include/wx/dynload.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:         wx/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 // ----------------------------------------------------------------------------
  17 // headers
  18 // ----------------------------------------------------------------------------
  19
  20 #include "wx/defs.h"
  21
  22 #if wxUSE_DYNAMIC_LOADER
  23
  24 #include "wx/dynlib.h"
  25 #include "wx/hashmap.h"
  26 #include "wx/module.h"
  27
  28 class WXDLLIMPEXP_FWD_BASE wxPluginLibrary;
  29
  30
  31 WX_DECLARE_STRING_HASH_MAP_WITH_DECL(wxPluginLibrary *, wxDLManifest,
  32                                      class WXDLLIMPEXP_BASE);
  33 typedef wxDLManifest wxDLImports;
  34
  35 // ---------------------------------------------------------------------------
  36 // wxPluginLibrary
  37 // ---------------------------------------------------------------------------
  38
  39 // NOTE: Do not attempt to use a base class pointer to this class.
  40 //       wxDL is not virtual and we deliberately hide some of it's
  41 //       methods here.
  42 //
  43 //       Unless you know exacty why you need to, you probably shouldn't
  44 //       instantiate this class directly anyway, use wxPluginManager
  45 //       instead.
  46
  47 class WXDLLIMPEXP_BASE wxPluginLibrary : public wxDynamicLibrary
  48 {
  49 public:
  50
  51     static wxDLImports* ms_classes;  // Static hash of all imported classes.
  52
  53     wxPluginLibrary( const wxString &libname, int flags = wxDL_DEFAULT );
  54     ~wxPluginLibrary();
  55
  56     wxPluginLibrary  *RefLib();
  57     bool              UnrefLib();
  58
  59         // These two are called by the PluginSentinel on (PLUGGABLE) object
  60         // creation/destruction.  There is usually no reason for the user to
  61         // call them directly.  We have to separate this from the link count,
  62         // since the two are not interchangeable.
  63
  64         // FIXME: for even better debugging PluginSentinel should register
  65         //        the name of the class created too, then we can state
  66         //        exactly which object was not destroyed which may be
  67         //        difficult to find otherwise.  Also this code should
  68         //        probably only be active in DEBUG mode, but let's just
  69         //        get it right first.
  70
  71     void  RefObj() { ++m_objcount; }
  72     void  UnrefObj()
  73     {
  74         wxASSERT_MSG( m_objcount > 0, wxT("Too many objects deleted??") );
  75         --m_objcount;
  76     }
  77
  78         // Override/hide some base class methods
  79
  80     bool  IsLoaded() const { return m_linkcount > 0; }
  81     void  Unload() { UnrefLib(); }
  82
  83 private:
  84
  85     // These pointers may be NULL but if they are not, then m_ourLast follows
  86     // m_ourFirst in the linked list, i.e. can be found by calling GetNext() a
  87     // sufficient number of times.
  88     const wxClassInfo    *m_ourFirst; // first class info in this plugin
  89     const wxClassInfo    *m_ourLast;  // ..and the last one
  90
  91     size_t          m_linkcount;    // Ref count of library link calls
  92     size_t          m_objcount;     // ..and (pluggable) object instantiations.
  93     wxModuleList    m_wxmodules;    // any wxModules that we initialised.
  94
  95     void    UpdateClasses();        // Update ms_classes
  96     void    RestoreClasses();       // Removes this library from ms_classes
  97     void    RegisterModules();      // Init any wxModules in the lib.
  98     void    UnregisterModules();    // Cleanup any wxModules we installed.
  99
 100     wxDECLARE_NO_COPY_CLASS(wxPluginLibrary);
 101 };
 102
 103
 104 class WXDLLIMPEXP_BASE wxPluginManager
 105 {
 106 public:
 107
 108         // Static accessors.
 109
 110     static wxPluginLibrary    *LoadLibrary( const wxString &libname,
 111                                             int flags = wxDL_DEFAULT );
 112     static bool                UnloadLibrary(const wxString &libname);
 113
 114         // Instance methods.
 115
 116     wxPluginManager() : m_entry(NULL) {}
 117     wxPluginManager(const wxString &libname, int flags = wxDL_DEFAULT)
 118     {
 119         Load(libname, flags);
 120     }
 121     ~wxPluginManager() { if ( IsLoaded() ) Unload(); }
 122
 123     bool   Load(const wxString &libname, int flags = wxDL_DEFAULT);
 124     void   Unload();
 125
 126     bool   IsLoaded() const { return m_entry && m_entry->IsLoaded(); }
 127     void  *GetSymbol(const wxString &symbol, bool *success = 0)
 128     {
 129         return m_entry->GetSymbol( symbol, success );
 130     }
 131
 132     static void CreateManifest() { ms_manifest = new wxDLManifest(wxKEY_STRING); }
 133     static void ClearManifest() { delete ms_manifest; ms_manifest = NULL; }
 134
 135 private:
 136     // return the pointer to the entry for the library with given name in
 137     // ms_manifest or NULL if none
 138     static wxPluginLibrary *FindByName(const wxString& name)
 139     {
 140         const wxDLManifest::iterator i = ms_manifest->find(name);
 141
 142         return i == ms_manifest->end() ? NULL : i->second;
 143     }
 144
 145     static wxDLManifest* ms_manifest;  // Static hash of loaded libs.
 146     wxPluginLibrary*     m_entry;      // Cache our entry in the manifest.
 147
 148     // We could allow this class to be copied if we really
 149     // wanted to, but not without modification.
 150     wxDECLARE_NO_COPY_CLASS(wxPluginManager);
 151 };
 152
 153
 154 #endif  // wxUSE_DYNAMIC_LOADER
 155 #endif  // _WX_DYNAMICLOADER_H__
 156