include/wx/dynload.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:         dynload.h
   3 // Purpose:      Dynamic loading framework
   4 // Author:       Ron Lee, David Falkinder, Vadim Zeitlin and a cast of 1000's
   5 //               (derived in part from dynlib.cpp (c) 1998 Guilhem Lavaux)
   6 // Modified by:
   7 // Created:      03/12/01
   8 // RCS-ID:       $Id$
   9 // Copyright:    (c) 2001 Ron Lee <ron@debian.org>
  10 // Licence:      wxWindows licence
  11 /////////////////////////////////////////////////////////////////////////////
  12
  13 #ifndef _WX_DYNAMICLOADER_H__
  14 #define _WX_DYNAMICLOADER_H__
  15
  16 #if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
  17 #pragma interface "dynload.h"
  18 #endif
  19
  20 // ----------------------------------------------------------------------------
  21 // headers
  22 // ----------------------------------------------------------------------------
  23
  24 #include "wx/defs.h"
  25
  26 #if wxUSE_DYNAMIC_LOADER
  27
  28 #include "wx/dynlib.h"
  29 #include "wx/hashmap.h"
  30 #include "wx/module.h"
  31
  32 class WXDLLIMPEXP_BASE wxPluginLibrary;
  33
  34
  35 WX_DECLARE_STRING_HASH_MAP_WITH_DECL(wxPluginLibrary *, wxDLManifest,
  36                                      class WXDLLIMPEXP_BASE);
  37 typedef wxDLManifest wxDLImports;
  38
  39 // ---------------------------------------------------------------------------
  40 // wxPluginLibrary
  41 // ---------------------------------------------------------------------------
  42
  43 // NOTE: Do not attempt to use a base class pointer to this class.
  44 //       wxDL is not virtual and we deliberately hide some of it's
  45 //       methods here.
  46 //
  47 //       Unless you know exacty why you need to, you probably shouldn't
  48 //       instantiate this class directly anyway, use wxPluginManager
  49 //       instead.
  50
  51 class WXDLLIMPEXP_BASE wxPluginLibrary : public wxDynamicLibrary
  52 {
  53 public:
  54
  55     static wxDLImports* ms_classes;  // Static hash of all imported classes.
  56
  57     wxPluginLibrary( const wxString &libname, int flags = wxDL_DEFAULT );
  58     ~wxPluginLibrary();
  59
  60     wxPluginLibrary  *RefLib();
  61     bool              UnrefLib();
  62
  63         // These two are called by the PluginSentinel on (PLUGGABLE) object
  64         // creation/destruction.  There is usually no reason for the user to
  65         // call them directly.  We have to separate this from the link count,
  66         // since the two are not interchangeable.
  67
  68         // FIXME: for even better debugging PluginSentinel should register
  69         //        the name of the class created too, then we can state
  70         //        exactly which object was not destroyed which may be
  71         //        difficult to find otherwise.  Also this code should
  72         //        probably only be active in DEBUG mode, but let's just
  73         //        get it right first.
  74
  75     void  RefObj() { ++m_objcount; }
  76     void  UnrefObj()
  77     {
  78         wxASSERT_MSG( m_objcount > 0, _T("Too many objects deleted??") );
  79         --m_objcount;
  80     }
  81
  82         // Override/hide some base class methods
  83
  84     bool  IsLoaded() const { return m_linkcount > 0; }
  85     void  Unload() { UnrefLib(); }
  86
  87 private:
  88
  89     wxClassInfo    *m_before;       // sm_first before loading this lib
  90     wxClassInfo    *m_after;        // ..and after.
  91
  92     size_t          m_linkcount;    // Ref count of library link calls
  93     size_t          m_objcount;     // ..and (pluggable) object instantiations.
  94     wxModuleList    m_wxmodules;    // any wxModules that we initialised.
  95
  96     void    UpdateClasses();        // Update ms_classes
  97     void    RestoreClasses();       // Removes this library from ms_classes
  98     void    RegisterModules();      // Init any wxModules in the lib.
  99     void    UnregisterModules();    // Cleanup any wxModules we installed.
 100
 101     DECLARE_NO_COPY_CLASS(wxPluginLibrary)
 102 };
 103
 104
 105 class WXDLLIMPEXP_BASE wxPluginManager
 106 {
 107 public:
 108
 109         // Static accessors.
 110
 111     static wxPluginLibrary    *LoadLibrary( const wxString &libname,
 112                                             int flags = wxDL_DEFAULT );
 113     static bool                UnloadLibrary(const wxString &libname);
 114
 115         // This is used by wxDllLoader.  It's wrapped in the compatibility
 116         // macro because it's of arguable use outside of that.
 117
 118 #if WXWIN_COMPATIBILITY_2_2
 119     static wxPluginLibrary *GetObjectFromHandle(wxDllType handle);
 120 #endif
 121
 122         // Instance methods.
 123
 124     wxPluginManager() : m_entry(NULL) {}
 125     wxPluginManager(const wxString &libname, int flags = wxDL_DEFAULT)
 126     {
 127         Load(libname, flags);
 128     }
 129     ~wxPluginManager() { if ( IsLoaded() ) Unload(); }
 130
 131     bool   Load(const wxString &libname, int flags = wxDL_DEFAULT);
 132     void   Unload();
 133
 134     bool   IsLoaded() const { return m_entry && m_entry->IsLoaded(); }
 135     void  *GetSymbol(const wxString &symbol, bool *success = 0)
 136     {
 137         return m_entry->GetSymbol( symbol, success );
 138     }
 139
 140     static void CreateManifest() { ms_manifest = new wxDLManifest(wxKEY_STRING); }
 141     static void ClearManifest() { delete ms_manifest; ms_manifest = NULL; }
 142
 143 private:
 144     // return the pointer to the entry for the library with given name in
 145     // ms_manifest or NULL if none
 146     static wxPluginLibrary *FindByName(const wxString& name)
 147     {
 148         const wxDLManifest::iterator i = ms_manifest->find(name);
 149
 150         return i == ms_manifest->end() ? NULL : i->second;
 151     }
 152
 153     static wxDLManifest* ms_manifest;  // Static hash of loaded libs.
 154     wxPluginLibrary*     m_entry;      // Cache our entry in the manifest.
 155
 156     // We could allow this class to be copied if we really
 157     // wanted to, but not without modification.
 158     DECLARE_NO_COPY_CLASS(wxPluginManager)
 159 };
 160
 161
 162 #endif  // wxUSE_DYNAMIC_LOADER
 163 #endif  // _WX_DYNAMICLOADER_H__
 164