include/wx/dynlib.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        dynlib.cpp
   3 // Purpose:     Dynamic library management
   4 // Author:      Guilhem Lavaux
   5 // Modified by:
   6 // Created:     20/07/98
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Guilhem Lavaux
   9 // Licence:     wxWindows license
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 #ifndef _WX_DYNLIB_H__
  13 #define _WX_DYNLIB_H__
  14
  15 #ifdef __GNUG__
  16 #   pragma interface
  17 #endif
  18
  19 #include "wx/setup.h"
  20
  21 #if wxUSE_DYNLIB_CLASS
  22
  23 #include "wx/string.h"
  24 #include "wx/list.h"
  25 #include "wx/hash.h"
  26
  27 // this is normally done by configure, but I leave it here for now...
  28 #if defined(__UNIX__) && !(defined(HAVE_DLOPEN) || defined(HAVE_SHL_LOAD))
  29 #   if defined(__LINUX__) || defined(__SOLARIS__) || defined(__SUNOS__) || defined(__FREEBSD__)
  30 #      define HAVE_DLOPEN
  31 #   elif defined(__HPUX__)
  32 #      define HAVE_SHL_LOAD
  33 #   endif // Unix flavour
  34 #endif // !Unix or already have some HAVE_xxx defined
  35
  36 // Note: WXPM/EMX has to be tested first, since we want to use
  37 // native version, even if configure detected presence of DLOPEN.
  38 #if defined(__WXPM__) || defined(__EMX__)
  39 #   define INCL_DOS
  40 #   include <os2.h>
  41     typedef HMODULE wxDllType;
  42 #elif defined(HAVE_DLOPEN)
  43 #   include <dlfcn.h>
  44     typedef void *wxDllType;
  45 #elif defined(HAVE_SHL_LOAD)
  46 #   include <dl.h>
  47     typedef shl_t wxDllType;
  48 #elif defined(__WINDOWS__)
  49 #   include <windows.h>         // needed to get HMODULE
  50     typedef HMODULE wxDllType;
  51 #elif defined(__APPLE__) && defined(__UNIX__)
  52     typedef void *wxDllType;
  53 #elif defined(__WXMAC__)
  54     typedef CFragConnectionID wxDllType;
  55 #else
  56 #   error "wxLibrary can't be compiled on this platform, sorry."
  57 #endif // OS
  58
  59 // LoadLibrary is defined in windows.h as LoadLibraryA, but wxDllLoader method
  60 // should be called LoadLibrary, not LoadLibraryA or LoadLibraryW!
  61 #if defined(__WIN32__) && defined(LoadLibrary)
  62 #   include "wx/msw/winundef.h"
  63 #endif
  64
  65 // ----------------------------------------------------------------------------
  66 // wxDllLoader
  67 // ----------------------------------------------------------------------------
  68
  69 /** wxDllLoader is a class providing an interface similar to unix's
  70     dlopen(). It is used by the wxLibrary framework and manages the
  71     actual loading of DLLs and the resolving of symbols in them.
  72     There are no instances of this class, it simply serves as a
  73     namespace for its static member functions.
  74 */
  75 class WXDLLEXPORT wxDllLoader
  76 {
  77 public:
  78     /** This function loads a shared library into memory, with libname
  79       being the basename of the library, without the filename
  80       extension. No initialisation of the library will be done.
  81       @param libname Name of the shared object to load.
  82       @param success Must point to a bool variable which will be set to TRUE or FALSE.
  83       @return A handle to the loaded DLL. Use success parameter to test if it is valid.
  84      */
  85     static wxDllType LoadLibrary(const wxString & libname, bool *success = NULL);
  86     /** This function unloads the shared library. */
  87     static void UnloadLibrary(wxDllType dll);
  88     /** This function returns a valid handle for the main program
  89       itself. */
  90     static wxDllType GetProgramHandle(void);
  91     /** This function resolves a symbol in a loaded DLL, such as a
  92       variable or function name.
  93       @param dllHandle Handle of the DLL, as returned by LoadDll().
  94       @param name Name of the symbol.
  95       @return A pointer to the symbol.
  96      */
  97     static void * GetSymbol(wxDllType dllHandle, const wxString &name);
  98
  99     // return the standard DLL extension (with leading dot) for this platform
 100     static wxString GetDllExt();
 101
 102 private:
 103     /// forbid construction of objects
 104     wxDllLoader();
 105 };
 106
 107 // ----------------------------------------------------------------------------
 108 // wxDynamicLibrary - friendly interface to wxDllLoader
 109 // ----------------------------------------------------------------------------
 110
 111 class wxDynamicLibrary
 112 {
 113 public:
 114     wxDynamicLibrary() { m_library = 0; }
 115     wxDynamicLibrary(const wxString& name) { Load(name); }
 116
 117     bool IsLoaded() const { return m_library != 0; }
 118
 119     bool Load(const wxString& name)
 120     {
 121         m_library = wxDllLoader::LoadLibrary(name);
 122
 123         return IsLoaded();
 124     }
 125
 126     void Unload()
 127     {
 128         if ( IsLoaded() )
 129             wxDllLoader::UnloadLibrary(m_library)
 130     }
 131
 132     void *GetSymbol(const wxString& name) const
 133     {
 134         wxCHECK_MSG( IsLoaded(), NULL,
 135                      _T("can't load symbol from unloaded library") );
 136
 137         return wxDllLoader::GetSymbol(m_library, name);
 138     }
 139
 140     ~wxDynamicLibrary() { Unload(); }
 141
 142 private:
 143     wxDllType m_library;
 144 };
 145
 146
 147 // ----------------------------------------------------------------------------
 148 // wxLibrary
 149 // ----------------------------------------------------------------------------
 150
 151 class WXDLLEXPORT wxLibrary : public wxObject
 152 {
 153 public:
 154     wxHashTable classTable;
 155
 156 public:
 157     wxLibrary(wxDllType handle);
 158     ~wxLibrary();
 159
 160     // Get a symbol from the dynamic library
 161     void *GetSymbol(const wxString& symbname);
 162
 163     // Create the object whose classname is "name"
 164     wxObject *CreateObject(const wxString& name);
 165
 166 protected:
 167     void PrepareClasses(wxClassInfo *first);
 168
 169     wxDllType m_handle;
 170 };
 171
 172
 173
 174 // ----------------------------------------------------------------------------
 175 // wxLibraries
 176 // ----------------------------------------------------------------------------
 177
 178 class WXDLLEXPORT wxLibraries
 179 {
 180 public:
 181     wxLibraries();
 182     ~wxLibraries();
 183
 184     // caller is responsible for deleting the returned pointer if !NULL
 185     wxLibrary *LoadLibrary(const wxString& basename);
 186
 187     wxObject *CreateObject(const wxString& name);
 188
 189 protected:
 190     wxList m_loaded;
 191 };
 192
 193 // ----------------------------------------------------------------------------
 194 // Global variables
 195 // ----------------------------------------------------------------------------
 196
 197 extern wxLibraries wxTheLibraries;
 198
 199 // ----------------------------------------------------------------------------
 200 // Interesting defines
 201 // ----------------------------------------------------------------------------
 202
 203 #define WXDLL_ENTRY_FUNCTION() \
 204 extern "C" wxClassInfo *wxGetClassFirst(); \
 205 wxClassInfo *wxGetClassFirst() { \
 206   return wxClassInfo::GetFirst(); \
 207 }
 208
 209 #endif // wxUSE_DYNLIB_CLASS
 210
 211 #endif // _WX_DYNLIB_H__