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