+};
+
+enum wxDynamicLibraryCategory
+{
+ wxDL_LIBRARY, // standard library
+ wxDL_MODULE // loadable module/plugin
+};
+
+enum wxPluginCategory
+{
+ wxDL_PLUGIN_GUI, // plugin that uses GUI classes
+ wxDL_PLUGIN_BASE // wxBase-only plugin
+};
+
+// ----------------------------------------------------------------------------
+// macros
+// ----------------------------------------------------------------------------
+
+// when loading a function from a DLL you always have to cast the returned
+// "void *" pointer to the correct type and, even more annoyingly, you have to
+// repeat this type twice if you want to declare and define a function pointer
+// all in one line
+//
+// this macro makes this slightly less painful by allowing you to specify the
+// type only once, as the first parameter, and creating a variable of this type
+// called "pfn<name>" initialized with the "name" from the "dynlib"
+#define wxDYNLIB_FUNCTION(type, name, dynlib) \
+ type pfn ## name = (type)(dynlib).GetSymbol(_T(#name))
+
+// ---------------------------------------------------------------------------
+// wxDynamicLibrary
+// ---------------------------------------------------------------------------
+
+class WXDLLIMPEXP_BASE wxDynamicLibrary
+{
+public:
+ // return a valid handle for the main program itself or NULL if back
+ // linking is not supported by the current platform (e.g. Win32)
+ static wxDllType GetProgramHandle();
+
+ // return the platform standard DLL extension (with leading dot)
+ static const wxChar *GetDllExt() { return ms_dllext; }
+
+ wxDynamicLibrary() : m_handle(0) { }
+ wxDynamicLibrary(const wxString& libname, int flags = wxDL_DEFAULT)
+ : m_handle(0)
+ {
+ Load(libname, flags);
+ }
+
+ // NOTE: this class is (deliberately) not virtual, do not attempt
+ // to use it polymorphically.
+ ~wxDynamicLibrary() { Unload(); }
+
+ // return true if the library was loaded successfully
+ bool IsLoaded() const { return m_handle != 0; }
+
+ // load the library with the given name (full or not), return true if ok
+ bool Load(wxString libname, int flags = wxDL_DEFAULT);
+
+ // detach the library object from its handle, i.e. prevent the object from
+ // unloading the library in its dtor -- the caller is now responsible for
+ // doing this
+ wxDllType Detach() { wxDllType h = m_handle; m_handle = 0; return h; }
+
+ // unload the given library handle (presumably returned by Detach() before)
+ static void Unload(wxDllType handle);
+
+ // unload the library, also done automatically in dtor
+ void Unload() { if ( IsLoaded() ) { Unload(m_handle); m_handle = 0; } }
+
+ // Return the raw handle from dlopen and friends.
+ wxDllType GetLibHandle() const { return m_handle; }
+
+ // check if the given symbol is present in the library, useful to verify if
+ // a loadable module is our plugin, for example, without provoking error
+ // messages from GetSymbol()
+ bool HasSymbol(const wxString& name) const
+ {
+ bool ok;
+ DoGetSymbol(name, &ok);
+ return ok;
+ }
+
+ // resolve a symbol in a loaded DLL, such as a variable or function name.
+ // 'name' is the (possibly mangled) name of the symbol. (use extern "C" to
+ // export unmangled names)
+ //
+ // Since it is perfectly valid for the returned symbol to actually be NULL,
+ // that is not always indication of an error. Pass and test the parameter
+ // 'success' for a true indication of success or failure to load the
+ // symbol.
+ //
+ // Returns a pointer to the symbol on success, or NULL if an error occurred
+ // or the symbol wasn't found.
+ void *GetSymbol(const wxString& name, bool *success = 0) const;
+
+
+ // return platform-specific name of dynamic library with proper extension
+ // and prefix (e.g. "foo.dll" on Windows or "libfoo.so" on Linux)
+ static wxString CanonicalizeName(const wxString& name,
+ wxDynamicLibraryCategory cat = wxDL_LIBRARY);
+
+ // return name of wxWidgets plugin (adds compiler and version info
+ // to the filename):
+ static wxString
+ CanonicalizePluginName(const wxString& name,
+ wxPluginCategory cat = wxDL_PLUGIN_GUI);
+
+ // return plugin directory on platforms where it makes sense and empty
+ // string on others:
+ static wxString GetPluginsDirectory();
+
+
+#if WXWIN_COMPATIBILITY_2_2
+ operator bool() const { return IsLoaded(); }
+#endif
+
+protected:
+ // the real implementation of GetSymbol()
+ void *DoGetSymbol(const wxString& name, bool *success = 0) const;
+
+
+ // platform specific shared lib suffix.
+ static const wxChar *ms_dllext;
+
+ // the handle to DLL or NULL
+ wxDllType m_handle;
+
+ // no copy ctor/assignment operators (or we'd try to unload the library
+ // twice)
+ DECLARE_NO_COPY_CLASS(wxDynamicLibrary)
+};
+
projects / wxWidgets.git / blobdiff