Implement automatic registration of image loaders

[libs/gui.git] / source / graphics / imageloader.cpp

diff --git a/source/graphics/imageloader.cpp b/source/graphics/imageloader.cpp
index 6cdaef912e65062740c284559b3851c742bd102b..15f0e50f7e14b1142f2ce664f542d7f4fbcd7618 100644 (file)
--- a/source/graphics/imageloader.cpp
+++ b/source/graphics/imageloader.cpp
@@ -2,18 +2,14 @@
 #include <msp/io/file.h>
 #include <msp/strings/format.h>
 #include "imageloader.h"
-#ifdef WITH_LIBPNG
-#include "png/pngloader.h"
-#endif
-#ifdef WITH_DEVIL
-#include "devil/devilloader.h"
-#endif
 
 using namespace std;
 
 namespace Msp {
 namespace Graphics {
 
+bool ImageLoader::registered_loaders_changed = false;
+
 ImageLoader::ImageLoader():
        source(0)
 { }
@@ -40,24 +36,25 @@ ImageLoader *ImageLoader::open_file(const string &fn)
 
 ImageLoader *ImageLoader::open_io(IO::Seekable &io)
 {
-       char sig_buf[8];
-       unsigned sig_len = io.read(sig_buf, sizeof(sig_buf));
-       string sig(sig_buf, sig_len);
-       io.seek(0, IO::S_BEG);
+       list<RegisterBase *> &loaders = get_registered_loaders();
+       if(registered_loaders_changed)
+       {
+               registered_loaders_changed = false;
+               loaders.sort(signature_size_compare);
+       }
+
+       vector<char> sig_buf(loaders.back()->get_signature_size());
+       unsigned sig_len = io.read(&sig_buf[0], sig_buf.size());
+       string signature(sig_buf.begin(), sig_buf.end());
 
-       // TODO register loader classes automatically
        ImageLoader *loader = 0;
-       if(0)
-               ;
-#ifdef WITH_LIBPNG
-       else if(PngLoader::detect(sig))
-               loader = new PngLoader(io);
-#endif
-#ifdef WITH_DEVIL
-       else if(DevilLoader::detect(sig))
-               loader = new DevilLoader(io);
-#endif
-       else
+       for(list<RegisterBase *>::const_iterator i=loaders.begin(); (!loader && i!=loaders.end()); ++i)
+               if((*i)->detect(signature))
+                       loader = (*i)->create(io);
+
+       io.seek(0, IO::S_BEG);
+
+       if(!loader)
        {
                string sig_hex;
                for(unsigned i=0; i<sig_len; ++i)
@@ -72,5 +69,24 @@ ImageLoader *ImageLoader::open_io(IO::Seekable &io)
        return loader;
 }
 
+
+ImageLoader::RegisterBase::RegisterBase()
+{
+       get_registered_loaders().push_back(this);
+       registered_loaders_changed = true;
+}
+
+
+list<ImageLoader::RegisterBase *> &ImageLoader::get_registered_loaders()
+{
+       static list<RegisterBase *> regs;
+       return regs;
+}
+
+bool ImageLoader::signature_size_compare(RegisterBase *r1, RegisterBase *r2)
+{
+       return r1->get_signature_size()<r2->get_signature_size();
+}
+
 } // namespace Graphics
 } // namespace Msp