factory.c

   1 #include <shlobj.h>
   2 #include "menuengine.h"
   3 #include "factory.h"
   4 #include "ext.h"
   5 #include "menu.h"
   6
   7 /*
   8  * Since COM objects cannot be constructed like your traditional object (i.e.
   9  * with a proper constructor), they have to be constructed by another object,
  10  * the class factory.
  11  *
  12  * The class factory is an object which exists exactly once, and it cannot
  13  * be constructed or destroyed.  Its sole purpose is to construct objects
  14  * given an interface.
  15  */
  16
  17 STDMETHODIMP class_factory_query_interface(IClassFactory *this,
  18                                            REFIID guid, void **pointer)
  19 {
  20         if (!IsEqualIID(guid, &IID_IUnknown) &&
  21                         !IsEqualIID(guid, &IID_IClassFactory)) {
  22                 *pointer = 0;
  23                 return E_NOINTERFACE;
  24         }
  25
  26         *pointer = this;
  27         return NOERROR;
  28 }
  29
  30 static ULONG STDMETHODCALLTYPE return_one(IClassFactory *this)
  31 {
  32         return(1);
  33 }
  34
  35 static STDMETHODIMP create_instance(IClassFactory *this_,
  36                 IUnknown *outer, REFIID guid, void **pointer)
  37 {
  38         HRESULT result;
  39         struct git_data *data;
  40
  41         *pointer = 0;
  42
  43         if (outer)
  44                 return CLASS_E_NOAGGREGATION;
  45
  46         if (!(data = GlobalAlloc(GMEM_FIXED, sizeof(struct git_data))))
  47                 return E_OUTOFMEMORY;
  48         memset(data, 0, sizeof(struct git_data));
  49
  50         data->shell_ext.virtual_table = &git_shell_ext_virtual_table;
  51         data->menu.virtual_table = &git_menu_virtual_table;
  52         data->shell_ext.git_data = data->menu.git_data = data;
  53
  54         result = query_interface_git_data(data, guid, pointer);
  55         if (!result)
  56                 InterlockedIncrement(&object_count);
  57         return result;
  58 }
  59
  60 static STDMETHODIMP lock_server(IClassFactory *this, BOOL lock)
  61 {
  62         if (lock)
  63                 InterlockedIncrement(&lock_count);
  64         else
  65                 InterlockedDecrement(&lock_count);
  66
  67         return NOERROR;
  68 }
  69
  70 IClassFactoryVtbl factory_virtual_table = {
  71         class_factory_query_interface,
  72         return_one,
  73         return_one,
  74         create_instance,
  75         lock_server
  76 };
  77
  78 IClassFactory factory = {
  79         &factory_virtual_table
  80 };