 && memcmp(buf+8, "ILBM", 4) == 0);
+    return (memcmp(buf, "FORM", 4) == 0) && (memcmp(buf+8, "ILBM", 4) == 0);
 }
 
 
@@ -376,7 +380,7 @@ int wxIFFDecoder::ReadIFF()
     // main decoding loop. searches IFF chunks and handles them.
     // terminates when BODY chunk was found or dataptr ran over end of file
     //
-    bool BMHDok = false, CMAPok = false, CAMGok = false;
+    bool BMHDok = FALSE, CMAPok = FALSE, CAMGok = FALSE;
     int bmhd_width = 0, bmhd_height = 0, bmhd_bitplanes = 0, bmhd_transcol = -1;
     byte bmhd_masking = 0, bmhd_compression = 0;
     long camg_viewmode = 0;
@@ -406,7 +410,7 @@ int wxIFFDecoder::ReadIFF()
         bmhd_masking  = *(dataptr + 8 + 9);
         bmhd_compression = *(dataptr + 8 + 10);     // get compression
         bmhd_transcol    = iff_getword(dataptr + 8 + 12);
-        BMHDok = true;                              // got BMHD
+        BMHDok = TRUE;                              // got BMHD
         dataptr += 8 + chunkLen;                    // to next chunk
     }
     else if (strncmp((char *)dataptr, "CMAP", 4) == 0) { // CMAP ?
@@ -437,14 +441,14 @@ int wxIFFDecoder::ReadIFF()
         wxLogTrace(_T("iff"), _T("Read %d colors from IFF file."),
             colors);
 
-        CMAPok = true;                              // got CMAP
+        CMAPok = TRUE;                              // got CMAP
         dataptr += 8 + chunkLen;                    // to next chunk
     } else if (strncmp((char *)dataptr, "CAMG", 4) == 0) { // CAMG ?
         if (chunkLen < 4 || truncated) {
         break;
         }
         camg_viewmode = iff_getlong(dataptr + 8);   // get viewmodes
-        CAMGok = true;                              // got CAMG
+        CAMGok = TRUE;                              // got CAMG
         dataptr += 8 + chunkLen;                    // to next chunk
     }
     else if (strncmp((char *)dataptr, "BODY", 4) == 0) { // BODY ?
@@ -727,7 +731,7 @@ IMPLEMENT_DYNAMIC_CLASS(wxIFFHandler, wxImageHandler)
 
 #if wxUSE_STREAMS
 
-bool wxIFFHandler::LoadFile(wxImage *image, wxInputStream& stream, 
+bool wxIFFHandler::LoadFile(wxImage *image, wxInputStream& stream,
                             bool verbose, int WXUNUSED(index))
 {
     wxIFFDecoder *decod;
@@ -781,14 +785,9 @@ bool wxIFFHandler::SaveFile(wxImage * WXUNUSED(image),
 
 bool wxIFFHandler::DoCanRead(wxInputStream& stream)
 {
-    wxIFFDecoder *decod;
-    bool ok;
+    wxIFFDecoder decod(&stream);
 
-    decod = new wxIFFDecoder(&stream);
-    ok = decod->CanRead();
-    delete decod;
-
-    return ok;
+    return decod.CanRead();
 }
 
 #endif // wxUSE_STREAMS