Index: ui_fileinterface.cpp
===================================================================
--- ui_fileinterface.cpp    (revision 16715)
+++ ui_fileinterface.cpp    (working copy)
@@ -14,7 +14,7 @@
 UI_FileInterface::UI_FileInterface() : Rocket::Core::FileInterface()
 {
    // TODO Auto-generated constructor stub
-
+   fileSizeMap.clear();
 }

 UI_FileInterface::~UI_FileInterface()
@@ -29,17 +29,23 @@
    if( path2[0] == '/' )
        path2.Erase( 0, 1 );

-   if( trap::FS_FOpenFile( path2.CString(), &filenum, FS_READ ) == -1 )
+   int length = trap::FS_FOpenFile( path2.CString(), &filenum, FS_READ );
+   if( length == -1 )
        return 0;

+   // cache file length
+   fileSizeMap[filenum] = length;
+
    Com_Printf("UI_FileInterface opened %s\n", path2.CString() );
    return static_cast<Rocket::Core::FileHandle>( filenum );
 }

 void UI_FileInterface::Close(Rocket::Core::FileHandle file)
 {
-   if( file != 0 )
+   if( file != 0 ) {
+       fileSizeMap.erase( static_cast<int>( file ) );
        trap::FS_FCloseFile( static_cast<int>( file ) );
+   }
 }

 size_t UI_FileInterface::Read(void *buffer, size_t size, Rocket::Core::FileHandle file)
@@ -66,4 +72,18 @@
    return trap::FS_Tell( static_cast<int>( file ) );
 }

+size_t UI_FileInterface::Length(Rocket::Core::FileHandle file)
+{
+   int filenum = static_cast<int>( file );
+   UI_FileSizeMap::iterator it = fileSizeMap.find( filenum );
+
+   // assertion failure here means that Length was called without preceeding Open call
+   assert( it != fileSizeMap.end() );
+   if( it == fileSizeMap.end() ) {
+       return 0;
+   }
+
+   return fileSizeMap[filenum];
 }
+
+}
Index: ui_fileinterface.h
===================================================================
--- ui_fileinterface.h  (revision 16715)
+++ ui_fileinterface.h  (working copy)
@@ -13,6 +13,8 @@
 namespace WSWUI
 {

+typedef std::map<int, size_t> UI_FileSizeMap;
+
 class UI_FileInterface : public Rocket::Core::FileInterface
 {
 public:
@@ -35,6 +37,12 @@

    /// Returns the current position of the file pointer.
    virtual size_t Tell(Rocket::Core::FileHandle file);
+
+   /// Returns the length of the file.
+   virtual size_t Length(Rocket::Core::FileHandle file);
+
+private:
+   UI_FileSizeMap fileSizeMap;
 };

 }